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Bjegovic K, Sun L, Pandey P, Grilj V, Ballesteros-Zebadua P, Paisley R, Gonzalez G, Wang S, Vozenin MC, Limoli CL, Xiang SL. 4D in vivodosimetry for a FLASH electron beam using radiation-induced acoustic imaging. Phys Med Biol 2024; 69:115053. [PMID: 38722574 DOI: 10.1088/1361-6560/ad4950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2024] [Accepted: 05/09/2024] [Indexed: 06/01/2024]
Abstract
Objective. The primary goal of this research is to demonstrate the feasibility of radiation-induced acoustic imaging (RAI) as a volumetric dosimetry tool for ultra-high dose rate FLASH electron radiotherapy (FLASH-RT) in real time. This technology aims to improve patient outcomes by accurate measurements ofin vivodose delivery to target tumor volumes.Approach. The study utilized the FLASH-capable eRT6 LINAC to deliver electron beams under various doses (1.2 Gy pulse-1to 4.95 Gy pulse-1) and instantaneous dose rates (1.55 × 105Gy s-1to 2.75 × 106Gy s-1), for imaging the beam in water and in a rabbit cadaver with RAI. A custom 256-element matrix ultrasound array was employed for real-time, volumetric (4D) imaging of individual pulses. This allowed for the exploration of dose linearity by varying the dose per pulse and analyzing the results through signal processing and image reconstruction in RAI.Main Results. By varying the dose per pulse through changes in source-to-surface distance, a direct correlation was established between the peak-to-peak amplitudes of pressure waves captured by the RAI system and the radiochromic film dose measurements. This correlation demonstrated dose rate linearity, including in the FLASH regime, without any saturation even at an instantaneous dose rate up to 2.75 × 106Gy s-1. Further, the use of the 2D matrix array enabled 4D tracking of FLASH electron beam dose distributions on animal tissue for the first time.Significance. This research successfully shows that 4Din vivodosimetry is feasible during FLASH-RT using a RAI system. It allows for precise spatial (∼mm) and temporal (25 frames s-1) monitoring of individual FLASH beamlets during delivery. This advancement is crucial for the clinical translation of FLASH-RT as enhancing the accuracy of dose delivery to the target volume the safety and efficacy of radiotherapeutic procedures will be improved.
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Affiliation(s)
- Kristina Bjegovic
- The Department of Biomedical Engineering, University of California, Irvine, CA 92617, United States of America
| | - Leshan Sun
- The Department of Biomedical Engineering, University of California, Irvine, CA 92617, United States of America
| | - Prabodh Pandey
- Department of Radiological Sciences, University of California, Irvine, Irvine, CA 92697, United States of Americaica
| | - Veljko Grilj
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Paola Ballesteros-Zebadua
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Laboratory of Medical Physics, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | - Ryan Paisley
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Gilberto Gonzalez
- Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104, United States of America
| | - Siqi Wang
- The Department of Biomedical Engineering, University of California, Irvine, CA 92617, United States of America
| | - Marie Catherine Vozenin
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Sector of Radiobiology applied to Radiation Oncology, Radiation Oncology Service, Geneva University Hospital and University of Geneva, Geneva, Switzerland
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, Irvine, CA 92697-2695, United States of America
| | - Shawn Liangzhong Xiang
- The Department of Biomedical Engineering, University of California, Irvine, CA 92617, United States of America
- Department of Radiological Sciences, University of California, Irvine, Irvine, CA 92697, United States of Americaica
- Beckman Laser Institute & Medical Clinic, University of California, Irvine, Irvine, CA 92612, United States of America
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Chow JCL, Ruda HE. Mechanisms of Action in FLASH Radiotherapy: A Comprehensive Review of Physicochemical and Biological Processes on Cancerous and Normal Cells. Cells 2024; 13:835. [PMID: 38786057 PMCID: PMC11120005 DOI: 10.3390/cells13100835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/09/2024] [Accepted: 05/11/2024] [Indexed: 05/25/2024] Open
Abstract
The advent of FLASH radiotherapy (FLASH-RT) has brought forth a paradigm shift in cancer treatment, showcasing remarkable normal cell sparing effects with ultra-high dose rates (>40 Gy/s). This review delves into the multifaceted mechanisms underpinning the efficacy of FLASH effect, examining both physicochemical and biological hypotheses in cell biophysics. The physicochemical process encompasses oxygen depletion, reactive oxygen species, and free radical recombination. In parallel, the biological process explores the FLASH effect on the immune system and on blood vessels in treatment sites such as the brain, lung, gastrointestinal tract, skin, and subcutaneous tissue. This review investigated the selective targeting of cancer cells and the modulation of the tumor microenvironment through FLASH-RT. Examining these mechanisms, we explore the implications and challenges of integrating FLASH-RT into cancer treatment. The potential to spare normal cells, boost the immune response, and modify the tumor vasculature offers new therapeutic strategies. Despite progress in understanding FLASH-RT, this review highlights knowledge gaps, emphasizing the need for further research to optimize its clinical applications. The synthesis of physicochemical and biological insights serves as a comprehensive resource for cell biology, molecular biology, and biophysics researchers and clinicians navigating the evolution of FLASH-RT in cancer therapy.
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Affiliation(s)
- James C. L. Chow
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1X6, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, ON M5T 1P5, Canada
| | - Harry E. Ruda
- Centre of Advance Nanotechnology, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON M5S 3E4, Canada;
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON M5S 3E4, 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] [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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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] [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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5
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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] [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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6
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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] [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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7
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Cengel KA, Kim MM, Diffenderfer ES, Busch TM. FLASH Radiotherapy: What Can FLASH's Ultra High Dose Rate Offer to the Treatment of Patients With Sarcoma? Semin Radiat Oncol 2024; 34:218-228. [PMID: 38508786 DOI: 10.1016/j.semradonc.2024.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/22/2024]
Abstract
FLASH is an emerging treatment paradigm in radiotherapy (RT) that utilizes ultra-high dose rates (UHDR; >40 Gy)/s) of radiation delivery. Developing advances in technology support the delivery of UHDR using electron and proton systems, as well as some ion beam units (eg, carbon ions), while methods to achieve UHDR with photons are under investigation. The major advantage of FLASH RT is its ability to increase the therapeutic index for RT by shifting the dose response curve for normal tissue toxicity to higher doses. Numerous preclinical studies have been conducted to date on FLASH RT for murine sarcomas, alongside the investigation of its effects on relevant normal tissues of skin, muscle, and bone. The tumor control achieved by FLASH RT of sarcoma models is indistinguishable from that attained by treatment with standard RT to the same total dose. FLASH's high dose rates are able to mitigate the severity or incidence of RT side effects on normal tissues as evaluated by endpoints ranging from functional sparing to histological damage. Large animal studies and clinical trials of canine patients show evidence of skin sparing by FLASH vs. standard RT, but also caution against delivery of high single doses with FLASH that exceed those safely applied with standard RT. Also, a human clinical trial has shown that FLASH RT can be delivered safely to bone metastasis. Thus, data to date support continued investigations of clinical translation of FLASH RT for the treatment of patients with sarcoma. Toward this purpose, hypofractionated irradiation schemes are being investigated for FLASH effects on sarcoma and relevant normal tissues.
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Affiliation(s)
- Keith A Cengel
- 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
| | - Eric S Diffenderfer
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Theresa M Busch
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
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8
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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] [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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9
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Kinj R, Gaide O, Jeanneret-Sozzi W, Dafni U, Viguet-Carrin S, Sagittario E, Kypriotou M, Chenal J, Duclos F, Hebeisen M, Falco T, Geyer R, Gonçalves Jorge P, Moeckli R, Bourhis J. Randomized phase II selection trial of FLASH and conventional radiotherapy for patients with localized cutaneous squamous cell carcinoma or basal cell carcinoma: A study protocol. Clin Transl Radiat Oncol 2024; 45:100743. [PMID: 38362466 PMCID: PMC10867306 DOI: 10.1016/j.ctro.2024.100743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 01/03/2024] [Accepted: 02/03/2024] [Indexed: 02/17/2024] Open
Abstract
Background Cutaneous basal cell carcinoma (BCC) and squamous cell carcinoma (SCC) are the most prevalent skin cancers in western countries. Surgery is the standard of care for these cancers and conventional external radiotherapy (CONV-RT) with conventional dose rate (0.03-0.06 Gy/sec) represents a good alternative when the patients or tumors are not amenable to surgery but routinely generates skin side effects. Low energy electron FLASH radiotherapy (FLASH-RT) is a new form of radiotherapy exploiting the biological advantage of the FLASH effect, which consists in delivering radiation dose in milliseconds instead of minutes in CONV-RT. In pre-clinical studies, when compared to CONV-RT, FLASH-RT induced a robust, reproducible and remarkable sparing of the normal healthy tissues, while the efficacy on tumors was preserved. In this context, we aim to prospectively evaluate FLASH-RT versus CONV-RT with regards to toxicity and oncological outcome in localized cutaneous BCC and SCC. Methods This is a randomized selection, non-comparative, phase II study of curative FLASH-RT versus CONV-RT in patients with T1-T2 N0 M0 cutaneous BCC and SCC. Patients will be randomly allocated to low energy electron FLASH-RT (dose rate: 220-270 Gy/s) or to CONV-RT arm. Small lesions (T1) will receive a single dose of 22 Gy and large lesions (T2) will receive 30 Gy in 5 fractions of 6 Gy over two weeks.The primary endpoint evaluates safety at 6 weeks after RT through grade ≥ 3 toxicity and efficacy through local control rate at 12 months. Approximately 60 patients in total will be randomized, considering on average 1-2 lesions and a maximum of 3 lesions per patients corresponding to the total of 96 lesions required. FLASH-RT will be performed using the Mobetron® (IntraOp, USA) with high dose rate functionality.LANCE (NCT05724875) is the first randomized trial evaluating FLASH-RT and CONV-RT in a curative setting.
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Affiliation(s)
- Rémy Kinj
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, CHUV, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Olivier Gaide
- Service of Dermatology, CHUV, Lausanne University Hospital, Lausanne, Switzerland
| | - Wendy Jeanneret-Sozzi
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, CHUV, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Urania Dafni
- Laboratory of Biostatistics School of Health Sciences University of Athens, Greece
| | - Stéphanie Viguet-Carrin
- Center of Experimental Therapeutics (CTE), Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Enea Sagittario
- Center of Experimental Therapeutics (CTE), Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Magdalini Kypriotou
- Center of Experimental Therapeutics (CTE), Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Julie Chenal
- Center of Experimental Therapeutics (CTE), Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Frederic Duclos
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, CHUV, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Marine Hebeisen
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, CHUV, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Teresa Falco
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, CHUV, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland
| | - Reiner Geyer
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Patrik Gonçalves Jorge
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, CHUV, Rue du Bugnon 46, CH-1011 Lausanne, Switzerland
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10
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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] [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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11
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Miles D, Sforza D, Wong J, Rezaee M. Dosimetric characterization of a rotating anode x-ray tube for FLASH radiotherapy research. Med Phys 2024; 51:1474-1483. [PMID: 37458068 PMCID: PMC10792113 DOI: 10.1002/mp.16609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2023] [Revised: 05/16/2023] [Accepted: 06/20/2023] [Indexed: 07/18/2023] Open
Abstract
PURPOSE Most current research toward ultra-high dose rate (FLASH) radiation is conducted with advanced proton and electron accelerators, which are of limited accessibility to basic laboratory research. An economical alternative to charged particle accelerators is to employ high-capacity rotating anode x-ray tubes to produce kilovoltage x-rays at FLASH dose rates at short source-to-surface distances (SSD). This work describes a comprehensive dosimetric evaluation of a rotating anode x-ray tube for potential application in laboratory FLASH study. METHODS AND MATERIALS A commercially available high-capacity fluoroscopy x-ray tube with 75 kW input power was implemented as a potential FLASH irradiator. Radiochromic EBT3 film and thermoluminescent dosimeters (TLDs) were used to investigate the effects of SSD and field size on dose rates and depth-dose characteristics in kV-compatible solid water phantoms. Custom 3D printed accessories were developed to enable reproducible phantom setup at very short SSD. Open and collimated radiation fields were assessed. RESULTS Despite the lower x-ray energy and short SSD used, FLASH dose rates above 40 Gy/s were achieved for targets up to 10-mm depth in solid water. Maximum surface dose rates of 96 Gy/s were measured in the open field at 47 mm SSD. A non-uniform high-to-low dose gradient was observed in the planar dose distribution, characteristic of anode heel effects. With added collimation, beams up to 10-mm diameter with reasonable uniformity can be produced. Typical 80%-20% penumbra in the collimated x-ray FLASH beams were less than 1 mm at 5-mm depth in phantom. Ramp-up times at the maximum input current were less than 1 ms. CONCLUSION Our dosimetric characterization demonstrates that rotating anode x-ray tube technology is capable of producing radiation beams in support of preclinical FLASH radiobiology research.
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Affiliation(s)
- Devin Miles
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, 21231 MD, USA
| | - Daniel Sforza
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, 21231 MD, USA
| | - John Wong
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, 21231 MD, USA
| | - Mohammad Rezaee
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, 21231 MD, USA
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12
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Rudigkeit S, Schmid TE, Dombrowsky AC, Stolz J, Bartzsch S, Chen CB, Matejka N, Sammer M, Bergmaier A, Dollinger G, Reindl J. Proton-FLASH: effects of ultra-high dose rate irradiation on an in-vivo mouse ear model. Sci Rep 2024; 14:1418. [PMID: 38228747 PMCID: PMC10791610 DOI: 10.1038/s41598-024-51951-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 01/11/2024] [Indexed: 01/18/2024] Open
Abstract
FLASH-radiotherapy may provide significant sparing of healthy tissue through ultra-high dose rates in protons, electrons, and x-rays while maintaining the tumor control. Key factors for the FLASH effect might be oxygen depletion, the immune system, and the irradiated blood volume, but none could be fully confirmed yet. Therefore, further investigations are necessary. We investigated the protective (tissue sparing) effect of FLASH in proton treatment using an in-vivo mouse ear model. The right ears of Balb/c mice were irradiated with 20 MeV protons at the ion microprobe SNAKE in Garching near Munich by using three dose rates (Conv = 0.06 Gy/s, Flash9 = 9.3 Gy/s and Flash930 = 930 Gy/s) at a total dose of 23 Gy or 33 Gy. The ear thickness, desquamation, and erythema combined in an inflammation score were measured for 180 days. The cytokines TGF-β1, TNF-α, IL1α, and IL1β were analyzed in the blood sampled in the first 4 weeks and at termination day. No differences in inflammation reactions were visible in the 23 Gy group for the different dose rates. In the 33 Gy group, the ear swelling and the inflammation score for Flash9 was reduced by (57 ± 12) % and (67 ± 17) % and for Flash930 by (40 ± 13) % and (50 ± 17) % compared to the Conv dose rate. No changes in the cytokines in the blood could be measured. However, an estimation of the irradiated blood volume demonstrates, that 100-times more blood is irradiated when using Conv compared to using Flash9 or Flash930. This indicates that blood might play a role in the underlying mechanisms in the protective effect of FLASH.
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Affiliation(s)
- Sarah Rudigkeit
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Thomas E Schmid
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
- Department of Radiooncology, School of Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Annique C Dombrowsky
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
| | - Jessica Stolz
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
| | - Stefan Bartzsch
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
- Department of Radiooncology, School of Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Ce-Belle Chen
- Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore, Singapore
- Singapore Synchrotron Light Source, National University of Singapore, Singapore, Singapore
| | - Nicole Matejka
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Matthias Sammer
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Andreas Bergmaier
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Günther Dollinger
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Judith Reindl
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany.
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13
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Fu J, Yang Z, Melemenidis S, Viswanathan V, Dutt S, Manjappa R, Lau B, Soto LA, Ashraf MR, Skinner L, Yu SJ, Surucu M, Casey KM, Rankin EB, Graves E, Lu W, Loo BW, Gu X. Exploring Deep Learning for Estimating the Isoeffective Dose of FLASH Irradiation From Mouse Intestinal Histological Images. Int J Radiat Oncol Biol Phys 2024:S0360-3016(23)08306-2. [PMID: 38171387 DOI: 10.1016/j.ijrobp.2023.12.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Revised: 12/09/2023] [Accepted: 12/23/2023] [Indexed: 01/05/2024]
Abstract
PURPOSE Ultrahigh-dose-rate (FLASH) irradiation has been reported to reduce normal tissue damage compared with conventional dose rate (CONV) irradiation without compromising tumor control. This proof-of-concept study aims to develop a deep learning (DL) approach to quantify the FLASH isoeffective dose (dose of CONV that would be required to produce the same effect as the given physical FLASH dose) with postirradiation mouse intestinal histology images. METHODS AND MATERIALS Eighty-four healthy C57BL/6J female mice underwent 16 MeV electron CONV (0.12 Gy/s; n = 41) or FLASH (200 Gy/s; n = 43) single fraction whole abdominal irradiation. Physical dose ranged from 12 to 16 Gy for FLASH and 11 to 15 Gy for CONV in 1 Gy increments. Four days after irradiation, 9 jejunum cross-sections from each mouse were hematoxylin and eosin stained and digitized for histological analysis. CONV data set was randomly split into training (n = 33) and testing (n = 8) data sets. ResNet101-based DL models were retrained using the CONV training data set to estimate the dose based on histological features. The classical manual crypt counting (CC) approach was implemented for model comparison. Cross-section-wise mean squared error was computed to evaluate the dose estimation accuracy of both approaches. The validated DL model was applied to the FLASH data set to map the physical FLASH dose into the isoeffective dose. RESULTS The DL model achieved a cross-section-wise mean squared error of 0.20 Gy2 on the CONV testing data set compared with 0.40 Gy2 of the CC approach. Isoeffective doses estimated by the DL model for FLASH doses of 12, 13, 14, 15, and 16 Gy were 12.19 ± 0.46, 12.54 ± 0.37, 12.69 ± 0.26, 12.84 ± 0.26, and 13.03 ± 0.28 Gy, respectively. CONCLUSIONS Our proposed DL model achieved accurate CONV dose estimation. The DL model results indicate that in the physical dose range of 13 to 16 Gy, the biologic dose response of small intestinal tissue to FLASH irradiation is represented by a lower isoeffective dose compared with the physical dose. Our DL approach can be a tool for studying isoeffective doses of other radiation dose modifying interventions.
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Affiliation(s)
- Jie Fu
- Department of Radiation Oncology, University of Washington, Seattle, Washington; Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Zi Yang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Luis A Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Shu-Jung 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
| | - Kerriann M Casey
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California
| | - Erinn B Rankin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Edward Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Weiguo Lu
- Medical Artificial Intelligence and Automation (MAIA) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
| | - Xuejun Gu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
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14
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Zhu H, Schuemann J, Zhang Q, Gerweck LE. Modeling the impact of tissue oxygen profiles and oxygen depletion parameter uncertainties on biological response and therapeutic benefit of FLASH. Med Phys 2024; 51:670-681. [PMID: 36939370 PMCID: PMC10509320 DOI: 10.1002/mp.16366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 02/22/2023] [Accepted: 03/06/2023] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND Ultra-high dose rate (FLASH) radiation has been reported to efficiently suppress tumor growth while sparing normal tissue; however, the mechanism of the differential tissue sparing effect is still not known. Oxygen has long been known to profoundly impact radiobiological responses, and radiolytic oxygen depletion has been considered to be a possible cause or contributor to the FLASH phenomenon. PURPOSE This work investigates the impact of tissue pO2 profiles, oxygen depletion per unit dose (g), and the oxygen concentration yielding half-maximum radiosensitization (the average of its maximum value and one) (k) in tumor and normal tissue. METHODS We developed a model that considers the dependent relationship between oxygen depletion and change of radiosensitivity by FLASH irradiation. The model assumed that FLASH irradiation depletes intracellular oxygen more rapidly than it diffuses into the cell from the extracellular environment. Cell survival was calculated based on the linear quadratic-linear model and the radiosensitivity related parameters were adjusted in 1 Gy increments of the administered dose. The model reproduced published experimental data that were obtained with different cell lines and oxygen concentrations, and was used to analyze the impact of parameter uncertainties on the radiobiological responses. This study expands the oxygen depletion analysis of FLASH to normal human tissue and tumor based on clinically determined aggregate and individual patient pO2 profiles. RESULTS The results show that the pO2 profile is the most essential factor that affects biological response and analyses based on the median pO2 rather than the full pO2 profile can be unreliable and misleading. Additionally, the presence of a small fraction of cells on the threshold of radiobiologic hypoxia substantially alters biological response due to FLASH oxygen depletion. We found that an increment in the k value is generally more protective of tumor than normal tissue due to a higher frequency of lower pO2 values in tumors. Variation in the g value affects the dose at which oxygen depletion impacts response, but does not alter the dose-dependent response trends, if the g value is identical in both tumor and normal tissue. CONCLUSIONS The therapeutic efficacy of FLASH oxygen depletion is likely patient and tissue-dependent. For breast cancer, FLASH is beneficial in a minority of cases; however, in a subset of well oxygenated tumors, a therapeutic gain may be realized due to induced normal tissue hypoxia.
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Affiliation(s)
- Hongyu Zhu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangzhou 510060, China
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Qixian Zhang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China
| | - Leo E Gerweck
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America
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15
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Hamada K, Fujibuchi T, Arakawa H, Yokoyama Y, Yoshida N, Ohura H, Kunitake N, Masuda M, Honda T, Tokuda S, Sasaki M. A novel approach to predict acute radiation dermatitis in patients with head and neck cancer using a model based on Bayesian probability. Phys Med 2023; 116:103181. [PMID: 38000101 DOI: 10.1016/j.ejmp.2023.103181] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 10/04/2023] [Accepted: 11/17/2023] [Indexed: 11/26/2023] Open
Abstract
PURPOSE In this study, we aimed to establish a method for predicting the probability of each acute radiation dermatitis (ARD) grade during the head and neck Volumetric Modulated Arc Therapy (VMAT) radiotherapy planning phase based on Bayesian probability. METHODS The skin dose volume >50 Gy (V50), calculated using the treatment planning system, was used as a factor related to skin toxicity. The empirical distribution of each ARD grade relative to V50 was obtained from the ARD grades of 119 patients (55, 50, and 14 patients with G1, G2, and G3, respectively) determined by head and neck cancer specialists. Using Bayes' theorem, the Bayesian probabilities of G1, G2, and G3 for each value of V50 were calculated with an empirical distribution. Conversely, V50 was obtained based on the Bayesian probabilities of G1, G2, and G3. RESULTS The empirical distribution for each graded patient group demonstrated a normal distribution. The method predicted ARD grades with 92.4 % accuracy and provided a V50 value for each grade. For example, using the graph, we could predict that V50 should be ≤24.5 cm3 to achieve G1 with 70 % probability. CONCLUSIONS The Bayesian probability-based ARD prediction method could predict the ARD grade at the treatment planning stage using limited patient diagnostic data that demonstrated a normal distribution. If the probability of an ARD grade is high, skin care can be initiated in advance. Furthermore, the V50 value during treatment planning can provide radiation oncologists with data for strategies to reduce ARD.
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Affiliation(s)
- Keisuke Hamada
- Department of Radiological Technology, National Hospital Organization Kyushu Cancer Center, 3-1-1, Notame, Minami-ku, Fukuoka City, Fukuoka 811-1395, Japan; Department of Health Sciences, Graduate School of Medicine, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Toshioh Fujibuchi
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Hiroyuki Arakawa
- Department of Health Sciences, Faculty of Medical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan.
| | - Yuichi Yokoyama
- Department of Radiological Technology, National Hospital Organization Kyushu Cancer Center, 3-1-1, Notame, Minami-ku, Fukuoka City, Fukuoka 811-1395, Japan.
| | - Naoki Yoshida
- Department of Radiological Technology, National Hospital Organization Kyushu Cancer Center, 3-1-1, Notame, Minami-ku, Fukuoka City, Fukuoka 811-1395, Japan.
| | - Hiroki Ohura
- Department of Radiological Technology, National Hospital Organization Kyushu Medical Center, 1-8-1 Jigyohama, Chuo-ku, Fukuoka City, Fukuoka 810-8563, Japan.
| | - Naonobu Kunitake
- Department of Radiation Oncology, National Hospital Organization Kyushu Cancer Center, 3-1-1, Notame, Minami-ku, Fukuoka City, Fukuoka 811-1395, Japan.
| | - Muneyuki Masuda
- Department of Head and Neck Surgery, National Hospital Organization Kyushu Cancer Center, 3-1-1, Notame, Minami-ku, Fukuoka City, Fukuoka 811-1395, Japan.
| | - Takeo Honda
- Department of Radiological Technology, National Hospital Organization Kyushu Cancer Center, 3-1-1, Notame, Minami-ku, Fukuoka City, Fukuoka 811-1395, Japan.
| | - Satoru Tokuda
- Research Institute for Information Technology, Kyushu University, 6-1, Kasuga koen, Kasuga City, Fukuoka 816-8580, Japan.
| | - Makoto Sasaki
- College of Industrial Technology, Nihon University, 1-2-1 Izumi-cho, Narashino City, Chiba 275-8575, Japan.
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16
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Miles D, Sforza D, Wong JW, Gabrielson K, Aziz K, Mahesh M, Coulter JB, Siddiqui I, Tran PT, Viswanathan AN, Rezaee M. FLASH Effects Induced by Orthovoltage X-Rays. Int J Radiat Oncol Biol Phys 2023; 117:1018-1027. [PMID: 37364800 DOI: 10.1016/j.ijrobp.2023.06.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Revised: 05/16/2023] [Accepted: 06/11/2023] [Indexed: 06/28/2023]
Abstract
PURPOSE This work describes the first implementation and in vivo study of ultrahigh-dose-rate radiation (>37 Gy/s; FLASH) effects induced by kilovoltage (kV) x-ray from a rotating-anode x-ray source. METHODS AND MATERIALS A high-capacity rotating-anode x-ray tube with an 80-kW generator was implemented for preclinical FLASH radiation research. A custom 3-dimensionally printed immobilization and positioning tool was developed for reproducible irradiation of a mouse hind limb. Calibrated Gafchromic (EBT3) film and thermoluminescent dosimeters (LiF:Mg,Ti) were used for in-phantom and in vivo dosimetry. Healthy FVB/N and FVBN/C57BL/6 outbred mice were irradiated on 1 hind leg to doses up to 43 Gy at FLASH (87 Gy/s) and conventional (CONV; <0.05 Gy/s) dose rates. The radiation doses were delivered using a single pulse with the widths up to 500 ms and 15 minutes at FLASH and CONV dose rates. Histologic assessment of radiation-induced skin damage was performed at 8 weeks posttreatment. Tumor growth suppression was assessed using a B16F10 flank tumor model in C57BL6J mice irradiated to 35 Gy at both FLASH and CONV dose rates. RESULTS FLASH-irradiated mice experienced milder radiation-induced skin injuries than CONV-irradiated mice, visible by 4 weeks posttreatment. At 8 weeks posttreatment, normal tissue injury was significantly reduced in FLASH-irradiated animals compared with CONV-irradiated animals for histologic endpoints including inflammation, ulceration, hyperplasia, and fibrosis. No difference in tumor growth response was observed between FLASH and CONV irradiations at 35 Gy. The normal tissue sparing effects of FLASH irradiations were observed only for high-severity endpoint of ulceration at 43 Gy, which suggests the dependency of biologic endpoints to FLASH radiation dose. CONCLUSIONS Rotating-anode x-ray sources can achieve FLASH dose rates in a single pulse with dosimetric properties suitable for small-animal experiments. We observed FLASH normal tissue sparing of radiation toxicities in mouse skin irradiated at 35 Gy with no sacrifice to tumor growth suppression. This study highlights an accessible new modality for laboratory study of the FLASH effect.
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Affiliation(s)
- Devin Miles
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Daniel Sforza
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - John W Wong
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Kathleen Gabrielson
- Department of Molecular and Comparative Pathobiology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Khaled Aziz
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mahadevappa Mahesh
- Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Jonathan B Coulter
- Department of Urology, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ismaeel Siddiqui
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Phuoc T Tran
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland; Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland
| | - Akila N Viswanathan
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Mohammad Rezaee
- Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University School of Medicine, Baltimore, Maryland.
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17
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Lin B, Fan M, Niu T, Liang Y, Xu H, Tang W, Du X. Key changes in the future clinical application of ultra-high dose rate radiotherapy. Front Oncol 2023; 13:1244488. [PMID: 37941555 PMCID: PMC10628486 DOI: 10.3389/fonc.2023.1244488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023] Open
Abstract
Ultra-high dose rate radiotherapy (FLASH-RT) is an external beam radiotherapy strategy that uses an extremely high dose rate (≥40 Gy/s). Compared with conventional dose rate radiotherapy (≤0.1 Gy/s), the main advantage of FLASH-RT is that it can reduce damage of organs at risk surrounding the cancer and retain the anti-tumor effect. An important feature of FLASH-RT is that an extremely high dose rate leads to an extremely short treatment time; therefore, in clinical applications, the steps of radiotherapy may need to be adjusted. In this review, we discuss the selection of indications, simulations, target delineation, selection of radiotherapy technologies, and treatment plan evaluation for FLASH-RT to provide a theoretical basis for future research.
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Affiliation(s)
- Binwei Lin
- Department of Oncology, National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital), Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology, Mianyang, China
| | - Mi Fan
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Tingting Niu
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Yuwen Liang
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Haonan Xu
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Wenqiang Tang
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Xiaobo Du
- Department of Oncology, National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital), Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology, Mianyang, China
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18
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Ursino S, Gadducci G, Giannini N, Gonnelli A, Fuentes T, Di Martino F, Paiar F. New insights on clinical perspectives of FLASH radiotherapy: from low- to very high electron energy. Front Oncol 2023; 13:1254601. [PMID: 37936603 PMCID: PMC10626470 DOI: 10.3389/fonc.2023.1254601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 09/25/2023] [Indexed: 11/09/2023] Open
Abstract
Radiotherapy (RT) is performed in approximately 75% of patients with cancer, and its efficacy is often hampered by the low tolerance of the surrounding normal tissues. Recent advancements have demonstrated the potential to widen the therapeutic window using "very short" radiation treatment delivery (from a conventional dose rate between 0.5 Gy/min and 2 Gy/min to more than 40 Gy/s) causing a significant increase of normal tissue tolerance without varying the tumor effect. This phenomenon is called "FLASH Effect (FE)" and has been discovered by using electrons. Although several physical, dosimetric, and radiobiological aspects need to be clarified, current preclinical "in vivo" studies have reported a significant protective effect of FLASH RT on neurocognitive function, skin toxicity, lung fibrosis, and bowel injury. Therefore, the current radiobiological premises lay the foundation for groundbreaking potentials in clinical translation, which could be addressed to an initial application of Low Energy Electron FLASH (LEE) for the treatment of superficial tumors to a subsequent Very High Energy Electron FLASH (VHEE) for the treatment of deep tumors. Herein, we report a clinical investigational scenario that, if supported by preclinical studies, could be drawn in the near future.
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Affiliation(s)
- Stefano Ursino
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Centro Pisano Multidisciplinare sulla Ricerca e implementazione clinica della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Center for Instrument Sharing University of Pisa (CISUP), University of Pisa, Pisa, Italy
| | - Giovanni Gadducci
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Centro Pisano Multidisciplinare sulla Ricerca e implementazione clinica della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Noemi Giannini
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, 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, Italy
- Centro Pisano Multidisciplinare sulla Ricerca e implementazione clinica della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
| | - Taiushia Fuentes
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, 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, S. Chiara University Hospital, Pisa, Italy
| | - Fabiola Paiar
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
- Centro Pisano Multidisciplinare sulla Ricerca e implementazione clinica della Flash Radiotherapy (CPFR), University of Pisa, Pisa, Italy
- Center for Instrument Sharing University of Pisa (CISUP), University of Pisa, Pisa, Italy
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19
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Dubail M, Heinrich S, Portier L, Bastian J, Giuliano L, Aggar L, Berthault N, Londoño-Vallejo JA, Vilalta M, Boivin G, Sharma RA, Dutreix M, Fouillade C. Lung Organotypic Slices Enable Rapid Quantification of Acute Radiotherapy Induced Toxicity. Cells 2023; 12:2435. [PMID: 37887279 PMCID: PMC10605600 DOI: 10.3390/cells12202435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/03/2023] [Accepted: 10/07/2023] [Indexed: 10/28/2023] Open
Abstract
To rapidly assess healthy tissue toxicities induced by new anti-cancer therapies (i.e., radiation alone or in combination with drugs), there is a critical need for relevant and easy-to-use models. Consistent with the ethical desire to reduce the use of animals in medical research, we propose to monitor lung toxicity using an ex vivo model. Briefly, freshly prepared organotypic lung slices from mice were irradiated, with or without being previously exposed to chemotherapy, and treatment toxicity was evaluated by analysis of cell division and viability of the slices. When exposed to different doses of radiation, this ex vivo model showed a dose-dependent decrease in cell division and viability. Interestingly, monitoring cell division was sensitive enough to detect a sparing effect induced by FLASH radiotherapy as well as the effect of combined treatment. Altogether, the organotypic lung slices can be used as a screening platform to rapidly determine in a quantitative manner the level of lung toxicity induced by different treatments alone or in combination with chemotherapy while drastically reducing the number of animals. Translated to human lung samples, this ex vivo assay could serve as an innovative method to investigate patients' sensitivity to radiation and drugs.
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Affiliation(s)
- Maxime Dubail
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - Sophie Heinrich
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - Lucie Portier
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - Jessica Bastian
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - Lucia Giuliano
- SBAI Department, Sapienza University of Rome, 00161 Rome, Italy
| | - Lilia Aggar
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - Nathalie Berthault
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - José-Arturo Londoño-Vallejo
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - Marta Vilalta
- Global Translational Science, Varian, a Siemens Healthineers Company, Palo Alto, CA 94304, USA
| | - Gael Boivin
- Global Translational Science, Varian, a Siemens Healthineers Company, Palo Alto, CA 94304, USA
| | - Ricky A. Sharma
- Global Translational Science, Varian, a Siemens Healthineers Company, Palo Alto, CA 94304, USA
- UCL Cancer Institute, University College London, London WC1E 6DD, UK
| | - Marie Dutreix
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
| | - Charles Fouillade
- Institut Curie, Inserm U1021-CNRS UMR 3347, Paris Saclay University, Centre Universitaire, 91405 Orsay Cedex, France
- Institut Curie, PSL Research University, 75006 Paris, France
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20
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No HJ, Wu YF, Dworkin ML, Manjappa R, Skinner L, Ashraf MR, Lau B, Melemenidis S, Viswanathan V, Yu ASJ, Surucu M, Schüler E, Graves EE, Maxim PG, Loo BW. Clinical Linear Accelerator-Based Electron FLASH: Pathway for Practical Translation to FLASH Clinical Trials. Int J Radiat Oncol Biol Phys 2023; 117:482-492. [PMID: 37105403 DOI: 10.1016/j.ijrobp.2023.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Revised: 03/03/2023] [Accepted: 04/11/2023] [Indexed: 04/29/2023]
Abstract
PURPOSE Ultrahigh-dose-rate (UHDR) radiation therapy (RT) has produced the FLASH effect in preclinical models: reduced toxicity with comparable tumor control compared with conventional-dose-rate RT. Early clinical trials focused on UHDR RT feasibility using specialized devices. We explore the technical feasibility of practical electron UHDR RT on a standard clinical linear accelerator (LINAC). METHODS AND MATERIALS We tuned the program board of a decommissioned electron energy for UHDR electron delivery on a clinical LINAC without hardware modification. Pulse delivery was controlled using the respiratory gating interface. A short source-to-surface distance (SSD) electron setup with a standard scattering foil was configured and tested on an anthropomorphic phantom using circular blocks with 3- to 20-cm field sizes. Dosimetry was evaluated using radiochromic film and an ion chamber profiler. RESULTS UHDR open-field mean dose rates at 100, 80, 70, and 59 cm SSD were 36.82, 59.52, 82.01, and 112.83 Gy/s, respectively. At 80 cm SSD, mean dose rate was ∼60 Gy/s for all collimated field sizes, with an R80 depth of 6.1 cm corresponding to an energy of 17.5 MeV. Heterogeneity was <5.0% with asymmetry of 2.2% to 6.2%. The short SSD setup was feasible under realistic treatment conditions simulating broad clinical indications on an anthropomorphic phantom. CONCLUSIONS Short SSD and tuning for high electron beam current on a standard clinical LINAC can deliver flat, homogenous UHDR electrons over a broad, clinically relevant range of field sizes and depths with practical working distances in a configuration easily reversible to standard clinical use.
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Affiliation(s)
- Hyunsoo Joshua No
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Yufan Fred Wu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Michael Louis Dworkin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Amy Shu-Jung 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
| | - Emil Schüler
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Edward Elliot Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Peter Gregor Maxim
- Department of Radiation Oncology, University of California, Irvine, Orange, California
| | - 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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21
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Dal Bello R, von der Grün J, Fabiano S, Rudolf T, Saltybaeva N, Stark LS, Ahmed M, Bathula M, Kucuker Dogan S, McNeur J, Guckenberger M, Tanadini-Lang S. Enabling ultra-high dose rate electron beams at a clinical linear accelerator for isocentric treatments. Radiother Oncol 2023; 187:109822. [PMID: 37516362 DOI: 10.1016/j.radonc.2023.109822] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Revised: 06/20/2023] [Accepted: 07/17/2023] [Indexed: 07/31/2023]
Abstract
BACKGROUND AND PURPOSE Radiotherapy delivery with ultra-high dose rates (UHDR) has consistently produced normal tissue sparing while maintaining efficacy for tumour control in preclinical studies, known as the FLASH effect. Modified clinical electron linacs have been used for pre-clinical studies at reduced source-surface distance (SSD) and novel intra-operative devices are becoming available. In this context, we modified a clinical linac to deliver 16 MeV UHDR electron beams with an isocentric setup. MATERIALS AND METHODS The first Varian TrueBeam (SN 1001) was clinically operative between 2009-2022, it was then decommissioned and converted into a research platform. The 18 MeV electron beam was converted into the experimental 16 MeV UHDR. Modifications were performed by Varian and included a software patch, thinner scattering foil and beam tuning. The dose rate, beam characteristics and reproducibility were measured with electron applicators at SSD = 100 cm. RESULTS The dose per pulse at isocenter was up to 1.28 Gy/pulse, corresponding to average and instantaneous dose rates up to 256 Gy/s and 3⋅105 Gy/s, respectively. Beam characteristics were equivalent between 16 MeV UHDR and conventional for field sizes up to 10x10cm2 and an overall beam reproducibility within ± 2.5% was measured. CONCLUSIONS We report on the first technical conversion of a Varian TrueBeam to produce 16 MeV UHDR electron beams. This research platform will allow isocenter experiments and deliveries with conventional setups up to field sizes of 10x10 cm2 within a hospital environment, reducing the gap between preclinical and clinical electron FLASH investigations.
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Affiliation(s)
- Riccardo Dal Bello
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland.
| | - Jens von der Grün
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Silvia Fabiano
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Thomas Rudolf
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Natalia Saltybaeva
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Luisa S Stark
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Md Ahmed
- Varian Medical Systems a Siemens Healthineers Company, Palo Alto, CA, USA
| | - Manohar Bathula
- Varian Medical Systems a Siemens Healthineers Company, Palo Alto, CA, USA
| | | | - Joshua McNeur
- Varian Medical Systems a Siemens Healthineers Company, Palo Alto, CA, USA
| | - Matthias Guckenberger
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
| | - Stephanie Tanadini-Lang
- Department of Radiation Oncology, University Hospital Zurich and University of Zurich, Zurich, Switzerland
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22
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Vanreusel V, Gasparini A, Galante F, Mariani G, Pacitti M, Colijn A, Reniers B, Yalvac B, Vandenbroucke D, Peeters M, Leblans P, Felici G, Verellen D, de Freitas Nascimento L. Optically stimulated luminescence system as an alternative for radiochromic film for 2D reference dosimetry in UHDR electron beams. Phys Med 2023; 114:103147. [PMID: 37804712 DOI: 10.1016/j.ejmp.2023.103147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 08/18/2023] [Accepted: 09/21/2023] [Indexed: 10/09/2023] Open
Abstract
Radiotherapy is part of the treatment of over 50% of cancer patients. Its efficacy is limited by the radiotoxicity to the healthy tissue. FLASH-RT is based on the biological effect that ultra-high dose rates (UHDR) and very short treatment times strongly reduce normal tissue toxicity, while preserving the anti-tumoral effect. Despite many positive preclinical results, the translation of FLASH-RT to the clinic is hampered by the lack of accurate dosimetry for UHDR beams. To date radiochromic film is commonly used for dose assessment but has the drawback of lengthy and cumbersome read out procedures. In this work, we investigate the equivalence of a 2D OSL system to radiochromic film dosimetry in terms of dose rate independency. The comparison of both systems was done using the ElectronFlash linac. We investigated the dose rate dependence by variation of the (1) modality, (2) pulse repetition frequency, (3) pulse length and (4) source to surface distance. Additionally, we compared the 2D characteristics by field size measurements. The OSL calibration showed transferable between conventional and UHDR modality. Both systems are equally independent of average dose rate, pulse length and instantaneous dose rate. The OSL system showed equivalent in field size determination within 3 sigma. We show the promising nature of the 2D OSL system to serve as alternative for radiochromic film in UHDR electron beams. However, more in depth characterization is needed to assess its full potential.
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Affiliation(s)
- Verdi Vanreusel
- Research in Dosimetric Applications, SCK CEN, Boeretang 200, 2400 Mol, Belgium; CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Iridium Netwerk, Oosterveldlaan 22, 2610 Wilrijk, Belgium.
| | - Alessia Gasparini
- CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Iridium Netwerk, Oosterveldlaan 22, 2610 Wilrijk, Belgium
| | - Federica Galante
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Giulia Mariani
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Matteo Pacitti
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Arnaud Colijn
- CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium
| | - Brigitte Reniers
- NuTeC, CMK, Hasselt University, Wetenschapspark 27, 3590 Diepenbeek, Belgium
| | - Burak Yalvac
- NuTeC, CMK, Hasselt University, Wetenschapspark 27, 3590 Diepenbeek, Belgium
| | | | | | - Paul Leblans
- Agfa N.V., Septestraat 27, 2640 Mortsel, Belgium
| | - Giuseppe Felici
- Sordina IORT Technologies S.p.A., Via dell'Industria, 1/A, 04011 Aprilia, Latina, Italy
| | - Dirk Verellen
- CORE, University of Antwerp, Universiteitsplein 1, 2610 Wilrijk, Belgium; Iridium Netwerk, Oosterveldlaan 22, 2610 Wilrijk, Belgium
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23
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Duval KEA, Aulwes E, Zhang R, Rahman M, Ashraf MR, Sloop A, Sunnerberg J, Williams BB, Cao X, Bruza P, Kheirollah A, Tavakkoli A, Jarvis LA, Schaner PE, Swartz HM, Gladstone DJ, Pogue BW, Hoopes PJ. Comparison of Tumor Control and Skin Damage in a Mouse Model after Ultra-High Dose Rate Irradiation and Conventional Irradiation. Radiat Res 2023; 200:223-231. [PMID: 37590482 PMCID: PMC10551764 DOI: 10.1667/rade-23-00057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 07/07/2023] [Indexed: 08/19/2023]
Abstract
Recent studies suggest ultra-high dose rate radiation treatment (UHDR-RT) reduces normal tissue damage compared to conventional radiation treatment (CONV-RT) at the same dose. In this study, we compared first, the kinetics and degree of skin damage in wild-type C57BL/6 mice, and second, tumor treatment efficacy in GL261 and B16F10 dermal tumor models, at the same UHDR-RT and CONV-RT doses. Flank skin of wild-type mice received UHDR-RT or CONV-RT at 25 Gy and 30 Gy. Normal skin damage was tracked by clinical observation to determine the time to moist desquamation, an endpoint which was verified by histopathology. Tumors were inoculated on the right flank of the mice, then received UHDR-RT or CONV-RT at 1 × 11 Gy, 1 × 15, 1 × 25, 3 × 6 and 3 × 8 Gy, and time to tumor tripling volume was determined. Tumors also received 1 × 11, 1 × 15, 3 × 6 and 3 × 8 Gy doses for assessment of CD8+/CD4+ tumor infiltrate and genetic expression 96 h postirradiation. All irradiations of the mouse tumor or flank skin were performed with megavoltage electron beams (10 MeV, 270 Gy/s for UHDR-RT and 9 MeV, 0.12 Gy/s for CONV-RT) delivered via a clinical linear accelerator. Tumor control was statistically equal for similar doses of UHDR-RT and CONV-RT in B16F10 and GL261 murine tumors. There were variable qualitative differences in genetic expression of immune and cell damage-associated pathways between UHDR and CONV irradiated B16F10 tumors. Compared to CONV-RT, UHDR-RT resulted in an increased latent period to skin desquamation after a single 25 Gy dose (7 days longer). Time to moist skin desquamation did not significantly differ between UHDR-RT and CONV-RT after a 30 Gy dose. The histomorphological characteristics of skin damage were similar for UHDR-RT and CONV-RT. These studies demonstrated similar tumor control responses for equivalent single and fractionated radiation doses, with variable difference in expression of tumor progression and immune related gene pathways. There was a modest UHDR-RT skin sparing effect after a 1 × 25 Gy dose but not after a 1 × 30 Gy dose.
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Affiliation(s)
- Kayla E. A. Duval
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - Ethan Aulwes
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - Rongxiao Zhang
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Mahbubur Rahman
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - M. Ramish Ashraf
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Austin Sloop
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jacob Sunnerberg
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Benjamin B. Williams
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Xu Cao
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Petr Bruza
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | | | - Armin Tavakkoli
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - Lesley A. Jarvis
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Philip E. Schaner
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Harold M. Swartz
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - David J. Gladstone
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Brian W. Pogue
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin
| | - P. Jack Hoopes
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
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Zou W, Zhang R, Schüler E, Taylor PA, Mascia AE, Diffenderfer ES, Zhao T, Ayan AS, Sharma M, Yu SJ, Lu W, Bosch WR, Tsien C, Surucu M, Pollard-Larkin JM, Schuemann J, Moros EG, Bazalova-Carter M, Gladstone DJ, Li H, Simone CB, Petersson K, Kry SF, Maity A, Loo BW, Dong L, Maxim PG, Xiao Y, Buchsbaum JC. Framework for Quality Assurance of Ultrahigh Dose Rate Clinical Trials Investigating FLASH Effects and Current Technology Gaps. Int J Radiat Oncol Biol Phys 2023; 116:1202-1217. [PMID: 37121362 PMCID: PMC10526970 DOI: 10.1016/j.ijrobp.2023.04.018] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 03/28/2023] [Accepted: 04/17/2023] [Indexed: 05/02/2023]
Abstract
FLASH radiation therapy (FLASH-RT), delivered with ultrahigh dose rate (UHDR), may allow patients to be treated with less normal tissue toxicity for a given tumor dose compared with currently used conventional dose rate. Clinical trials are being carried out and are needed to test whether this improved therapeutic ratio can be achieved clinically. During the clinical trials, quality assurance and credentialing of equipment and participating sites, particularly pertaining to UHDR-specific aspects, will be crucial for the validity of the outcomes of such trials. This report represents an initial framework proposed by the NRG Oncology Center for Innovation in Radiation Oncology FLASH working group on quality assurance of potential UHDR clinical trials and reviews current technology gaps to overcome. An important but separate consideration is the appropriate design of trials to most effectively answer clinical and scientific questions about FLASH. This paper begins with an overview of UHDR RT delivery methods. UHDR beam delivery parameters are then covered, with a focus on electron and proton modalities. The definition and control of safe UHDR beam delivery and current and needed dosimetry technologies are reviewed and discussed. System and site credentialing for large, multi-institution trials are reviewed. Quality assurance is then discussed, and new requirements are presented for treatment system standard analysis, patient positioning, and treatment planning. The tables and figures in this paper are meant to serve as reference points as we move toward FLASH-RT clinical trial performance. Some major questions regarding FLASH-RT are discussed, and next steps in this field are proposed. FLASH-RT has potential but is associated with significant risks and complexities. We need to redefine optimization to focus not only on the dose but also on the dose rate in a manner that is robust and understandable and that can be prescribed, validated, and confirmed in real time. Robust patient safety systems and access to treatment data will be critical as FLASH-RT moves into the clinical trials.
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Affiliation(s)
- Wei Zou
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA.
| | - Rongxiao Zhang
- Department of Radiation Oncology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Emil Schüler
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Paige A Taylor
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | | | - Eric S Diffenderfer
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Tianyu Zhao
- Department of Radiation Oncology, Washington University, St. Louis, MO, USA
| | - Ahmet S Ayan
- Department of Radiation Oncology, Ohio State University, Columbus, OH, USA
| | - Manju Sharma
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA, USA
| | - Shu-Jung Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Weiguo Lu
- Department of Radiation Oncology, University of Texas Southwestern, Dallas, TX, USA
| | - Walter R Bosch
- Department of Radiation Oncology, Washington University, St. Louis, MO, USA
| | - Christina Tsien
- Department of Radiation Oncology, McGill University Health Center, Montreal, QC, Canada
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Julianne M Pollard-Larkin
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Eduardo G Moros
- Department of Radiation Oncology, Moffitt Cancer Center, Tampa, FL, USA
| | | | - David J Gladstone
- Department of Radiation Oncology, Geisel School of Medicine, Dartmouth College, Hanover, NH, USA
| | - Heng Li
- Department of Radiation Oncology, Johns Hopkins University, Baltimore, MD, USA
| | - Charles B Simone
- Department of Radiation Oncology, New York Proton Center, New York, NY, USA
| | - Kristoffer Petersson
- Department of Radiation Oncology, MRC Oxford Institute for Radiation Oncology, University of Oxford, Oxford, UK
| | - Stephen F Kry
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
| | - Amit Maity
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Lei Dong
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Peter G Maxim
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA
| | - Ying Xiao
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jeffrey C Buchsbaum
- Radiation Research Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute, National Institute of Health, Bethesda, MD, USA
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Cuitiño MC, Fleming JL, Jain S, Cetnar A, Ayan AS, Woollard J, Manring H, Meng W, McElroy JP, Blakaj DM, Gupta N, Chakravarti A. Comparison of Gonadal Toxicity of Single-Fraction Ultra-High Dose Rate and Conventional Radiation in Mice. Adv Radiat Oncol 2023; 8:101201. [PMID: 37008254 PMCID: PMC10050676 DOI: 10.1016/j.adro.2023.101201] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Accepted: 02/08/2023] [Indexed: 02/25/2023] Open
Abstract
Purpose Increasing evidence suggests that ultra-high-dose-rate (UHDR) radiation could result in similar tumor control as conventional (CONV) radiation therapy (RT) while reducing toxicity to surrounding healthy tissues. Considering that radiation toxicity to gonadal tissues can cause hormone disturbances and infertility in young patients with cancer, the purpose of this study was to assess the possible role of UHDR-RT in reducing toxicity to healthy gonads in mice compared with CONV-RT. Methods and Materials Radiation was delivered to the abdomen or pelvis of female (8 or 16 Gy) and male (5 Gy) C57BL/6J mice, respectively, at conventional (∼0.4 Gy/s) or ultrahigh (>100 Gy/s) dose rates using an IntraOp Mobetron linear accelerator. Organ weights along with histopathology and immunostaining of irradiated gonads were used to compare toxicity between radiation modalities. Results CONV-RT and UHDR-RT induced a similar decrease in uterine weights at both studied doses (∼50% of controls), which indicated similarly reduced ovarian follicular activity. Histologically, ovaries of CONV- and UHDR-irradiated mice exhibited a comparable lack of follicles. Weights of CONV- and UHDR-irradiated testes were reduced to ∼30% of controls, and the percentage of degenerate seminiferous tubules was also similar between radiation modalities (∼80% above controls). Pairwise comparisons of all quantitative data indicated statistical significance between irradiated (CONV or UHDR) and control groups (from P ≤ .01 to P ≤ .0001) but not between radiation modalities. Conclusions The data presented here suggest that the short-term effects of UHDR-RT on the mouse gonads are comparable to those of CONV-RT.
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Affiliation(s)
- Maria C. Cuitiño
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Jessica L. Fleming
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Sagarika Jain
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Ashley Cetnar
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Ahmet S. Ayan
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Jeffrey Woollard
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Heather Manring
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Wei Meng
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Joseph P. McElroy
- Department of Biomedical Informatics, Center for Biostatistics, Ohio State University, Columbus, Ohio
| | - Dukagjin M. Blakaj
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Nilendu Gupta
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
| | - Arnab Chakravarti
- Department of Radiation Oncology, Arthur G. James Hospital, Comprehensive Cancer Center, Columbus, Ohio
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Zhang Q, Gerweck LE, Cascio E, Gu L, Yang Q, Dong X, Huang P, Bertolet A, Nesteruk KP, Sung W, McNamara AL, Schuemann J. Absence of Tissue-Sparing Effects in Partial Proton FLASH Irradiation in Murine Intestine. Cancers (Basel) 2023; 15:cancers15082269. [PMID: 37190197 DOI: 10.3390/cancers15082269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 05/17/2023] Open
Abstract
Ultra-high dose rate irradiation has been reported to protect normal tissues more than conventional dose rate irradiation. This tissue sparing has been termed the FLASH effect. We investigated the FLASH effect of proton irradiation on the intestine as well as the hypothesis that lymphocyte depletion is a cause of the FLASH effect. A 16 × 12 mm2 elliptical field with a dose rate of ~120 Gy/s was provided by a 228 MeV proton pencil beam. Partial abdominal irradiation was delivered to C57BL/6j and immunodeficient Rag1-/-/C57 mice. Proliferating crypt cells were counted at 2 days post exposure, and the thickness of the muscularis externa was measured at 280 days following irradiation. FLASH irradiation did not reduce the morbidity or mortality of conventional irradiation in either strain of mice; in fact, a tendency for worse survival in FLASH-irradiated mice was observed. There were no significant differences in lymphocyte numbers between FLASH and conventional-dose-rate mice. A similar number of proliferating crypt cells and a similar thickness of the muscularis externa following FLASH and conventional dose rate irradiation were observed. Partial abdominal FLASH proton irradiation at 120 Gy/s did not spare normal intestinal tissue, and no difference in lymphocyte depletion was observed. This study suggests that the effect of FLASH irradiation may depend on multiple factors, and in some cases dose rates of over 100 Gy/s do not induce a FLASH effect and can even result in worse outcomes.
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Affiliation(s)
- Qixian Zhang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Leo E Gerweck
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Ethan Cascio
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Liqun Gu
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Qingyuan Yang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Xinyue Dong
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Peigen Huang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Alejandro Bertolet
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Konrad Pawel Nesteruk
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Wonmo Sung
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Aimee L McNamara
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Jan Schuemann
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
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27
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Barghouth PG, Melemenidis S, Montay-Gruel P, Ollivier J, Viswanathan V, Jorge PG, Soto LA, Lau BC, Sadeghi C, Edlabadkar A, Manjappa R, Wang J, Le Bouteiller M, Surucu M, Yu A, Bush K, Skinner L, Maxim PG, Loo BW, Limoli CL, Vozenin MC, Frock RL. FLASH-RT does not affect chromosome translocations and junction structures beyond that of CONV-RT dose-rates. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.27.534408. [PMID: 37034651 PMCID: PMC10081175 DOI: 10.1101/2023.03.27.534408] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/19/2023]
Abstract
The molecular and cellular mechanisms driving the enhanced therapeutic ratio of ultra-high dose-rate radiotherapy (FLASH-RT) over slower conventional (CONV-RT) radiotherapy dose-rate remain to be elucidated. However, attenuated DNA damage and transient oxygen depletion are among several proposed models. Here, we tested whether FLASH-RT under physioxic (4% O 2 ) and hypoxic conditions (≤2% O 2 ) reduces genome-wide translocations relative to CONV-RT and whether any differences identified revert under normoxic (21% O 2 ) conditions. We employed high-throughput rejoin and genome-wide translocation sequencing ( HTGTS-JoinT-seq ), using S. aureus and S. pyogenes Cas9 "bait" DNA double strand breaks (DSBs), to measure differences in bait-proximal repair and their genome-wide translocations to "prey" DSBs generated by electron beam CONV-RT (0.08-0.13Gy/s) and FLASH-RT (1×10 2 -5×10 6 Gy/s), under varying ionizing radiation (IR) doses and oxygen tensions. Normoxic and physioxic irradiation of HEK293T cells increased translocations at the cost of decreasing bait-proximal repair but were indistinguishable between CONV-RT and FLASH-RT. Although no apparent increase in chromosome translocations was observed with hypoxia-induced apoptosis, the combined decrease in oxygen tension with IR dose-rate modulation did not reveal significant differences in the level of translocations nor in their junction structures. Thus, Irrespective of oxygen tension, FLASH-RT produces translocations and junction structures at levels and proportions that are indistinguishable from CONV-RT.
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Affiliation(s)
- Paul G. Barghouth
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Pierre Montay-Gruel
- Laboratory of Radiation Oncology, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Jonathan Ollivier
- Laboratory of Radiation Oncology, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Patrik G. Jorge
- Institute of Radiation Physics/CHUV, Lausanne University Hospital, Switzerland
| | - Luis A. Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Brianna C. Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Cheyenne Sadeghi
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Anushka Edlabadkar
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jinghui Wang
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marie Le Bouteiller
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Amy Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Karl Bush
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Peter G. Maxim
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Billy W. Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Charles L. Limoli
- Department of Radiation Oncology, University of California, Irvine, CA 92697-2695, USA
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
| | - Richard L. Frock
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94305, USA
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28
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Zhang Q, Gerweck LE, Cascio E, Yang Q, Huang P, Niemierko A, Bertolet A, Nesteruk KP, McNamara A, Schuemann J. Proton FLASH effects on mouse skin at different oxygen tensions. Phys Med Biol 2023; 68:055010. [PMID: 36731139 DOI: 10.1088/1361-6560/acb888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 02/02/2023] [Indexed: 02/04/2023]
Abstract
Objective. Irradiation at FLASH dose rates (>40 Gy s-1) has received great attention due to its reported normal tissue sparing effect. The FLASH effect was originally observed in electron irradiations but has since been shown to also occur with both photon and proton beams. Several mechanisms have been proposed to explain the tissue sparing at high dose rates, including effects involving oxygen, such as depletion of oxygen within the irradiated cells. In this study, we investigated the protective role of FLASH proton irradiation on the skin when varying the oxygen concentration.Approach. Our double scattering proton system provided a 1.2 × 1.6 cm2elliptical field at a dose rate of ∼130 Gy s-1. The conventional dose rate was ∼0.4 Gy s-1. The legs of the FVB/N mice were marked with two tattooed dots and fixed in a holder for exposure. To alter the skin oxygen concentration, the mice were breathing pure oxygen or had their legs tied to restrict blood flow. The distance between the two dots was measured to analyze skin contraction over time.Main results. FLASH irradiation mitigated skin contraction by 15% compared to conventional dose rate irradiation. The epidermis thickness and collagen deposition at 75 d following 25 to 30 Gy exposure suggested a long-term protective function in the skin from FLASH irradiation. Providing the mice with oxygen or reducing the skin oxygen concentration removed the dose-rate-dependent difference in response.Significance. FLASH proton irradiation decreased skin contraction, epidermis thickness and collagen deposition compared to standard dose rate irradiations. The observed oxygen-dependence of the FLASH effect is consistent with, but not conclusive of, fast oxygen depletion during the exposure.
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Affiliation(s)
- Qixian Zhang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Leo E Gerweck
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Ethan Cascio
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Qingyuan Yang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Peigen Huang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Andrzej Niemierko
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Alejandro Bertolet
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Konrad Pawel Nesteruk
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Aimee McNamara
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Jan Schuemann
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
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29
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Böhlen TT, Germond JF, Bourhis J, Bailat C, Bochud F, Moeckli R. The minimal FLASH sparing effect needed to compensate the increase of radiobiological damage due to hypofractionation for late-reacting tissues. Med Phys 2022; 49:7672-7682. [PMID: 35933554 PMCID: PMC10087769 DOI: 10.1002/mp.15911] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 07/06/2022] [Accepted: 07/28/2022] [Indexed: 12/27/2022] Open
Abstract
PURPOSE Normal tissue (NT) sparing by ultra-high dose rate (UHDR) irradiations compared to conventional dose rate (CONV) irradiations while being isotoxic to the tumor has been termed "FLASH effect" and has been observed when large doses per fraction (d ≳ 5 Gy) have been delivered. Since hypofractionated treatment schedules are known to increase toxicities of late-reacting tissues compared to normofractionated schedules for many clinical scenarios at CONV dose rates, we developed a formalism based on the biologically effective dose (BED) to assess the minimum magnitude of the FLASH effect needed to compensate the loss of late-reacting NT sparing when reducing the number of fractions compared to a normofractionated CONV treatment schedule while remaining isoeffective to the tumor. METHODS By requiring the same BED for the tumor, we derived the "break-even NT sparing weighting factor" WBE for the linear-quadratic (LQ) and LQ-linear (LQ-L) models for an NT region irradiated at a relative dose r (relative to the prescribed dose per fraction d to the tumor). WBE was evaluated numerically for multiple values of d and r, and for different tumor and NT α/β-ratios. WBE was compared against currently available experimental data on the magnitude of the NT sparing provided by the FLASH effect for single fraction doses. RESULTS For many clinically relevant scenarios, WBE decreases steeply initially for d > 2 Gy for late-reacting tissues with (α/β)NT ≈ 3 Gy, implying that a significant NT sparing by the FLASH effect (between 15% and 30%) is required to counteract the increased radiobiological damage experienced by late-reacting NT for hypofractionated treatments with d < 10 Gy compared to normofractionated treatments that are equieffective to the tumor. When using the LQ model with generic α/β-ratios for tumor and late-reacting NT of (α/β)T = 10 Gy and (α/β)NT = 3 Gy, respectively, most currently available experimental evidence about the magnitude of NT sparing by the FLASH effect suggests no net NT sparing benefit for hypofractionated FLASH radiotherapy (RT) in the high-dose region when compared with WBE . Instead, clinical indications with more similar α/β-ratios of the tumor and dose-limiting NT toxicities [i.e., (α/β)T ≈ (α/β)NT ], such as prostate treatments, are generally less penalized by hypofractionated treatments and need consequently smaller magnitudes of NT sparing by the FLASH effect to achieve a net benefit. For strongly hypofractionated treatments (>10-15 Gy/fraction), the LQ-L model predicts, unlike the LQ model, a larger WBE suggesting a possible benefit of strongly hypofractionated FLASH RT, even for generic α/β-ratios of (α/β)T = 10 Gy and (α/β)NT = 3 Gy. However, knowledge on the isoeffect scaling for high doses per fraction (≳10 Gy/fraction) and its modeling is currently limited and impedes accurate and reliable predictions for such strongly hypofractionated treatments. CONCLUSIONS We developed a formalism that quantifies the minimal NT sparing by the FLASH effect needed to compensate for hypofractionation, based on the LQ and LQ-L models. For a given hypofractionated UHDR treatment scenario and magnitude of the FLASH effect, the formalism predicts if a net NT sparing benefit is expected compared to a respective normofractionated CONV treatment.
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Affiliation(s)
- Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
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30
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FLASHlab@PITZ: New R&D platform with unique capabilities for electron FLASH and VHEE radiation therapy and radiation biology under preparation at PITZ. Phys Med 2022; 104:174-187. [PMID: 36463582 DOI: 10.1016/j.ejmp.2022.10.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 09/19/2022] [Accepted: 10/31/2022] [Indexed: 12/03/2022] Open
Abstract
At the Photo Injector Test facility at DESY in Zeuthen (PITZ), an R&D platform for electron FLASH and very high energy electron radiation therapy and radiation biology is being prepared (FLASHlab@PITZ). The beam parameters available at PITZ are worldwide unique. They are based on experiences from 20 + years of developing high brightness beam sources and an ultra-intensive THz light source demonstrator for ps scale electron bunches with up to 5 nC bunch charge at MHz repetition rate in bunch trains of up to 1 ms length, currently 22 MeV (upgrade to 250 MeV planned). Individual bunches can provide peak dose rates up to 1014 Gy/s, and 10 Gy can be delivered within picoseconds. Upon demand, each bunch of the bunch train can be guided to a different transverse location, so that either a "painting" with micro beams (comparable to pencil beam scanning in proton therapy) or a cumulative increase of absorbed dose, using a wide beam distribution, can be realized at the tumor. Full tumor treatment can hence be completed within 1 ms, mitigating organ movement issues. With extremely flexible beam manipulation capabilities, FLASHlab@PITZ will cover the current parameter range of successfully demonstrated FLASH effects and extend the parameter range towards yet unexploited short treatment times and high dose rates. A summary of the plans for FLASHlab@PITZ and the status of its realization will be presented.
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Kranzer R, Schüller A, Gómez Rodríguez F, Weidner J, Paz-Martín J, Looe HK, Poppe B. Charge collection efficiency, underlying recombination mechanisms, and the role of electrode distance of vented ionization chambers under ultra-high dose-per-pulse conditions. Phys Med 2022; 104:10-17. [PMID: 36356499 PMCID: PMC9719440 DOI: 10.1016/j.ejmp.2022.10.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 09/23/2022] [Accepted: 10/23/2022] [Indexed: 11/09/2022] Open
Abstract
PURPOSE Investigating and understanding of the underlying mechanisms affecting the charge collection efficiency (CCE) of vented ionization chambers under ultra-high dose rate pulsed electron radiation. This is an important step towards real-time dosimetry with ionization chambers in FLASH radiotherapy. METHODS Parallel-plate ionization chambers (PPIC) with three different electrode distances were build and investigated with electron beams with ultra-high dose-per-pulse (DPP) up to 5.4 Gy. The measurements were compared with simulations. The experimental determination of the CCE was done by comparison against the reference dose based on alanine dosimetry. The numerical solution of a system of partial differential equations taking into account charge creations by the radiation, their transport and reaction in an applied electric field was used for the simulations of the CCE and the underlying effects. RESULTS A good agreement between the experimental results and the simulated CCE could be achieved. The recombination losses found under ultra-high DPP could be attributed to a temporal and spatial charge carrier imbalance and the associated electric field distortion. With ultra-thin electrode distances down to 0.25 mm and a suitable chamber voltage, a CCE greater than 99 % could be achieved under the ultra-high DPP conditions investigated. CONCLUSIONS Well-guarded ultra-thin PPIC are suited for real-time dosimetry under ultra-high DPP conditions. This allows dosimetry also for FLASH RT according to common codes of practice, traceable to primary standards. The numerical approach used allows the determination of appropriate correction factors beyond the DPP ranges where established theories are applicable to account for remaining recombination losses.
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Affiliation(s)
- Rafael Kranzer
- PTW-Freiburg (R&D), Freiburg 79115, Germany,University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University Oldenburg, 26121, Germany,Corresponding author
| | - Andreas Schüller
- Physikalisch-Technische Bundesanstalt, Braunschweig 38116, Germany
| | - Faustino Gómez Rodríguez
- Departamento de Fisica de Particulas, Universidad de Santiago, Santiago de Compostela, Spain,Laboratorio de Radiofisica, Universidad de Santiago, Santiago de Compostela, Spain
| | | | - Jose Paz-Martín
- Departamento de Fisica de Particulas, Universidad de Santiago, Santiago de Compostela, Spain
| | - Hui Khee Looe
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University Oldenburg, 26121, Germany
| | - Björn Poppe
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University Oldenburg, 26121, Germany
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Lv Y, Lv Y, Wang Z, Lan T, Feng X, Chen H, Zhu J, Ma X, Du J, Hou G, Liao W, Yuan K, Wu H. FLASH radiotherapy: A promising new method for radiotherapy. Oncol Lett 2022; 24:419. [PMID: 36284652 PMCID: PMC9580247 DOI: 10.3892/ol.2022.13539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/10/2022] [Indexed: 11/06/2022] Open
Abstract
Among the treatments for malignant tumors, radiotherapy is of great significance both as a main treatment and as an adjuvant treatment. Radiation therapy damages cancer cells with ionizing radiation, leading to their death. However, radiation-induced toxicity limits the dose delivered to the tumor, thereby constraining the control effect of radiotherapy on tumor growth. In addition, the delayed toxicity caused by radiotherapy significantly harms the physical and mental health of patients. FLASH-RT, an emerging class of radiotherapy, causes a phenomenon known as the 'FLASH effect', which delivers radiotherapy at an ultra-high dose rate with lower toxicity to normal tissue than conventional radiotherapy to achieve local tumor control. Although its mechanism remains to be fully elucidated, this modality constitutes a potential new approach to treating malignant tumors. In the present review, the current research progress of FLASH-RT and its various particular effects are described, including the status of research on FLASH-RT and its influencing factors. The hypothetic mechanism of action of FLASH-RT is also summarized, providing insight into future tumor treatments.
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Affiliation(s)
- Yinghao Lv
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Yue Lv
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Zhen Wang
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Tian Lan
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Xuping Feng
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Hao Chen
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Jiang Zhu
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Xiao Ma
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Jinpeng Du
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Guimin Hou
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Wenwei Liao
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Kefei Yuan
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Hong Wu
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
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Ha B, Liang K, Liu C, Melemenidis S, Manjappa R, Viswanathan V, Das N, Ashraf R, Lau B, Soto L, Graves EE, Rao J, Loo BW, Pratx G. Real-time optical oximetry during FLASH radiotherapy using a phosphorescent nanoprobe. Radiother Oncol 2022; 176:239-243. [PMID: 35964762 DOI: 10.1016/j.radonc.2022.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Revised: 08/04/2022] [Accepted: 08/07/2022] [Indexed: 12/14/2022]
Abstract
The rapid depletion of oxygen during irradiation at ultra-high dose rate calls for tissue oximeters capable of high temporal resolution. This study demonstrates a water-soluble phosphorescent nanoprobe and fiber-coupled instrument, which together are used to measure the kinetics of oxygen depletion at 200 Hz during irradiation of in vitro solutions.
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Affiliation(s)
- Byunghang Ha
- Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA; Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Kaitlyn Liang
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA; Department of Applied Physics, Stanford University, Stanford, CA 94305, USA
| | - Cheng Liu
- Molecular Imaging Program at Stanford, Departments of Radiology and Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Neeladrisingha Das
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Ramish Ashraf
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Luis Soto
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Jianghong Rao
- Molecular Imaging Program at Stanford, Departments of Radiology and Chemistry, Stanford University, Stanford, CA 94305, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA
| | - Guillem Pratx
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA.
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Konradsson E, Liljedahl E, Gustafsson E, Adrian G, Beyer S, Ilaahi SE, Petersson K, Ceberg C, Nittby Redebrandt H. Comparable Long-Term Tumor Control for Hypofractionated FLASH Versus Conventional Radiation Therapy in an Immunocompetent Rat Glioma Model. Adv Radiat Oncol 2022; 7:101011. [PMID: 36092986 PMCID: PMC9449779 DOI: 10.1016/j.adro.2022.101011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 06/20/2022] [Indexed: 11/29/2022] Open
Abstract
Purpose To ensure a clinical translation of FLASH radiation therapy (FLASH-RT) for a specific tumor type, studies on tumor control and toxicity within the same biological system are needed. In this study, our objective was to evaluate tumor control and toxicity for hypofractionated FLASH-RT and conventional radiation therapy (CONV-RT) in an immunocompetent rat glioma model. Methods and Materials Fisher 344 rats (N = 68) were inoculated subcutaneously with NS1 glioma cells and randomized into groups (n = 9-10 per group). CONV-RT (∼8 Gy/min) or FLASH-RT (70-90 Gy/s) was administered in 3 fractions of either 8 Gy, 12.5 Gy, or 15 Gy using a 10-MeV electron beam. The maximum tumor diameter was measured weekly, and overall survival was determined until day 100. Long-term tumor control was defined as no evident tumor on day 100. Animals were evaluated for acute dermal side effects at 2 to 5 weeks after completed RT and for late dermal side effects at 3 months after initiation of treatment. Results Survival was significantly increased in all irradiated groups compared with control animals (P < .001). In general, irradiated tumors started to shrink at 1 week post-completed RT. In 40% (23 of 58) of the irradiated animals, long-term tumor control was achieved. Radiation-induced skin toxic effects were mild and consisted of hair loss, erythema, and dry desquamation. No severe toxic effect was observed. There was no significant difference between FLASH-RT and CONV-RT in overall survival, acute side effects, or late side effects for any of the dose levels. Conclusions This study shows that hypofractionated FLASH-RT results in long-term tumor control rates similar to those of CONV-RT for the treatment of large subcutaneous glioblastomas in immunocompetent rats. Neither treatment technique induced severe skin toxic effects. Consequently, no significant difference in toxicity could be resolved, suggesting that higher doses may be required to detect a FLASH sparing of skin.
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Affiliation(s)
- Elise Konradsson
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Emma Liljedahl
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Emma Gustafsson
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Gabriel Adrian
- Division of Oncology and Pathology, Department of Clinical Sciences, Skåne University Hospital, Lund University, Lund, Sweden
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Sarah Beyer
- Division of Oncology and Pathology, Department of Clinical Sciences, Skåne University Hospital, Lund University, Lund, Sweden
| | - Suhayb Ehsaan Ilaahi
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Kristoffer Petersson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Crister Ceberg
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Henrietta Nittby Redebrandt
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
- Department of Neurosurgery, Skåne University Hospital, Lund, Sweden
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Potential Molecular Mechanisms behind the Ultra-High Dose Rate "FLASH" Effect. Int J Mol Sci 2022; 23:ijms232012109. [PMID: 36292961 PMCID: PMC9602825 DOI: 10.3390/ijms232012109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/26/2022] [Accepted: 10/08/2022] [Indexed: 11/17/2022] Open
Abstract
FLASH radiotherapy, or the delivery of a dose at an ultra-high dose rate (>40 Gy/s), has recently emerged as a promising tool to enhance the therapeutic index in cancer treatment. The remarkable sparing of normal tissues and equivalent tumor control by FLASH irradiation compared to conventional dose rate irradiation—the FLASH effect—has already been demonstrated in several preclinical models and even in a first patient with T-cell cutaneous lymphoma. However, the biological mechanisms responsible for the differential effect produced by FLASH irradiation in normal and cancer cells remain to be elucidated. This is of great importance because a good understanding of the underlying radiobiological mechanisms and characterization of the specific beam parameters is required for a successful clinical translation of FLASH radiotherapy. In this review, we summarize the FLASH investigations performed so far and critically evaluate the current hypotheses explaining the FLASH effect, including oxygen depletion, the production of reactive oxygen species, and an altered immune response. We also propose a new theory that assumes an important role of mitochondria in mediating the normal tissue and tumor response to FLASH dose rates.
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Xie DH, Li YC, Ma S, Yang X, Lan RM, Chen AQ, Zhu HY, Mei Y, Peng LX, Li ZF, Huang BJ, Chen Y, Huang XY, Qian CN. Electron Ultra-High Dose Rate FLASH irradiation Study Using a Clinical Linac: Linac Modification, Dosimetry and Radiobiological outcome. Med Phys 2022; 49:6728-6738. [PMID: 35959736 DOI: 10.1002/mp.15920] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 05/24/2022] [Accepted: 08/02/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Ultra-high dose rate FLASH irradiation (FLASH-IR) has been shown to cause less normal tissue damage compared with conventional irradiation (CONV-IR), this is known as the "FLASH effect". It has attracted immense research interest because its underlying mechanism is scarcely known. The purpose of this study was to determine whether FLASH-IR and CONV-IR induce differential inflammatory cytokine expression using a modified clinical linac. MATERIALS AND METHODS An Elekta Synergy linac was used to deliver 6 MeV CONV-IR and modified to deliver FLASH-IR. Female FvB mice were randomly assigned to three different groups: a non-irradiated control, CONV-IR, or FLASH-IR. The FLASH-IR beam was produced by single pulses repeated manually with a 20-second interval (Strategy 1), or single-trigger multiple pulses with a 10 millisecond (ms) interval (Strategy 2). Mice were immobilized in the prone position in a custom-designed applicator with Gafchromic films positioned under the body. The prescribed doses for the mice were 6 to 18 Gy and verified using Gafchromic films. Cytokine expression of three pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6)] and one anti-inflammatory cytokine (IL-10) in serum samples and skin tissue were examined within 1- month post-IR. RESULTS The modified linac delivered radiation at an intra-pulse dose rate of around 1×106 Gy/s and a dose per pulse over 2 Gy at a source-to-surface distance (SSD) of 13 to 15 cms. The achieved dose coverage was 90 - 105% of the maximum dose within -20 ∼ 20 mm in the X direction and 95% within -30 ∼ 30 mm in the Y direction. The absolute deviations between the prescribed dose and the actual dose were 2.21, 6.04, 2.09 and 2.73% for 6, 9, 12 and 15 Gy as measured by EBT3 films, respectively; and 4.00, 4.49 and 2.30% for 10, 14 and 18 Gy as measured by the EBT XD films, respectively. The reductions in the CONV-IR versus the FLASH-IR group were 4.89, 10.28, -7.8 and -22.17 % for TNF-α, IFN-γ, IL-6 and IL-10 in the serum on D6, respectively; 37.26, 67.16, 56.68 and -18.95% in the serum on D31, respectively; and 62.67, 35.65, 37.75 and -12.20% for TNF-α, IFN-γ, IL-6 and IL-10 in the skin tissue, respectively. CONCLUSIONS Ultra-high dose rate electron FLASH caused lower pro-inflammatory cytokine levels in serum and skin tissue which might mediate differential tissue damage between FLASH-IR and CONV-IR. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- De-Huan Xie
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | | | - Sai Ma
- Elekta Instrument Ltd. Beijing Branch
| | - Xin Yang
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Ruo-Ming Lan
- School of Physics and Electronics, Shandong Normal University
| | - Ao-Qiang Chen
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Hong-Yu Zhu
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Yan Mei
- Department of Pathology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Li-Xia Peng
- Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | | | - Bi-Jun Huang
- Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Yan Chen
- Elekta Instrument Ltd. Beijing Branch
| | - Xiao-Yan Huang
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Chao-Nan Qian
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine.,Guangzhou Concord Cancer Center
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Rahman M, Trigilio A, Franciosini G, Moeckli R, Zhang R, Böhlen TT. FLASH radiotherapy treatment planning and models for electron beams. Radiother Oncol 2022; 175:210-221. [PMID: 35964763 DOI: 10.1016/j.radonc.2022.08.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 12/18/2022]
Abstract
The FLASH effect designates normal tissue sparing at ultra-high dose rate (UHDR, >40 Gy/s) compared to conventional dose rate (∼0.1 Gy/s) irradiation while maintaining tumour control and has the potential to improve the therapeutic ratio of radiotherapy (RT). UHDR high-energy electron (HEE, 4-20 MeV) beams are currently a mainstay for investigating the clinical potential of FLASH RT for superficial tumours. In the future very-high energy electron (VHEE, 50-250 MeV) UHDR beams may be used to treat deep-seated tumours. UHDR HEE treatment planning focused at its initial stage on accurate dosimetric modelling of converted and dedicated UHDR electron RT devices for the clinical transfer of FLASH RT. VHEE treatment planning demonstrated promising dosimetric performance compared to clinical photon RT techniques in silico and was used to evaluate and optimise the design of novel VHEE RT devices. Multiple metrics and models have been proposed for a quantitative description of the FLASH effect in treatment planning, but an improved experimental characterization and understanding of the FLASH effect is needed to allow for an accurate and validated modelling of the effect in treatment planning. The importance of treatment planning for electron FLASH RT will augment as the field moves forward to treat more complex clinical indications and target sites. In this review, TPS developments in HEE and VHEE are presented considering beam models, characteristics, and future FLASH applications.
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Affiliation(s)
- Mahbubur Rahman
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Antonio Trigilio
- Physics Department, "La Sapienza" University of Rome, Rome, Italy; INFN National Institute of Nuclear Physics, Rome Section, Rome, Italy
| | - Gaia Franciosini
- Physics Department, "La Sapienza" University of Rome, Rome, Italy; INFN National Institute of Nuclear Physics, Rome Section, Rome, Italy
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland.
| | - Rongxiao Zhang
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA; Dartmouth Hitchcock Medical Center, Lebanon, NH, USA
| | - Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
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Böhlen TT, Germond JF, Bourhis J, Vozenin MC, Ozsahin EM, Bochud F, Bailat C, Moeckli R. Normal tissue sparing by FLASH as a function of single fraction dose: A quantitative analysis. Int J Radiat Oncol Biol Phys 2022; 114:1032-1044. [PMID: 35810988 DOI: 10.1016/j.ijrobp.2022.05.038] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/26/2022] [Accepted: 05/24/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE The FLASH effect designates normal tissue sparing by ultra-high dose rate (UHDR) compared to conventional dose rate (CONV) irradiation without compromising tumor control. Understanding the magnitude of this effect and its dependency on dose are essential requirements for an optimized clinical translation of FLASH radiation therapy. In this context, we evaluated available experimental data on the magnitudes of normal tissue sparing provided by the FLASH effect as a function of dose, and followed a phenomenological data-driven approach for its parameterization. METHODS We gathered available in vivo data of the normal tissue sparing of CONV compared to UHDR single fraction doses and converted it to a common scale using isoeffect dose ratios, hereafter referred to as FLASH modifying factors (FMF). We then evaluated the suitability of a piecewise linear function with two pieces to parametrize FMF × D as a function of dose D. RESULTS We found that the magnitude of FMF generally decreases (i.e., sparing increases) as function of single fraction dose and that individual data series can be described by the piecewise linear function. The sparing magnitude appears organ specific. Pooled skin reaction data followed a consistent trend as a function of dose. Average FMF values and their standard deviations were 0.95±0.11 for all data below 10 Gy, 0.92±0.06 for mouse gut data between 10-25 Gy, and 0.96±0.07 and 0.71±0.06 for mammalian skin reaction data between 10-25 Gy and >25 Gy, respectively. CONCLUSIONS The magnitude of normal tissue sparing by FLASH is increasing with dose and is dependent on the irradiated tissue. A piecewise linear function can parameterize currently available individual data series.
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Affiliation(s)
- Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Esat Mahmut Ozsahin
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland..
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Sørensen BS, Sitarz MK, Ankjærgaard C, Johansen JG, Andersen CE, Kanouta E, Grau C, Poulsen P. Pencil beam scanning proton FLASH maintains tumor control while normal tissue damage is reduced in a mouse model. Radiother Oncol 2022; 175:178-184. [PMID: 35595175 DOI: 10.1016/j.radonc.2022.05.014] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 01/16/2023]
Abstract
PURPOSE Preclinical studies indicate a normal tissue sparing effect when ultra-high dose rate (FLASH) radiation is used, while tumor response is maintained. This differential response has promising perspectives for improved clinical outcome. This study investigates tumor control and normal tissue toxicity of pencil beam scanning (PBS) proton FLASH in a mouse model. METHODS AND MATERIALS Tumor bearing hind limbs of non-anaesthetized CDF1 mice were irradiated in a single fraction with a PBS proton beam using either conventional (CONV) dose rate (0.33-0.63 Gy/s field dose rate, 244 MeV) or FLASH (71-89 Gy/s field dose rate, 250 MeV). 162 mice with a C3H mouse mammary carcinoma subcutaneously implanted in the foot were irradiated with physical doses of 40-60 Gy (8-14 mice per dose point). The endpoints were tumor control (TC) assessed as no recurrent tumor at 90 days after treatment, the level of acute moist desquamation (MD) to the skin of the foot within 25 days post irradiation, and radiation induced fibrosis (RIF) within 24 weeks post irradiation. RESULTS TCD50 (dose for 50% tumor control) was similar for CONV and FLASH with values (and 95% confidence intervals) of 49.1 (47.0-51.4) Gy for CONV and 51.3 (48.6-54.2) Gy for FLASH. RIF analysis was restricted to mice with tumor control. Both endpoints showed distinct normal tissue sparing effect of proton FLASH with MDD50 (dose for 50% of mice displaying moist desquamation) of <40.1 Gy for CONV and 52.3 (50.0-54.6) Gy for FLASH, (dose modifying factor at least 1.3) and FD50 (dose for 50% of mice displaying fibrosis) of 48.6 (43.2-50.8) Gy for CONV and 55.6 (52.5-60.1) Gy for FLASH (dose modifying factor of 1.14). CONCLUSIONS FLASH had the same tumor control as CONV, but reduced normal tissue damage assessed as acute skin damage and radiation induced fibrosis.
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Affiliation(s)
- Brita Singers Sørensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark.
| | | | | | - Jacob G Johansen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | - Eleni Kanouta
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Cai Grau
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Per Poulsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
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40
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Farr J, Grilj V, Malka V, Sudharsan S, Schippers M. Ultra‐High dose rate radiation production and delivery systems intended for FLASH. Med Phys 2022; 49:4875-4911. [PMID: 35403262 PMCID: PMC9544515 DOI: 10.1002/mp.15659] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2021] [Revised: 02/21/2022] [Accepted: 03/15/2022] [Indexed: 11/05/2022] Open
Abstract
Higher dose rates, a trend for radiotherapy machines, can be beneficial in shortening treatment times for radiosurgery and mitigating the effects of motion. Recently, even higher doses (e.g., 100 times greater) have become targeted because of their potential to generate the FLASH effect (FE). We refer to these physical dose rates as ultra‐high (UHDR). The complete relationship between UHDR and the FE is unknown. But UHDR systems are needed to explore the relationship further and to deliver clinical UHDR treatments, where indicated. Despite the challenging set of unknowns, the authors seek to make reasonable assumptions to probe how existing and developing technology can address the UHDR conditions needed to provide beam generation capable of producing the FE in preclinical and clinical applications. As a preface, this paper discusses the known and unknown relationships between UHDR and the FE. Based on these, different accelerator and ionizing radiation types are then discussed regarding the relevant UHDR needs. The details of UHDR beam production are discussed for existing and potential future systems such as linacs, cyclotrons, synchrotrons, synchrocyclotrons, and laser accelerators. In addition, various UHDR delivery mechanisms are discussed, along with required developments in beam diagnostics and dose control systems.
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Affiliation(s)
- Jonathan Farr
- Applications of Detectors and Accelerators to Medicine Meyrin 1217 Switzerland
| | - Veljko Grilj
- Lausanne University Hospital Lausanne 1011 Switzerland
| | - Victor Malka
- Weizmann Institute of Science Rehovot 7610001 Israel
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41
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Kranzer R, Schüller A, Bourgouin A, Hackel T, Poppinga D, Lapp M, Looe HK, Poppe B. Response of diamond detectors in ultra-high dose-per-pulse electron beams for dosimetry at FLASH radiotherapy. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac594e] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 02/28/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. With increasing investigation of the so-called FLASH effect, the need for accurate real time dosimetry for ultra-high dose rates is also growing. Considering the ultra-high dose-per-pulse (DPP) necessary to produce the ultra-high dose rates for investigations of the FLASH effect, real time dosimetry is a major challenge. In particular, vented ionization chambers, as used for dosimetry in conventional radiotherapy, show significant deviations from linearity with increasing DPP. This is due to recombination losses in the sensitive air volume. Solid state detectors could be an alternative. Due to their good stability of the response with regard to the accumulated dose, diamond detectors such as the microDiamond could be suitable here. The aims of this work are to investigate the response of microDiamond and adapted microDiamond prototypes in ultra-high DPP electron beams, to understand the underlying effects and to draw conclusions for further detector developments. Approach. For the study, an electron beam with a DPP up to 6.5 Gy and a pulse duration of 2.5 μs was used to fulfill the conditions under which the FLASH effect was observed. As a dose rate-independent reference, alanine dosimeters were used. Main Results. It has been shown that the commercially available microDiamond detectors have limitations in terms of linearity at ultra-high DPP. But this is not an intrinsic limitation of the detector principle. The deviations from linearity were correlated with the series resistance and the sensitivity. It could be shown that the linear range can be extended towards ultra-high DPP range by reducing the sensitivity in combination with a low series resistance of the detectors. Significance. The work shows that synthetic single crystal diamond detectors working as Schottky photodiodes are in principle suitable for FLASH-RT dosimetry at electron linear accelerators.
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42
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Guo Z, Buonanno M, Harken A, Zhou G, Hei TK. Mitochondrial Damage Response and Fate of Normal Cells Exposed to FLASH Irradiation with Protons. Radiat Res 2022; 197:569-582. [PMID: 35290449 DOI: 10.1667/rade-21-00181.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 02/24/2022] [Indexed: 11/03/2022]
Abstract
Radiation therapy (RT) plays an important role in cancer treatment. The clinical efficacy of radiation therapy is, however, limited by normal tissue toxicity in areas surrounding the irradiated tumor. Compared to conventional radiation therapy (CONV-RT) in which doses are typically delivered at dose rates between 0.03-0.05 Gy/s, there is evidence that radiation delivered at dose rates of orders of magnitude higher (known as FLASH-RT), dramatically reduces the adverse side effects in normal tissues while achieving similar tumor control. The present study focused on normal cell response and tested the hypothesis that proton-FLASH irradiation preserves mitochondria function of normal cells through the induction of phosphorylated Drp1. Normal human lung fibroblasts (IMR90) were irradiated under ambient oxygen concentration (21%) with protons (LET = 10 keV/μm) delivered at dose rates of either 0.33 Gy/s or 100 Gy/s. Mitochondrial dynamics, functions, cell growth and changes in protein expression levels were investigated. Compared to lower dose-rate proton irradiation, FLASH-RT prevented mitochondria damage characterized by morphological changes, functional changes (membrane potential, mtDNA copy number and oxidative enzyme levels) and oxyradical production. After CONV-RT, the phosphorylated form of Dynamin-1-like protein (p-Drp1) underwent dephosphorylation and aggregated into the mitochondria resulting in mitochondria fission and subsequent cell death. In contrast, p-Drp1 protein level did not significantly change after delivery of similar FLASH doses. Compared with CONV irradiation, FLASH irradiation using protons induces minimal mitochondria damage; our results highlight a possible contribution of Drp1-mediated mitochondrial homeostasis in this potential novel cancer treatment modality.
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Affiliation(s)
- Ziyang Guo
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York.,State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Institute of Space Life Sciences, Medical College of Soochow University, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China.,Department of Ultrasound Medicine, Peking University First Hospital, Beijing, China
| | - Manuela Buonanno
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York
| | - Andrew Harken
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York
| | - Guangming Zhou
- State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Institute of Space Life Sciences, Medical College of Soochow University, Collaborative Innovation Center of Radiological Medicine of Jiangsu Higher Education Institutions, Suzhou 215123, China
| | - Tom K Hei
- Center for Radiological Research, College of Physician and Surgeons, Columbia University Medical Center, New York, New York
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43
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Friedl AA, Prise KM, Butterworth KT, Montay-Gruel P, Favaudon V. Radiobiology of the FLASH effect. Med Phys 2022; 49:1993-2013. [PMID: 34426981 DOI: 10.1002/mp.15184] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 12/17/2022] Open
Abstract
Radiation exposures at ultrahigh dose rates (UHDRs) at several orders of magnitude greater than in current clinical radiotherapy (RT) have been shown to manifest differential radiobiological responses compared to conventional (CONV) dose rates. This has led to studies investigating the application of UHDR for therapeutic advantage (FLASH-RT) that have gained significant interest since the initial discovery in 2014 that demonstrated reduced lung toxicity with equivalent levels of tumor control compared with conventional dose-rate RT. Many subsequent studies have demonstrated the potential protective role of FLASH-RT in normal tissues, yet the underlying molecular and cellular mechanisms of the FLASH effect remain to be fully elucidated. Here, we summarize the current evidence of the FLASH effect and review FLASH-RT studies performed in preclinical models of normal tissue response. To critically examine the underlying biological mechanisms of responses to UHDR radiation exposures, we evaluate in vitro studies performed with normal and tumor cells. Differential responses to UHDR versus CONV irradiation recurrently involve reduced inflammatory processes and differential expression of pro- and anti-inflammatory genes. In addition, frequently reduced levels of DNA damage or misrepair products are seen after UHDR irradiation. So far, it is not clear what signal elicits these differential responses, but there are indications for involvement of reactive species. Different susceptibility to FLASH effects observed between normal and tumor cells may result from altered metabolic and detoxification pathways and/or repair pathways used by tumor cells. We summarize the current theories that may explain the FLASH effect and highlight important research questions that are key to a better mechanistic understanding and, thus, the future implementation of FLASH-RT in the clinic.
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Affiliation(s)
- Anna A Friedl
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Kevin M Prise
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Karl T Butterworth
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Pierre Montay-Gruel
- Department of Radiation Oncology, University of California at Irvine, Irvine, California, USA
| | - Vincent Favaudon
- Institut Curie, Inserm U 1021-CNRS UMR 3347, Université Paris-Saclay, PSL Research University, Centre Universitaire, Orsay, France
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44
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Schüler E, Acharya M, Montay-Gruel P, Loo BW, Vozenin MC, Maxim PG. Ultra-high dose rate electron beams and the FLASH effect: From preclinical evidence to a new radiotherapy paradigm. Med Phys 2022; 49:2082-2095. [PMID: 34997969 PMCID: PMC9032195 DOI: 10.1002/mp.15442] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 11/14/2021] [Accepted: 12/17/2021] [Indexed: 12/30/2022] Open
Abstract
In their seminal paper from 2014, Fauvadon et al. coined the term FLASH irradiation to describe ultra-high-dose rate irradiation with dose rates greater than 40 Gy/s, which results in delivery times of fractions of a second. The experiments presented in that paper were performed with a high-dose-per-pulse 4.5 MeV electron beam, and the results served as the basis for the modern-day field of FLASH radiation therapy (RT). In this article, we review the studies that have been published after those early experiments, demonstrating the robust effects of FLASH RT on normal tissue sparing in preclinical models. We also outline the various irradiation parameters that have been used. Although the robustness of the biological response has been established, the mechanisms behind the FLASH effect are currently under investigation in a number of laboratories. However, differences in the magnitude of the FLASH effect between experiments in different labs have been reported. Reasons for these differences even within the same animal model are currently unknown, but likely has to do with the marked differences in irradiation parameter settings used. Here, we show that these parameters are often not reported, which complicates large multistudy comparisons. For this reason, we propose a new standard for beam parameter reporting and discuss a systematic path to the clinical translation of FLASH RT.
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Affiliation(s)
- Emil Schüler
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030 USA,Graduate School of Biomedical Sciences, The University of Texas, Houston, TX 77030 USA
| | - Munjal Acharya
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA, USA
| | - Pierre Montay-Gruel
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA
| | - Billy W. Loo
- Department of Radiation Oncology and Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology/DO/Radio-Oncology/CHUV, Lausanne University Hospital and University of Lausanne, 1011 Lausanne, Switzerland,Corresponding authors: Peter G. Maxim, PhD, Department of Radiation Oncology, University of California, Irvine, Irvine, CA 713-563-4019, , Marie-Catherine Vozenin, PhD, Laboratory of Radiation Oncology/DO/Radio-Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Switzerland. +41 216925901,
| | - Peter G. Maxim
- Department of Radiation Oncology, University of California Irvine, Irvine, CA, USA,Corresponding authors: Peter G. Maxim, PhD, Department of Radiation Oncology, University of California, Irvine, Irvine, CA 713-563-4019, , Marie-Catherine Vozenin, PhD, Laboratory of Radiation Oncology/DO/Radio-Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Switzerland. +41 216925901,
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45
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Abstract
FLASH radiotherapy is a novel technique that has been shown in numerous preclinical in vivo studies to have the potential to be the next important improvement in cancer treatment. However, the biological mechanisms responsible for the selective FLASH sparing effect of normal tissues are not yet known. An optimal translation of FLASH radiotherapy into the clinic would require a good understanding of the specific beam parameters that induces a FLASH effect, environmental conditions affecting the response, and the radiobiological mechanisms involved. Even though the FLASH effect has generally been considered as an in vivo effect, studies finding these answers would be difficult and ethically challenging to carry out solely in animals. Hence, suitable in vitro studies aimed towards finding these answers are needed. In this review, we describe and summarise several in vitro assays that have been used or could be used to finally elucidate the mechanisms behind the FLASH effect.
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46
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Okoro CM, Schüler E, Taniguchi CM. The Therapeutic Potential of FLASH-RT for Pancreatic Cancer. Cancers (Basel) 2022; 14:cancers14051167. [PMID: 35267474 PMCID: PMC8909276 DOI: 10.3390/cancers14051167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 11/21/2022] Open
Abstract
Simple Summary Ultra-high dose rate radiation, widely nicknamed FLASH-RT, kills tumors without significantly damaging nearby normal tissues. This selective sparing of normal tissue by FLASH-RT tissue is called the FLASH effect. This review explores some of the proposed mechanisms of the FLASH effect and the current data that might support its use in pancreatic cancer. Since radiation for pancreatic cancer treatment is limited by GI toxicity issues and is a disease with one of the lowest five-year survival rates, FLASH-RT could have a large impact in the treatment of this disease with further study. Abstract Recent preclinical evidence has shown that ionizing radiation given at an ultra-high dose rate (UHDR), also known as FLASH radiation therapy (FLASH-RT), can selectively reduce radiation injury to normal tissue while remaining isoeffective to conventional radiation therapy (CONV-RT) with respect to tumor killing. Unresectable pancreatic cancer is challenging to control without ablative doses of radiation, but this is difficult to achieve without significant gastrointestinal toxicity. In this review article, we explore the propsed mechanisms of FLASH-RT and its tissue-sparing effect, as well as its relevance and suitability for the treatment of pancreatic cancer. We also briefly discuss the challenges with regard to dosimetry, dose rate, and fractionation for using FLASH-RT to treat this disease.
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Affiliation(s)
- Chidi M. Okoro
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Emil Schüler
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Correspondence: (E.S.); (C.M.T.)
| | - Cullen M. Taniguchi
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Correspondence: (E.S.); (C.M.T.)
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47
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A comprehensive analysis of the relationship between dose-rate and biological effects in pre-clinical and clinical studies, from brachytherapy to flattening filter-free radiation therapy and FLASH irradiation. Int J Radiat Oncol Biol Phys 2022; 113:985-995. [DOI: 10.1016/j.ijrobp.2022.02.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 02/01/2022] [Accepted: 02/05/2022] [Indexed: 01/16/2023]
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48
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Gaide O, Herrera F, Sozzi WJ, Gonçalves Jorge P, Kinj R, Bailat C, Duclos F, Bochud F, Germond JF, Gondré M, Boelhen T, Schiappacasse L, Ozsahin M, Moeckli R, Bourhis J. Comparison of ultra-high versus conventional dose rate radiotherapy in a patient with cutaneous lymphoma. Radiother Oncol 2022; 174:87-91. [PMID: 34998899 DOI: 10.1016/j.radonc.2021.12.045] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2021] [Revised: 12/12/2021] [Accepted: 12/29/2021] [Indexed: 10/19/2022]
Abstract
A patient with a cutaneous lymphoma was treated on the same day for 2 distinct tumors using a 15 Gy single electron dose given in a dose rate of 0.08 Gy/second versus 166 Gy/second. Comparing the two treatments, there was no difference for acute reactions, late effects at 2 years and tumor control.
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Affiliation(s)
- Olivier Gaide
- Department of Dermatology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Fernanda Herrera
- Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland; Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Wendy Jeanneret Sozzi
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Patrik Gonçalves Jorge
- Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland; Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Rémy Kinj
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Fréderic Duclos
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Jean-François Germond
- Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland; Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Maud Gondré
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Till Boelhen
- Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland; Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Luis Schiappacasse
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Mahmut Ozsahin
- Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Jean Bourhis
- Radiation Oncology Laboratory, Department of Radiation Oncology. Lausanne University Hospital and University of Lausanne, Switzerland; Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Switzerland.
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Moon EJ, Petersson K, Oleina MM. The importance of hypoxia in radiotherapy for the immune response, metastatic potential and FLASH-RT. Int J Radiat Biol 2022; 98:439-451. [PMID: 34726575 PMCID: PMC7612434 DOI: 10.1080/09553002.2021.1988178] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
PURPOSE Hypoxia (low oxygen) is a common feature of solid tumors that has been intensely studied for more than six decades. Here we review the importance of hypoxia to radiotherapy with a particular focus on the contribution of hypoxia to immune responses, metastatic potential and FLASH radiotherapy, active areas of research by leading women in the field. CONCLUSION Although hypoxia-driven metastasis and immunosuppression can negatively impact clinical outcome, understanding these processes can also provide tumor-specific vulnerabilities that may be therapeutically exploited. The different oxygen tensions present in tumors and normal tissues may underpin the beneficial FLASH sparing effect seen in normal tissue and represents a perfect example of advances in the field that can leverage tumor hypoxia to improve future radiotherapy treatments.
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Affiliation(s)
- Eui Jung Moon
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK,Equal Contribution and to whom correspondence should be addressed. ; :
| | - Kristoffer Petersson
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK,Radiation Physics, Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden,Equal Contribution and to whom correspondence should be addressed. ; :
| | - Monica M. Oleina
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, OX3 7DQ, UK,Equal Contribution and to whom correspondence should be addressed. ; :
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50
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Eggold JT, Chow S, Melemenidis S, Wang J, Natarajan S, Loo PE, Manjappa R, Viswanathan V, Kidd EA, Engleman E, Dorigo O, Loo BW, Rankin EB. Abdominopelvic FLASH Irradiation Improves PD-1 Immune Checkpoint Inhibition in Preclinical Models of Ovarian Cancer. Mol Cancer Ther 2021; 21:371-381. [PMID: 34866044 DOI: 10.1158/1535-7163.mct-21-0358] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/20/2021] [Accepted: 11/11/2021] [Indexed: 11/16/2022]
Abstract
Treatment of advanced ovarian cancer using PD-1/PD-L1 immune checkpoint blockade shows promise, however current clinical trials are limited by modest response rates. Radiation therapy has been shown to synergize with PD-1/PD-L1 blockade in some cancers but has not been utilized in advanced ovarian cancer due to toxicity associated with conventional abdominopelvic irradiation. While ultra-high dose rate (FLASH) irradiation has emerged as a strategy to reduce radiation-induced toxicity, the immunomodulatory properties of FLASH irradiation remain unknown. Here we demonstrate that single high dose abdominopelvic FLASH irradiation promoted intestinal regeneration and maintained tumor control in a preclinical mouse model of ovarian cancer. Reduced tumor burden in conventional and FLASH treated mice was associated with an early decrease in intratumoral regulatory T cells and a late increase in cytolytic CD8+ T cells. Compared to conventional irradiation, FLASH irradiation increased intratumoral T cell infiltration at early timepoints. Moreover, FLASH irradiation maintained the ability to increase intratumoral CD8+ T cell infiltration and enhance the efficacy of αPD-1 therapy in preclinical models of ovarian cancer. These data highlight the potential for FLASH irradiation to improve the therapeutic efficacy of checkpoint inhibition in the treatment of ovarian cancer.
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Affiliation(s)
| | - Stephanie Chow
- Radiation Oncology and Obstetrics & Gynecology, Stanford University
| | | | | | | | | | | | | | | | - Edgar Engleman
- Department of Pathology, Stanford University School of Medicine
| | - Oliver Dorigo
- Obstetrics and Gynecology/Gynecologic Oncology, Stanford University
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University
| | - Erinn B Rankin
- Radiation Oncology and Obstetrics & Gynecology, Stanford University
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