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Shen H, Wang H, Mo J, Zhang J, Xu C, Sun F, Ou X, Zhu X, Du L, Ju H, Ye R, Shi G, Kwok RT, Lam JW, Sun J, Zhang T, Ning S, Tang BZ. Unrestricted molecular motions enable mild photothermy for recurrence-resistant FLASH antitumor radiotherapy. Bioact Mater 2024; 37:299-312. [PMID: 38694765 PMCID: PMC11061705 DOI: 10.1016/j.bioactmat.2024.03.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Revised: 03/05/2024] [Accepted: 03/15/2024] [Indexed: 05/04/2024] Open
Abstract
Ultrahigh dose-rate (FLASH) radiotherapy is an emerging technology with excellent therapeutic effects and low biological toxicity. However, tumor recurrence largely impede the effectiveness of FLASH therapy. Overcoming tumor recurrence is crucial for practical FLASH applications. Here, we prepared an agarose-based thermosensitive hydrogel containing a mild photothermal agent (TPE-BBT) and a glutaminase inhibitor (CB-839). Within nanoparticles, TPE-BBT exhibits aggregation-induced emission peaked at 900 nm, while the unrestricted molecular motions endow TPE-BBT with a mild photothermy generation ability. The balanced photothermal effect and photoluminescence are ideal for phototheranostics. Upon 660-nm laser irradiation, the temperature-rising effect softens and hydrolyzes the hydrogel to release TPE-BBT and CB-839 into the tumor site for concurrent mild photothermal therapy and chemotherapy, jointly inhibiting homologous recombination repair of DNA. The enhanced FLASH radiotherapy efficiently kills the tumor tissue without recurrence and obvious systematic toxicity. This work deciphers the unrestricted molecular motions in bright organic fluorophores as a source of photothermy, and provides novel recurrence-resistant radiotherapy without adverse side effects.
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Affiliation(s)
- Hanchen Shen
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Hongbin Wang
- The Second Ward of Breast Surgery, Cancer Hospital Affiliated to Harbin Medical University, Heilongjiang, 150081, China
| | - Jianlan Mo
- Department of Anesthesiology, Maternal and Child Health Hospital of Guangxi Zhuang Autonomous Region, Nanning, China
| | - Jianyu Zhang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Changhuo Xu
- MOE Frontiers Science Center for Precision Oncology, Faculty of Health Sciences, University of Macau, Macao, China
| | - Feiyi Sun
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Xinwen Ou
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Xinyan Zhu
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Lidong Du
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- MOE Frontiers Science Center for Precision Oncology, Faculty of Health Sciences, University of Macau, Macao, China
| | - Huaqiang Ju
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Ruquan Ye
- Department of Chemistry, State Key Laboratory of Marine Pollution, City University of Hong Kong, Hong Kong, China
| | - Guangfu Shi
- Department of Breast Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ryan T.K. Kwok
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Jacky W.Y. Lam
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Jianwei Sun
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
| | - Tianfu Zhang
- Affiliated Cancer Hospital & Institute of Guangzhou Medical University, School of Biomedical Engineering, Guangzhou Medical University, Guangzhou, China
| | - Shipeng Ning
- Department of Breast Surgery, The Second Affiliated Hospital of Guangxi Medical University, Nanning, China
| | - Ben Zhong Tang
- Department of Chemistry, Hong Kong Branch of Chinese National Engineering Research Center for Tissue Restoration and Reconstruction, Division of Life Science, and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Kowloon, Hong Kong, China
- School of Science and Engineering, Shenzhen Institute of Aggregate Science and Technology, The Chinese University of Hong Kong, Shenzhen (CUHK-Shenzhen), Guangdong, 518172, China
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Yilmaz MT, Gok A, Gedik ME, Caglayan A, Yedekci FY, Aydin Dilsiz S, Gunaydin G, Akyol A, Hurmuz P. The Impact of Dose Rate on the Tumor Microenvironment Using Flattening-filter-free Beams. Clin Oncol (R Coll Radiol) 2024; 36:390-398. [PMID: 38570205 DOI: 10.1016/j.clon.2024.03.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2023] [Revised: 03/03/2024] [Accepted: 03/13/2024] [Indexed: 04/05/2024]
Abstract
AIMS Recently, dose delivery technology has rapidly evolved with flattening filter-free beams (FFF), and the biological effects of high dose rates are a matter of interest. We hypothesized that FFF beams at different dose rates obtained with modern linear accelerators have different effects on the TME. MATERIALS AND METHODS The B16-F10 melanoma syngeneic tumor model was established, and mice were randomized to 2 different doses (2 Gy and 10 Gy) and 3 different dose rates (1 Gy/min, 6 Gy/min, and 14 Gy/min) along with the control group. Euthanasia was performed on the seventh day after RT, and intracardiac blood was collected for a comet assay. Tumors were harvested and examined histomorphologically and immunohistochemically. Statistical analyses were performed using SPSS software version 23 (SPSS Inc., Chicago, IL, USA). RESULTS The daily growth rate was uniform, and no difference was observed between tumor volumes across all three dose rates for each dose. Deoxyribonucleic acid (DNA) damage in blood mononuclear cells was not affected by dose or dose rate. In the TME histomorphological examination, the number of mitosis is less in the 10 Gy arm, whereas the pleomorphism score was greater. Nevertheless, varying dose rates had no effect on the number of mitosis or the pleomorphism score. The severity of the inflammation, cell densities in the TME, and expression of immunohistochemical markers were comparable across all doses and dose rates. CONCLUSION In our study involving the B16-F10 syngeneic tumor model, varying dose rates obtained with FFF beams had no effect on tumor volume, blood mononuclear cell DNA damage, or TME parameters. However, in order to fully understand the biological impacts of novel techniques, our study should be validated with alternative preclinical setups.
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Affiliation(s)
- M T Yilmaz
- Hacettepe University Faculty of Medicine, Department of Radiation Oncology, Ankara, Turkey.
| | - A Gok
- Hacettepe University, Stem Cell Research and Application Center, Ankara, Turkey.
| | - M E Gedik
- Hacettepe University Faculty of Medicine, Basic Oncology Department, Ankara, Turkey.
| | - A Caglayan
- Hacettepe University Faculty of Pharmacy, Department of Toxicology, Ankara, Turkey.
| | - F Y Yedekci
- Hacettepe University Faculty of Medicine, Department of Radiation Oncology, Ankara, Turkey.
| | - S Aydin Dilsiz
- Hacettepe University Faculty of Pharmacy, Department of Toxicology, Ankara, Turkey.
| | - G Gunaydin
- Hacettepe University Faculty of Medicine, Basic Oncology Department, Ankara, Turkey.
| | - A Akyol
- Hacettepe University Faculty of Medicine, Pathology Department, Ankara, Turkey.
| | - P Hurmuz
- Hacettepe University Faculty of Medicine, Department of Radiation Oncology, Ankara, Turkey.
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Pageot C, Zerouali K, Guillet D, Muir B, Renaud J, Lalonde A. The effect of electron backscatter and charge build up in media on beam current transformer signal for ultra-high dose rate (FLASH) electron beam monitoring. Phys Med Biol 2024; 69:105016. [PMID: 38640916 DOI: 10.1088/1361-6560/ad40f7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 04/19/2024] [Indexed: 04/21/2024]
Abstract
Objective.Beam current transformers (BCT) are promising detectors for real-time beam monitoring in ultra-high dose rate (UHDR) electron radiotherapy. However, previous studies have reported a significant sensitivity of the BCT signal to changes in source-to-surface distance (SSD), field size, and phantom material which have until now been attributed to the fluctuating levels of electrons backscattered within the BCT. The purpose of this study is to evaluate this hypothesis, with the goal of understanding and mitigating the variations in BCT signal due to changes in irradiation conditions.Approach.Monte Carlo simulations and experimental measurements were conducted with a UHDR-capable intra-operative electron linear accelerator to analyze the impact of backscattered electrons on BCT signal. The potential influence of charge accumulation in media as a mechanism affecting BCT signal perturbation was further investigated by examining the effects of phantom conductivity and electrical grounding. Finally, the effectiveness of Faraday shielding to mitigate BCT signal variations is evaluated.Main Results.Monte Carlo simulations indicated that the fraction of electrons backscattered in water and on the collimator plastic at 6 and 9 MeV is lower than 1%, suggesting that backscattered electrons alone cannot account for the observed BCT signal variations. However, our experimental measurements confirmed previous findings of BCT response variation up to 15% for different field diameters. A significant impact of phantom type on BCT response was also observed, with variations in BCT signal as high as 14.1% when comparing measurements in water and solid water. The introduction of a Faraday shield to our applicators effectively mitigated the dependencies of BCT signal on SSD, field size, and phantom material.Significance.Our results indicate that variations in BCT signal as a function of SSD, field size, and phantom material are likely driven by an electric field originating in dielectric materials exposed to the UHDR electron beam. Strategies such as Faraday shielding were shown to effectively prevent these electric fields from affecting BCT signal, enabling reliable BCT-based electron UHDR beam monitoring.
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Affiliation(s)
- Charles Pageot
- École Polytechnique de Montréal, Montreal, QC, Canada
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
| | - Karim Zerouali
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
| | - Dominique Guillet
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
| | - Bryan Muir
- National Research Council, Ottawa, ON, Canada
| | | | - Arthur Lalonde
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
- Université de Montréal , Montreal, QC, Canada
- Centre de Recherche du Centre Hospitalier de l'Université de Montreal (CRCHUM), Montreal, QC, Canada
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Horst F, Bodenstein E, Brand M, Hans S, Karsch L, Lessmann E, Löck S, Schürer M, Pawelke J, Beyreuther E. Dose and dose rate dependence of the tissue sparing effect at ultra-high dose rate studied for proton and electron beams using the zebrafish embryo model. Radiother Oncol 2024; 194:110197. [PMID: 38447870 DOI: 10.1016/j.radonc.2024.110197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Revised: 02/16/2024] [Accepted: 02/26/2024] [Indexed: 03/08/2024]
Abstract
PURPOSE A better characterization of the dependence of the tissue sparing effect at ultra-high dose rate (UHDR) on physical beam parameters (dose, dose rate, radiation quality) would be helpful towards a mechanistic understanding of the FLASH effect and for its broader clinical translation. To address this, a comprehensive study on the normal tissue sparing at UHDR using the zebrafish embryo (ZFE) model was conducted. METHODS One-day-old ZFE were irradiated over a wide dose range (15-95 Gy) in three different beams (proton entrance channel, proton spread out Bragg peak and 30 MeV electrons) at UHDR and reference dose rate. After irradiation the ZFE were incubated for 4 days and then analyzed for four different biological endpoints (pericardial edema, curved spine, embryo length and eye diameter). RESULTS Dose-effect curves were obtained and a sparing effect at UHDR was observed for all three beams. It was demonstrated that proton relative biological effectiveness and UHDR sparing are both relevant to predict the resulting dose response. Dose dependent FLASH modifying factors (FMF) for ZFE were found to be compatible with rodent data from the literature. It was found that the UHDR sparing effect saturates at doses above ∼ 50 Gy with an FMF of ∼ 0.7-0.8. A strong dose rate dependence of the tissue sparing effect in ZFE was observed. The magnitude of the maximum sparing effect was comparable for all studied biological endpoints. CONCLUSION The ZFE model was shown to be a suitable pre-clinical high-throughput model for radiobiological studies on FLASH radiotherapy, providing results comparable to rodent models. This underlines the relevance of ZFE studies for FLASH radiotherapy research.
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Affiliation(s)
- Felix Horst
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Elisabeth Bodenstein
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Michael Brand
- Center for Regenerative Therapies TU Dresden and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Stefan Hans
- Center for Regenerative Therapies TU Dresden and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Leonhard Karsch
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Elisabeth Lessmann
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Steffen Löck
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Schürer
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; National Center for Tumor Diseases Dresden (NCT/UCC), Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Jörg Pawelke
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Elke Beyreuther
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany.
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Ciarrocchi E, Ravera E, Cavalieri A, Celentano M, Del Sarto D, Di Martino F, Linsalata S, Massa M, Masturzo L, Moggi A, Morrocchi M, Pensavalle JH, Bisogni MG. Plastic scintillator-based dosimeters for ultra-high dose rate (UHDR) electron radiotherapy. Phys Med 2024; 121:103360. [PMID: 38692114 DOI: 10.1016/j.ejmp.2024.103360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 03/28/2024] [Accepted: 04/19/2024] [Indexed: 05/03/2024] Open
Abstract
This paper reports the development of dosimeters based on plastic scintillating fibers imaged by a charge-coupled device camera, and their performance evaluation through irradiations with the electron Flash research accelerator located at the Centro Pisano Flash Radiotherapy. The dosimeter prototypes were composed of a piece of plastic scintillating fiber optically coupled to a clear optical fiber which transported the scintillation signal to the readout systems (an imaging system and a photodiode). The following properties were tested: linearity, capability to reconstruct the percentage depth dose curve in solid water and to sample in time the single beam pulse. The stem effect contribution was evaluated with three methods, and a proof-of-concept one-dimensional array was developed and tested for online beam profiling. Results show linearity up to 10 Gy per pulse, and good capability to reconstruct both the timing and spatial profiles of the beam, thus suggesting that plastic scintillating fibers may be good candidates for low-energy electron Flash dosimetry.
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Affiliation(s)
- E Ciarrocchi
- University of Pisa, Department of Physics, Pisa, Italy; National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy
| | - E Ravera
- University of Pisa, Department of Physics, Pisa, Italy; National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy
| | - A Cavalieri
- University of Pisa, Department of Physics, Pisa, Italy; National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy
| | - M Celentano
- University of Pisa, Department of Physics, Pisa, Italy; Azienda ospedaliero-universitaria pisana, U.O. Fisica Sanitaria, Pisa, Italy; Centro Pisano ricerca e implementazione clinical Flash Radiotherapy (CPFR-CISUP), Pisa, Italy
| | - D Del Sarto
- National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy; Azienda ospedaliero-universitaria pisana, U.O. Fisica Sanitaria, Pisa, Italy; Centro Pisano ricerca e implementazione clinical Flash Radiotherapy (CPFR-CISUP), Pisa, Italy; University of Pisa, Center for Instrument Sharing of the University of Pisa (CISUP), Pisa, Italy
| | - F Di Martino
- National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy; Azienda ospedaliero-universitaria pisana, U.O. Fisica Sanitaria, Pisa, Italy; Centro Pisano ricerca e implementazione clinical Flash Radiotherapy (CPFR-CISUP), Pisa, Italy
| | - S Linsalata
- Azienda ospedaliero-universitaria pisana, U.O. Fisica Sanitaria, Pisa, Italy
| | - M Massa
- National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy
| | - L Masturzo
- University of Pisa, Department of Physics, Pisa, Italy; Azienda ospedaliero-universitaria pisana, U.O. Fisica Sanitaria, Pisa, Italy; Centro Pisano ricerca e implementazione clinical Flash Radiotherapy (CPFR-CISUP), Pisa, Italy; SIT Sordina IORT Technologies, Aprilia, Italy
| | - A Moggi
- National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy
| | - M Morrocchi
- University of Pisa, Department of Physics, Pisa, Italy; National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy.
| | - J H Pensavalle
- University of Pisa, Department of Physics, Pisa, Italy; Azienda ospedaliero-universitaria pisana, U.O. Fisica Sanitaria, Pisa, Italy; Centro Pisano ricerca e implementazione clinical Flash Radiotherapy (CPFR-CISUP), Pisa, Italy; SIT Sordina IORT Technologies, Aprilia, Italy
| | - M G Bisogni
- University of Pisa, Department of Physics, Pisa, Italy; National Institute of Nuclear Physics, Section of Pisa, Pisa, Italy; Centro Pisano ricerca e implementazione clinical Flash Radiotherapy (CPFR-CISUP), Pisa, Italy
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Schneider M, Schilz JD, Schürer M, Gantz S, Dreyer A, Rothe G, Tillner F, Bodenstein E, Horst F, Beyreuther E. SAPPHIRE -establishment of small animal proton and photon image-guided radiation experiments. Phys Med Biol 2024; 69:095020. [PMID: 38537301 DOI: 10.1088/1361-6560/ad3887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024]
Abstract
Thein vivoevolution of radiotherapy necessitates innovative platforms for preclinical investigation, bridging the gap between bench research and clinical applications. Understanding the nuances of radiation response, specifically tailored to proton and photon therapies, is critical for optimizing treatment outcomes. Within this context, preclinicalin vivoexperimental setups incorporating image guidance for both photon and proton therapies are pivotal, enabling the translation of findings from small animal models to clinical settings. TheSAPPHIREproject represents a milestone in this pursuit, presenting the installation of the small animal radiation therapy integrated beamline (SmART+ IB, Precision X-Ray Inc., Madison, Connecticut, USA) designed for preclinical image-guided proton and photon therapy experiments at University Proton Therapy Dresden. Through Monte Carlo simulations, low-dose on-site cone beam computed tomography imaging and quality assurance alignment protocols, the project ensures the safe and precise application of radiation, crucial for replicating clinical scenarios in small animal models. The creation of Hounsfield lookup tables and comprehensive proton and photon beam characterizations within this system enable accurate dose calculations, allowing for targeted and controlled comparison experiments. By integrating these capabilities,SAPPHIREbridges preclinical investigations and potential clinical applications, offering a platform for translational radiobiology research and cancer therapy advancements.
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Affiliation(s)
- Moritz Schneider
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Joshua D Schilz
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Michael Schürer
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- National Center for Tumor Diseases (NCT/UCC), Dresden, Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany; Medizinische Fakultät and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Dresden, Germany; Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Sebastian Gantz
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Anne Dreyer
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Gert Rothe
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Falk Tillner
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
| | - Elisabeth Bodenstein
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Felix Horst
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Elke Beyreuther
- OncoRay-National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TUD Dresden University of Technology, Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Dresden, Germany
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7
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Liu K, Waldrop T, Aguilar E, Mims N, Neill D, Delahoussaye A, Li Z, Swanson D, Lin SH, Koong AC, Taniguchi CM, Loo BW, Mitra D, Schüler E. Redefining FLASH RT: the impact of mean dose rate and dose per pulse in the gastrointestinal tract. bioRxiv 2024:2024.04.19.590158. [PMID: 38712109 PMCID: PMC11071383 DOI: 10.1101/2024.04.19.590158] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Background The understanding of how varying radiation beam parameter settings affect the induction and magnitude of the FLASH effect remains limited. Purpose We sought to evaluate how the magnitude of radiation-induced gastrointestinal (GI) toxicity (RIGIT) depends on the interplay between mean dose rate (MDR) and dose per pulse (DPP). Methods C57BL/6J mice were subjected to total abdominal irradiation (11-14 Gy single fraction) under conventional irradiation (low DPP and low MDR, CONV) and various combinations of DPP and MDR up to ultra-high-dose-rate (UHDR) beam conditions. The effects of DPP were evaluated for DPPs of 1-6 Gy while the total dose and MDR were kept constant; the effects of MDR were evaluated for the range 0.3- 1440 Gy/s while the total dose and DPP were kept constant. RIGIT was quantified in non-tumor-bearing mice through the regenerating crypt assay and survival assessment. Tumor response was evaluated through tumor growth delay. Results Within each tested total dose using a constant MDR (>100 Gy/s), increasing DPP led to better sparing of regenerating crypts, with a more prominent effect seen at 12 and 14 Gy TAI. However, at fixed DPPs >4 Gy, similar sparing of crypts was demonstrated irrespective of MDR (from 0.3 to 1440 Gy/s). At a fixed high DPP of 4.7 Gy, survival was equivalently improved relative to CONV for all MDRs from 0.3 Gy/s to 104 Gy/s, but at a lower DPP of 0.93 Gy, increasing MDR produced a greater survival effect. We also confirmed that high DPP, regardless of MDR, produced the same magnitude of tumor growth delay relative to CONV using a clinically relevant melanoma mouse model. Conclusions This study demonstrates the strong influence that the beam parameter settings have on the magnitude of the FLASH effect. Both high DPP and UHDR appeared independently sufficient to produce FLASH sparing of GI toxicity, while isoeffective tumor response was maintained across all conditions.
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McGarrigle JM, Long KR, Prezado Y. The FLASH effect-an evaluation of preclinical studies of ultra-high dose rate radiotherapy. Front Oncol 2024; 14:1340190. [PMID: 38711846 PMCID: PMC11071325 DOI: 10.3389/fonc.2024.1340190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 03/20/2024] [Indexed: 05/08/2024] Open
Abstract
FLASH radiotherapy (FLASH-RT) is a novel radiotherapy approach based on the use of ultra-high dose radiation to treat malignant cells. Although tumours can be reduced or eradicated using radiotherapy, toxicities induced by radiation can compromise healthy tissues. The FLASH effect is the observation that treatment delivered at an ultra-high dose rate is able to reduce adverse toxicities present at conventional dose rates. While this novel technique may provide a turning point for clinical practice, the exact mechanisms underlying the causes or influences of the FLASH effect are not fully understood. The study presented here uses data collected from 41 experimental investigations (published before March 2024) of the FLASH effect. Searchable databases were constructed to contain the outcomes of the various experiments in addition to values of beam parameters that may have a bearing on the FLASH effect. An in-depth review of the impact of the key beam parameters on the results of the experiments was carried out. Correlations between parameter values and experimental outcomes were studied. Pulse Dose Rate had positive correlations with almost all end points, suggesting viability of FLASH-RT as a new modality of radiotherapy. The collective results of this systematic review study suggest that beam parameter qualities from both FLASH and conventional radiotherapy can be valuable for tissue sparing and effective tumour treatment.
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Affiliation(s)
| | - Kenneth Richard Long
- Department of Physics, Imperial College London, London, United Kingdom
- Science and Technology Facilities Council (STFC), Rutherford Appleton Laboratory, Oxford, United Kingdom
| | - Yolanda Prezado
- Institut Curie, Universite Paris-Saclay, Centre national de la recherche scientifique (CNRS) UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Universite Paris-Saclay, Centre national de la recherche scientifique (CNRS) UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
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9
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Franciosini G, Carlotti D, Cattani F, De Gregorio A, De Liso V, De Rosa F, Di Francesco M, Di Martino F, Felici G, Pensavalle JH, Leonardi MC, Marafini M, Muscato A, Paiar F, Patera V, Poortmans P, Sciubba A, Schiavi A, Toppi M, Traini G, Trigilio A, Sarti A. IOeRT conventional and FLASH treatment planning system implementation exploiting fast GPU Monte Carlo: The case of breast cancer. Phys Med 2024; 121:103346. [PMID: 38608421 DOI: 10.1016/j.ejmp.2024.103346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/05/2024] [Revised: 03/13/2024] [Accepted: 04/01/2024] [Indexed: 04/14/2024] Open
Abstract
Partial breast irradiation for the treatment of early-stage breast cancer patients can be performed by means of Intra Operative electron Radiation Therapy (IOeRT). One of the main limitations of this technique is the absence of a treatment planning system (TPS) that could greatly help in ensuring a proper coverage of the target volume during irradiation. An IOeRT TPS has been developed using a fast Monte Carlo (MC) and an ultrasound imaging system to provide the best irradiation strategy (electron beam energy, applicator position and bevel angle) and to facilitate the optimisation of dose prescription and delivery to the target volume while maximising the organs at risk sparing. The study has been performed in silico, exploiting MC simulations of a breast cancer treatment. Ultrasound-based input has been used to compute the absorbed dose maps in different irradiation strategies and a quantitative comparison between the different options was carried out using Dose Volume Histograms. The system was capable of exploring different beam energies and applicator positions in few minutes, identifying the best strategy with an overall computation time that was found to be completely compatible with clinical implementation. The systematic uncertainty related to tissue deformation during treatment delivery with respect to imaging acquisition was taken into account. The potential and feasibility of a GPU based full MC TPS implementation of IOeRT breast cancer treatments has been demonstrated in-silico. This long awaited tool will greatly improve the treatment safety and efficacy, overcoming the limits identified within the clinical trials carried out so far.
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Affiliation(s)
- G Franciosini
- Sapienza, University of Rome, Department of Scienze di Base e Applicate all'Ingegneria, Rome, Italy; National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy
| | - D Carlotti
- Operative Research Unit of Radiation Oncology, Fondazione Policlinico Universitatio Campus-Bio Medico, Rome, Italy
| | - F Cattani
- Unit of Medical Physics, European Institute of Oncology IRCCS, Milan, Italy
| | - A De Gregorio
- National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy; Sapienza, University of Rome, Department of Physics, Rome, Italy
| | - V De Liso
- S.I.T. Sordina IORT Technologies S.p.A, Aprilia, Italy
| | - F De Rosa
- Sapienza, University of Rome, Department of Scienze di Base e Applicate all'Ingegneria, Rome, Italy
| | | | - F Di Martino
- Centro Pisano Multidisciplinare sulla Ricerca e Implementazione Clinica della Flash Radiotherapy (CPFR), Pisa, Italy; University of Pisa, Department of Physics, Pisa, Italy; Azienda Ospedaliero Universitaria Pisa (AOUP), Fisica Sanitaria, Pisa, Italy; National Institute of Nuclear Physics, INFN, Section of Pisa, Pisa, Italy
| | - G Felici
- S.I.T. Sordina IORT Technologies S.p.A, Aprilia, Italy
| | - J Harold Pensavalle
- S.I.T. Sordina IORT Technologies S.p.A, Aprilia, Italy; Centro Pisano Multidisciplinare sulla Ricerca e Implementazione Clinica della Flash Radiotherapy (CPFR), Pisa, Italy; National Institute of Nuclear Physics, INFN, Section of Pisa, Pisa, Italy
| | - M C Leonardi
- Division of Radiation Oncology, European Institute of Oncology IRCCS, Milan, Italy
| | - M Marafini
- National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy; Museo Storico della Fisica e Centro Studi e Ricerche "E. Fermi", Rome, Italy
| | - A Muscato
- National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy; Specialty School of Medical Physics, La Sapienza University of Rome, Rome, Italy
| | - F Paiar
- Centro Pisano Multidisciplinare sulla Ricerca e Implementazione Clinica della Flash Radiotherapy (CPFR), Pisa, Italy; Azienda Ospedaliero Universitaria Pisa (AOUP), Fisica Sanitaria, Pisa, Italy
| | - V Patera
- Sapienza, University of Rome, Department of Scienze di Base e Applicate all'Ingegneria, Rome, Italy; National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy
| | - P Poortmans
- Department of Radiation Oncology, Iridium Netwerk, Antwerp, Belgium; University of Antwerp, Faculty of Medicine and Health Sciences, Antwerp, Belgium
| | - A Sciubba
- Sapienza, University of Rome, Department of Scienze di Base e Applicate all'Ingegneria, Rome, Italy; National Institute of Nuclear Physics, INFN, Frascati National Laboratories (LNF), Rome, Italy
| | - A Schiavi
- Sapienza, University of Rome, Department of Scienze di Base e Applicate all'Ingegneria, Rome, Italy; National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy
| | - M Toppi
- Sapienza, University of Rome, Department of Scienze di Base e Applicate all'Ingegneria, Rome, Italy; National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy
| | - G Traini
- National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy
| | - A Trigilio
- Sapienza, University of Rome, Department of Physics, Rome, Italy; National Institute of Nuclear Physics, INFN, Frascati National Laboratories (LNF), Rome, Italy
| | - A Sarti
- Sapienza, University of Rome, Department of Scienze di Base e Applicate all'Ingegneria, Rome, Italy; National Institute of Nuclear Physics, INFN, Section of Rome I, Rome, Italy.
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10
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Chen D, Motlagh SAO, Stappen FV, Labarbe R, Bell B, Kim M, Teo BKK, Dong L, Zou W, Diffenderfer ES. Secondary neutron dosimetry for conformal FLASH proton therapy. Med Phys 2024. [PMID: 38597815 DOI: 10.1002/mp.17050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 04/11/2024] Open
Abstract
BACKGROUND Cyclotron-based proton therapy systems utilize the highest proton energies to achieve an ultra-high dose rate (UHDR) for FLASH radiotherapy. The deep-penetrating range associated with this high energy can be modulated by inserting a uniform plate of proton-stopping material, known as a range shifter, in the beam path at the nozzle to bring the Bragg peak within the target while ensuring high proton transport efficiency for UHDR. Aluminum has been recently proposed as a range shifter material mainly due to its high compactness and its mechanical properties. A possible drawback lies in the fact that aluminum has a larger cross-section of producing secondary neutrons compared to conventional plastic range shifters. Accordingly, an increase in secondary neutron contamination was expected during the delivery of range-modulated FLASH proton therapy, potentially heightening neutron-induced carcinogenic risks to the patient. PURPOSE We conducted neutron dosimetry using simulations and measurements to evaluate excess dose due to neutron exposure during UHDR proton irradiation with aluminum range shifters compared to plastic range shifters. METHODS Monte Carlo simulations in TOPAS were performed to investigate the secondary neutron production characteristics with aluminum range shifter during 225 MeV single-spot proton irradiation. The computational results were validated against measurements with a pair of ionization chambers in an out-of-field region ( ≤ $\le$ 30 cm) and with a Proton Recoil Scintillator-Los Alamos rem meter in a far-out-of-field region (0.5-2.5 m). The assessments were repeated with solid water slabs as a surrogate for the conventional range shifter material to evaluate the impact of aluminum on neutron yield. The results were compared with the International Electrotechnical Commission (IEC) standards to evaluate the clinical acceptance of the secondary neutron yield. RESULTS For a range modulation up to 26 cm in water, the maximum simulated and measured values of out-of-field secondary neutron dose equivalent per therapeutic dose with aluminum range shifter were found to be( 0.57 ± 0.02 ) mSv/Gy $(0.57\pm 0.02)\ \text{mSv/Gy}$ and( 0.46 ± 0.04 ) mSv/Gy $(0.46\pm 0.04)\ \text{mSv/Gy}$ , respectively, overall higher than the solid water cases (simulation:( 0.332 ± 0.003 ) mSv/Gy $(0.332\pm 0.003)\ \text{mSv/Gy}$ ; measurement:( 0.33 ± 0.03 ) mSv/Gy $(0.33\pm 0.03)\ \text{mSv/Gy}$ ). The maximum far out-of-field secondary neutron dose equivalent was found to be (8.8 ± 0.5 $8.8 \pm 0.5$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ and (1.62 ± 0.02 $1.62 \pm 0.02$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ for the simulations and rem meter measurements, respectively, also higher than the solid water counterparts (simulation: (3.3 ± 0.3 $3.3 \pm 0.3$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ ; measurement: (0.63 ± 0.03 $0.63 \pm 0.03$ ) μ Sv / Gy $\umu {\rm Sv/Gy}$ ). CONCLUSIONS We conducted simulations and measurements of secondary neutron production under proton irradiation at FLASH energy with range shifters. We found that the secondary neutron yield increased when using aluminum range shifters compared to conventional materials while remaining well below the non-primary radiation limit constrained by the IEC regulations.
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Affiliation(s)
- Dixin Chen
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | - Rudi Labarbe
- Ion Beam Applications S.A. (IBA), Louvain-la-Neuve, Belgium
| | - Beryl Bell
- Ion Beam Applications S.A. (IBA), Louvain-la-Neuve, Belgium
| | - Michele Kim
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Boon-Keng Kevin Teo
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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11
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Tang R, Yin J, Liu Y, Xue J. FLASH radiotherapy: A new milestone in the field of cancer radiotherapy. Cancer Lett 2024; 587:216651. [PMID: 38342233 DOI: 10.1016/j.canlet.2024.216651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/03/2023] [Accepted: 01/13/2024] [Indexed: 02/13/2024]
Abstract
Radiotherapy plays a pivotal role in the control and eradication of tumors, but it can also induce radiation injury to surrounding normal tissues while targeting tumor cells. In recent years, FLASH-Radiotherapy (FLASH-RT) has emerged as a cutting-edge research focus in the field of radiation therapy. By delivering high radiation doses to the treatment target in an ultra-short time, FLASH-RT produces the FLASH effect, which reduces the toxicity to normal tissues while achieving comparable tumor control efficacy to conventional radiotherapy. This review provides a brief overview of the development history of FLASH-RT and its impact on tumor control. Additionally, it focuses on introducing the protective effects and molecular mechanisms of this technology on various normal tissues, as well as exploring its synergistic effects when combined with other tumor therapies. Importantly, this review discusses the challenges faced in translating FLASH-RT into clinical practice and outlines its promising future applications.
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Affiliation(s)
- Rui Tang
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, Sichuan, China; Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jianqiong Yin
- Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yuanxin Liu
- Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jianxin Xue
- Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Laboratory of Clinical Cell Therapy, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Disaster Medical Center, Sichuan University, Chengdu, 610041, Sichuan, China.
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12
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Giannini N, Gadducci G, Fuentes T, Gonnelli A, Di Martino F, Puccini P, Naso M, Pasqualetti F, Capaccioli S, Paiar F. Electron FLASH radiotherapy in vivo studies. A systematic review. Front Oncol 2024; 14:1373453. [PMID: 38655137 PMCID: PMC11035725 DOI: 10.3389/fonc.2024.1373453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2024] [Accepted: 03/15/2024] [Indexed: 04/26/2024] Open
Abstract
FLASH-radiotherapy delivers a radiation beam a thousand times faster compared to conventional radiotherapy, reducing radiation damage in healthy tissues with an equivalent tumor response. Although not completely understood, this radiobiological phenomenon has been proved in several animal models with a spectrum of all kinds of particles currently used in contemporary radiotherapy, especially electrons. However, all the research teams have performed FLASH preclinical studies using industrial linear accelerator or LINAC commonly employed in conventional radiotherapy and modified for the delivery of ultra-high-dose-rate (UHDRs). Unfortunately, the delivering and measuring of UHDR beams have been proved not to be completely reliable with such devices. Concerns arise regarding the accuracy of beam monitoring and dosimetry systems. Additionally, this LINAC totally lacks an integrated and dedicated Treatment Planning System (TPS) able to evaluate the internal dose distribution in the case of in vivo experiments. Finally, these devices cannot modify dose-time parameters of the beam relevant to the flash effect, such as average dose rate; dose per pulse; and instantaneous dose rate. This aspect also precludes the exploration of the quantitative relationship with biological phenomena. The dependence on these parameters need to be further investigated. A promising advancement is represented by a new generation of electron LINAC that has successfully overcome some of these technological challenges. In this review, we aim to provide a comprehensive summary of the existing literature on in vivo experiments using electron FLASH radiotherapy and explore the promising clinical perspectives associated with this technology.
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Affiliation(s)
- Noemi Giannini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Giovanni Gadducci
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Taiusha Fuentes
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Alessandra Gonnelli
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Fabio Di Martino
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Unit of Medical Physics, Azienda Ospedaliero-Universitaria Pisana, Pisa, Tuscany, Italy
- National Institute of Nuclear Physics (INFN)-section of Pisa, Pisa, Tuscany, Italy
| | - Paola Puccini
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
| | - Monica Naso
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
| | - Francesco Pasqualetti
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
| | - Simone Capaccioli
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Department of Physics, University of Pisa, Pisa, Tuscany, Italy
| | - Fabiola Paiar
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Tuscany, Italy
- Centro Pisano Multidisciplinare Sulla Ricerca e Implementazione Clinica Della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Department of Radiation Oncology, Azienda Ospedaliera Universitaria Pisana, University of Pisa, Pisa, Tuscany, Italy
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Vidal M, Gérard A, Floquet V, Forthomme J, Christensen JB, Almhagen E, Grusell E, Heymans V, Rossomme S, Dumas S, Trimaud R, Hérault J. Beam monitor chamber calibration of a synchro-cyclotron high dose rate per pulse pulsed scanned proton beam. Phys Med Biol 2024; 69:085016. [PMID: 38252970 DOI: 10.1088/1361-6560/ad2123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 01/22/2024] [Indexed: 01/24/2024]
Abstract
Objective. Ionization chambers, mostly used for beam calibration and for reference dosimetry, can show high recombination effects in pulsed high dose rate proton beams. The aims of this paper are: first, to characterize the linearity response of newly designed asymmetrical beam monitor chambers (ABMC) in a 100-226 MeV pulsed high dose rate per pulse scanned proton beam; and secondly, to calibrate the ABMC with a PPC05 (IBA Dosimetry) plane parallel ionization chamber and compare to calibration with a home-made Faraday cup (FC).Approach. The ABMC response linearity was evaluated with both the FC and a PTW 60019 microDiamond detector. Regarding ionometry-based ABMC calibration, recombination factors were evaluated theoretically, then numerically, and finally experimentally measured in water for a plane parallel ionization chamber PPC05 (IBA Dosimetry) throughkssaturation curves. Finally, ABMC calibration was also achieved with FC and compared to the ionometry method for 7 energies.Main results. Linearity measurements showed that recombination losses in the new ABMC design were well taken into account for the whole range of the machine dose rates. The two-voltage-method was not suitable for recombination correction, but Jaffé's plots analysis was needed, emphasizing the current IAEA TRS-398 reference protocol limitations. Concerning ABMC calibration, FC based absorbed dose estimation and PPC05-based absorbed dose estimation differ by less than 6.3% for the investigated energies.Significance.So far, no update on reference dosimetry protocols is available to estimate the absorbed dose in ionization chambers for clinical high dose rate per pulse pulsed scanned proton beams. This work proposes a validation of the new ABMC design, a method to take into account the recombination effect for ionometry-based ABMC calibration and a comparison with FC dose estimation in this type of proton beams.
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Affiliation(s)
- Marie Vidal
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Anaïs Gérard
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Vincent Floquet
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | | | - Jeppe Brage Christensen
- DTU Health Tech, Technical University of Denmark, Roskilde, Denmark
- Department of Radiation Safety and Security, Paul Scherrer Institute, PSI Villigen, Switzerland
| | - Erik Almhagen
- Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science-Skandion Clinics Uppsala, Sweden
| | - Erik Grusell
- Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science-Skandion Clinics Uppsala, Sweden
| | | | | | - Serge Dumas
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Richard Trimaud
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Joël Hérault
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
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Bateman JJ, Buchanan E, Corsini R, Farabolini W, Korysko P, Garbrecht Larsen R, Malyzhenkov A, Ortega Ruiz I, Rieker V, Gerbershagen A, Dosanjh M. Development of a novel fibre optic beam profile and dose monitor for very high energy electron radiotherapy at ultrahigh dose rates. Phys Med Biol 2024; 69:085006. [PMID: 38478998 DOI: 10.1088/1361-6560/ad33a0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 03/13/2024] [Indexed: 04/04/2024]
Abstract
Objective. Very high energy electrons (VHEE) in the range of 50-250 MeV are of interest for treating deep-seated tumours with FLASH radiotherapy (RT). This approach offers favourable dose distributions and the ability to deliver ultra-high dose rates (UHDR) efficiently. To make VHEE-based FLASH treatment clinically viable, a novel beam monitoring technology is explored as an alternative to transmission ionisation monitor chambers, which have non-linear responses at UHDR. This study introduces the fibre optic flash monitor (FOFM), which consists of an array of silica optical fibre-based Cherenkov sensors with a photodetector for signal readout.Approach. Experiments were conducted at the CLEAR facility at CERN using 200 MeV and 160 MeV electrons to assess the FOFM's response linearity to UHDR (characterised with radiochromic films) required for FLASH radiotherapy. Beam profile measurements made on the FOFM were compared to those using radiochromic film and scintillating yttrium aluminium garnet (YAG) screens.Main results. A range of photodetectors were evaluated, with a complementary-metal-oxide-semiconductor (CMOS) camera being the most suitable choice for this monitor. The FOFM demonstrated excellent response linearity from 0.9 Gy/pulse to 57.4 Gy/pulse (R2= 0.999). Furthermore, it did not exhibit any significant dependence on the energy between 160 MeV and 200 MeV nor the instantaneous dose rate. Gaussian fits applied to vertical beam profile measurements indicated that the FOFM could accurately provide pulse-by-pulse beam size measurements, agreeing within the error range of radiochromic film and YAG screen measurements, respectively.Significance. The FOFM proves to be a promising solution for real-time beam profile and dose monitoring for UHDR VHEE beams, with a linear response in the UHDR regime. Additionally it can perform pulse-by-pulse beam size measurements, a feature currently lacking in transmission ionisation monitor chambers, which may become crucial for implementing FLASH radiotherapy and its associated quality assurance requirements.
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Affiliation(s)
- Joseph J Bateman
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
| | - Emma Buchanan
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Roberto Corsini
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Wilfrid Farabolini
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Pierre Korysko
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Robert Garbrecht Larsen
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
- Particle Therapy Research Centre (PARTREC), Department of Radiation Oncology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander Malyzhenkov
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Iñaki Ortega Ruiz
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Vilde Rieker
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
- Department of Physics, University of Oslo, NO-0316 Blindern, Oslo, Norway
| | - Alexander Gerbershagen
- Particle Therapy Research Centre (PARTREC), Department of Radiation Oncology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Manjit Dosanjh
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
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Levin DS, Friedman PS, Ferretti C, Ristow N, Tecchio M, Litzenberg DW, Bashkirov V, Schulte R. A prototype scintillator real-time beam monitor for ultra-high dose rate radiotherapy. Med Phys 2024; 51:2905-2923. [PMID: 38456622 DOI: 10.1002/mp.17018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 02/24/2024] [Accepted: 02/26/2024] [Indexed: 03/09/2024] Open
Abstract
BACKGROUND FLASH Radiotherapy (RT) is an emergent cancer RT modality where an entire therapeutic dose is delivered at more than 1000 times higher dose rate than conventional RT. For clinical trials to be conducted safely, a precise and fast beam monitor that can generate out-of-tolerance beam interrupts is required. This paper describes the overall concept and provides results from a prototype ultra-fast, scintillator-based beam monitor for both proton and electron beam FLASH applications. PURPOSE A FLASH Beam Scintillator Monitor (FBSM) is being developed that employs a novel proprietary scintillator material. The FBSM has capabilities that conventional RT detector technologies are unable to simultaneously provide: (1) large area coverage; (2) a low mass profile; (3) a linear response over a broad dynamic range; (4) radiation hardness; (5) real-time analysis to provide an IEC-compliant fast beam-interrupt signal based on true two-dimensional beam imaging, radiation dosimetry and excellent spatial resolution. METHODS The FBSM uses a proprietary low mass, less than 0.5 mm water equivalent, non-hygroscopic, radiation tolerant scintillator material (designated HM: hybrid material) that is viewed by high frame rate CMOS cameras. Folded optics using mirrors enable a thin monitor profile of ∼10 cm. A field programmable gate array (FPGA) data acquisition system generates real-time analysis on a time scale appropriate to the FLASH RT beam modality: 100-1000 Hz for pulsed electrons and 10-20 kHz for quasi-continuous scanning proton pencil beams. An ion beam monitor served as the initial development platform for this work and was tested in low energy heavy-ion beams (86Kr+26 and protons). A prototype FBSM was fabricated and then tested in various radiation beams that included FLASH level dose per pulse electron beams, and a hospital RT clinic with electron beams. RESULTS Results presented in this report include image quality, response linearity, radiation hardness, spatial resolution, and real-time data processing. The HM scintillator was found to be highly radiation damage resistant. It exhibited a small 0.025%/kGy signal decrease from a 216 kGy cumulative dose resulting from continuous exposure for 15 min at a FLASH compatible dose rate of 237 Gy/s. Measurements of the signal amplitude versus beam fluence demonstrate linear response of the FBSM at FLASH compatible dose rates of >40 Gy/s. Comparison with commercial Gafchromic film indicates that the FBSM produces a high resolution 2D beam image and can reproduce a nearly identical beam profile, including primary beam tails. The spatial resolution was measured at 35-40 µm. Tests of the firmware beta version show successful operation at 20 000 Hz frame rate or 50 µs/frame, where the real-time analysis of the beam parameters is achieved in less than 1 µs. CONCLUSIONS The FBSM is designed to provide real-time beam profile monitoring over a large active area without significantly degrading the beam quality. A prototype device has been staged in particle beams at currents of single particles up to FLASH level dose rates, using both continuous ion beams and pulsed electron beams. Using a novel scintillator, beam profiling has been demonstrated for currents extending from single particles to 10 nA currents. Radiation damage is minimal and even under FLASH conditions would require ≥50 kGy of accumulated exposure in a single spot to result in a 1% decrease in signal output. Beam imaging is comparable to radiochromic films, and provides immediate images without hours of processing. Real-time data processing, taking less than 50 µs (combined data transfer and analysis times), has been implemented in firmware for 20 kHz frame rates for continuous proton beams.
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Affiliation(s)
- Daniel S Levin
- Department of Physics, University of Michigan, Ann Arbor, Michigan, USA
| | | | - Claudio Ferretti
- Department of Physics, University of Michigan, Ann Arbor, Michigan, USA
| | - Nicholas Ristow
- Department of Physics, University of Michigan, Ann Arbor, Michigan, USA
| | - Monica Tecchio
- Department of Physics, University of Michigan, Ann Arbor, Michigan, USA
| | - Dale W Litzenberg
- Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA
| | - Vladimir Bashkirov
- Division of Biomedical Engineering Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
| | - Reinhard Schulte
- Division of Biomedical Engineering Sciences, Loma Linda University School of Medicine, Loma Linda, California, USA
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Ma C, Zhou J, Chang CW, Wang Y, Patel PR, Yu DS, Tian S, Yang X. Streamlined pin-ridge-filter design for single-energy proton FLASH planning. Med Phys 2024; 51:2955-2966. [PMID: 38214381 DOI: 10.1002/mp.16939] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 11/24/2023] [Accepted: 12/21/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND FLASH radiotherapy (FLASH-RT) with ultra-high dose rate has yielded promising results in reducing normal tissue toxicity while maintaining tumor control. Planning with single-energy proton beams modulated by ridge filters (RFs) has been demonstrated feasible for FLASH-RT. PURPOSE This study explored the feasibility of a streamlined pin-shaped RF (pin-RF) design, characterized by coarse resolution and sparsely distributed ridge pins, for single-energy proton FLASH planning. METHODS An inverse planning framework integrated within a treatment planning system was established to design streamlined pin RFs for single-energy FLASH planning. The framework involves generating a multi-energy proton beam plan using intensity-modulated proton therapy (IMPT) planning based on downstream energy modulation strategy (IMPT-DS), followed by a nested pencil-beam-direction-based (PBD-based) spot reduction process to iteratively reduce the total number of PBDs and energy layers along each PBD for the IMPT-DS plan. The IMPT-DS plan is then translated into the pin-RFs and the single-energy beam configurations for IMPT planning with pin-RFs (IMPT-RF). This framework was validated on three lung cases, quantifying the FLASH dose of the IMPT-RF plan using the FLASH effectiveness model. The FLASH dose was then compared to the reference dose of a conventional IMPT plan to measure the clinical benefit of the FLASH planning technique. RESULTS The IMPT-RF plans closely matched the corresponding IMPT-DS plans in high dose conformity (conformity index of <1.2), with minimal changes in V7Gy and V7.4 Gy for the lung (<3%) and small increases in maximum doses (Dmax) for other normal structures (<3.4 Gy). Comparing the FLASH doses to the doses of corresponding IMPT-RF plans, drastic reductions of up to nearly 33% were observed in Dmax for the normal structures situated in the high-to-moderate-dose regions, while negligible changes were found in Dmax for normal structures in low-dose regions. Positive clinical benefits were seen in comparing the FLASH doses to the reference doses, with notable reductions of 21.4%-33.0% in Dmax for healthy tissues in the high-dose regions. However, in the moderate-to-low-dose regions, only marginal positive or even negative clinical benefit for normal tissues were observed, such as increased lung V7Gy and V7.4 Gy (up to 17.6%). CONCLUSIONS A streamlined pin-RF design was developed and its effectiveness for single-energy proton FLASH planning was validated, revealing positive clinical benefits for the normal tissues in the high dose regions. The coarsened design of the pin-RF demonstrates potential advantages, including cost efficiency and ease of adjustability, making it a promising option for efficient production.
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Affiliation(s)
- Chaoqiong Ma
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
| | - Jun Zhou
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
| | - Chih-Wei Chang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
| | - Yinan Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
| | - Pretesh R Patel
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
| | - David S Yu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
| | - Sibo Tian
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia, USA
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Evin M, Koumeir C, Bongrand A, Delpon G, Haddad F, Mouchard Q, Potiron V, Saade G, Servagent N, Villoing D, Métivier V, Chiavassa S. Methodology for small animals targeted irradiations at conventional and ultra-high dose rates 65 MeV proton beam. Phys Med 2024; 120:103332. [PMID: 38518627 DOI: 10.1016/j.ejmp.2024.103332] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2023] [Revised: 02/20/2024] [Accepted: 03/11/2024] [Indexed: 03/24/2024] Open
Abstract
As part of translational research projects, mice may be irradiated on radiobiology platforms such as the one at the ARRONAX cyclotron. Generally, these platforms do not feature an integrated imaging system. Moreover, in the context of ultra-high dose-rate radiotherapy (FLASH-RT), treatment planning should consider potential changes in the beam characteristics and internal movements in the animal. A patient-like set-up and methodology has been implemented to ensure target coverage during conformal irradiations of the brain, lungs and intestines. In addition, respiratory cycle amplitudes were quantified by fluoroscopic acquisitions on a mouse, to ensure organ coverage and to assess the impact of respiration during FLASH-RT using the 4D digital phantom MOBY. Furthermore, beam incidence direction was studied from mice µCBCT and Monte Carlo simulations. Finally,in vivodosimetry with dose-rate independent radiochromic films (OC-1) and their LET dependency were investigated. The immobilization system ensures that the animal is held in a safe and suitable position. The geometrical evaluation of organ coverage, after the addition of the margins around the organs, was satisfactory. Moreover, no measured differences were found between CONV and FLASH beams enabling a single model of the beamline for all planning studies. Finally, the LET-dependency of the OC-1 film was determined and experimentally verified with phantoms, as well as the feasibility of using these filmsin vivoto validate the targeting. The methodology developed ensures accurate and reproducible preclinical irradiations in CONV and FLASH-RT without in-room image guidance in terms of positioning, dose calculation andin vivodosimetry.
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Affiliation(s)
- Manon Evin
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France.
| | - Charbel Koumeir
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France; GIP ARRONAX, Saint-Herblain, France
| | - Arthur Bongrand
- GIP ARRONAX, Saint-Herblain, France; Institut de Cancérologie de l'Ouest, site de Saint-Herblain, France
| | - Gregory Delpon
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France; Institut de Cancérologie de l'Ouest, site de Saint-Herblain, France
| | - Ferid Haddad
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France; GIP ARRONAX, Saint-Herblain, France
| | - Quentin Mouchard
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France
| | - Vincent Potiron
- Institut de Cancérologie de l'Ouest, site de Saint-Herblain, France; Nantes Université, CNRS, US2B, UMR 6286, F-44000 Nantes, France
| | - Gaëlle Saade
- Nantes Université, CNRS, US2B, UMR 6286, F-44000 Nantes, France
| | - Noël Servagent
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France
| | - Daphnée Villoing
- Institut de Cancérologie de l'Ouest, site de Saint-Herblain, France
| | - Vincent Métivier
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France
| | - Sophie Chiavassa
- Nantes Université, IMT Atlantique, CNRS/IN2P3, SUBATECH, F-44000 Nantes, France; Institut de Cancérologie de l'Ouest, site de Saint-Herblain, France
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Martínez-Rovira I, Montay-Gruel P, Petit B, Leavitt RJ, González-Vegas R, Froidevaux P, Juchaux M, Prezado Y, Yousef I, Vozenin MC. Infrared microspectroscopy to elucidate the underlying biomolecular mechanisms of FLASH radiotherapy. Radiother Oncol 2024; 196:110238. [PMID: 38527626 DOI: 10.1016/j.radonc.2024.110238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
BACKGROUND FLASH-radiotherapy (FLASH-RT) is an emerging modality that uses ultra-high dose rates of radiation to enable curative doses to the tumor while preserving normal tissue. The biological studies showed the potential of FLASH-RT to revolutionize radiotherapy cancer treatments. However, the complex biological basis of FLASH-RT is not fully known yet. AIM Within this context, our aim is to get deeper insights into the biomolecular mechanisms underlying FLASH-RT through Fourier Transform Infrared Microspectroscopy (FTIRM). METHODS C57Bl/6J female mice were whole brain irradiated at 10 Gy with the eRT6-Oriatron system. 10 Gy FLASH-RT was delivered in 1 pulse of 1.8μs and conventional irradiations at 0.1 Gy/s. Brains were sampled and prepared for analysis 24 h post-RT. FTIRM was performed at the MIRAS beamline of ALBA Synchrotron. Infrared raster scanning maps of the whole mice brain sections were collected for each sample condition. Hyperspectral imaging and Principal Component Analysis (PCA) were performed in several regions of the brain. RESULTS PCA results evidenced a clear separation between conventional and FLASH irradiations in the 1800-950 cm-1 region, with a significant overlap between FLASH and Control groups. An analysis of the loading plots revealed that most of the variance accounting for the separation between groups was associated to modifications in the protein backbone (Amide I). This protein degradation and/or conformational rearrangement was concomitant with nucleic acid fragmentation/condensation. Cluster separation between FLASH and conventional groups was also present in the 3000-2800 cm-1 region, being correlated with changes in the methylene and methyl group concentrations and in the lipid chain length. Specific vibrational features were detected as a function of the brain region. CONCLUSION This work provided new insights into the biomolecular effects involved in FLASH-RT through FTIRM. Our results showed that beyond nucleic acid investigations, one should take into account other dose-rate responsive molecules such as proteins, as they might be key to understand FLASH effect.
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Affiliation(s)
| | - Pierre Montay-Gruel
- Department of Radiation Oncology, Iridium Network, 2610, Wilrijk (Antwerp), Belgium; Centre for Oncological Research (CORE), University of Antwerp, 2610, Antwerp, Belgium
| | - Benoît Petit
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland
| | - Ron J Leavitt
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland
| | - Roberto González-Vegas
- Physics Department, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Barcelona), Spain
| | - Pascal Froidevaux
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland
| | - Marjorie Juchaux
- Centre de recherche d'Orsay, Institut Curie, 91401, Orsay, France
| | - Yolanda Prezado
- Centre de recherche d'Orsay, Institut Curie, 91401, Orsay, France
| | - Ibraheem Yousef
- MIRAS Beamline, ALBA Synchotron, 08290, Cerdanyola del Vallès (Barcelona), Spain
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland; Radiotherapy and Radiobiology sector, Radiation Therapy service, University hospital of Geneva (Current address), 1205, Geneva, Switzerland
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Liu K, Holmes S, Schüler E, Beddar S. A comprehensive investigation of the performance of a commercial scintillator system for applications in electron FLASH radiotherapy. Med Phys 2024. [PMID: 38507253 DOI: 10.1002/mp.17030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 02/08/2024] [Accepted: 03/04/2024] [Indexed: 03/22/2024] Open
Abstract
BACKGROUND Dosimetry in ultra-high dose rate (UHDR) beamlines is significantly challenged by limitations in real-time monitoring and accurate measurement of beam output, beam parameters, and delivered doses using conventional radiation detectors, which exhibit dependencies in ultra-high dose-rate (UHDR) and high dose-per-pulse (DPP) beamline conditions. PURPOSE In this study, we characterized the response of the Exradin W2 plastic scintillator (Standard Imaging, Inc.), a water-equivalent detector that provides measurements with a time resolution of 100 Hz, to determine its feasibility for use in UHDR electron beamlines. METHODS The W2 scintillator was exposed to an UHDR electron beam with different beam parameters by varying the pulse repetition frequency (PRF), pulse width (PW), and pulse amplitude settings of an electron UHDR linear accelerator system. The response of the W2 scintillator was evaluated as a function of the total integrated dose delivered, DPP, and mean and instantaneous dose rate. To account for detector radiation damage, the signal sensitivity (pC/Gy) of the W2 scintillator was measured and tracked as a function of dose history. RESULTS The W2 scintillator demonstrated mean dose rate independence and linearity as a function of integrated dose and DPP for DPP ≤ 1.5 Gy (R2 > 0.99) and PRF ≤ 90 Hz. At DPP > 1.5 Gy, nonlinear behavior and signal saturation in the blue and green signals as a function of DPP, PRF, and integrated dose became apparent. In the absence of Cerenkov correction, the W2 scintillator exhibited PW dependence, even at DPP values <1.5 Gy, with a difference of up to 31% and 54% in the measured blue and green signal for PWs ranging from 0.5 to 3.6 µs. The change in signal sensitivity of the W2 scintillator as a function of accumulated dose was approximately 4%/kGy and 0.3%/kGy for the measured blue and green signal responses, respectively, as a function of integrated dose history. CONCLUSION The Exradin W2 scintillator can provide output measurements that are both dose rate independent and linear in response if the DPP is kept ≤1.5 Gy (corresponding to a mean dose rate up to 290 Gy/s in the used system), as long as proper calibration is performed to account for PW and changes in signal sensitivity as a function of accumulated dose. For DPP > 1.5 Gy, the W2 scintillator's response becomes nonlinear, likely due to limitations in the electrometer related to the high signal intensity.
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Affiliation(s)
- Kevin Liu
- Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- UTHealth Houston Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | | | - Emil Schüler
- Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- UTHealth Houston Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
| | - Sam Beddar
- Division of Radiation Oncology, Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
- UTHealth Houston Graduate School of Biomedical Sciences, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA
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Vasyltsiv R, Rahman M, Harms J, Clark M, Gladstone DJ, Pogue BW, Zhang R, Bruza P. Imaging and characterization of optical emission from ex vivotissue during conventional and UHDR PBS proton therapy. Phys Med Biol 2024; 69:075011. [PMID: 38422545 PMCID: PMC10945384 DOI: 10.1088/1361-6560/ad2ee6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 02/21/2024] [Accepted: 02/29/2024] [Indexed: 03/02/2024]
Abstract
Objective. Imaging of optical photons emitted from tissue during radiotherapy is a promising technique for real-time visualization of treatment delivery, offering applications in dose verification, treatment monitoring, and retrospective treatment plan comparison. This research aims to explore the feasibility of intensified imaging of tissue luminescence during proton therapy (PT), under both conventional and ultra-high dose rate (UHDR) conditions.Approach. Conventional and UHDR pencil beam scanning (PBS) PT irradiation of freshex vivoporcine tissue and tissue-mimicking plastic phantom was imaged using intensified complementary metal-oxide-semiconductor(CMOS) cameras. The optical emission from tissue was characterized during conventional irradiation using both blue and red-sensitive intensifiers to ensure adequate spectral coverage. Spectral characterization was performed using bandpass filters between the lens and sensor. Imaging of conventional proton fields (240 MeV, 10 nA) was performed at 100 Hz frame rate, while UHDR PBS proton delivery (250 MeV, 99 nA) was recorded at 1 kHz frame rate. Dependence of optical emission yield on proton energy was studied using an optical tissue-mimicking plastic phantom and a range shifter. Finally, we demonstrated fast beam tracking capability of fast camera towardsin vivomonitoring of FLASH PT.Main results. Under conventional treatment dose rates optical emission was imaged with single spot resolution. Spot profiles were found to agree with the treatment planning system calculation within >90% for all spectral bands and spot intensity was found to vary with spectral filtration. The resultant polychromatic emission presented a maximum intensity at 650 nm and decreasing signal at lower wavelengths, which is consistent with expected attenuation patterns of high fat and muscle tissue. For UHDR beam imaging, optical yield increased with higher proton energy. Imaging at 1 kHz allowed continuous monitoring of delivery during porcine tissue irradiation, with clear identification of individual dwell positions. The number of dwell positions matched the treatment plan in total and per row showing adequate temporal capability of iCMOS imaging.Significance. For the first time, this study characterizes optical emission from tissue during PT and demonstrates our capability of fast optical tracking of pencil proton beam on the tissue anatomy in both conventional and UHDR setting. Similar to the Cherenkov imaging in radiotherapy, this imaging modality could enable a seamless, independent validation of PT treatments.
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Affiliation(s)
- Roman Vasyltsiv
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States of America
| | - Mahbubur Rahman
- UT Southwestern Medical Center, Dallas, TX, United States of America
| | - Joseph Harms
- Department of Radiation Oncology, University of Alabama at Birmingham, Birmingham, AL, United States of America
| | - Megan Clark
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States of America
| | - David J Gladstone
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States of America
| | - Brian W Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States of America
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI, United States of America
| | - Rongxiao Zhang
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States of America
- Department of Radiation Oncology, New York Medical College, Valhalla, NY, United States of America
| | - Petr Bruza
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States of America
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Grandvillain M, Vidal M, Hérault J, Benabdesselam M, Hofverberg P, Mady F. Silica-based scintillators: basic properties of radioluminescence kinetics. J Phys Condens Matter 2024; 36:245701. [PMID: 38447159 DOI: 10.1088/1361-648x/ad3094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Accepted: 03/06/2024] [Indexed: 03/08/2024]
Abstract
Radioluminescent silica-based fiber dosimeters offer great advantages for designing miniaturized realtime sensors for high dose-rate dosimetry. Rise and fall kinetics of their response must be properly understood to better assess their performances in terms of measurement speed and repeatability. A standard model of radioluminescence (RL) has already been quantitatively validated for doped silica glasses, but beyond conclusive comparisons with specific experiments, a comprehensive understanding of the processes and parameters determining transient and equilibrium kinetics of RL is still lacking. We analyze in detail the kinetics inherent in the standard RL model. Several asymptotical regimes in the RL growth are demonstrated in the case of a pristine sample (succesive quadratic, linear and power-law time dependencies before the plateau is reached). We show how this situation is modified when a pre-irradiation partly fills traps beforehand. RL growth is then greatly accelerated because of the pre-formation of recombination centers (RCs) from dopant ions, but not due to pre-filling of trapping levels. In all cases, the RL intensity eventually tends to a constant level equal to the pair generation rate, long before all carrier densities themselves reach equilibrium. This occurs late under irradiation, when deep traps get to saturation. The fraction of dopants converted into RCs is then 'frozen' at a lower level the smaller the density of deep traps. Controlling RL kinetics through the engineering of material traps is not an option. Pre-irradiation appears to be the simplest way to obtain accelerated and repeatable kinetics.
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Affiliation(s)
- Marjorie Grandvillain
- Université Côte d'Azur, Fédération de recherche Claude Lalanne, Institut de Physique de Nice, CNRS UMR7010, 17 rue Julien Lauprêtre, 06200 Nice, France
| | - Marie Vidal
- Centre Antoine Lacassagne, Fédération de recherche Claude Lalanne, 227 avenue de la Lanterne, 06200 Nice, France
| | - Joël Hérault
- Centre Antoine Lacassagne, Fédération de recherche Claude Lalanne, 227 avenue de la Lanterne, 06200 Nice, France
| | - Mourad Benabdesselam
- Université Côte d'Azur, Fédération de recherche Claude Lalanne, Institut de Physique de Nice, CNRS UMR7010, 17 rue Julien Lauprêtre, 06200 Nice, France
| | - Petter Hofverberg
- Centre Antoine Lacassagne, Fédération de recherche Claude Lalanne, 227 avenue de la Lanterne, 06200 Nice, France
| | - Franck Mady
- Université Côte d'Azur, Fédération de recherche Claude Lalanne, Institut de Physique de Nice, CNRS UMR7010, 17 rue Julien Lauprêtre, 06200 Nice, France
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Ashraf MR, Melemenidis S, Liu K, Grilj V, Jansen J, Velasquez B, Connell L, Schulz JB, Bailat C, Libed A, Manjappa R, Dutt S, Soto L, Lau B, Garza A, Larsen W, Skinner L, Yu AS, Surucu M, Graves EE, Maxim PG, Kry SF, Vozenin MC, Schüler E, Loo BW. Multi-Institutional Audit of FLASH and Conventional Dosimetry With a 3D Printed Anatomically Realistic Mouse Phantom. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00433-4. [PMID: 38493902 DOI: 10.1016/j.ijrobp.2024.03.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2023] [Revised: 03/03/2024] [Accepted: 03/10/2024] [Indexed: 03/19/2024]
Abstract
PURPOSE We conducted a multi-institutional dosimetric audit between FLASH and conventional dose rate (CONV) electron irradiations by using an anatomically realistic 3-dimensional (3D) printed mouse phantom. METHODS AND MATERIALS A computed tomography (CT) scan of a live mouse was used to create a 3D model of bony anatomy, lungs, and soft tissue. A dual-nozzle 3D printer was used to print the mouse phantom using acrylonitrile butadiene styrene (∼1.02 g/cm3) and polylactic acid (∼1.24 g/cm3) simultaneously to simulate soft tissue and bone densities, respectively. The lungs were printed separately using lightweight polylactic acid (∼0.64 g/cm3). Hounsfield units (HU), densities, and print-to-print stability of the phantoms were assessed. Three institutions were each provided a phantom and each institution performed 2 replicates of irradiations at selected anatomic regions. The average dose difference between FLASH and CONV dose distributions and deviation from the prescribed dose were measured with radiochromic film. RESULTS Compared with the reference CT scan, CT scans of the phantom demonstrated mass density differences of 0.10 g/cm3 for bone, 0.12 g/cm3 for lung, and 0.03 g/cm3 for soft tissue regions. Differences in HU between phantoms were <10 HU for soft tissue and bone, with lung showing the most variation (54 HU), but with minimal effect on dose distribution (<0.5%). Mean differences between FLASH and CONV decreased from the first to the second replicate (4.3%-1.2%), and differences from the prescribed dose decreased for both CONV (3.6%-2.5%) and FLASH (6.4%-2.7%). Total dose accuracy suggests consistent pulse dose and pulse number, although these were not specifically assessed. Positioning variability was observed, likely due to the absence of robust positioning aids or image guidance. CONCLUSIONS This study marks the first dosimetric audit for FLASH using a nonhomogeneous phantom, challenging conventional calibration practices reliant on homogeneous phantoms. The comparison protocol offers a framework for credentialing multi-institutional studies in FLASH preclinical research to enhance reproducibility of biologic findings.
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Affiliation(s)
- M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Kevin Liu
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Jeannette Jansen
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland
| | - Brett Velasquez
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Luke Connell
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Joseph B Schulz
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Aaron Libed
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Luis Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Aaron Garza
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - William Larsen
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, California
| | - Stephen F Kry
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston, USA
| | - Marie-Catherine Vozenin
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland; Radiotherapy and Radiobiology Sector, Radiation Therapy Service, University Hospital of Geneva, Geneva, Switzerland.
| | - Emil Schüler
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California.
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Almeida A, Godfroid C, Leavitt RJ, Montay-Gruel P, Petit B, Romero J, Ollivier J, Meziani L, Sprengers K, Paisley R, Grilj V, Limoli CL, Romero P, Vozenin MC. Antitumor Effect by Either FLASH or Conventional Dose Rate Irradiation Involves Equivalent Immune Responses. Int J Radiat Oncol Biol Phys 2024; 118:1110-1122. [PMID: 37951550 DOI: 10.1016/j.ijrobp.2023.10.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 10/05/2023] [Accepted: 10/14/2023] [Indexed: 11/14/2023]
Abstract
PURPOSE The capability of ultrahigh dose rate FLASH radiation therapy to generate the FLASH effect has opened the possibility to enhance the therapeutic index of radiation therapy. The contribution of the immune response has frequently been hypothesized to account for a certain fraction of the antitumor efficacy and tumor kill of FLASH but has yet to be rigorously evaluated. METHODS AND MATERIALS To investigate the immune response as a potentially important mechanism of the antitumor effect of FLASH, various murine tumor models were grafted either subcutaneously or orthotopically into immunocompetent mice or in moderately and severely immunocompromised mice. Mice were locally irradiated with single dose (20 Gy) or hypofractionated regimens (3 × 8 or 2 × 6 Gy) using FLASH (≥2000 Gy/s) and conventional (CONV) dose rates (0.1 Gy/s), with/without anti-CTLA-4. Tumor growth was monitored over time and immune profiling performed. RESULTS FLASH and CONV 20 Gy were isoeffective in delaying tumor growth in immunocompetent and moderately immunodeficient hosts and increased tumor doubling time to >14 days versus >7 days in control animals. Similar observations were obtained with a hypofractionated scheme, regardless of the microenvironment (subcutaneous flank vs ortho lungs). Interestingly, in profoundly immunocompromised mice, 20 Gy FLASH retained antitumor activity and significantly increased tumor doubling time to >14 days versus >8 days in control animals, suggesting a possible antitumor mechanism independent of the immune response. Analysis of the tumor microenvironment showed similar immune profiles after both irradiation modalities with significant decrease of lymphoid cells by ∼40% and a corresponding increase of myeloid cells. In addition, FLASH and CONV did not increase transforming growth factor-β1 levels in tumors compared with unirradiated control animals. Furthermore, when a complete and long-lasting antitumor response was obtained (>140 days), both modalities of irradiation were able to generate a long-term immunologic memory response. CONCLUSIONS The present results clearly document that the tumor responses across multiple immunocompetent and immunodeficient mouse models are largely dose rate independent and simultaneously contradict a major role of the immune response in the antitumor efficacy of FLASH. Therefore, our study indicates that FLASH is as potent as CONV in modulating antitumor immune response and can be used as an immunomodulatory agent.
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Affiliation(s)
- Aymeric Almeida
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Céline Godfroid
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland; Department of Oncology UNIL CHUV, University of Lausanne, Épalinges, Switzerland
| | - Ron J Leavitt
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Pierre Montay-Gruel
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland; Radiation Oncology Department, Iridium Netwerk, Wilrijk (Antwerp), Belgium; Antwerp Research in Radiation Oncology (AReRO), Centre for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | - Benoit Petit
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jackeline Romero
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jonathan Ollivier
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Lydia Meziani
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Kevin Sprengers
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Ryan Paisley
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, California
| | - Pedro Romero
- Department of Oncology UNIL CHUV, University of Lausanne, Épalinges, Switzerland
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
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Lopez Paz I, Fleta C, Gomez F, González DM, Pellegrini G. First use of silicon carbide detectors with graphene-enhanced contacts for medical dosimetry. Sci Rep 2024; 14:6131. [PMID: 38480838 PMCID: PMC10937979 DOI: 10.1038/s41598-024-56544-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 03/07/2024] [Indexed: 03/17/2024] Open
Abstract
Silicon Carbide (SiC) is a radiation hard wide bandgap semiconductor, which makes it an interesting alternative for radiation detector fabrication, with potential applications such as High Energy Physics, synchrotron and radiotherapy instrumentation. In addition, by reducing the amount of metal over the active area of said detectors (typically used for electrical connectivity with the implant of the pn-junction) unwanted effects from secondary interactions which can affect the accuracy of the measurement can be diminished, essential to meet the medical standards of precision. In this article, the use of epitaxially-grown graphene is explored as an alternative to metallic contacts with these prototypes. To this end, the first prototypes of SiC diodes with epitaxial graphene contacts were produced at IMB-CNM for radiation detection,along with reference devices. In order to characterise the feasibility of the technology in the medical application, the dose rate linearity of the SiC device with graphene was measured in a radiotherapy Linac in the dose rate range of 1-6 Gy/min. The response of the device was compared to that observed on devices with similar geometries reported elsewhere. To fully characterise the devices, the same exercise was repeated in a laboratory X-ray tube. Under the later set-up, the prototype is compared against a device with a fully metallised active region.
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Affiliation(s)
- Ivan Lopez Paz
- Instituto de Microelectronica de Barcelona, IMB-CNM-CSIC, Cerdanyola del Valles, 08193, Barcelona, Spain.
| | - Celeste Fleta
- Instituto de Microelectronica de Barcelona, IMB-CNM-CSIC, Cerdanyola del Valles, 08193, Barcelona, Spain
| | - Faustino Gomez
- Departamento de Física de Partículas, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Diego Miguel González
- Departamento de Física de Partículas, Universidade de Santiago de Compostela, 15782, Santiago de Compostela, Spain
| | - Giulio Pellegrini
- Instituto de Microelectronica de Barcelona, IMB-CNM-CSIC, Cerdanyola del Valles, 08193, Barcelona, Spain
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Daugherty EC, Zhang Y, Xiao Z, Mascia AE, Sertorio M, Woo J, McCann C, Russell KJ, Sharma RA, Khuntia D, Bradley JD, Simone CB, Breneman JC, Perentesis JP. FLASH radiotherapy for the treatment of symptomatic bone metastases in the thorax (FAST-02): protocol for a prospective study of a novel radiotherapy approach. Radiat Oncol 2024; 19:34. [PMID: 38475815 PMCID: PMC10935811 DOI: 10.1186/s13014-024-02419-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 02/08/2024] [Indexed: 03/14/2024] Open
Abstract
BACKGROUND FLASH therapy is a treatment technique in which radiation is delivered at ultra-high dose rates (≥ 40 Gy/s). The first-in-human FAST-01 clinical trial demonstrated the clinical feasibility of proton FLASH in the treatment of extremity bone metastases. The objectives of this investigation are to assess the toxicities of treatment and pain relief in study participants with painful thoracic bone metastases treated with FLASH radiotherapy, as well as workflow metrics in a clinical setting. METHODS This single-arm clinical trial is being conducted under an FDA investigational device exemption (IDE) approved for 10 patients with 1-3 painful bone metastases in the thorax, excluding bone metastases in the spine. Treatment will be 8 Gy in a single fraction administered at ≥ 40 Gy/s on a FLASH-enabled proton therapy system delivering a single transmission proton beam. Primary study endpoints are efficacy (pain relief) and safety. Patient questionnaires evaluating pain flare at the treatment site will be completed for 10 consecutive days post-RT. Pain response and adverse events (AEs) will be evaluated on the day of treatment and on day 7, day 15, months 1, 2, 3, 6, 9, and 12, and every 6 months thereafter. The outcomes for clinical workflow feasibility are the occurrence of any device issues as well as time on the treatment table. DISCUSSION This prospective clinical trial will provide clinical data for evaluating the efficacy and safety of proton FLASH for palliation of bony metastases in the thorax. Positive findings will support the further exploration of FLASH radiation for other clinical indications including patient populations treated with curative intent. REGISTRATION ClinicalTrials.gov NCT05524064.
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Affiliation(s)
- E C Daugherty
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, USA
| | - Y Zhang
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, USA
- Cancer and Blood Disease Institute , Cincinnati Children's Hospital , Cincinnati, OH, USA
| | - Z Xiao
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, USA
- Cancer and Blood Disease Institute , Cincinnati Children's Hospital , Cincinnati, OH, USA
| | - A E Mascia
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, USA
- Cancer and Blood Disease Institute , Cincinnati Children's Hospital , Cincinnati, OH, USA
| | - M Sertorio
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, USA
| | - J Woo
- Varian, a Siemens Healthineers Company, Palo Alto, USA
| | - C McCann
- Varian, a Siemens Healthineers Company, Palo Alto, USA
| | - K J Russell
- Varian, a Siemens Healthineers Company, Palo Alto, USA
| | - R A Sharma
- Varian, a Siemens Healthineers Company, Palo Alto, USA
| | - D Khuntia
- Varian, a Siemens Healthineers Company, Palo Alto, USA
| | - J D Bradley
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - C B Simone
- Department of Radiation Oncology, New York Proton Center , New York, NY, USA
| | - J C Breneman
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, OH, USA
| | - J P Perentesis
- Cancer and Blood Disease Institute , Cincinnati Children's Hospital , Cincinnati, OH, USA.
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26
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Poulsen PR, Johansen JG, Sitarz MK, Kanouta E, Kristensen L, Grau C, Sørensen BS. Oxygen Enhancement Ratio-Weighted Dose Quantitatively Describes Acute Skin Toxicity Variations in Mice After Pencil Beam Scanning Proton FLASH Irradiation With Changing Doses and Time Structures. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00358-4. [PMID: 38462015 DOI: 10.1016/j.ijrobp.2024.02.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 02/12/2024] [Accepted: 02/24/2024] [Indexed: 03/12/2024]
Abstract
PURPOSE The aim of this work was to investigate the ability of a biological oxygen enhancement ratio-weighted dose, DOER, to describe acute skin toxicity variations observed in mice after proton pencil beam scanning irradiations with changing doses and beam time structures. METHODS AND MATERIALS In five independent experiments, the right hind leg of a total of 621 CDF1 mice was irradiated previously in the entrance plateau of a pencil beam scanning proton beam. The incidence of acute skin toxicity (of level 1.5-2.0-2.5-3.0-3.5) was scored for 47 different mouse groups that mapped toxicity as function of dose for conventional and FLASH dose rate, toxicity as function of field dose rate with and without repainting, and toxicity when splitting the treatment into 1 to 6 identical deliveries separated by 2 minutes. DOER was calculated for all mouse groups using a simple oxygen kinetics model to describe oxygen depletion. The three independent model parameters (oxygen-depletion rate, oxygen-recovery rate, oxygen level without irradiation) were fitted to the experimental data. The ability of DOER to describe the toxicity variations across all experiments was investigated by comparing DOER-response curves across the five independent experiments. RESULTS After conversion from the independent variable tested in each experiment to DOER, all five experiments had similar MDDOER50 (DOER giving 50% toxicity incidence) with standard deviations of 0.45 - 1.6 Gy for the five toxicity levels. DOER could thus describe the observed toxicity variations across all experiments. CONCLUSIONS DOER described the varying FLASH-sparing effect observed for a wide range of conditions. Calculation of DOER for other irradiation conditions can quantitatively estimate the FLASH-sparing effect for arbitrary irradiations for the investigated murine model. With appropriate fitting parameters DOER also may be able to describe FLASH effect variations with dose and dose rate for other assays and endpoints.
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Affiliation(s)
- Per Rugaard Poulsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Jacob Graversen Johansen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Mateusz Krzysztof Sitarz
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Eleni Kanouta
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Line Kristensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Cai Grau
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Brita Singers Sørensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
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27
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Rank L, Dogan O, Kopp B, Mein S, Verona-Rinati G, Kranzer R, Marinelli M, Mairani A, Tessonnier T. Development and benchmarking of a dose rate engine for raster-scanned FLASH helium ions. Med Phys 2024; 51:2251-2262. [PMID: 37847027 PMCID: PMC10939952 DOI: 10.1002/mp.16793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 09/14/2023] [Accepted: 10/06/2023] [Indexed: 10/18/2023] Open
Abstract
BACKGROUND Radiotherapy with charged particles at high dose and ultra-high dose rate (uHDR) is a promising technique to further increase the therapeutic index of patient treatments. Dose rate is a key quantity to predict the so-called FLASH effect at uHDR settings. However, recent works introduced varying calculation models to report dose rate, which is susceptible to the delivery method, scanning path (in active beam delivery) and beam intensity. PURPOSE This work introduces an analytical dose rate calculation engine for raster scanned charged particle beams that is able to predict dose rate from the irradiation plan and recorded beam intensity. The importance of standardized dose rate calculation methods is explored here. METHODS Dose is obtained with an analytical pencil beam algorithm, using pre-calculated databases for integrated depth dose distributions and lateral penumbra. Dose rate is then calculated by combining dose information with the respective particle fluence (i.e., time information) using three dose-rate-calculation models (mean, instantaneous, and threshold-based). Dose rate predictions for all three models are compared to uHDR helium ion beam (145.7 MeV/u, range in water of approximatively 14.6 cm) measurements performed at the Heidelberg Ion Beam Therapy Center (HIT) with a diamond-detector prototype. Three scanning patterns (scanned or snake-like) and four field sizes are used to investigate the dose rate differences. RESULTS Dose rate measurements were in good agreement with in-silico generated distributions using the here introduced engine. Relative differences in dose rate were below 10% for varying depths in water, from 2.3 to 14.8 cm, as well as laterally in a near Bragg peak area. In the entrance channel of the helium ion beam, dose rates were predicted within 7% on average for varying irradiated field sizes and scanning patterns. Large differences in absolute dose rate values were observed for varying calculation methods. For raster-scanned irradiations, the deviation between mean and threshold-based dose rate at the investigated point was found to increase with the field size up to 63% for a 10 mm × 10 mm field, while no significant differences were observed for snake-like scanning paths. CONCLUSIONS This work introduces the first dose rate calculation engine benchmarked to instantaneous dose rate, enabling dose rate predictions for physical and biophysical experiments. Dose rate is greatly affected by varying particle fluence, scanning path, and calculation method, highlighting the need for a consensus among the FLASH community on how to calculate and report dose rate in the future. The here introduced engine could help provide the necessary details for the analysis of the sparing effect and uHDR conditions.
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Affiliation(s)
- Luisa Rank
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Karlsruhe Institute of Technology (KIT), Faculty of Physics, Karlsruhe, Germany
| | - Ozan Dogan
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Heidelberg University, Faculty of Physics and Astronomy, Heidelberg, Germany
| | - Benedikt Kopp
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
| | - Stewart Mein
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Department of Radiation Oncology, Heidelberg University Hospital (UKHD), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital (UKHD), Heidelberg Faculty of Medicine (MFHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | | | - Rafael Kranzer
- PTW-Freiburg, Freiburg, Germany
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University Oldenburg, Germany
| | - Marco Marinelli
- Industrial Engineering Department, University of Rome “Tor Vergata”, Rome, Italy
| | - Andrea Mairani
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Department of Radiation Oncology, Heidelberg University Hospital (UKHD), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital (UKHD), Heidelberg Faculty of Medicine (MFHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Medical Physics, National Centre of Oncological Hadrontherapy (CNAO), Pavia, Italy
| | - Thomas Tessonnier
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital (UKHD), Heidelberg Faculty of Medicine (MFHD) and German Cancer Research Center (DKFZ), Heidelberg, Germany
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28
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Zeng Y, Li H, Wang W, Liu X, Qin B, Dai S, Pang B, Liu M, Quan H, Yang K, Chang Y, Yang Z. Feasibility study of multiple-energy Bragg peak proton FLASH on a superconducting gantry with large momentum acceptance. Med Phys 2024; 51:2164-2174. [PMID: 38169535 DOI: 10.1002/mp.16932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 11/30/2023] [Accepted: 12/20/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND While the Bragg peak proton beam (BP) is capable of superior target conformity and organs-at-risk sparing than the transmission proton beam (TB), its efficacy in FLASH-RT is hindered by both a slow energy switching process and the beam current. A universal range shifter (URS) can pull back the high-energy proton beam while preserving the beam current. Meanwhile, a superconducting gantry with large momentum acceptance (LMA-SC gantry) enables fast energy switching. PURPOSE This study explores the feasibility of multiple-energy BP FLASH-RT on the LMA-SC gantry. METHOD AND MATERIALS A simultaneous dose and spot map optimization algorithm was developed for BP FLASH-RT treatment planning to improve the dose delivery efficiency. The URS was designed to be 0-27 cm thick, with 1 cm per step. BP plans using the URS were optimized using single-field optimization (SFO) and multiple-field optimization (MFO) for ten prostate cancer patients and ten lung cancer patients. The plan delivery parameters, dose, and dose rate metrics of BP plans were compared to those of TB plans using the parameters of the LMA-SC gantry. RESULTS Compared to TB plans, BP plans significantly reduced MUs by 42.7% (P < 0.001) with SFO and 33.3% (P < 0.001) with MFO for prostate cases. For lung cases, the reduction in MUs was 56.8% (P < 0.001) with SFO and 36.4% (P < 0.001) with MFO. BP plans also outperformed TB plans by reducing mean normal tissue doses. BP-SFO plans achieved a reduction of 56.7% (P < 0.001) for prostate cases and 57.7% (P < 0.001) for lung cases, while BP-MFO plans achieved a reduction of 54.2% (P < 0.001) for the prostate case and 40.0% (P < 0.001) for lung cases. For both TB and BP plans, normal tissues in prostate and lung cases received 100.0% FLASH dose rate coverage (>40 Gy/s). CONCLUSIONS By utilizing the URS and the LMA-SC gantry, it is possible to perform multiple-energy BP FLASH-RT, resulting in better normal tissue sparing, as compared to TB plans.
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Affiliation(s)
- Yiling Zeng
- Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan, China
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, China
| | - Heng Li
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland, USA
| | - Wei Wang
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, China
| | - Xu Liu
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, China
| | - Bin Qin
- State Key Laboratory of Advanced Electromagnetic Engineering and Technology, School of Electrical and Electronic Engineering, Huazhong University of Science and Technology, Wuhan, China
| | - Shuyang Dai
- School of Mathematics and Statistics, Wuhan University, Wuhan, P. R. China
| | - Bo Pang
- Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan, China
| | - Muyu Liu
- Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan, China
| | - Hong Quan
- Department of Medical Physics, School of Physics and Technology, Wuhan University, Wuhan, China
| | - Kunyu Yang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, China
| | - Yu Chang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, China
| | - Zhiyong Yang
- Cancer Center, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- Hubei Key Laboratory of Precision Radiation Oncology, Wuhan, China
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Schoenauen L, Stubbe FX, Van Gestel D, Penninckx S, Heuskin AC. C. elegans: A potent model for high-throughput screening experiments investigating the FLASH effect. Clin Transl Radiat Oncol 2024; 45:100712. [PMID: 38125649 PMCID: PMC10731598 DOI: 10.1016/j.ctro.2023.100712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2023] [Revised: 11/30/2023] [Accepted: 12/06/2023] [Indexed: 12/23/2023] Open
Abstract
This study explores the effects of UHDR irradiation on Caenorhabditis elegans embryos. UHDR proton and electron beams demonstrate a sparing effect, aligning with literature findings. This highlights C. elegans suitability as a screening model for studying the LET impact on the FLASH effect, reinforcing its potential in radiation research.
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Affiliation(s)
- Lucas Schoenauen
- NAmur Research Insitute for Life Sciences, University of Namur, Belgium
| | | | - Dirk Van Gestel
- Department of Radiation Oncology, Institut Jules Bordet, Hopital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles, Brussels, Belgium
| | - Sébastien Penninckx
- Department of Radiation Oncology, Institut Jules Bordet, Hopital Universitaire de Bruxelles (HUB), Université Libre de Bruxelles, Brussels, Belgium
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Cao N, Erickson DPJ, Ford EC, Emery RC, Kranz M, Goff P, Schwarz M, Meyer J, Wong T, Saini J, Bloch C, Stewart RD, Sandison GA, Morimoto A, DeLonais-Dick A, Shaver BA, Rengan R, Zeng J. Preclinical Ultra-High Dose Rate (FLASH) Proton Radiation Therapy System for Small Animal Studies. Adv Radiat Oncol 2024; 9:101425. [PMID: 38379895 PMCID: PMC10877683 DOI: 10.1016/j.adro.2023.101425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Accepted: 11/30/2023] [Indexed: 02/22/2024] Open
Abstract
Purpose Animal studies with ultrahigh dose-rate radiation therapy (FLASH, >40 Gy/s) preferentially spare normal tissues without sacrificing antitumor efficacy compared with conventional dose-rate radiation therapy (CONV). At the University of Washington, we developed a cyclotron-generated preclinical scattered proton beam with FLASH dose rates. We present the technical details of our FLASH radiation system and preliminary biologic results from whole pelvis radiation. Methods and Materials A Scanditronix MC50 compact cyclotron beamline has been modified to produce a 48.7 MeV proton beam at dose rates between 0.1 and 150 Gy/s. The system produces a 6 cm diameter scattered proton beam (flat to ± 3%) at the target location. Female C57BL/6 mice 5 to 6 weeks old were used for all experiments. To study normal tissue effects in the distal colon, mice were irradiated using the entrance region of the proton beam to the whole pelvis, 18.5 Gy at different dose rates: control, CONV (0.6-1 Gy/s) and FLASH (50-80 Gy/s). Survival was monitored daily and EdU (5-ethynyl-2´-deoxyuridine) staining was performed at 24- and 96-hours postradiation. Cleaved caspase-3 staining was performed 24-hours postradiation. To study tumor control, allograft B16F10 tumors were implanted in the right flank and received 18 Gy CONV or FLASH proton radiation. Tumor growth and survival were monitored. Results After 18.5 Gy whole pelvis radiation, survival was 100% in the control group, 0% in the CONV group, and 44% in the FLASH group (P < .01). EdU staining showed cell proliferation was significantly higher in the FLASH versus CONV group at both 24-hours and 96-hours postradiation in the distal colon, although both radiation groups showed decreased proliferation compared with controls (P < .05). Lower cleaved caspase-3 staining was seen in the FLASH versus conventional group postradiation (P < .05). Comparable flank tumor control was observed in the CONV and FLASH groups. Conclusions We present our preclinical FLASH proton radiation system and biologic results showing improved survival after whole pelvis radiation, with equivalent tumor control.
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Affiliation(s)
- Ning Cao
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | | | - Eric C. Ford
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Robert C. Emery
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Marissa Kranz
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Peter Goff
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Marco Schwarz
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Juergen Meyer
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Tony Wong
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Jatinder Saini
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Charles Bloch
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Robert D. Stewart
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - George A. Sandison
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Alec Morimoto
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Ava DeLonais-Dick
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Ben A. Shaver
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Ramesh Rengan
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Jing Zeng
- Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
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Sesink A, Becerra M, Ruan JL, Leboucher S, Dubail M, Heinrich S, Jdey W, Petersson K, Fouillade C, Berthault N, Dutreix M, Girard PM. The AsiDNA™ decoy mimicking DSBs protects the normal tissue from radiation toxicity through a DNA-PK/p53/p21-dependent G1/S arrest. NAR Cancer 2024; 6:zcae011. [PMID: 38476631 PMCID: PMC10928987 DOI: 10.1093/narcan/zcae011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Revised: 02/01/2024] [Accepted: 02/27/2024] [Indexed: 03/14/2024] Open
Abstract
AsiDNA™, a cholesterol-coupled oligonucleotide mimicking double-stranded DNA breaks, was developed to sensitize tumour cells to radio- and chemotherapy. This drug acts as a decoy hijacking the DNA damage response. Previous studies have demonstrated that standalone AsiDNA™ administration is well tolerated with no additional adverse effects when combined with chemo- and/or radiotherapy. The lack of normal tissue complication encouraged further examination into the role of AsiDNA™ in normal cells. This research demonstrates the radioprotective properties of AsiDNA™. In vitro, AsiDNA™ induces a DNA-PK/p53/p21-dependent G1/S arrest in normal epithelial cells and fibroblasts that is absent in p53 deficient and proficient tumour cells. This cell cycle arrest improved survival after irradiation only in p53 proficient normal cells. Combined administration of AsiDNA™ with conventional radiotherapy in mouse models of late and early radiation toxicity resulted in decreased onset of lung fibrosis and increased intestinal crypt survival. Similar results were observed following FLASH radiotherapy in standalone or combined with AsiDNA™. Mechanisms comparable to those identified in vitro were detected both in vivo, in the intestine and ex vivo, in precision cut lung slices. Collectively, the results suggest that AsiDNA™ can partially protect healthy tissues from radiation toxicity by triggering a G1/S arrest in normal cells.
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Affiliation(s)
- Anouk Sesink
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
| | - Margaux Becerra
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
| | - Jia-Ling Ruan
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
| | - Sophie Leboucher
- Histology platform, Institut Curie, CNRS UMR3348, 91405 Orsay, France
| | - Maxime Dubail
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
| | - Sophie Heinrich
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
| | - Wael Jdey
- Valerio Therapeutics, 49 Bd du Général Martial Valin, 75015 Paris, France
| | - Kristoffer Petersson
- Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Old Road Campus Research Building, Roosevelt Drive, Oxford, UK
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund University, Lund, Sweden
| | - Charles Fouillade
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
| | - Nathalie Berthault
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
| | - Marie Dutreix
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
| | - Pierre-Marie Girard
- Institut Curie, Université PSL, CNRS UMR3347, INSERM U1021, 91405 Orsay, France
- Université Paris-Saclay, CNRS UMR 3347, INSERM U1021, 91405 Orsay, France
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Freitag R, Stern J, Masters J, Kowalski G, Miller DM, Eley JG. High-Dose Ionizing Radiation Impairs Healthy Dendrite Growth in C. elegans. Adv Radiat Oncol 2024; 9:101415. [PMID: 38379892 PMCID: PMC10876608 DOI: 10.1016/j.adro.2023.101415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 11/19/2023] [Indexed: 02/22/2024] Open
Abstract
Purpose The nervous system is vulnerable to radiation damage, and further optimization is required to increase the efficacy of radiation therapy while reducing harm to neurons. Given recent developments in heavy ion therapy, experimental models would be valuable to improve these therapies. We used the nematode Caenorhabditis elegans (C. elegans) to evaluate the effects of high-dose radiation on neuron development. Methods and Materials In this study, we used confocal microscopy to assess dendritic growth of the PVD nociceptor after high-dose gamma-irradiation from a Cs-137 source. Results Irradiation during an early larval stage (L2) delayed overall development but also independently impaired dendrite outgrowth in the PVD nociceptive neuron. Irradiation at L4 larval stage did not result in significant alterations in dendrite morphology. Conclusions The nematode C. elegans can serve as a high-throughput model to study the effects of high-dose radiation on dendrite growth. We propose that C. elegans can be useful for studies of experimental radiation therapy modalities and dose rates for translational research.
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Affiliation(s)
- Robert Freitag
- Program in Neuroscience, Vanderbilt University, Nashville, Tennessee
| | - Jamie Stern
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
- Agilent Technologies, Winooski, Vermont
| | - Joseph Masters
- Department of Radiation Oncology, Vanderbilt University School of Medicine, Nashville Tennessee
| | - Greta Kowalski
- Department of Radiation Oncology, Vanderbilt University School of Medicine, Nashville Tennessee
| | - David M. Miller
- Program in Neuroscience, Vanderbilt University, Nashville, Tennessee
- Department of Cell and Developmental Biology, Vanderbilt University, Nashville, Tennessee
| | - John G. Eley
- Department of Radiation Oncology, Vanderbilt University School of Medicine, Nashville Tennessee
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Kuipers ME, van Doorn-Wink KCJ, Hiemstra PS, Slats AM. Predicting Radiation-Induced Lung Injury in Patients With Lung Cancer: Challenges and Opportunities. Int J Radiat Oncol Biol Phys 2024; 118:639-649. [PMID: 37924986 DOI: 10.1016/j.ijrobp.2023.10.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 10/06/2023] [Accepted: 10/22/2023] [Indexed: 11/06/2023]
Abstract
Radiation-induced lung injury (RILI) is one of the main dose-limiting toxicities in radiation therapy (RT) for lung cancer. Approximately 10% to 20% of patients show signs of RILI of variable severity. The reason for the wide range of RILI severity and the mechanisms underlying its development are only partially understood. A number of clinical risk factors have been identified that can aid in clinical decision making. Technological advancements in RT and the use of strict organ-at-risk dose constraints have helped to reduce RILI. Predicting patients at risk for RILI may be further improved with a combination of cytokine assessments, γH2AX-assays in leukocytes, or epigenetic markers. A complicating factor is the lack of an objective definition of RILI. Tools such as computed tomography densitometry, fluorodeoxyglucose-positron emission tomography uptake, changes in lung function measurements, and exhaled breath analysis can be implemented to better define and quantify RILI. This can aid in the search for new biomarkers, which can be accelerated by omics techniques, single-cell RNA sequencing, mass cytometry, and advances in patient-specific in vitro cell culture models. An objective quantification of RILI combined with these novel techniques can aid in the development of biomarkers to better predict patients at risk and allow personalized treatment decisions.
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Affiliation(s)
- Merian E Kuipers
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands.
| | | | - Pieter S Hiemstra
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands
| | - Annelies M Slats
- Department of Pulmonology, Leiden University Medical Center, Leiden, The Netherlands
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Shiraishi Y, Matsuya Y, Fukunaga H. Possible mechanisms and simulation modeling of FLASH radiotherapy. Radiol Phys Technol 2024; 17:11-23. [PMID: 38184508 DOI: 10.1007/s12194-023-00770-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 12/01/2023] [Accepted: 12/02/2023] [Indexed: 01/08/2024]
Abstract
FLASH radiotherapy (FLASH-RT) has great potential to improve patient outcomes. It delivers radiation doses at an ultra-high dose rate (UHDR: ≥ 40 Gy/s) in a single instant or a few pulses. Much higher irradiation doses can be administered to tumors with FLASH-RT than with conventional dose rate (0.01-0.40 Gy/s) radiotherapy. UHDR irradiation can suppress toxicity in normal tissues while sustaining antitumor efficiency, which is referred to as the FLASH effect. However, the mechanisms underlying the effects of the FLASH remain unclear. To clarify these mechanisms, the development of simulation models that can contribute to treatment planning for FLASH-RT is still underway. Previous studies indicated that transient oxygen depletion or augmented reactions between secondary reactive species produced by irradiation may be involved in this process. To discuss the possible mechanisms of the FLASH effect and its clinical potential, we summarized the physicochemical, chemical, and biological perspectives as well as the development of simulation modeling for FLASH-RT.
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Affiliation(s)
- Yuta Shiraishi
- Graduate School of Health Sciences, Hokkaido University, N12 W5 Kita-Ku, Sapporo, Hokkaido, 060-0812, Japan
- Faculty of Health Sciences, Japan Healthcare University, 3-11-1-50 Tsukisamu-Higashi, Toyohira-Ku, Sapporo, Hokkaido, 062-0053, Japan
| | - Yusuke Matsuya
- Faculty of Health Sciences, Hokkaido University, N12 W5 Kita-Ku, Sapporo, Hokkaido, 060-0812, Japan
| | - Hisanori Fukunaga
- Faculty of Health Sciences, Hokkaido University, N12 W5 Kita-Ku, Sapporo, Hokkaido, 060-0812, Japan.
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Rezaee M, Adhikary A. The Effects of Particle LET and Fluence on the Complexity and Frequency of Clustered DNA Damage. DNA (Basel) 2024; 4:34-51. [PMID: 38282954 PMCID: PMC10810015 DOI: 10.3390/dna4010002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2024]
Abstract
Motivation Clustered DNA-lesions are predominantly induced by ionizing radiation, particularly by high-LET particles, and considered as lethal damage. Quantification of this specific type of damage as a function of radiation parameters such as LET, dose rate, dose, and particle type can be informative for the prediction of biological outcome in radiobiological studies. This study investigated the induction and complexity of clustered DNA damage for three different types of particles at an LET range of 0.5-250 keV/μm. Methods Nanometric volumes (36.0 nm3) of 15 base-pair DNA with its hydration shell was modeled. Electron, proton, and alpha particles at various energies were simulated to irradiate the nanometric volumes. The number of ionization events, low-energy electron spectra, and chemical yields for the formation of °OH, H°, e aq - , and H2O2 were calculated for each particle as a function of LET. Single- and double-strand breaks (SSB and DSB), base release, and clustered DNA-lesions were computed from the Monte-Carlo based quantification of the reactive species and measured yields of the species responsible for the DNA lesion formation. Results The total amount of DNA damage depends on particle type and LET. The number of ionization events underestimates the quantity of DNA damage at LETs higher than 10 keV/μm. Minimum LETs of 9.4 and 11.5 keV/μm are required to induce clustered damage by a single track of proton and alpha particles, respectively. For a given radiation dose, an increase in LET reduces the number of particle tracks, leading to more complex clustered DNA damage, but a smaller number of separated clustered damage sites. Conclusions The dependency of the number and the complexity of clustered DNA damage on LET and fluence suggests that the quantification of this damage can be a useful method for the estimation of the biological effectiveness of radiation. These results also suggest that medium-LET particles are more appropriate for the treatment of bulk targets, whereas high-LET particles can be more effective for small targets.
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Affiliation(s)
- Mohammad Rezaee
- Department of Radiation Oncology and Molecular Radiation Sciences, School of Medicine, Johns Hopkins University, 1550 Orleans St., Baltimore, MD 21231, USA
| | - Amitava Adhikary
- Department of Chemistry, Oakland University, 146 Library Drive, Rochester, MI 48309, USA
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El Khatib M, Motlagh AO, Beyer JN, Troxler T, Allu SR, Sun Q, Burslem GM, Vinogradov SA. Direct Measurements of FLASH-Induced Changes in Intracellular Oxygenation. Int J Radiat Oncol Biol Phys 2024; 118:781-789. [PMID: 37729972 DOI: 10.1016/j.ijrobp.2023.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/01/2023] [Accepted: 09/13/2023] [Indexed: 09/22/2023]
Abstract
PURPOSE The goal of our study was to characterize the dynamics of intracellular oxygen during application of radiation at conventional (CONV) and FLASH dose rates and obtain evidence for or against the oxygen depletion hypothesis as a mechanism of the FLASH effect. METHODS AND MATERIALS The measurements were performed by the phosphorescence quenching method using probe Oxyphor PtG4, which was delivered into the cellular cytosol by electroporation. RESULTS Intracellular radiochemical oxygen depletion (ROD) g-value for a dose rate of 100 Gy/s in the normoxic range was found to be 0.58 ± 0.03 μM/Gy. Intracellular ROD g-values for FLASH and CONV dose rates in the normoxic range were found to be nearly equal. As in solution-based studies, intracellular ROD was found to exhibit strong dependence on oxygen concentration in the range of 0 to ∼40 μM [O2]. CONCLUSIONS Depletion of oxygen in cells in vitro by a clinical dose of proton radiation delivered as FLASH is unable to produce a transient state of hypoxia and, therefore, unable to induce radioprotection. The difference between ROD g-values for FLASH and CONV dose rates, detected previously in solutions-based experiments, disappears when measurements are conducted inside cells. Understanding this phenomenon should provide additional insight into the role of oxygen in FLASH radiation therapy and help to decipher the mechanism of the FLASH effect.
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Affiliation(s)
- Mirna El Khatib
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Azar O Motlagh
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jenna N Beyer
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Thomas Troxler
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Srinivasa Rao Allu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Qi Sun
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | - George M Burslem
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania.
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Liu W, Feng H, Taylor PA, Kang M, Shen J, Saini J, Zhou J, Giap HB, Yu NY, Sio TS, Mohindra P, Chang JY, Bradley JD, Xiao Y, Simone CB, Lin L. NRG Oncology and PTCOG Patterns of Practice Survey and Consensus Recommendations on Pencil-Beam Scanning Proton Stereotactic Body Radiation Therapy and Hypofractionated Radiation Therapy for Thoracic Malignancies. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00297-9. [PMID: 38395086 DOI: 10.1016/j.ijrobp.2024.01.216] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2023] [Revised: 11/25/2023] [Accepted: 01/28/2024] [Indexed: 02/25/2024]
Abstract
Stereotactic body radiation therapy (SBRT) and hypofractionation using pencil-beam scanning (PBS) proton therapy (PBSPT) is an attractive option for thoracic malignancies. Combining the advantages of target coverage conformity and critical organ sparing from both PBSPT and SBRT, this new delivery technique has great potential to improve the therapeutic ratio, particularly for tumors near critical organs. Safe and effective implementation of PBSPT SBRT/hypofractionation to treat thoracic malignancies is more challenging than the conventionally fractionated PBSPT because of concerns of amplified uncertainties at the larger dose per fraction. The NRG Oncology and Particle Therapy Cooperative Group Thoracic Subcommittee surveyed proton centers in the United States to identify practice patterns of thoracic PBSPT SBRT/hypofractionation. From these patterns, we present recommendations for future technical development of proton SBRT/hypofractionation for thoracic treatment. Among other points, the recommendations highlight the need for volumetric image guidance and multiple computed tomography-based robust optimization and robustness tools to minimize further the effect of uncertainties associated with respiratory motion. Advances in direct motion analysis techniques are urgently needed to supplement current motion management techniques.
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Affiliation(s)
- Wei Liu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona.
| | - Hongying Feng
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona; College of Mechanical and Power Engineering, China Three Gorges University, Yichang, Hubei, China; Department of Radiation Oncology, Guangzhou Concord Cancer Center, Guangzhou, Guangdong, China
| | - Paige A Taylor
- Imaging and Radiation Oncology Core Houston Quality Assurance Center, University of Texas MD Anderson Cancer Center, Houston, Texas
| | | | - Jiajian Shen
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona
| | - Jatinder Saini
- Seattle Cancer Care Alliance Proton Therapy Center and Department of Radiation Oncology, University of Washington School of Medicine, Seattle, Washington
| | - Jun Zhou
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia
| | - Huan B Giap
- Department of Radiation Oncology, Medical University of South Carolina, Charleston, South Carolina
| | - Nathan Y Yu
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona
| | - Terence S Sio
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona
| | - Pranshu Mohindra
- Department of Radiation Oncology, University Hospitals Cleveland Medical Center, Cleveland, Ohio
| | - Joe Y Chang
- Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Jeffrey D Bradley
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Ying Xiao
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Liyong Lin
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta, Georgia
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Borghini A, Labate L, Piccinini S, Panaino CMV, Andreassi MG, Gizzi LA. FLASH Radiotherapy: Expectations, Challenges, and Current Knowledge. Int J Mol Sci 2024; 25:2546. [PMID: 38473799 DOI: 10.3390/ijms25052546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2023] [Revised: 02/12/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
Major strides have been made in the development of FLASH radiotherapy (FLASH RT) in the last ten years, but there are still many obstacles to overcome for transfer to the clinic to become a reality. Although preclinical and first-in-human clinical evidence suggests that ultra-high dose rates (UHDRs) induce a sparing effect in normal tissue without modifying the therapeutic effect on the tumor, successful clinical translation of FLASH-RT depends on a better understanding of the biological mechanisms underpinning the sparing effect. Suitable in vitro studies are required to fully understand the radiobiological mechanisms associated with UHDRs. From a technical point of view, it is also crucial to develop optimal technologies in terms of beam irradiation parameters for producing FLASH conditions. This review provides an overview of the research progress of FLASH RT and discusses the potential challenges to be faced before its clinical application. We critically summarize the preclinical evidence and in vitro studies on DNA damage following UHDR irradiation. We also highlight the ongoing developments of technologies for delivering FLASH-compliant beams, with a focus on laser-driven plasma accelerators suitable for performing basic radiobiological research on the UHDR effects.
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Affiliation(s)
| | - Luca Labate
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
| | - Simona Piccinini
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
| | | | | | - Leonida Antonio Gizzi
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
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Leavitt RJ, Almeida A, Grilj V, Montay-Gruel P, Godfroid C, Petit B, Bailat C, Limoli CL, Vozenin MC. Acute Hypoxia Does Not Alter Tumor Sensitivity to FLASH Radiation Therapy. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00320-1. [PMID: 38387809 DOI: 10.1016/j.ijrobp.2024.02.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2023] [Revised: 01/10/2024] [Accepted: 02/08/2024] [Indexed: 02/24/2024]
Abstract
PURPOSE Tumor hypoxia is a major cause of treatment resistance, especially to radiation therapy at conventional dose rate (CONV), and we wanted to assess whether hypoxia does alter tumor sensitivity to FLASH. METHODS AND MATERIALS We engrafted several tumor types (glioblastoma [GBM], head and neck cancer, and lung adenocarcinoma) subcutaneously in mice to provide a reliable and rigorous way to modulate oxygen supply via vascular clamping or carbogen breathing. We irradiated tumors using a single 20-Gy fraction at either CONV or FLASH, measured oxygen tension, monitored tumor growth, and sampled tumors for bulk RNAseq and pimonidazole analysis. Next, we inhibited glycolysis with trametinib in GBM tumors to enhance FLASH efficacy. RESULTS Using various subcutaneous tumor models, and in contrast to CONV, FLASH retained antitumor efficacy under acute hypoxia. These findings show that in addition to normal tissue sparing, FLASH could overcome hypoxia-mediated tumor resistance. Follow-up molecular analysis using RNAseq profiling uncovered a FLASH-specific profile in human GBM that involved cell-cycle arrest, decreased ribosomal biogenesis, and a switch from oxidative phosphorylation to glycolysis. Glycolysis inhibition by trametinib enhanced FLASH efficacy in both normal and clamped conditions. CONCLUSIONS These data provide new and specific insights showing the efficacy of FLASH in a radiation-resistant context, proving an additional benefit of FLASH over CONV.
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Affiliation(s)
- Ron J Leavitt
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Aymeric Almeida
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Veljko Grilj
- Institute of Radiation Physics, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Pierre Montay-Gruel
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland; Radiation Oncology Department, Iridium Netwerk, Wilrijk (Antwerp), Belgium; Antwerp Research in Radiation Oncology (AReRO), Center for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | - Céline Godfroid
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Benoit Petit
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, California
| | - Marie-Catherine Vozenin
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland.
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Clements N, Esplen N, Bateman J, Robertson C, Dosanjh M, Korysko P, Farabolini W, Corsini R, Bazalova-Carter M. Mini-GRID radiotherapy on the CLEAR very-high-energy electron beamline: collimator optimization, film dosimetry, and Monte Carlo simulations. Phys Med Biol 2024; 69:055003. [PMID: 38295408 DOI: 10.1088/1361-6560/ad247d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 01/31/2024] [Indexed: 02/02/2024]
Abstract
Objective.Spatially-fractionated radiotherapy (SFRT) delivered with a very-high-energy electron (VHEE) beam and a mini-GRID collimator was investigated to achieve synergistic normal tissue-sparing through spatial fractionation and the FLASH effect.Approach.A tungsten mini-GRID collimator for delivering VHEE SFRT was optimized using Monte Carlo (MC) simulations. Peak-to-valley dose ratios (PVDRs), depths of convergence (DoCs, PVDR ≤ 1.1), and peak and valley doses in a water phantom from a simulated 150 MeV VHEE source were evaluated. Collimator thickness, hole width, and septal width were varied to determine an optimal value for each parameter that maximized PVDR and DoC. The optimized collimator (20 mm thick rectangular prism with a 15 mm × 15 mm face with a 7 × 7 array of 0.5 mm holes separated by 1.1 mm septa) was 3D-printed and used for VHEE irradiations with the CERN linear electron accelerator for research beam. Open beam and mini-GRID irradiations were performed at 140, 175, and 200 MeV and dose was recorded with radiochromic films in a water tank. PVDR, central-axis (CAX) and valley dose rates and DoCs were evaluated.Main results.Films demonstrated peak and valley dose rates on the order of 100 s of MGy/s, which could promote FLASH-sparing effects. Across the three energies, PVDRs of 2-4 at 13 mm depth and DoCs between 39 and 47 mm were achieved. Open beam and mini-GRID MC simulations were run to replicate the film results at 200 MeV. For the mini-GRID irradiations, the film CAX dose was on average 15% higher, the film valley dose was 28% higher, and the film PVDR was 15% lower than calculated by MC.Significance.Ultimately, the PVDRs and DoCs were determined to be too low for a significant potential for SFRT tissue-sparing effects to be present, particularly at depth. Further beam delivery optimization and investigations of new means of spatial fractionation are warranted.
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Affiliation(s)
- Nathan Clements
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Nolan Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Joseph Bateman
- Department of Physics, University of Oxford, Oxford, United Kingdom
| | | | - Manjit Dosanjh
- Department of Physics, University of Oxford, Oxford, United Kingdom
- CERN, Geneva, Switzerland
| | - Pierre Korysko
- Department of Physics, University of Oxford, Oxford, United Kingdom
- CERN, Geneva, Switzerland
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Kaulfers T, Lattery G, Cheng C, Zhao X, Selvaraj B, Wu H, Chhabra AM, Choi JI, Lin H, Simone CB, Hasan S, Kang M, Chang J. Pencil Beam Scanning Proton Bragg Peak Conformal FLASH in Prostate Cancer Stereotactic Body Radiotherapy. Cancers (Basel) 2024; 16:798. [PMID: 38398188 PMCID: PMC10886659 DOI: 10.3390/cancers16040798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2023] [Revised: 01/29/2024] [Accepted: 02/12/2024] [Indexed: 02/25/2024] Open
Abstract
Bragg peak FLASH radiotherapy (RT) uses a distal tracking method to eliminate exit doses and can achieve superior OAR sparing. This study explores the application of this novel method in stereotactic body radiotherapy prostate FLASH-RT. An in-house platform was developed to enable intensity-modulated proton therapy (IMPT) planning using a single-energy Bragg peak distal tracking method. The patients involved in the study were previously treated with proton stereotactic body radiotherapy (SBRT) using the pencil beam scanning (PBS) technique to 40 Gy in five fractions. FLASH plans were optimized using a four-beam arrangement to generate a dose distribution similar to the conventional opposing beams. All of the beams had a small angle of two degrees from the lateral direction to increase the dosimetry quality. Dose metrics were compared between the conventional PBS and the Bragg peak FLASH plans. The dose rate histogram (DRVH) and FLASH metrics of 40 Gy/s coverage (V40Gy/s) were investigated for the Bragg peak plans. There was no significant difference between the clinical and Bragg peak plans in rectum, bladder, femur heads, large bowel, and penile bulb dose metrics, except for Dmax. For the CTV, the FLASH plans resulted in a higher Dmax than the clinical plans (116.9% vs. 103.3%). For the rectum, the V40Gy/s reached 94% and 93% for 1 Gy dose thresholds in composite and single-field evaluations, respectively. Additionally, the FLASH ratio reached close to 100% after the application of the 5 Gy threshold in composite dose rate assessment. In conclusion, the Bragg peak distal tracking method can yield comparable plan quality in most OARs while preserving sufficient FLASH dose rate coverage, demonstrating that the ultra-high dose technique can be applied in prostate FLASH SBRT.
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Affiliation(s)
- Tyler Kaulfers
- Department of Physics and Astronomy, Hofstra University, Hempstead, NY 11549, USA; (T.K.); (G.L.)
| | - Grant Lattery
- Department of Physics and Astronomy, Hofstra University, Hempstead, NY 11549, USA; (T.K.); (G.L.)
| | - Chingyun Cheng
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, 195 Little Albany Street, New Brunswick, NJ 08901, USA;
| | - Xingyi Zhao
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Balaji Selvaraj
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Hui Wu
- Department of Radiation Oncology, The Affiliated Cancer Hospital of Zhengzhou University, Henan Cancer Hospital, Zhengzhou 450008, China;
| | - Arpit M. Chhabra
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Jehee Isabelle Choi
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Haibo Lin
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Charles B. Simone
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Shaakir Hasan
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Minglei Kang
- New York Proton Center, 225 E 126th Street, New York, NY 10035, USA; (X.Z.); (B.S.); (A.M.C.); (J.I.C.); (H.L.); (S.H.)
| | - Jenghwa Chang
- Department of Physics and Astronomy, Hofstra University, Hempstead, NY 11549, USA; (T.K.); (G.L.)
- Northwell, 2000 Marcus Ave, Suite 300, New Hyde Park, NY 11042, USA
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Kim K, Kim MM, Skoufos G, Diffenderfer ES, Motlagh SAO, Kokkorakis M, Koliaki I, Morcos G, Shoniyozov K, Griffin J, Hatzigeorgiou AG, Metz JM, Lin A, Feigenberg SJ, Cengel KA, Ky B, Koumenis C, Verginadis II. FLASH Proton Radiation Therapy Mitigates Inflammatory and Fibrotic Pathways and Preserves Cardiac Function in a Preclinical Mouse Model of Radiation-Induced Heart Disease. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00301-8. [PMID: 38364948 DOI: 10.1016/j.ijrobp.2024.01.224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2023] [Revised: 01/12/2024] [Accepted: 01/28/2024] [Indexed: 02/18/2024]
Abstract
PURPOSE Studies during the past 9 years suggest that delivering radiation at dose rates exceeding 40 Gy/s, known as "FLASH" radiation therapy, enhances the therapeutic index of radiation therapy (RT) by decreasing normal tissue damage while maintaining tumor response compared with conventional (or standard) RT. This study demonstrates the cardioprotective benefits of FLASH proton RT (F-PRT) compared with standard (conventional) proton RT (S-PRT), as evidenced by reduced acute and chronic cardiac toxicities. METHODS AND MATERIALS Mice were imaged using cone beam computed tomography to precisely determine the heart's apex as the beam isocenter. Irradiation was conducted using a shoot-through technique with a 5-mm diameter circular collimator. Bulk RNA-sequencing was performed on nonirradiated samples, as well as apexes treated with F-PRT or S-PRT, at 2 weeks after a single 40 Gy dose. Inflammatory responses were assessed through multiplex cytokine/chemokine microbead assay and immunofluorescence analyses. Levels of perivascular fibrosis were quantified using Masson's Trichrome and Picrosirius red staining. Additionally, cardiac tissue functionality was evaluated by 2-dimensional echocardiograms at 8- and 30-weeks post-PRT. RESULTS Radiation damage was specifically localized to the heart's apex. RNA profiling of cardiac tissues treated with PRT revealed that S-PRT uniquely upregulated pathways associated with DNA damage response, induction of tumor necrosis factor superfamily, and inflammatory response, and F-PRT primarily affected cytoplasmic translation, mitochondrion organization, and adenosine triphosphate synthesis. Notably, F-PRT led to a milder inflammatory response, accompanied by significantly attenuated changes in transforming growth factor β1 and α smooth muscle actin levels. Critically, F-PRT decreased collagen deposition and better preserved cardiac functionality compared with S-PRT. CONCLUSIONS This study demonstrated that F-PRT reduces the induction of an inflammatory environment with lower expression of inflammatory cytokines and profibrotic factors. Importantly, the results indicate that F-PRT better preserves cardiac functionality, as confirmed by echocardiography analysis, while also mitigating the development of long-term fibrosis.
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Affiliation(s)
- Kyle Kim
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michele M Kim
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Giorgos Skoufos
- Department of Electrical & Computer Engineering, University of Thessaly, Greece; Hellenic Pasteur Institute, Athens, Greece
| | - Eric S Diffenderfer
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Seyyedeh Azar Oliaei Motlagh
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Michail Kokkorakis
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Ilektra Koliaki
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Clinical Pharmacy and Pharmacology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - George Morcos
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Khayrullo Shoniyozov
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joanna Griffin
- Department of Medicine, Cardiovascular Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Artemis G Hatzigeorgiou
- Department of Electrical & Computer Engineering, University of Thessaly, Greece; Hellenic Pasteur Institute, Athens, Greece; DIANA-Laboratory, Department of Computer Science and Biomedical Informatics, University of Thessaly, Thessaly, Greece
| | - James M Metz
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Alexander Lin
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Steven J Feigenberg
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Keith A Cengel
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Bonnie Ky
- Department of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Constantinos Koumenis
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Ioannis I Verginadis
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
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Portier L, Daira P, Fourmaux B, Heinrich S, Becerra M, Fouillade C, Berthault N, Dutreix M, Londoño-Vallejo A, Verrelle P, Bernoud-Hubac N, Favaudon V. Differential Remodeling of the Oxylipin Pool After FLASH Versus Conventional Dose-Rate Irradiation In Vitro and In Vivo. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00281-5. [PMID: 38340776 DOI: 10.1016/j.ijrobp.2024.01.210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 01/09/2024] [Accepted: 01/13/2024] [Indexed: 02/12/2024]
Abstract
PURPOSE The products of lipid peroxidation have been implicated in human diseases and aging. This prompted us to investigate the response to conventional (CONV) versus FLASH irradiation of oxylipins, a family of bioactive lipid metabolites derived from omega-3 or omega-6 polyunsaturated fatty acids through oxygen-dependent non-enzymatic as well as dioxygenase-mediated free radical reactions. METHODS AND MATERIALS Ultrahigh performance liquid chromatography coupled to tandem mass spectrometry was used to quantify the expression of 37 oxylipins derived from eicosatetraenoic, eicosapentaenoic and docosahexaenoic acid in mouse lung and in normal or cancer cells exposed to either radiation modality under precise monitoring of the temperature and oxygenation. Among the 37 isomers assayed, 14-16 were present in high enough amount to enable quantitative analysis. The endpoints were the expression of oxylipins as a function of the dose of radiation, normoxia versus hypoxia, temperature and post-irradiation time. RESULTS In normal, normoxic cells at 37°C radiation elicited destruction and neosynthesis of oxylipins acting antagonistically on a background subject to rapid remodeling by oxygenases. Neosynthesis was observed in the CONV mode only, in such a way that the level of oxylipins at 5 minutes after FLASH irradiation was 20-50% lower than in non-irradiated and CONV-irradiated cells. Hypoxia mitigated the differential CONV versus FLASH response in some oxylipins. These patterns were not reproduced in tumor cells. Depression of specific oxylipins following FLASH irradiation was observed in mouse lung at 5 min following irradiation, with near complete recovery in 24 hours and further remodeling at one week and two months post-irradiation. CONCLUSIONS Down-regulation of oxylipins was a hallmark of FLASH irradiation specific of normal cells. Temperature effects suggest that this process occurs via diffusion-controlled, bimolecular recombination of a primary radical species upstream from peroxyl radical formation and evoke a major role of the membrane composition and fluidity in response to the FLASH modality.
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Affiliation(s)
- Lucie Portier
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Patricia Daira
- Univ Lyon, INSA Lyon, CNRS, LaMCoS, UMR 5259, Villeurbanne, France
| | | | - Sophie Heinrich
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Margaux Becerra
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Charles Fouillade
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Nathalie Berthault
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Marie Dutreix
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Arturo Londoño-Vallejo
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Pierre Verrelle
- Institut Curie, Hospital Section, Department of Radiotherapy-Oncology, 26 rue d'Ulm, 75248 Paris Cedex 05, France; Institut Curie, Research Division, Inserm U 1196-CNRS UMR 9187, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | | | - Vincent Favaudon
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France.
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Oh K, Gallagher KJ, Yan Y, Zhou S. Commissioning and initial validation of Eclipse eMC algorithm for the electron FLASH research extension (FLEX) system for pre-clinical studies. J Appl Clin Med Phys 2024:e14289. [PMID: 38319666 DOI: 10.1002/acm2.14289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2023] [Revised: 12/13/2023] [Accepted: 01/22/2024] [Indexed: 02/07/2024] Open
Abstract
PURPOSE To investigate the feasibility of commissioning the 16 MeV electron FLASH Extension (FLEX) in the commercial treatment planning system (TPS) for biomedical research with cell and mouse models, and in silico treatment planning studies. METHODS To commission the FLEX system with the electron Monte Carlo (eMC) algorithm in the commercial TPS, radiochromic film was used to measure the vendor-recommended beam data. Once the beam model was generated for the eMC algorithm, supplemental measurements were collected for validation purposes and compared against the TPS-calculated results. Additionally, the newly commissioned 16 MeV FLASH beam was compared to the corresponding 16 MeV conventional electron beam. RESULTS The eMC algorithm effectively modeled the FLEX system. The eMC-calculated PDDs and profiles for the 16 MeV electron FLASH beam agreed with measured values within 1%, on average, for 6 × 6 cm2 and 10 × 10 cm2 applicators. Flatness and symmetry deviated by less than 1%, while FWHM and penumbra agreed within 1 mm for both eMC-calculated and measured profiles. Additionally, the small field (i.e., 2-cm diameter cutout) that was measured for validation purposes agreed with TPS-calculated results within 1%, on average, for both the PDD and profiles. The FLASH and conventional dose rate 16 MeV electron beam were in agreement in regard to energy, but the profiles for larger field sizes began to deviate (>10 × 10 cm2 ) due to the forward-peaked nature of the FLASH beam. For cell irradiation experiments, the measured and eMC-calculated in-plane and cross-plane absolute dose profiles agreed within 1%, on average. CONCLUSIONS The FLEX system was successfully commissioned in the commercial TPS using the eMC algorithm, which accurately modeled the forward-peaked nature of the FLASH beam. A commissioned TPS for FLASH will be useful for pre-clinical cell and animal studies, as well as in silico FLASH treatment planning studies for future clinical implementation.
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Affiliation(s)
- Kyuhak Oh
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Kyle J Gallagher
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Ying Yan
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, USA
| | - Sumin Zhou
- Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, Nebraska, USA
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Buczek D, Zaucha R, Jassem J. Neurotoxicity-sparing radiotherapy for brain metastases in breast cancer: a narrative review. Front Oncol 2024; 13:1215426. [PMID: 38370347 PMCID: PMC10869626 DOI: 10.3389/fonc.2023.1215426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Accepted: 12/19/2023] [Indexed: 02/20/2024] Open
Abstract
Breast cancer brain metastasis (BCBM) has a devastating impact on patient survival, cognitive function and quality of life. Radiotherapy remains the standard management of BM but may result in considerable neurotoxicity. Herein, we describe the current knowledge on methods for reducing radiation-induced cognitive dysfunction in patients with BCBM. A better understanding of the biology and molecular underpinnings of BCBM, as well as more sophisticated prognostic models and individualized treatment approaches, have appeared to enable more effective neuroprotection. The therapeutic armamentarium has expanded from surgery and whole-brain radiotherapy to stereotactic radiosurgery, targeted therapies and immunotherapies, used sequentially or in combination. Advances in neuroimaging have allowed more accurate screening for intracranial metastases, precise targeting of intracranial lesions and the differentiation of the effects of treatment from disease progression. The availability of numerous treatment options for patients with BCBM and multidisciplinary approaches have led to personalized treatment and improved therapeutic outcomes. Ongoing studies may define the optimal sequencing of available and emerging treatment options for patients with BCBM.
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Naceur A, Bienvenue C, Romano P, Chilian C, Carrier JF. Extending deterministic transport capabilities for very-high and ultra-high energy electron beams. Sci Rep 2024; 14:2796. [PMID: 38307920 DOI: 10.1038/s41598-023-51143-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 12/31/2023] [Indexed: 02/04/2024] Open
Abstract
Focused Very-High Energy Electron (VHEE, 50-300 MeV) and Ultra-High Energy Electron (UHEE, > 300 MeV) beams can accurately target both large and deeply seated human tumors with high sparing properties, while avoiding the spatial requirements and cost of proton and heavy ion facilities. Advanced testing phases are underway at the CLEAR facilities at CERN (Switzerland), NLCTA at Stanford (USA), and SPARC at INFN (Italy), aiming to accelerate the transition to clinical application. Currently, Monte Carlo (MC) transport is the sole paradigm supporting preclinical trials and imminent clinical deployment. In this paper, we propose an alternative: the first extension of the nuclear-reactor deterministic chain NJOY-DRAGON for VHEE and UHEE applications. We have extended the Boltzmann-Fokker-Planck (BFP) multigroup formalism and validated it using standard radio-oncology benchmarks, complex assemblies with a wide range of atomic numbers, and comprehensive irradiation of the entire periodic table. We report that [Formula: see text] of water voxels exhibit a BFP-MC deviation below [Formula: see text] for electron energies under [Formula: see text]. Additionally, we demonstrate that at least [Formula: see text] of voxels of bone, lung, adipose tissue, muscle, soft tissue, tumor, steel, and aluminum meet the same criterion between [Formula: see text] and [Formula: see text]. For water, the thorax, and the breast intra-operative benchmark, typical average BFP-MC deviations of [Formula: see text] and [Formula: see text] were observed at [Formula: see text] and [Formula: see text], respectively. By irradiating the entire periodic table, we observed similar performance between lithium ([Formula: see text]) and cerium ([Formula: see text]). Deficiencies observed between praseodymium ([Formula: see text]) and einsteinium ([Formula: see text]) have been reported, analyzed, and quantified, offering critical insights for the ongoing development of the Evaluated Nuclear Data File mode in NJOY.
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Affiliation(s)
- Ahmed Naceur
- École Polytechnique, SLOWPOKE Nuclear Reactor Laboratory, Nuclear Engineering Institute, Montréal, H3T1J4, Canada.
- CRCHUM, Centre hospitalier de l'Université de Montréal, Montréal, H2L4M1, Canada.
| | - Charles Bienvenue
- École Polytechnique, Engineering Physics Department, Biomedical Engineering Institute, Montréal, H3T1J4, Canada
| | - Paul Romano
- Computational Science Division, Argonne National Laboratory, Lemont, IL, 60439, USA
| | - Cornelia Chilian
- École Polytechnique, SLOWPOKE Nuclear Reactor Laboratory, Nuclear Engineering Institute, Montréal, H3T1J4, Canada
| | - Jean-François Carrier
- Department of Physics, Université de Montréal, Montréal, H3T1J4, Canada
- CRCHUM, Centre hospitalier de l'Université de Montréal, Montréal, H2L4M1, Canada
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Spruijt K, Mossahebi S, Lin H, Lee E, Kraus J, Dhabaan A, Poulsen P, Lowe M, Ayan A, Spiessens S, Godart J, Hoogeman M. Multi-institutional consensus on machine QA for isochronous cyclotron-based systems delivering ultra-high dose rate (FLASH) pencil beam scanning proton therapy in transmission mode. Med Phys 2024; 51:786-798. [PMID: 38103260 DOI: 10.1002/mp.16854] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 10/07/2023] [Accepted: 10/31/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND The first clinical trials to assess the feasibility of FLASH radiotherapy in humans have started (FAST-01, FAST-02) and more trials are foreseen. To increase comparability between trials it is important to assure treatment quality and therefore establish a standard for machine quality assurance (QA). Currently, the AAPM TG-224 report is considered as the standard on machine QA for proton therapy, however, it was not intended to be used for ultra-high dose rate (UHDR) proton beams, which have gained interest due to the observation of the FLASH effect. PURPOSE The aim of this study is to find consensus on practical guidelines on machine QA for UHDR proton beams in transmission mode in terms of which QA is required, how they should be done, which detectors are suitable for UHDR machine QA, and what tolerance limits should be applied. METHODS A risk assessment to determine the gaps in the current standard for machine QA was performed by an international group of medical physicists. Based on that, practical guidelines on how to perform machine QA for UHDR proton beams were proposed. RESULTS The risk assessment clearly identified the need for additional guidance on temporal dosimetry, addressing dose rate (constancy), dose spillage, and scanning speed. In addition, several minor changes from AAPM TG-224 were identified; define required dose rate levels, the use of clinically relevant dose levels, and the use of adapted beam settings to minimize activation of detector and phantom materials or to avoid saturation effects of specific detectors. The final report was created based on discussions and consensus. CONCLUSIONS Consensus was reached on what QA is required for UHDR scanning proton beams in transmission mode for isochronous cyclotron-based systems and how they should be performed. However, the group discussions also showed that there is a lack of high temporal resolution detectors and sufficient QA data to set appropriate limits for some of the proposed QA procedures.
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Affiliation(s)
- Kees Spruijt
- HollandPTC, Delft, The Netherlands
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Sina Mossahebi
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Haibo Lin
- New York Proton Center, New York, New York, USA
| | - Eunsin Lee
- Department of Radiation Oncology, University of Cincinnati, Cincinnati, Ohio, USA
| | - James Kraus
- Department of Radiation Oncology, University of Alabama-Birmingham, Birmingham, Alabama, USA
| | - Anees Dhabaan
- Department of Radiation Oncology, Emory University of Medicine, Atlanta, Georgia, USA
| | - Per Poulsen
- Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark and Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Matthew Lowe
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | - Ahmet Ayan
- Department of Radiation Oncology, Ohio State University Medical Center, Columbus, Ohio, USA
| | - Sylvie Spiessens
- Varian, a Siemens Healthineers Company, Groot-Bijgaarden, Belgium
| | - Jeremy Godart
- HollandPTC, Delft, The Netherlands
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Mischa Hoogeman
- HollandPTC, Delft, The Netherlands
- Department of Radiotherapy, Erasmus MC Cancer Institute, University Medical Center Rotterdam, Rotterdam, The Netherlands
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Oesterle R, Bailat C, Buhlmann D, Bochud F, Grilj V. Construction and dosimetric characterization of a motorized scanning-slit system for electron FLASH experiments. Med Phys 2024; 51:1396-1404. [PMID: 37439505 PMCID: PMC10787038 DOI: 10.1002/mp.16610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 07/14/2023] Open
Abstract
BACKGROUND Beam scanning is a useful technique for the treatment of large tumors when the primary beam size is limited, which is the case with radiation beams used in FLASH radiotherapy. PURPOSE To optimize beam scanning as a dose delivery method for FLASH radiotherapy, it is necessary to first understand the effects of beam scanning on the FLASH effect. To do so, biological FLASH experiments need to be done using defined beam parameters with beam scanning and compared to the situation without beam scanning. In this regard, we propose implementation of a simple slit scanning system with an electron FLASH beam to obtain a scanned radiation field that closely resembles a static field. METHODS A pulsed electron linear accelerator (linac) was used in combination with a scanning slit system in order to simulate a scanned electron beam. Three configurations that produced homogeneous lateral profiles and high enough doses per pulse for FLASH experiments were established. The optimal scanning parameters were found for each configuration by examining the flatness of the obtained lateral dose profiles. Using the optimal scanning parameters, the scanned FLASH beams were dosimetrically characterized and compared to non-scanned open field beam. RESULTS A final electron FLASH beam scanning configuration was found for a 1 mm wide slit at a distance of 350 mm from the linac and a 2 mm wide slit at distances of 350 and 490 mm from the linac. The lateral profiles for these final configurations were found to have a homogeneity that is comparable to the open field profiles. The percentage depth dose (PDD) values found for these final configurations closely matched (by a few percentage) the PDD of the open field beam. CONCLUSIONS Three electron FLASH beam scanning configurations achieved by the motorized slit system were found to produce radiation fields similar to a non-scanned open field electron beam. These final configurations can therefore be used in future biological FLASH experiments to compare to non-scanned beam experiments in order to optimize beam scanning as a technique permitting the treatment of larger tumors with FLASH radiotherapy.
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Affiliation(s)
- Roxane Oesterle
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Damien Buhlmann
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Francois Bochud
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
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Byrne KE, Poirier Y, Xu J, Gerry A, Foley MJ, Jackson IL, Sawant A, Jiang K. Technical note: A small animal irradiation platform for investigating the dependence of the FLASH effect on electron beam parameters. Med Phys 2024; 51:1421-1432. [PMID: 38207016 DOI: 10.1002/mp.16909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2023] [Revised: 10/30/2023] [Accepted: 12/12/2023] [Indexed: 01/13/2024] Open
Abstract
BACKGROUND The recent rediscovery of the FLASH effect, a normal tissue sparing phenomenon observed in ultra-high dose rate (UHDR) irradiations, has instigated a surge of research endeavors aiming to close the gap between experimental observation and clinical treatment. However, the dependences of the FLASH effect and its underpinning mechanisms on beam parameters are not well known, and large-scale in vivo studies using murine models of human cancer are needed for these investigations. PURPOSE To commission a high-throughput, variable dose rate platform providing uniform electron fields (≥15 cm diameter) at conventional (CONV) and UHDRs for in vivo investigations of the FLASH effect and its dependences on pulsed electron beam parameters. METHODS A murine whole-thoracic lung irradiation (WTLI) platform was constructed using a 1.3 cm thick Cerrobend collimator forming a 15 × 1.6 cm2 slit. Control of dose and dose rate were realized by adjusting the number of monitor units and couch vertical position, respectively. Achievable doses and dose rates were investigated using Gafchromic EBT-XD film at 1 cm depth in solid water and lung-density phantoms. Percent depth dose (PDD) and dose profiles at CONV and various UHDRs were also measured at depths from 0 to 2 cm. A radiation survey was performed to assess radioactivation of the Cerrobend collimator by the UHDR electron beam in comparison to a precision-machined copper alternative. RESULTS This platform allows for the simultaneous thoracic irradiation of at least three mice. A linear relationship between dose and number of monitor units at a given UHDR was established to guide the selection of dose, and an inverse-square relationship between dose rate and source distance was established to guide the selection of dose rate between 20 and 120 Gy·s-1 . At depths of 0.5 to 1.5 cm, the depth range relevant to murine lung irradiation, measured PDDs varied within ±1.5%. Similar lateral dose profiles were observed at CONV and UHDRs with the dose penumbrae widening from 0.3 mm at 0 cm depth to 5.1 mm at 2.0 cm. The presence of lung-density plastic slabs had minimal effect on dose distributions as compared to measurements made with only solid water slabs. Instantaneous dose rate measurements of the activated copper collimator were up to two orders of magnitude higher than that of the Cerrobend collimator. CONCLUSIONS A high-throughput, variable dose rate platform has been developed and commissioned for murine WTLI electron FLASH radiotherapy. The wide field of our UHDR-enabled linac allows for the simultaneous WTLI of at least three mice, and for the average dose rate to be modified by changing the source distance, without affecting dose distribution. The platform exhibits uniform, and comparable dose distributions at CONV and UHDRs up to 120 Gy·s-1 , owing to matched and flattened 16 MeV CONV and UHDR electron beams. Considering radioactivation and exposure to staff, Cerrobend collimators are recommended above copper alternatives for electron FLASH research. This platform enables high-throughput animal irradiation, which is preferred for experiments using a large number of animals, which are required to effectively determine UHDR treatment efficacies.
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Affiliation(s)
- Kevin E Byrne
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
- Department of Physics, School of Natural Sciences, University of Galway, Galway, Ireland
| | - Yannick Poirier
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Junliang Xu
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Andrew Gerry
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Mark J Foley
- Department of Physics, School of Natural Sciences, University of Galway, Galway, Ireland
| | - Isabel Lauren Jackson
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Amit Sawant
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Kai Jiang
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland, USA
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Cetnar AJ, Jain S, Gupta N, Chakravarti A. Technical note: Commissioning of a linear accelerator producing ultra-high dose rate electrons. Med Phys 2024; 51:1415-1420. [PMID: 38159300 DOI: 10.1002/mp.16925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 12/12/2023] [Accepted: 12/18/2023] [Indexed: 01/03/2024] Open
Abstract
BACKGROUND Ultra-high dose rate radiation (UHDR) is being explored by researchers in promise of advancing radiation therapy treatments. PURPOSE This work presents the commissioning of Varian's Flash Extension for research (FLEX) conversion of a Clinac to deliver UHDR electrons. METHODS A Varian Clinac iX with the FLEX conversion was commissioned for non-clinical research use with 16 MeV UHDR (16H) energy. This involved addition of new hardware, optimizing the electron gun voltages, radiofrequency (RF) power, and steering coils in order to maximize the accelerated electron beam current, sending the beam through custom scattering foils to produce the UHDR with 16H beam. Profiles and percent depth dose (PDD) measurements for 16H were obtained using radiochromic film in a custom vertical film holder and were compared to 16 MeV conventional electrons (16C). Dose rate and dose per pulse (DPP) were calculated from measured dose in film. Linearity and stability were assessed using an Advanced Markus ionization chamber. RESULTS Energies for 16H and 16C had similar beam quality based on PDD measurements. Measurements at the head of the machine (61.3 cm SSD) with jaws set to 10×10 cm2 showed the FWHM of the profile as 7.2 cm, with 3.4 Gy as the maximum DPP and instantaneous dose rate of 8.1E5 Gy/s. Measurements at 100 cm SSD with 10 cm standard cone showed the full width at half max (FWHM) of the profile as 10.5 cm, 1.08 Gy as the maximum DPP and instantaneous dose rate of 2.E5 Gy/s. Machine output with number of pulses was linear (R = 1) from 1 to 99 delivered pulses. Output stability was measured within ±1% within the same session and within ±2% for daily variations. CONCLUSIONS The FLEX conversion of the Clinac is able to generate UHDR electron beams which are reproducible with beam properties similar to clinically used electrons at 16 MeV. Having a platform which can quickly transition between UHDR and conventional modes (<1 min) can be advantageous for future research applications.
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Affiliation(s)
- Ashley J Cetnar
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Sagarika Jain
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Nilendu Gupta
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
| | - Arnab Chakravarti
- Department of Radiation Oncology, James Cancer Hospital and Solove Research Institute, The Ohio State University, Columbus, Ohio, USA
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