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Grau C, Dasu A, Troost EGC, Haustermans K, Weber DC, Langendijk JA, Gregoire V, Orlandi E, Thariat J, Journy N, Chaikh A, Isambert A, Alicja Jereczek-Fossa B, Vaniqui A, Vitek P, Kopec R, Fijten R, Luetgendorf-Caucig C, Olko P. Towards a European prospective data registry for particle therapy. Radiother Oncol 2024; 196:110293. [PMID: 38653379 DOI: 10.1016/j.radonc.2024.110293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2024] [Revised: 04/18/2024] [Accepted: 04/18/2024] [Indexed: 04/25/2024]
Abstract
The evidence for the value of particle therapy (PT) is still sparse. While randomized trials remain a cornerstone for robust comparisons with photon-based radiotherapy, data registries collecting real-world data can play a crucial role in building evidence for new developments. This Perspective describes how the European Particle Therapy Network (EPTN) is actively working on establishing a prospective data registry encompassing all patients undergoing PT in European centers. Several obstacles and hurdles are discussed, for instance harmonization of nomenclature and structure of technical and dosimetric data and data protection issues. A preferred approach is the adoption of a federated data registry model with transparent and agile governance to meet European requirements for data protection, transfer, and processing. Funding of the registry, especially for operation after the initial setup process, remains a major challenge.
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Affiliation(s)
- Cai Grau
- Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark.
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden; Department of Immunology, Genetics and Pathology, Uppsala University, Sweden.
| | - Esther G C Troost
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany.
| | - Karin Haustermans
- Department of Radiation Oncology, University Hospital, KU Leuven, Leuven, Belgium.
| | - Damien C Weber
- Proton Therapy Center, Paul Scherrer Institute, ETH Domain, Switzerland; Radiation Oncology Department, University Hospital Zürich, Switzerland; Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, Switzerland.
| | - Johannes A Langendijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands.
| | | | - Ester Orlandi
- Department of Clinical, Surgical, Diagnostic, and Pediatric Sciences, University of Pavia, Pavia, Italy; Clinical Department, National Center for Oncological Hadrontherapy (Fondazione CNAO), Pavia, Italy.
| | - Juliette Thariat
- Université de Caen Normandie, ENSICAEN, CNRS/IN2P3, LPC Caen UMR6534, F-14000, Centre François Baclesse, Caen, France
| | - Neige Journy
- National Institute of Health and Medical Research (INSERM) Unit 1018, Centre for Research in Epidemiology and Population Health, Paris Saclay University, Gustave Roussy, Villejuif, France.
| | - Abdulhamid Chaikh
- Institut de Radioprotection et de Sûreté Nucléaire IRSN/PSE-SANTE/SER/UEM, France.
| | - Aurelie Isambert
- Institut de Radioprotection et de Sûreté Nucléaire IRSN/PSE-SANTE/SER/UEM, France.
| | - Barbara Alicja Jereczek-Fossa
- Dept. of Oncology and Hemato-oncology, University of Milan, Milan, Italy; Dept. of Radiation Oncology, IEO European Institute of Oncology IRCCS, Milan, Italy.
| | - Ana Vaniqui
- Belgian Nuclear Research Center (SCK CEN), Mol, Belgium.
| | - Pavel Vitek
- Proton Therapy Center Czech, Prague, Czech Republic.
| | - Renata Kopec
- Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland.
| | - Rianne Fijten
- Department of Radiation Oncology (Maastro), GROW School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, the Netherlands.
| | | | - Pawel Olko
- Institute of Nuclear Physics Polish Academy of Sciences, Kraków, Poland.
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Zubatkina I, Toma-Dasu I, Dasu A, Levivier M, Tuleasca C, Ivanov P. Clinically Driven Alpha/Beta Ratios for Melanoma Brain Metastases and Investigation of Biologically Effective Dose as a Predictor for Local Control After Radiosurgery: A Proof of Concept in a Retrospective Longitudinal Series of 274 Consecutive Lesions. Neurosurgery 2024; 94:423-430. [PMID: 37665222 DOI: 10.1227/neu.0000000000002639] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Accepted: 06/14/2023] [Indexed: 09/05/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Brain metastases (BM) develop in nearly half of the patients with advanced melanoma. The aim of this retrospective historical cohort study was to analyze radiological response of melanoma BM to single-fraction Gamma Knife radiosurgery (GKRS), in relation to biologically effective dose (BED) for various alpha/beta ratios. METHODS Included in the study were 274 lesions. Primary outcome was local control (LC). Mean marginal dose was 21.6 Gy (median 22, range 15-25). Biologically effective dose was calculated for an alpha/beta ratio of 3 (Gy 3 ), 5 (Gy 10 ), 10 (Gy 10 ), and 15 (Gy 15 ). RESULTS Receiver operating characteristic value for LC and BED was 85% (most statistically significant odds ratio 1.14 for BED Gy 15 , P = .006), while for LC and physical dose was 79% ( P = .02). When comparing equality of 2 receiver operating characteristic areas, this was statistically significant ( P = .02 and .03). Fractional polynomial regression revealed BED (Gy 10 and Gy 15 ) as statistically significant ( P = .05) with BED of more than 63 Gy 10 or 49 Gy 15 as relevant, also for higher probability of quick decrease in volume first month after GKRS and lower probability of radiation necrosis. Shorter irradiation time was associated with better LC ( P = .001), particularly less than 40 minutes (LC below 90%, P = .05). CONCLUSION BED Gy 10 and particularly Gy 15 were more statistically significant than physical dose for LC after GKRS for radioresistant melanoma BM. Irradiation time (per lesion) longer than 40 minutes was predictive for lower rates of LC. Such results need to be validated in larger cohorts.
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Affiliation(s)
- Irina Zubatkina
- Department of Radiosurgery, Stereotactic Radiotherapy and General Oncology Clinic MIBS, Saint Petersburg , Russia
- Peter the Great St. Petersburg Polytechnic University, Saint Petersburg , Russia
| | - Iuliana Toma-Dasu
- Oncology Pathology Department, Karolinska Institutet, Stockholm , Sweden
- Medical Radiation Physics, Stockholm University, Stockholm , Sweden
| | - Alexandru Dasu
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala , Sweden
| | - Marc Levivier
- Department of Clinical Neurosciences, Neurosurgery Service and Gamma Knife Center, Centre Hospitalier Universitaire Vaudois, Lausanne , Switzerland
- University of Lausanne (UNIL), Faculty of Biology and Medicine (FBM), Lausanne , Switzerland
| | - Constantin Tuleasca
- Department of Clinical Neurosciences, Neurosurgery Service and Gamma Knife Center, Centre Hospitalier Universitaire Vaudois, Lausanne , Switzerland
- University of Lausanne (UNIL), Faculty of Biology and Medicine (FBM), Lausanne , Switzerland
- Signal Processing Laboratory (LTS 5), Ecole Polytechnique Fédérale de Lausanne, Lausanne , Switzerland
| | - Pavel Ivanov
- Department of Radiosurgery, Stereotactic Radiotherapy and General Oncology Clinic MIBS, Saint Petersburg , Russia
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Tuleasca C, Toma-Dasu I, Duroux S, George M, Maire R, Daniel RT, Patin D, Schiappacasse L, Dasu A, Faouzi M, Levivier M. Impact of the Mean Cochlear Biologically Effective Dose on Hearing Preservation After Stereotactic Radiosurgery for Vestibular Schwannoma: A Retrospective Longitudinal Analysis. Neurosurgery 2024; 94:174-182. [PMID: 37431994 PMCID: PMC10695539 DOI: 10.1227/neu.0000000000002609] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 05/19/2023] [Indexed: 07/12/2023] Open
Abstract
BACKGROUND AND OBJECTIVES Stereotactic radiosurgery (SRS) is a useful alternative for small- to medium-sized vestibular schwannoma. To evaluate whether biologically effective dose (BED Gy2.47 ), calculated for mean (BED Gy2.47 mean) and maximal (BED Gy2.47 max) cochlear dose, is relevant for hearing preservation. METHODS This is a retrospective longitudinal single-center study. Were analyzed 213 patients with useful baseline hearing. Risk of hearing decline was assessed for Gardner-Robertson classes and pure tone average (PTA) loss. The mean follow-up period was 39 months (median 36, 6-84). RESULTS Hearing decline (Gardner-Robertson class) 3 years after SRS was associated with higher cochlear BED Gy2.47 mean (odds ratio [OR] 1.39, P = .009). Moreover, BED Gy2.47 mean was more relevant as compared with BED Gy2.47 max (OR 1.13, P = .04). Risk of PTA loss (continuous outcome, follow-up minus baseline) was significantly corelated with BED Gy2.47 mean at 24 (beta coefficient 1.55, P = .002) and 36 (beta coefficient 2.01, P = .004) months after SRS. Risk of PTA loss (>20 dB vs ≤) was associated with higher BED Gy2.47 mean at 6 (OR 1.36, P = .002), 12 (OR 1.36, P = .007), and 36 (OR 1.37, P = .02) months. Risk of hearing decline at 36 months for the BED Gy2.47 mean of 7-8, 10, and 12 Gy 2.47 was 28%, 57%, and 85%, respectively. CONCLUSION Cochlear BED Gy2.47 mean is relevant for hearing decline after SRS and more relevant as compared with BED Gy2.47 max. Three years after SRS, this was sustained for all hearing decline evaluation modalities. Our data suggest the BED Gy2.47 mean cut-off of ≤8 Gy 2.47 for better hearing preservation rates .
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Affiliation(s)
- Constantin Tuleasca
- Lausanne University Hospital (CHUV), Neurosurgery Service and Gamma Knife Center, Lausanne , Switzerland
- University of Lausanne (UNIL), Faculty of Biology and Medicine (FBM), Lausanne, Switzerland
- Ecole Polytechnique Fédérale de Lausanne (EPFL, LTS-5), Lausanne , Switzerland
| | - Iuliana Toma-Dasu
- Oncology Pathology Department, Karolinska Institutet, Stockholm , Sweden
- Medical Radiation Physics, Stockholm University, Stockholm , Sweden
| | - Sebastien Duroux
- University of Lausanne (UNIL), Faculty of Biology and Medicine (FBM), Lausanne, Switzerland
| | - Mercy George
- ENT Department, Lausanne University Hospital (CHUV), Lausanne , Switzerland
| | - Raphael Maire
- ENT Department, Lausanne University Hospital (CHUV), Lausanne , Switzerland
| | - Roy Thomas Daniel
- Lausanne University Hospital (CHUV), Neurosurgery Service and Gamma Knife Center, Lausanne , Switzerland
- University of Lausanne (UNIL), Faculty of Biology and Medicine (FBM), Lausanne, Switzerland
| | - David Patin
- Institute of Radiation Physics, Lausanne , Switzerland
| | - Luis Schiappacasse
- Radiation Oncology Department, Lausanne University Hospital (CHUV), Lausanne , Switzerland
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala , Sweden
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala , Sweden
| | - Mohamed Faouzi
- Division of Biostatistics, Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
| | - Marc Levivier
- Lausanne University Hospital (CHUV), Neurosurgery Service and Gamma Knife Center, Lausanne , Switzerland
- University of Lausanne (UNIL), Faculty of Biology and Medicine (FBM), Lausanne, Switzerland
- Ecole Polytechnique Fédérale de Lausanne (EPFL, LTS-5), Lausanne , Switzerland
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Edvardsson A, Gorgisyan J, Andersson KM, Vallhagen Dahlgren C, Dasu A, Gram D, Björk-Eriksson T, Munck af Rosenschöld P. Robustness and dosimetric verification of hippocampal-sparing craniospinal pencil beam scanning proton plans for pediatric medulloblastoma. Phys Imaging Radiat Oncol 2024; 29:100555. [PMID: 38405431 PMCID: PMC10891325 DOI: 10.1016/j.phro.2024.100555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Revised: 02/06/2024] [Accepted: 02/08/2024] [Indexed: 02/27/2024] Open
Abstract
Background and Purpose Hippocampal-sparing (HS) is a method that can potentially reduce late cognitive complications for pediatric medulloblastoma (MB) patients treated with craniospinal proton therapy (PT). The aim of this study was to investigate robustness and dosimetric plan verification of pencil beam scanning HS PT. Materials and Methods HS and non-HS PT plans for the whole brain part of craniospinal treatment were created for 15 pediatric MB patients. A robust evaluation of the plans was performed. Plans were recalculated in a water phantom and measured field-by-field using an ion chamber detector at depths corresponding to the central part of hippocampi. All HS and non-HS fields were measured with the standard resolution of the detector and in addition 16 HS fields were measured with high resolution. Measured and planned dose distributions were compared using gamma evaluation. Results The median mean hippocampus dose was reduced from 22.9 Gy (RBE) to 8.9 Gy (RBE), while keeping CTV V95% above 95 % for all nominal HS plans. HS plans were relatively robust regarding hippocampus mean dose, however, less robust regarding target coverage and maximum dose compared to non-HS plans. For standard resolution measurements, median pass rates were 99.7 % for HS and 99.5 % for non-HS plans (p < 0.001). For high-resolution measurements, median pass rates were 100 % in the hippocampus region and 98.2 % in the surrounding region. Conclusions A substantial reduction of dose in the hippocampus region appeared feasible. Dosimetric accuracy of HS plans was comparable to non-HS plans and agreed well with planned dose distribution in the hippocampus region.
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Affiliation(s)
- Anneli Edvardsson
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | - Jenny Gorgisyan
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
| | | | | | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Daniel Gram
- Department of Clinical Oncology and Palliative Care, Radiotherapy, Zealand University Hospital, Næstved, Denmark
- Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark
- Department of Oncology – Section of Radiotherapy, Rigshospitalet, Copenhagen, Denmark
| | - Thomas Björk-Eriksson
- Department of Oncology, Institute of Clinical Sciences, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden
- Regional Cancer Centre West, Western Sweden Healthcare Region, Gothenburg, Sweden
| | - Per Munck af Rosenschöld
- Radiation Physics, Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Sweden
- Medical Radiation Physics, Department of Clinical Sciences Lund, Lund University, Lund, Sweden
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Romero-Expósito M, Liszka M, Christou A, Toma-Dasu I, Dasu A. Range shifter contribution to neutron exposure of patients undergoing proton pencil beam scanning. Med Phys 2023. [PMID: 38112191 DOI: 10.1002/mp.16897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 11/30/2023] [Accepted: 12/03/2023] [Indexed: 12/21/2023] Open
Abstract
BACKGROUND Superficial targets require the use of the lowest energies within the available energy range in proton pencil-beam scanning (PBS) technique. However, the lower efficiency of the energy selection system at these energies and the requirement of a greater number of layers may represent disadvantages for this approach. The alternative is to use a range shifter (RS) at nozzle exit. However, one of the concerns of using this beamline element is that it becomes an additional source of neutrons that could irradiate organs situated far from the target. PURPOSE The purpose of this study is to assess the increase in neutron dose due to the RS in proton PBS technique. Additionally, an analytical model for the neutron production is tested. METHODS Two clinical plans, designed to achieve identical target coverage, were created for an anthropomorphic phantom. These plans consisted of a lateral field delivering an absorbed dose of 60 Gy (RBE) to the target. One of the plans employed the RS. The MCNP code was used to simulate the plans, evaluating the distribution of neutron dose equivalent (Hn ) and the equivalent dose in organ. In the plan with the RS plan, neutron production from both the patient and the RS were assessed separately. Hn values were also fitted versus the distance to field edge using a Gaussian function. RESULTS Hn per prescription dose, in the plan using the RS, ranged between 1.4 and 3.7 mSv/Gy at the field edge, whereas doses at 40 cm from the edge ranged from 9.9 to 32 μSv/Gy. These values are 1.2 to 10 times higher compared to those obtained without the RS. Both this factor and the contribution of neutrons originating from the RS increases with the distance from field edge. A triple-Gaussian function was able to reproduce the equivalent dose in organs within a factor of 2, although underestimating the values. CONCLUSIONS The dose deposited in the patient by the neutrons originating from the RS predominantly affects areas away from the target (beyond approximately 25 cm from field edge), resulting in a neutron dose equivalent of the order of mSv. This indicates an overall low neutron contribution from the use of RS in PBS.
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Affiliation(s)
- Maite Romero-Expósito
- The Skandion Clinic, Uppsala, Sweden
- Oncology Pathology Department, Karolinska Institutet, Solna, Sweden
| | | | | | - Iuliana Toma-Dasu
- Oncology Pathology Department, Karolinska Institutet, Solna, Sweden
- Medical Radiation Physics, Stockholm University, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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Almhagen E, Dasu A, Johansson S, Traneus E, Ahnesjö A. Plan robustness and RBE influence for proton dose painting by numbers for head and neck cancers. Phys Med 2023; 115:103157. [PMID: 37939480 DOI: 10.1016/j.ejmp.2023.103157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 08/25/2023] [Accepted: 09/26/2023] [Indexed: 11/10/2023] Open
Abstract
PURPOSE To investigate the feasibility of dose painting by numbers (DPBN) with respect to robustness for proton therapy for head and neck cancers (HNC), and to study the influence of variable RBE on the TCP and OAR dose burden. METHODS AND MATERIALS Data for 19 patients who have been scanned pretreatment with PET-FDG and subsequently treated with photon therapy were used in the study. A dose response model developed for photon therapy was implemented in a TPS, allowing DPBN plans to be created. Conventional homogeneous dose and DPBN plans were created for each patient, optimized with either fixed RBE = 1.1 or a variable RBE model. Robust optimization was used to create clinically acceptable plans. To estimate the maximum potential loss in TCP due to actual SUV variations from the pre-treatment imaging, we applied a test case with randomized SUV distribution. RESULTS Regardless of the use of variable RBE for optimization or evaluation, a statistically significant increase (p < 0.001) in TCP was found for DPBN plans as compared to homogeneous dose plans. Randomizing the SUV distribution decreased the TCP for all plans. A correlation between TCP increase and variance of the SUV distribution and target volume was also found. CONCLUSION DPBN for protons and HNC is feasible and could lead to a TCP gain. Risks associated with the temporal variation of SUV distributions could be mitigated by imposing minimum doses to targets. The correlation found between TCP increase and SUV variance and target volume may be used for patient selection.
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Affiliation(s)
- Erik Almhagen
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden; The Skandion Clinic, Uppsala, Sweden.
| | - Alexandru Dasu
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden; The Skandion Clinic, Uppsala, Sweden
| | - Silvia Johansson
- Divison of Oncology, Department of Immunology, Genetics and Pathology, Uppsala University Hospital, Uppsala, Sweden
| | | | - Anders Ahnesjö
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Akademiska Sjukhuset, Uppsala, Sweden
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Santacroce A, Trandafirescu MF, Levivier M, Peters D, Fürweger C, Toma-Dasu I, George M, Daniel RT, Maire R, Nakamura M, Faouzi M, Schiappacasse L, Dasu A, Tuleasca C. Proton beam radiation therapy for vestibular schwannomas-tumor control and hearing preservation rates: a systematic review and meta-analysis. Neurosurg Rev 2023; 46:163. [PMID: 37402894 PMCID: PMC10319703 DOI: 10.1007/s10143-023-02060-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 06/12/2023] [Accepted: 06/19/2023] [Indexed: 07/06/2023]
Abstract
OBJECTIVE Proton beam therapy is considered, by some authors, as having the advantage of delivering dose distributions more conformal to target compared with stereotactic radiosurgery (SRS). Here, we performed a systematic review and meta-analysis of proton beam for VSs, evaluating tumor control and cranial nerve preservation rates, particularly with regard to facial and hearing preservation. METHODS We reviewed, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) articles published between 1968 and September 30, 2022. We retained 8 studies reporting 587 patients. RESULTS Overall rate of tumor control (both stability and decrease in volume) was 95.4% (range 93.5-97.2%, p heterogeneity= 0.77, p<0.001). Overall rate of tumor progression was 4.6% (range 2.8-6.5%, p heterogeneity < 0.77, p<0.001). Overall rate of trigeminal nerve preservation (absence of numbness) was 95.6% (range 93.5-97.7%, I2 = 11.44%, p heterogeneity= 0.34, p<0.001). Overall rate of facial nerve preservation was 93.7% (range 89.6-97.7%, I2 = 76.27%, p heterogeneity<0.001, p<0.001). Overall rate of hearing preservation was 40.6% (range 29.4-51.8%, I2 = 43.36%, p heterogeneity= 0.1, p<0.001). CONCLUSION Proton beam therapy for VSs achieves high tumor control rates, as high as 95.4%. Facial rate preservation overall rates are 93%, which is lower compared to the most SRS series. Compared with most currently reported SRS techniques, proton beam radiation therapy for VSs does not offer an advantage for facial and hearing preservation compared to most of the currently reported SRS series.
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Affiliation(s)
- Antonio Santacroce
- European Radiosurgery Centre Munich, Munich, Germany
- Department of Medicine, Faculty of Health, Witten/Herdecke University, Witten, Germany
- Department of Neurosurgery, St. Barbara-Klinik Hamm-Heessen, Hamm, 59073, Germany
| | | | - Marc Levivier
- Neurosurgery Service and Gamma Knife Center, Centre Hospitalier Universitaire Vaudois, Lausanne University Hospital (CHUV), Rue du Bugnon 44-46, BH-08, CH-1011, Lausanne, Switzerland
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - David Peters
- Neurosurgery Service and Gamma Knife Center, Centre Hospitalier Universitaire Vaudois, Lausanne University Hospital (CHUV), Rue du Bugnon 44-46, BH-08, CH-1011, Lausanne, Switzerland
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | | | - Iuliana Toma-Dasu
- Oncology Pathology Department, Karolinska Institutet and Stockholm University, Stockholm, Sweden
- Medical Radiation Physics, Stockholm University, Stockholm, Sweden
| | - Mercy George
- ENT Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Roy Thomas Daniel
- Neurosurgery Service and Gamma Knife Center, Centre Hospitalier Universitaire Vaudois, Lausanne University Hospital (CHUV), Rue du Bugnon 44-46, BH-08, CH-1011, Lausanne, Switzerland
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Raphael Maire
- ENT Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Makoto Nakamura
- Department of Neurosurgery, Academic Hospital Köln-Merheim, Köln, 51058, Germany
- Department of Medicine, Faculty of Health, Witten/Herdecke University, Witten, 58455, Germany
| | - Mohamed Faouzi
- Division of Biostatistics, Center for Primary Care and Public Health (Unisanté), University of Lausanne, Lausanne, Switzerland
| | - Luis Schiappacasse
- Radiation Oncology Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Alexandru Dasu
- The Skandion Clinic and Uppsala University, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Constantin Tuleasca
- Neurosurgery Service and Gamma Knife Center, Centre Hospitalier Universitaire Vaudois, Lausanne University Hospital (CHUV), Rue du Bugnon 44-46, BH-08, CH-1011, Lausanne, Switzerland.
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Lausanne, Switzerland.
- Ecole Polytechnique Fédérale de Lausanne (EPFL, LTS-5), Lausanne, Switzerland.
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Tuleasca C, Toma-Dasu I, Duroux S, Starnoni D, George M, Maire R, Daniel RT, Patin D, Schiappacasse L, Dasu A, Faouzi M, Levivier M. The Relevance of Biologically Effective Dose for Hearing Preservation After Stereotactic Radiosurgery for Vestibular Schwannomas: A Retrospective Longitudinal Study. Neurosurgery 2023; 92:1216-1226. [PMID: 36727756 PMCID: PMC10150919 DOI: 10.1227/neu.0000000000002352] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 11/08/2022] [Indexed: 02/03/2023] Open
Abstract
BACKGROUND Stereotactic radiosurgery has become a common treatment approach for small-to-medium size vestibular schwannomas. OBJECTIVE To evaluate relationship between time (beam-on and treatment) and risk of hearing decline after stereotactic radiosurgery for vestibular schwannomas in patients with Gardner-Robertson (GR) baseline classes I and II. METHODS This retrospective longitudinal single-center study included 213 patients with GR I and II treated between June 2010 and December 2019. Risk of passing from GR classes I and II (coded 0) to other classes III, IV, and V (coded 1) and the increase in pure tone average (continuous outcome) were evaluated using a mixed-effect regression model. Biologically effective dose (BED) was further assessed for an alpha/beta ratio of 2.47 (Gy 2.47 ). RESULTS Binary outcome analysis revealed sex, dose rate, integral dose, time [beam-on time odds ratio 1.03, P = .03, 95% CI 1.00-1.06; treatment time ( P = .02) and BED ( P = .001) as relevant. Fitted multivariable model included the sex, dose rate, and BED. Pure tone average analysis revealed age, integral dose received by tumor, isocenter number, time (beam-on time odds ratio 0.20, P = .001, 95% CI 0.083-0.33) and BED ( P = .005) as relevant. CONCLUSION Our analysis showed that risk of hearing decline was associated with male sex, higher radiation dose rate (cutoff 2.5 Gy/minute), higher integral dose received by the tumor, higher beam-on time ≥20 minutes, and lower BED. A BED between 55 and 61 was considered as optimal for hearing preservation.
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Affiliation(s)
- Constantin Tuleasca
- Neurosurgery Service and Gamma Knife Center, Lausanne University Hospital (CHUV), Lausanne, Switzerland
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Switzerland
- Ecole Polytechnique Fédérale de Lausanne (EPFL, LTS-5), Lausanne, Switzerland
| | - Iuliana Toma-Dasu
- Oncology Pathology Department, Karolinska Institutet, Stockholm, Sweden
- Medical Radiation Physics, Stockholm University, Stockholm, Sweden
| | - Sebastien Duroux
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Switzerland
| | - Daniele Starnoni
- Neurosurgery Service and Gamma Knife Center, Lausanne University Hospital (CHUV), Lausanne, Switzerland
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Switzerland
| | - Mercy George
- ENT Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Raphael Maire
- ENT Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Roy Thomas Daniel
- Neurosurgery Service and Gamma Knife Center, Lausanne University Hospital (CHUV), Lausanne, Switzerland
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Switzerland
| | - David Patin
- Institute of Radiation Physics, Lausanne, Switzerland
| | - Luis Schiappacasse
- Radiation Oncology Department, Lausanne University Hospital (CHUV), Lausanne, Switzerland
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Mohamed Faouzi
- Division of Biostatistics, Center for Primary Care and Public Health (Unisanté), University of Lausanne, Switzerland
| | - Marc Levivier
- Neurosurgery Service and Gamma Knife Center, Lausanne University Hospital (CHUV), Lausanne, Switzerland
- Faculty of Biology and Medicine (FBM), University of Lausanne (UNIL), Switzerland
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Sánchez-Nieto B, Stolarczyk L, Dasu A, Newhauser WD, Sánchez-Doblado F. Editorial: Out-of-field second primary cancer induction: Dosimetry and modelling. Front Oncol 2022; 12:1076792. [PMID: 36544702 PMCID: PMC9761579 DOI: 10.3389/fonc.2022.1076792] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 10/28/2022] [Indexed: 12/07/2022] Open
Affiliation(s)
- Beatriz Sánchez-Nieto
- Institute of Physics, Faculty of Physics, Pontifical Catholic University of Chile, Santiago, Chile,*Correspondence: Beatriz Sánchez-Nieto,
| | - Liliana Stolarczyk
- Danish Center for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark,The Henryk Niewodniczański Institute of Nuclear Physics, Polish Academy of Sciences, Krakow, Poland
| | - Alexandru Dasu
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden,The Skandion Clinic, Uppsala, Sweden
| | - Wayne D. Newhauser
- Department of Physics and Astronomy, Louisiana State University, Baton Rouge, LA, United States
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Davídková M, Ankjærgaard C, Andersen C, Dasu A, De Angelis C, De Marzi L, De Saint-Hubert M, Ekendahl D, Henthorn N, Michaelidesová AJ, Knežević Ž, Krzempek D, Kukolowicz P, Liszka M, Lorentini S, Leite AM, Majer M, Navrátil M, Reniers B, Ślusarczyk-Kacprzyk W, Van Goethem MJ, Vestergaard A, Vilches-Freixas G, Vondráček V, Togno M, Stolarczyk L, Olko P. MAILED DOSIMETRY AUDIT OF ACTIVE SCANNING PROTON BEAMS IN TEN PROTON THERAPY CENTERS. Phys Med 2022. [DOI: 10.1016/s1120-1797(22)02370-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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11
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Schiavo MF, Lindblom EK, Barsoum P, Dasu A, Toma-Dasu I. BIOLOGICAL EFFECTIVENESS OF STEREOTACTIC RADIOTHERAPY INCREASES WITH FRACTIONATION IN HYPOXIC TUMORS. Phys Med 2022. [DOI: 10.1016/s1120-1797(22)02132-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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12
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Olofsson MN, Wikström K, Flejmer A, Ahnesjö A, Dasu A. DOSIMETRIC ROBUSTNESS OF LUNG TUMOR PHOTON RADIOTHERAPY EVALUATED FROM MULTIPLE EVENT CT IMAGING. Phys Med 2022. [DOI: 10.1016/s1120-1797(22)02410-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
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13
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Olofsson N, Wikström K, Flejmer A, Ahnesjö A, Dasu A. Dosimetric robustness of lung tumor photon radiotherapy evaluated from multiple event CT imaging. Phys Med 2022; 103:1-10. [PMID: 36182764 DOI: 10.1016/j.ejmp.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/02/2022] [Revised: 09/02/2022] [Accepted: 09/13/2022] [Indexed: 10/31/2022] Open
Abstract
PURPOSE Intrafractional respiratory motion is a concern for lung tumor radiotherapy but full evaluation of its impact is hampered by the lack of images representing the true motion. This study presents a novel evaluation using free-breathing images acquired over realistic treatment times to study the dosimetric impact of respiratory motion in photon radiotherapy. METHODS Cine-CT images of 14 patients with lung cancer acquired during eight minutes of free-breathing at three occasions were used to simulate dose tracking of four different planning methods. These methods aimed to deliver 54 Gy in three fractions to D50% of the target and were denoted as robust 4D (RB4), homogeneous fluence to the ITV (FLU) and an isodose prescription to the ITV with a high central dose (ISD), concurrently renormalized (IRN). Differences in dose coverage probability and homogeneity between the methods were quantified. Correlations between underdosage and attributes regarding the tumor and its motion were investigated. RESULTS Despite tumor motion amplitudes being larger than in the 4DCT all but FLU achieved the intended CTV D50% for the cohort average. For all methods but IRN at least 93% of the patients would have received 95% of the intended dose. No differences in D50% were found between RB4 and ISD nor IRN. However, RB4 led to better homogeneity. CONCLUSIONS Tumor motion in free-breathing not covered by the 4DCT had a small impact on dose. The RB4 is recommended for planning of free-breathing treatments. No factor was found that consistently correlated dose degradation with patient or motion attributes.
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Affiliation(s)
- Nils Olofsson
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden.
| | - Kenneth Wikström
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden; Uppsala University Hospital, Uppsala, Sweden
| | - Anna Flejmer
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden; Uppsala University Hospital, Uppsala, Sweden; The Skandion Clinic, Uppsala, Sweden
| | - Anders Ahnesjö
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Alexandru Dasu
- Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden; The Skandion Clinic, Uppsala, Sweden
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Eliasson L, Lillhök J, Bäck T, Billnert-Maróti R, Dasu A, Liszka M. Range-shifter effects on the stray field in proton therapy measured with the variance–covariance method. Front Oncol 2022; 12:882230. [PMID: 35982965 PMCID: PMC9380888 DOI: 10.3389/fonc.2022.882230] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 07/05/2022] [Indexed: 01/09/2023] Open
Abstract
Measurements in the stray radiation field from a proton therapy pencil beam at energies 70 and 146 MeV were performed using microdosimetric tissue-equivalent proportional counters (TEPCs). The detector volumes were filled with a propane-based tissue-equivalent gas at low pressure simulating a mean chord length of 2 μm in tissue. Investigations were performed with and without a beam range shifter, and with different air gaps between the range shifter and a solid water phantom. The absorbed dose, the dose-mean lineal energy, and the dose equivalent were determined for different detector positions using the variance–covariance method. The influence from beam energy, detector- and range-shifter positions on absorbed dose, LET, and dose equivalent were investigated. Monte Carlo simulations of the fluence, detector response, and absorbed dose contribution from different particles were performed with MCNP 6.2. The simulated dose response for protons, neutrons, and photons were compared with, and showed good agreement with, previously published experimental data. The simulations also showed that the TEPC absorbed dose agrees well with the ambient absorbed dose for neutron energies above 20 MeV. The results illustrate that changes in both dose and LET variations in the stray radiation field can be identified from TEPC measurements using the variance–covariance method. The results are in line with the changes seen in the simulated relative dose contributions from different particles associated with different proton energies and range-shifter settings. It is shown that the proton contribution scattered directly from the range shifter dominates in some situations, and although the LET of the radiation is decreased, the ambient dose equivalent is increased up to a factor of 3.
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Affiliation(s)
- Linda Eliasson
- Department of Physics, KTH, Stockholm, Sweden
- *Correspondence: Linda Eliasson,
| | - Jan Lillhök
- The Swedish Radiation Safety Authority, Solna, Sweden
| | | | | | - Alexandru Dasu
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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15
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Domingo C, Lagares JI, Romero-Expósito M, Sánchez-Nieto B, Nieto-Camero JJ, Terrón JA, Irazola L, Dasu A, Sánchez-Doblado F. Peripheral Organ Equivalent Dose Estimation Procedure in Proton Therapy. Front Oncol 2022; 12:882476. [PMID: 35692801 PMCID: PMC9176390 DOI: 10.3389/fonc.2022.882476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 04/19/2022] [Indexed: 11/23/2022] Open
Abstract
The aim of this work is to present a reproducible methodology for the evaluation of total equivalent doses in organs during proton therapy facilities. The methodology is based on measuring the dose equivalent in representative locations inside an anthropomorphic phantom where photon and neutron dosimeters were inserted. The Monte Carlo simulation was needed for obtaining neutron energy distribution inside the phantom. The methodology was implemented for a head irradiation case in the passive proton beam of iThemba Labs (South Africa). Thermoluminescent dosimeter (TLD)-600 and TLD-700 pairs were used as dosimeters inside the phantom and GEANT code for simulations. In addition, Bonner sphere spectrometry was performed inside the treatment room to obtain the neutron spectra, some relevant neutron dosimetric quantities per treatment Gy, and a percentual distribution of neutron fluence and ambient dose equivalent in four energy groups, at two locations. The neutron spectrum at one of those locations was also simulated so that a reasonable agreement between simulation and measurement allowed a validation of the simulation. Results showed that the total out-of-field dose equivalent inside the phantom ranged from 1.4 to 0.28 mSv/Gy, mainly due to the neutron contribution and with a small contribution from photons, 10% on average. The order of magnitude of the equivalent dose in organs was similar, displaying a slow reduction in values as the organ is farther from the target volume. These values were in agreement with those found by other authors in other passive beam facilities under similar irradiation and measurement conditions.
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Affiliation(s)
- Carles Domingo
- Departament de Fisica, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - Juan Ignacio Lagares
- Unidad de Aplicaciones Médicas, Departamento de Tecnología, Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Madrid, Spain
| | | | | | | | - Jose Antonio Terrón
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Sevilla, Spain
| | - Leticia Irazola
- Servicio de Radiofísica y Protección Radiológica, Clínica Universidad de Navarra, Pamplona, Spain
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden.,Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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Romero-Expósito M, Toma-Dasu I, Dasu A. Determining Out-of-Field Doses and Second Cancer Risk From Proton Therapy in Young Patients—An Overview. Front Oncol 2022; 12:892078. [PMID: 35712488 PMCID: PMC9197425 DOI: 10.3389/fonc.2022.892078] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Accepted: 05/02/2022] [Indexed: 11/13/2022] Open
Abstract
Proton therapy has the potential to provide survival and tumor control outcomes comparable and frequently superior to photon therapy. This has led to a significant concern in the medical physics community on the risk for the induction of second cancers in all patients and especially in younger patients, as they are considered more radiosensitive than adults and have an even longer expected lifetime after treatment. Thus, our purpose is to present an overview of the research carried out on the evaluation of out-of-field doses linked to second cancer induction and the prediction of this risk. Most investigations consisted of Monte Carlo simulations in passive beam facilities for clinical scenarios. These works established that equivalent doses in organs could be up to 200 mSv or 900 mSv for a brain or a craniospinal treatment, respectively. The major contribution to this dose comes from the secondary neutrons produced in the beam line elements. Few works focused on scanned-beam facilities, but available data show that, for these facilities, equivalent doses could be between 2 and 50 times lower. Patient age is a relevant factor in the dose level, especially for younger patients (by means of the size of the body) and, in addition, in the predicted risk by models (due to the age dependence of the radiosensitivity). For risks, the sex of the patient also plays an important role, as female patients show higher sensitivity to radiation. Thus, predicted risks of craniospinal irradiation can range from 8% for a 15-year-old male patient to 58% for a 2-year-old female patient, using a risk model from a radiological protection field. These values must be taken with caution due to uncertainties in risk models, and then dosimetric evaluation of stray radiation becomes mandatory in order to complement epidemiological studies and be able to model appropriate dose–response functions for this dose range. In this sense, analytical models represent a useful tool and some models have been implemented to be used for young patients. Research carried out so far confirmed that proton beam therapy reduces the out-of-field doses and second cancer risk. However, further investigations may be required in scanned-beam delivery systems.
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Affiliation(s)
- Maite Romero-Expósito
- The Skandion Clinic, Uppsala, Sweden
- Oncology Pathology Department, Karolinska Institutet, Stockholm, Sweden
- *Correspondence: Maite Romero-Expósito,
| | - Iuliana Toma-Dasu
- Oncology Pathology Department, Karolinska Institutet, Stockholm, Sweden
- Medical Radiation Physics, Stockholm University, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
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Olofsson N, Wikström K, Flejmer A, Ahnesjö A, Dasu A. MO-0469 Extensive evaluation of dosimetric robustness for respiratory motion of lung tumor radiotherapy. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)02363-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Hahn C, Ödén J, Dasu A, Vestergaard A, Fuglsang Jensen M, Sokol O, Pardi C, Bourhaleb F, Leite A, de Marzi L, Smith E, Aitkenhead A, Rose C, Merchant M, Kirkby K, Grzanka L, Pawelke J, Lühr A. Towards harmonizing clinical linear energy transfer (LET) reporting in proton radiotherapy: a European multi-centric study. Acta Oncol 2022; 61:206-214. [PMID: 34686122 DOI: 10.1080/0284186x.2021.1992007] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 10/06/2021] [Indexed: 10/20/2022]
Abstract
BACKGROUND Clinical data suggest that the relative biological effectiveness (RBE) in proton therapy (PT) varies with linear energy transfer (LET). However, LET calculations are neither standardized nor available in clinical routine. Here, the status of LET calculations among European PT institutions and their comparability are assessed. MATERIALS AND METHODS Eight European PT institutions used suitable treatment planning systems with their center-specific beam model to create treatment plans in a water phantom covering different field arrangements and fulfilling commonly agreed dose objectives. They employed their locally established LET simulation environments and procedures to determine the corresponding LET distributions. Dose distributions D1.1 and DRBE assuming constant and variable RBE, respectively, and LET were compared among the institutions. Inter-center variability was assessed based on dose- and LET-volume-histogram parameters. RESULTS Treatment plans from six institutions fulfilled all clinical goals and were eligible for common analysis. D1.1 distributions in the target volume were comparable among PT institutions. However, corresponding LET values varied substantially between institutions for all field arrangements, primarily due to differences in LET averaging technique and considered secondary particle spectra. Consequently, DRBE using non-harmonized LET calculations increased inter-center dose variations substantially compared to D1.1 and significantly in mean dose to the target volume of perpendicular and opposing field arrangements (p < 0.05). Harmonizing LET reporting (dose-averaging, all protons, LET to water or to unit density tissue) reduced the inter-center variability in LET to the order of 10-15% within and outside the target volume for all beam arrangements. Consequentially, inter-institutional variability in DRBE decreased to that observed for D1.1. CONCLUSION Harmonizing the reported LET among PT centers is feasible and allows for consistent multi-centric analysis and reporting of tumor control and toxicity in view of a variable RBE. It may serve as basis for harmonized variable RBE dose prescription in PT.
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Affiliation(s)
- Christian Hahn
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, 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
- Medical Physics and Radiotherapy, Department of Physics, TU Dortmund University, Dortmund, Germany
| | - Jakob Ödén
- RaySearch Laboratories AB, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Anne Vestergaard
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | - Olga Sokol
- GSI Helmholtz Centre for Heavy Ion Research, Darmstadt, Germany
| | - Claudia Pardi
- I-SEE (Internet-Simulation Evaluation Envision), Torino, Italy
| | - Faiza Bourhaleb
- I-SEE (Internet-Simulation Evaluation Envision), Torino, Italy
| | - Amélia Leite
- Institut Curie, PSL Research University, Radiation Oncology Department, Proton Therapy Centre, Centre Universitaire, Orsay, France
| | - Ludovic de Marzi
- Institut Curie, PSL Research University, Radiation Oncology Department, Proton Therapy Centre, Centre Universitaire, Orsay, France
- Institut Curie, PSL Research University, University Paris Saclay, Inserm LITO, Orsay, France
| | - Edward Smith
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Adam Aitkenhead
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Christopher Rose
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Michael Merchant
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Karen Kirkby
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, UK
| | - Leszek Grzanka
- Institute of Nuclear Physics Polish Academy of Sciences, Krakow, Poland
| | - Jörg Pawelke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Armin Lühr
- OncoRay - National Center for Radiation Research in 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
- Medical Physics and Radiotherapy, Department of Physics, TU Dortmund University, Dortmund, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
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Davídková M, Dasu A, De Angelis C, De Marzi L, De Saint-Hubert M, Ekendahl D, Michaelidesová AJ, Knežević Ž, Kukolowicz P, Liszka M, Lorentini S, Leite AM, Majer M, Michalec B, Navrátil M, Reniers B, Van Goethem M, Vestergaard A, Vilches-Freixas G, Vondráček V, Stolarczyk L, Olko P. FLASH Modalities Track (Oral Presentations) PRELIMINARY RESULTS OF DOSIMETRY AUDIT OF ACTIVE SCANNING PROTON BEAMS. Phys Med 2022. [DOI: 10.1016/s1120-1797(22)01562-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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20
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Sørensen BS, Pawelke J, Bauer J, Burnet NG, Dasu A, Høyer M, Karger CP, Krause M, Schwarz M, Underwood TSA, Wagenaar D, Whitfield GA, Lühr A. Does the uncertainty in relative biological effectiveness affect patient treatment in proton therapy? Radiother Oncol 2021; 163:177-184. [PMID: 34480959 DOI: 10.1016/j.radonc.2021.08.016] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2021] [Revised: 08/09/2021] [Accepted: 08/22/2021] [Indexed: 10/20/2022]
Abstract
Clinical treatment with protons uses the concept of relative biological effectiveness (RBE) to convert the absorbed dose into an RBE-weighted dose that equals the dose for radiotherapy with photons causing the same biological effect. Currently, in proton therapy a constant RBE of 1.1 is generically used. However, empirical data indicate that the RBE is not constant, but increases at the distal edge of the proton beam. This increase in RBE is of concern, as the clinical impact is still unresolved, and clinical studies demonstrating a clinical effect of an increased RBE are emerging. Within the European Particle Therapy Network (EPTN) work package 6 on radiobiology and RBE, a workshop was held in February 2020 in Manchester with one day of discussion dedicated to the impact of proton RBE in a clinical context. Current data on RBE effects, patient outcome and modelling from experimental as well as clinical studies were presented and discussed. Furthermore, representatives from European clinical proton therapy centres, who were involved in patient treatment, laid out their current clinical practice on how to consider the risk of a variable RBE in their centres. In line with the workshop, this work considers the actual impact of RBE issues on patient care in proton therapy by reviewing preclinical data on the relation between linear energy transfer (LET) and RBE, current clinical data sets on RBE effects in patients, and applied clinical strategies to manage RBE uncertainties. A better understanding of the variability in RBE would allow development of proton treatments which are safer and more effective.
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Affiliation(s)
- Brita S Sørensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Experimental Clinical Oncology - Department of Oncology, Aarhus University Hospital, Aarhus, Denmark.
| | - Jörg Pawelke
- 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 (HZDR), Institute of Radiooncology-OncoRay, Dresden, Germany
| | - Julia Bauer
- Department of Radiation Oncology, Heidelberg University Hospital, Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | | | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden; Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Morten Høyer
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Christian P Karger
- Dept. of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Heidelberg Institute for Radiation Oncology (HIRO) and National Center for Radiation Research in Oncology (NCRO), Heidelberg, Germany
| | - Mechthild Krause
- 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 (HZDR), Institute of Radiooncology-OncoRay, Dresden, Germany; German Cancer Consortium Dresden and German Cancer Research Center Heidelberg, Germany; Dept. of Radiation Oncology, University Hospital and Faculty of Medicine C.G. Carus, Dresden, Germany; National Center for Tumor Diseases Dresden, German Cancer Research Center Heidelberg, University Hospital and Faculty of Medicine C.G. Carus Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Marco Schwarz
- Protontherapy Department -Trento Hospital, and TIFPA-INFN, Trento, Italy
| | - Tracy S A Underwood
- Division of Cancer Sciences, School of Medical Sciences, The University of Manchester, UK
| | - Dirk Wagenaar
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, Groningen, the Netherlands
| | - Gillian A Whitfield
- The Christie NHS Foundation Trust, Manchester, UK; University of Manchester, UK
| | - Armin Lühr
- Department of Physics, TU Dortmund University, Dortmund, Germany
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Kvernby S, Flejmer AM, Dasu A, Bolger AF, Ebbers T, Engvall JE. T1 and T2 Mapping for Early Detection of Treatment-Related Myocardial Changes in Breast Cancer Patients. J Magn Reson Imaging 2021; 55:620-622. [PMID: 34231931 PMCID: PMC9290064 DOI: 10.1002/jmri.27820] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 11/12/2022] Open
Affiliation(s)
- Sofia Kvernby
- Department of Radiation Physics and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden.,Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden
| | - Anna M Flejmer
- Department of Oncology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden.,The Scandion Clinic, Uppsala, Sweden
| | - Alexandru Dasu
- The Scandion Clinic, Uppsala, Sweden.,Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | - Ann F Bolger
- Department of Medicine, University of California, San Francisco, US
| | - Tino Ebbers
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.,Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
| | - Jan E Engvall
- Center for Medical Image Science and Visualization (CMIV), Linköping University, Linköping, Sweden.,Department of Clinical Physiology and Department of Health, Medicine and Caring Sciences, Linköping University, Linköping, Sweden
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SandstrÖm H, Toma-Dasu I, Chung C, GÅrding J, Jokura H, Dasu A. Simultaneous Truth and Performance Level Estimation Method for Evaluation of Target Contouring in Radiosurgery. Anticancer Res 2021; 41:279-288. [PMID: 33419822 DOI: 10.21873/anticanres.14774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 12/04/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND/AIM The problem of lack of standardisation in target delineation and herewith the variability of target contours in Gamma Knife radiosurgery is as severe as in linac-based radiotherapy in general. The first aim of this study was to quantify the contouring variability for a group of five radiosurgery targets and estimate their true-volume based on multiple delineations using the Simultaneous Truth and Performance Level Estimation (STAPLE) algorithm. The second aim was to assess the robustness of the STAPLE method for the assessment of the true-volume, with respect to the number of contours available as input. PATIENTS AND METHODS A multicentre analysis of the variability in contouring of five cases was performed. Twelve contours were provided for each case by experienced planners for Gamma Knife. To assess the robustness of the STAPLE method with respect to the number of contours used as input, sets of contours were randomly selected in the analysis. RESULTS A high similarity was observed between the STAPLE generated true-volume and the 50%-agreement volume when all 12 available contours were used as input (90-100%). Lower similarity was observed with smaller sets of contours (10-70%). CONCLUSION If a high number of input contours is available, the STAPLE method provides a valuable tool in the estimation of the true volume of a target based on multiple contours as well as the sensitivity and specificity for each input contour relative to the true volume of that structure. The robustness of the STAPLE method for rendering the true target volume depends on the number of contours provided as input and their variability with respect to shape, size and position.
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Affiliation(s)
- Helena SandstrÖm
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden;
| | - Iuliana Toma-Dasu
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden.,Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
| | - Caroline Chung
- University of Texas MD Anderson Cancer Center, Houston, TX, U.S.A
| | | | - Hidefumi Jokura
- Jiro Suzuki Memorial Gamma House, Furukawa Seiryo Hospital, Osaki, Japan
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Ödén J, Eriksson K, Traneus E, Dasu A, Nyström PW, Toma-Dasu I. OC-0699: Relative biological effectiveness in proton therapy: accounting for variability and uncertainties. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00721-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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24
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Dasu A. SP-0388: Will SBRT, IMRT and protons alter the risks of second malignancy? Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)00412-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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25
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Henry T, Dasu A. PO-1431: Patient-specific dose calculations from a proton gantry mounted CBCT system: implementation in TOPAS. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01449-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Abstract
BACKGROUND This paper presents an insight into the critical discussions and the current strategies of the Nordic countries for handling the variable proton relative biological effectiveness (RBE) as presented at The Nordic Collaborative Workshop for Particle Therapy that took place at the Skandion Clinic on 14th and 15th of November 2019. MATERIAL AND METHODS In the current clinical practice at the two proton centres in operation at the date, Skandion Clinic, and the Danish Centre for Particle Therapy, a constant proton RBE of 1.1 is applied. The potentially increased effectiveness at the end of the particle range is however considered at the stage of treatment planning at both places based on empirical observations and knowledge. More elaborated strategies to evaluate the plans and mitigate the problem are intensely investigated internationally as well at the two centres. They involve the calculation of the dose-averaged linear energy transfer (LETd) values and the assessment of their distributions corroborated with the distribution of the dose and the location of the critical clinical structures. RESULTS Methods and tools for LETd calculations are under different stages of development as well as models to account for the variation of the RBE with LETd, dose per fraction, and type of tissue. The way they are currently used for evaluation and optimisation of the plans and their robustness are summarised. A critical but not exhaustive discussion of their potential future implementation in the clinical practice is also presented. CONCLUSIONS The need for collaboration between the clinical proton centres in establishing common platforms and perspectives for treatment planning evaluation and optimisation is highlighted as well as the need of close interaction with the research academic groups that could offer a complementary perspective and actively help developing methods and tools for clinical implementation of the more complex metrics for considering the variable effectiveness of the proton beams.
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Affiliation(s)
- Iuliana Toma-Dasu
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Medical Radiation Sciences, Department of Immunology, Genetics and Pathology, Uppsala University, Uppsala, Sweden
| | | | - Petra Witt Nyström
- The Skandion Clinic, Uppsala, Sweden
- Danish Centre for Particle Therapy, Aarhus, Denmark
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27
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Ödén J, Toma‐Dasu I, Witt Nyström P, Traneus E, Dasu A. Spatial correlation of linear energy transfer and relative biological effectiveness with suspected treatment‐related toxicities following proton therapy for intracranial tumors. Med Phys 2019; 47:342-351. [DOI: 10.1002/mp.13911] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 10/07/2019] [Accepted: 11/04/2019] [Indexed: 12/24/2022] Open
Affiliation(s)
- Jakob Ödén
- Department of Physics Medical Radiation Physics Stockholm University Stockholm171 76Sweden
- RaySearch Laboratories AB Stockholm111 34Sweden
| | - Iuliana Toma‐Dasu
- Department of Physics Medical Radiation Physics Stockholm University Stockholm171 76Sweden
- Department of Oncology and Pathology Medical Radiation Physics Karolinska Institutet Stockholm17176Sweden
| | - Petra Witt Nyström
- The Skandion Clinic Uppsala752 37Sweden
- Danish Centre for Particle Therapy Aarhus8200Denmark
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28
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Kjellsson Lindblom E, Ureba A, Dasu A, Wersäll P, Even AJG, van Elmpt W, Lambin P, Toma-Dasu I. Impact of SBRT fractionation in hypoxia dose painting - Accounting for heterogeneous and dynamic tumor oxygenation. Med Phys 2019; 46:2512-2521. [PMID: 30924937 DOI: 10.1002/mp.13514] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Revised: 02/18/2019] [Accepted: 03/13/2019] [Indexed: 12/11/2022] Open
Abstract
PURPOSE Tumor hypoxia, often found in nonsmall cell lung cancer (NSCLC), implies an increased resistance to radiotherapy. Pretreatment assessment of tumor oxygenation is, therefore, warranted in these patients, as functional imaging of hypoxia could be used as a basis for dose painting. This study aimed at investigating the feasibility of using a method for calculating the dose required in hypoxic subvolumes segmented on 18 F-HX4 positron emission tomography (PET) imaging of NSCLC. METHODS Positron emission tomography imaging data based on the hypoxia tracer 18 F-HX4 of 19 NSCLC patients were included in the study. Normalized tracer uptake was converted to oxygen partial pressure (pO2 ) and hypoxic target volumes (HTVs) were segmented using a threshold of 10 mmHg. Uniform doses required to overcome the hypoxic resistance in the target volumes were calculated based on a previously proposed method taking into account the effect of interfraction reoxygenation, for fractionation schedules ranging from extremely hypofractionated stereotactic body radiotherapy (SBRT) to conventionally fractionated radiotherapy. RESULTS Gross target volumes ranged between 6.2 and 859.6 cm3 , and the hypoxic fraction < 10 mmHg between 1.2% and 72.4%. The calculated doses for overcoming the resistance of cells in the HTVs were comparable to those currently prescribed in clinical practice as well as those previously tested in feasibility studies on dose escalation in NSCLC. Depending on the size of the HTV and the distribution of pO2 , HTV doses were calculated as 43.6-48.4 Gy for a three-fraction schedule, 51.7-57.6 Gy for five fractions, and 59.5-66.4 Gy for eight fractions. For patients in whom the HTV pO2 distribution was more favorable, a lower dose was required despite a bigger volume. Tumor control probability was lower for single-fraction schedules, while higher levels of tumor control probability were found for schedules employing several fractions. CONCLUSIONS The method to account for heterogeneous and dynamic hypoxia in target volume segmentation and dose prescription based on 18 F-HX4-PET imaging appears feasible in NSCLC patients. The distribution of oxygen partial pressure within HTV could impact the required prescribed dose more than the size of the volume.
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Affiliation(s)
- Emely Kjellsson Lindblom
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, S-17176, Sweden
| | - Ana Ureba
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, S-17176, Sweden
| | | | - Peter Wersäll
- Department of Oncology, Karolinska University Hospital, Stockholm, S-17176, Sweden
| | - Aniek J G Even
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, 6229, The Netherlands
| | - Wouter van Elmpt
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, 6229, The Netherlands
| | - Philippe Lambin
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, 6229, The Netherlands
| | - Iuliana Toma-Dasu
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, S-17176, Sweden.,Medical Radiation Physics, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, S-17176, Sweden
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Raptis A, Ödén J, Ardenfors O, Flejmer A, Toma-Dasu I, Dasu A. PO-0913 Cancer risk after breast proton therapy considering physiological and radiobiological uncertainties. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)31333-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Fura E, Dasu A, Ureba A, Isacsson U, Johansson S. PO-1032 The potential of CBCT for setup and treatment verification in proton therapy for prostate cancer. Radiother Oncol 2019. [DOI: 10.1016/s0167-8140(19)31452-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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32
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Ardenfors O, Henry T, Gudowska I, Poludniowski G, Dasu A. Organ doses from a proton gantry-mounted cone-beam computed tomography system characterized with MCNP6 and GATE. Phys Med 2018; 53:56-61. [PMID: 30241755 DOI: 10.1016/j.ejmp.2018.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/08/2018] [Accepted: 08/12/2018] [Indexed: 12/15/2022] Open
Abstract
PURPOSE To determine organ doses from a proton gantry-mounted cone-beam computed tomography (CBCT) system using two Monte Carlo codes and to study the influence on organ doses from different acquisition modes and repeated imaging. METHODS The CBCT system was characterized with MCNP6 and GATE using measurements of depth doses in water and spatial profiles in air. The beam models were validated against absolute dose measurements and used to simulate organ doses from CBCT imaging with head, thorax and pelvis protocols. Anterior and posterior 190° scans were simulated and the resulting organ doses per mAs were compared to those from 360° scans. The influence on organ doses from repeated imaging with different imaging schedules was also investigated. RESULTS The agreement between MCNP6, GATE and measurements with regard to depth doses and beam profiles was within 4% for all protocols and the corresponding average agreement in absolute dose validation was 4%. Absorbed doses for in-field organs from 360° scans ranged between 6 and 8 mGy, 15-17 mGy and 24-54 mGy for the head, thorax and pelvis protocols, respectively. Cumulative organ doses from repeated CBCT imaging ranged between 0.04 and 0.32 Gy for weekly imaging and 0.2-1.6 Gy for daily imaging. The anterior scans resulted in an average increase in dose per mAs of 24% to the organs of interest relative to the 360° scan, while the posterior scan showed a 37% decrease. CONCLUSIONS A proton gantry-mounted CBCT system was accurately characterized with MCNP6 and GATE. Organ doses varied greatly depending on acquisition mode, favoring posterior scans.
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Affiliation(s)
- Oscar Ardenfors
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden.
| | - Thomas Henry
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
| | - Irena Gudowska
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
| | - Gavin Poludniowski
- Medical Radiation Physics and Nuclear Medicine, Karolinska University Hospital, Stockholm, Sweden
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Ardenfors O, Dasu A, Lillhök J, Persson L, Gudowska I. Out-of-field doses from secondary radiation produced in proton therapy and the associated risk of radiation-induced cancer from a brain tumor treatment. Phys Med 2018; 53:129-136. [DOI: 10.1016/j.ejmp.2018.08.020] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/27/2018] [Accepted: 08/30/2018] [Indexed: 02/07/2023] Open
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Lillhök J, Persson L, Andersen CE, Dasu A, Ardenfors O. RADIATION PROTECTION MEASUREMENTS WITH THE VARIANCE-COVARIANCE METHOD IN THE STRAY RADIATION FIELDS FROM PHOTON AND PROTON THERAPY FACILITIES. Radiat Prot Dosimetry 2018; 180:338-341. [PMID: 29036696 DOI: 10.1093/rpd/ncx194] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Accepted: 09/04/2017] [Indexed: 06/07/2023]
Abstract
The microdosimetric variance-covariance method was used to study the stray radiation fields from the photon therapy facility at the Technical University of Denmark and the scanned proton therapy beam at the Skandion Clinic in Uppsala, Sweden. Two TEPCs were used to determine the absorbed dose, the dose-average lineal energy, the dose-average quality factor and the dose equivalent. The neutron component measured by the detectors at the proton beam was studied through Monte Carlo simulations using the code MCNP6. In the photon beam the stray absorbed dose ranged between 0.3 and 2.4 μGy per monitor unit, and the dose equivalent between 0.4 and 9 μSv per monitor unit, depending on beam energy and measurement position. In the proton beam the stray absorbed dose ranged between 3 and 135 μGy per prescribed Gy, depending on detector position and primary proton energy.
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Affiliation(s)
- J Lillhök
- Swedish Radiation Safety Authority, Stockholm, Sweden
| | - L Persson
- Swedish Radiation Safety Authority, Stockholm, Sweden
| | - C E Andersen
- Center for Nuclear Technologies, Technical University of Denmark, Roskilde, Denmark
| | - A Dasu
- The Skandion Clinic, Uppsala, Sweden
| | - O Ardenfors
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
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Ardenfors O, Gudowska I, Flejmer AM, Dasu A. Impact of irradiation setup in proton spot scanning brain therapy on organ doses from secondary radiation. Radiat Prot Dosimetry 2018; 180:261-266. [PMID: 30085315 DOI: 10.1093/rpd/ncy013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 01/16/2018] [Indexed: 06/08/2023]
Abstract
A Monte Carlo model of a proton spot scanning pencil beam was used to simulate organ doses from secondary radiation produced from brain tumour treatments delivered with either a lateral field or a vertex field to one adult and one paediatric patient. Absorbed doses from secondary neutrons, photons and protons and neutron equivalent doses were higher for the vertex field in both patients, but the differences were low in absolute terms. Absorbed doses ranged between 0.1 and 43 μGy.Gy-1 in both patients with the paediatric patient receiving higher doses. The neutron equivalent doses to the organs ranged between 0.5 and 141 μSv.Gy-1 for the paediatric patient and between 0.2 and 134 μSv.Gy-1 for the adult. The highest neutron equivalent dose from the entire treatment was 7 mSv regardless of field setup and patient size. The results indicate that different field setups do not introduce large absolute variations in out-of-field doses produced in patients undergoing proton pencil beam scanning of centrally located brain tumours.
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Affiliation(s)
- Oscar Ardenfors
- Medical Radiation Physics, Department of Physics, Stockholm University, Box 260, Stockholm, Sweden
| | - Irena Gudowska
- Medical Radiation Physics, Department of Physics, Stockholm University, Box 260, Stockholm, Sweden
| | - Anna Maria Flejmer
- Department of Oncology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
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de las Heras Gala H, Torresin A, Dasu A, Rampado O, Delis H, Giron IH, Theodorakou C, Andersson J, Holroyd J, Edyvean S, Delpon G, Caprile P, Peterlin P, Trianni A, Wg E. [OA176] The CBCT protocol of EFOMP-ESTRO-IAEA is alive: Update by eurados and din. Phys Med 2018. [DOI: 10.1016/j.ejmp.2018.06.248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
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Bolsi A, Peroni M, Amelio D, Dasu A, Stock M, Toma-Dasu I, Nyström PW, Hoffmann A. Practice patterns of image guided particle therapy in Europe: A 2016 survey of the European Particle Therapy Network (EPTN). Radiother Oncol 2018; 128:4-8. [DOI: 10.1016/j.radonc.2018.03.017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2018] [Accepted: 03/10/2018] [Indexed: 12/17/2022]
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Cases C, Flejmer A, Dasu A. EP-1926: Planning approaches and impact of breathing motion for proton radiotherapy in the mediastinum. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)32235-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Ureba A, Lindblom E, Dasu A, Uhrdin J, Even AJG, van Elmpt W, Lambin P, Wersäll P, Toma-Dasu I. Non-linear conversion of HX4 uptake for automatic segmentation of hypoxic volumes and dose prescription. Acta Oncol 2018; 57:485-490. [PMID: 29141489 DOI: 10.1080/0284186x.2017.1400177] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Tumour hypoxia is associated with increased radioresistance and poor response to radiotherapy. Pre-treatment assessment of tumour oxygenation could therefore give the possibility to tailor the treatment by calculating the required boost dose needed to overcome the increased radioresistance in hypoxic tumours. This study concerned the derivation of a non-linear conversion function between the uptake of the hypoxia-PET tracer 18F-HX4 and oxygen partial pressure (pO2). MATERIAL AND METHODS Building on previous experience with FMISO including experimental data on tracer uptake and pO2, tracer-specific model parameters were derived for converting the normalised HX4-uptake at the optimal imaging time point to pO2. The conversion function was implemented in a Python-based computational platform utilising the scripting and the registration modules of the treatment planning system RayStation. Subsequently, the conversion function was applied to determine the pO2 in eight non-small-cell lung cancer (NSCLC) patients imaged with HX4-PET before the start of radiotherapy. Automatic segmentation of hypoxic target volumes (HTVs) was then performed using thresholds around 10 mmHg. The HTVs were compared to sub-volumes segmented based on a tumour-to-blood ratio (TBR) of 1.4 using the aortic arch as the reference oxygenated region. The boost dose required to achieve 95% local control was then calculated based on the calibrated levels of hypoxia, assuming inter-fraction reoxygenation due to changes in acute hypoxia but no overall improvement of the oxygenation status. RESULTS Using the developed conversion tool, HTVs could be obtained using pO2 a threshold of 10 mmHg which were in agreement with the TBR segmentation. The dose levels required to the HTVs to achieve local control were feasible, being around 70-80 Gy in 24 fractions. CONCLUSIONS Non-linear conversion of tracer uptake to pO2 in NSCLC imaged with HX4-PET allows a quantitative determination of the dose-boost needed to achieve a high probability of local control.
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Affiliation(s)
- Ana Ureba
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
| | - Emely Lindblom
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
| | | | | | - Aniek J. G. Even
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Wouter van Elmpt
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Philippe Lambin
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Peter Wersäll
- Department of Oncology, Karolinska University Hospital, Stockholm, Sweden
| | - Iuliana Toma-Dasu
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
- Medical Radiation Physics, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
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Lazzeroni M, Uhrdin J, Carvalho S, van Elmpt W, Lambin P, Dasu A, Wersäll P, Toma-Dasu I. Evaluation of third treatment week as temporal window for assessing responsiveness on repeated FDG-PET-CT scans in Non-Small Cell Lung Cancer patients. Phys Med 2018. [DOI: 10.1016/j.ejmp.2018.01.012] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Ödén J, Toma-Dasu I, Eriksson K, Flejmer AM, Dasu A. The influence of breathing motion and a variable relative biological effectiveness in proton therapy of left-sided breast cancer. Acta Oncol 2017; 56:1428-1436. [PMID: 28826308 DOI: 10.1080/0284186x.2017.1348625] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND Proton breast radiotherapy has been suggested to improve target coverage as well as reduce cardiopulmonary and integral dose compared with photon therapy. This study aims to assess this potential when accounting for breathing motion and a variable relative biological effectiveness (RBE). METHODS Photon and robustly optimized proton plans were generated to deliver 50 Gy (RBE) in 25 fractions (RBE = 1.1) to the CTV (whole left breast) for 12 patients. The plan evaluation was performed using the constant RBE and a variable RBE model. Robustness against breathing motion, setup, range and RBE uncertainties was analyzed using CT data obtained at free-breathing, breath-hold-at-inhalation and breath-hold-at-exhalation. RESULTS All photon and proton plans (RBE = 1.1) met the clinical goals. The variable RBE model predicted an average RBE of 1.18 for the CTVs (range 1.14-1.21) and even higher RBEs in organs at risk (OARs). However, the dosimetric impact of this latter aspect was minor due to low OAR doses. The normal tissue complication probability (NTCP) for the lungs was low for all patients (<1%), and similar for photons and protons. The proton plans were generally considered robust for all patients. However, in the most extreme scenarios, the lowest dose received by 98% of the CTV dropped from 96 to 99% of the prescribed dose to around 92-94% for both protons and photons. Including RBE uncertainties in the robustness analysis resulted in substantially higher worst-case OAR doses. CONCLUSIONS Breathing motion seems to have a minor effect on the plan quality for breast cancer. The variable RBE might impact the potential benefit of protons, but could probably be neglected in most cases where the physical OAR doses are low. However, to be able to identify outlier cases at risk for high OAR doses, the biological evaluation of proton plans taking into account the variable RBE is recommended.
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Affiliation(s)
- Jakob Ödén
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- RaySearch Laboratories, Stockholm, Sweden
| | - Iuliana Toma-Dasu
- Department of Physics, Medical Radiation Physics, Stockholm University, Stockholm, Sweden
- Department of Oncology and Pathology, Medical Radiation Physics, Karolinska Institutet, Stockholm, Sweden
| | | | - Anna Maria Flejmer
- Department of Oncology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
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Dasu A, Toma-Dasu I. Models for the risk of secondary cancers from radiation therapy. Phys Med 2017; 42:232-238. [DOI: 10.1016/j.ejmp.2017.02.015] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/26/2016] [Revised: 02/10/2017] [Accepted: 02/15/2017] [Indexed: 11/25/2022] Open
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Abstract
BACKGROUND The majority of breast cancer patients who receive radiation treatment are affected by acute radiation-induced skin changes. The assessment of these changes is usually done by subjective methods, which complicates the comparison between different treatments or patient groups. This study investigates the feasibility of new robust methods for monitoring skin microcirculation to objectively assess and quantify acute skin reactions during radiation treatment. MATERIAL AND METHODS Laser Doppler flowmetry, laser speckle contrast imaging, and polarized light spectroscopy imaging were used to measure radiation-induced changes in microvascular perfusion and red blood cell concentration (RBC) in the skin of 15 patients undergoing adjuvant radiation therapy for breast cancer. Measurements were made before treatment, once a week during treatment, and directly after the last fraction. RESULTS In the treated breast, perfusion and RBC concentration were increased after 1-5 fractions (2.66-13.3 Gy) compared to baseline. The largest effects were seen in the areola and the medial area. No changes in perfusion and RBC concentration were seen in the untreated breast. In contrast, Radiation Therapy Oncology Group (RTOG) scores were increased only after 2 weeks of treatment, which demonstrates the potential of the proposed methods for early assessment of skin changes. Also, there was a moderate to good correlation between the perfusion (r = 0.52) and RBC concentration (r = 0.59) and the RTOG score given a week later. CONCLUSION We conclude that radiation-induced microvascular changes in the skin can be objectively measured using novel camera-based techniques before visual changes in the skin are apparent. Objective measurement of microvascular changes in the skin may be valuable in the comparison of skin reactions between different radiation treatments and possibly in predicting acute skin effects at an earlier stage.
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Affiliation(s)
- Erik Tesselaar
- Department of Radiation Physics and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | - Anna M. Flejmer
- Department of Oncology and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Simon Farnebo
- Department of Hand and Plastic Surgery and Burns and Department of Clinical and Experimental Medicine, Linköping University, Linköping, Sweden
| | - Alexandru Dasu
- Department of Radiation Physics and Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
- The Skandion Clinic, Uppsala, Sweden
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de Las Heras Gala H, Torresin A, Dasu A, Rampado O, Delis H, Hernández Girón I, Theodorakou C, Andersson J, Holroyd J, Nilsson M, Edyvean S, Gershan V, Hadid-Beurrier L, Hoog C, Delpon G, Sancho Kolster I, Peterlin P, Garayoa Roca J, Caprile P, Zervides C. Quality control in cone-beam computed tomography (CBCT) EFOMP-ESTRO-IAEA protocol (summary report). Phys Med 2017; 39:67-72. [PMID: 28602688 DOI: 10.1016/j.ejmp.2017.05.069] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Accepted: 05/24/2017] [Indexed: 10/19/2022] Open
Abstract
The aim of the guideline presented in this article is to unify the test parameters for image quality evaluation and radiation output in all types of cone-beam computed tomography (CBCT) systems. The applications of CBCT spread over dental and interventional radiology, guided surgery and radiotherapy. The chosen tests provide the means to objectively evaluate the performance and monitor the constancy of the imaging chain. Experience from all involved associations has been collected to achieve a consensus that is rigorous and helpful for the practice. The guideline recommends to assess image quality in terms of uniformity, geometrical precision, voxel density values (or Hounsfield units where available), noise, low contrast resolution and spatial resolution measurements. These tests usually require the use of a phantom and evaluation software. Radiation output can be determined with a kerma-area product meter attached to the tube case. Alternatively, a solid state dosimeter attached to the flat panel and a simple geometric relationship can be used to calculate the dose to the isocentre. Summary tables including action levels and recommended frequencies for each test, as well as relevant references, are provided. If the radiation output or image quality deviates from expected values, or exceeds documented action levels for a given system, a more in depth system analysis (using conventional tests) and corrective maintenance work may be required.
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Affiliation(s)
| | - Alberto Torresin
- Education and Training Chairperson of EFOMP, ASST Grande Ospedale Metropolitano Niguarda, Milano, Italy
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden; Linköping University, Linköping, Sweden
| | | | - Harry Delis
- International Atomic Energy Agency, Vienna, Austria
| | | | | | - Jonas Andersson
- Department of Radiation Sciences, Radiation Physics, University of Umeå, Umeå, Sweden
| | | | | | - Sue Edyvean
- Public Health England (PHE), Chilton, Didcot, Oxfordshire, UK
| | - Vesna Gershan
- Faculty of Natural Sciences and Mathematics, Skopje, Macedonia
| | | | | | | | | | | | | | - Paola Caprile
- Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Costas Zervides
- Zervides Radiation Protection Services, Limassol, Cyprus; University of Nicosia, Medical School, Nicosia, Cyprus
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Lindblom E, Dasu A, Uhrdin J, Even A, van Elmpt W, Lambin P, Wersäll P, Toma-Dasu I. Defining the hypoxic target volume based on positron emission tomography for image guided radiotherapy - the influence of the choice of the reference region and conversion function. Acta Oncol 2017; 56:819-825. [PMID: 28464740 DOI: 10.1080/0284186x.2017.1293289] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Hypoxia imaged by positron emission tomography (PET) is a potential target for optimization in radiotherapy. However, the implementation of this approach with respect to the conversion of intensities in the images into oxygenation and radiosensitivity maps is not straightforward. This study investigated the feasibility of applying two conversion approaches previously derived for 18F-labeled fluoromisonidazole (18F-FMISO)-PET images for the hypoxia tracer 18F-flortanidazole (18F-HX4). MATERIAL AND METHODS Ten non-small-cell lung cancer patients imaged with 18F-HX4 before the start of radiotherapy were considered in this study. PET image uptake was normalized to a well-oxygenated reference region and subsequently linear and non-linear conversions were used to determine tissue oxygenations maps. These were subsequently used to delineate hypoxic volumes based partial oxygen pressure (pO2) thresholds. The results were compared to hypoxic volumes segmented using a tissue-to-background ratio of 1.4 for 18F-HX4 uptake. RESULTS While the linear conversion function was not found to result in realistic oxygenation maps, the non-linear function resulted in reasonably sized sub-volumes in good agreement with uptake-based segmented volumes for a limited range of pO2 thresholds. However, the pO2 values corresponding to this range were significantly higher than what is normally considered as hypoxia. The similarity in size, shape, and relative location between uptake-based sub-volumes and volumes based on the conversion to pO2 suggests that the relationship between uptake and pO2 is similar for 18F-FMISO and 18F-HX4, but that the model parameters need to be adjusted for the latter. CONCLUSIONS A non-linear conversion function between uptake and oxygen partial pressure for 18F-FMISO-PET could be applied to 18F-HX4 images to delineate hypoxic sub-volumes of similar size, shape, and relative location as based directly on the uptake. In order to apply the model for e.g., dose-painting, new parameters need to be derived for the accurate calculation of dose-modifying factors for this tracer.
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Affiliation(s)
- Emely Lindblom
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
| | - Alexandru Dasu
- The Skandion Clinic, Uppsala, Sweden
- Department of Medical and Health Sciences, Linköping University, Linköping, Sweden
| | | | - Aniek Even
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Wouter van Elmpt
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Philippe Lambin
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Peter Wersäll
- Department of Oncology, Karolinska University Hospital, Stockholm, Sweden
| | - Iuliana Toma-Dasu
- Medical Radiation Physics, Department of Physics, Stockholm University, Stockholm, Sweden
- Medical Radiation Physics, Department of Oncology and Pathology, Karolinska Institutet, Stockholm, Sweden
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Tesselaar E, Flejmer A, Farnebo S, Dasu A. EP-1154: Changes in skin microcirculation during radiation therapy for breast cancer. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31590-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Odén J, Eriksson K, Flejmer A, Dasu A, Toma-Dasu I. PO-0832: The impact of variable RBE and breathing control in proton radiotherapy of breast cancer. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)31269-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Lazzeroni M, Uhrdin J, Carvalho S, Van Elmpt W, Lambin P, Dasu A, Toma-Dasu I. EP-1684: Optimal window for assessing treatment responsiveness on repeated FDG-PET scans in NSCLC patients. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)32216-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Lindblom E, Dasu A, Uhrdin J, Even A, Van Elmpt W, Lambin P, Toma-Dasu I. EP-1602: Treatment planning individualisation based on 18F-HX4 PET hypoxic subvolumes in NSCLC patients. Radiother Oncol 2017. [DOI: 10.1016/s0167-8140(17)32037-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Lindblom E, Dasu A, Beskow C, Toma-Dasu I. High brachytherapy doses can counteract hypoxia in cervical cancer—a modelling study. Phys Med Biol 2016; 62:560-572. [DOI: 10.1088/1361-6560/aa520f] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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