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Martínez-Rovira I, Montay-Gruel P, Petit B, Leavitt RJ, González-Vegas R, Froidevaux P, Juchaux M, Prezado Y, Yousef I, Vozenin MC. Infrared microspectroscopy to elucidate the underlying biomolecular mechanisms of FLASH radiotherapy. Radiother Oncol 2024; 196:110238. [PMID: 38527626 DOI: 10.1016/j.radonc.2024.110238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/18/2024] [Accepted: 03/19/2024] [Indexed: 03/27/2024]
Abstract
BACKGROUND FLASH-radiotherapy (FLASH-RT) is an emerging modality that uses ultra-high dose rates of radiation to enable curative doses to the tumor while preserving normal tissue. The biological studies showed the potential of FLASH-RT to revolutionize radiotherapy cancer treatments. However, the complex biological basis of FLASH-RT is not fully known yet. AIM Within this context, our aim is to get deeper insights into the biomolecular mechanisms underlying FLASH-RT through Fourier Transform Infrared Microspectroscopy (FTIRM). METHODS C57Bl/6J female mice were whole brain irradiated at 10 Gy with the eRT6-Oriatron system. 10 Gy FLASH-RT was delivered in 1 pulse of 1.8μs and conventional irradiations at 0.1 Gy/s. Brains were sampled and prepared for analysis 24 h post-RT. FTIRM was performed at the MIRAS beamline of ALBA Synchrotron. Infrared raster scanning maps of the whole mice brain sections were collected for each sample condition. Hyperspectral imaging and Principal Component Analysis (PCA) were performed in several regions of the brain. RESULTS PCA results evidenced a clear separation between conventional and FLASH irradiations in the 1800-950 cm-1 region, with a significant overlap between FLASH and Control groups. An analysis of the loading plots revealed that most of the variance accounting for the separation between groups was associated to modifications in the protein backbone (Amide I). This protein degradation and/or conformational rearrangement was concomitant with nucleic acid fragmentation/condensation. Cluster separation between FLASH and conventional groups was also present in the 3000-2800 cm-1 region, being correlated with changes in the methylene and methyl group concentrations and in the lipid chain length. Specific vibrational features were detected as a function of the brain region. CONCLUSION This work provided new insights into the biomolecular effects involved in FLASH-RT through FTIRM. Our results showed that beyond nucleic acid investigations, one should take into account other dose-rate responsive molecules such as proteins, as they might be key to understand FLASH effect.
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Affiliation(s)
| | - Pierre Montay-Gruel
- Department of Radiation Oncology, Iridium Network, 2610, Wilrijk (Antwerp), Belgium; Centre for Oncological Research (CORE), University of Antwerp, 2610, Antwerp, Belgium
| | - Benoît Petit
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland
| | - Ron J Leavitt
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland
| | - Roberto González-Vegas
- Physics Department, Universitat Autònoma de Barcelona, 08193, Cerdanyola del Vallès (Barcelona), Spain
| | - Pascal Froidevaux
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland
| | - Marjorie Juchaux
- Centre de recherche d'Orsay, Institut Curie, 91401, Orsay, France
| | - Yolanda Prezado
- Centre de recherche d'Orsay, Institut Curie, 91401, Orsay, France
| | - Ibraheem Yousef
- MIRAS Beamline, ALBA Synchotron, 08290, Cerdanyola del Vallès (Barcelona), Spain
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Radiation Oncology Service and Oncology Department, Lausanne University Hospital and University of Lausanne, 1066, Lausanne, Switzerland; Radiotherapy and Radiobiology sector, Radiation Therapy service, University hospital of Geneva (Current address), 1205, Geneva, Switzerland
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Zhao X, Huang S, Lin H, Choi JI, Zhu K, Simone CB, Yan X, Kang M. A Novel Dose Rate Optimization Method to Maximize Ultrahigh-Dose-Rate Coverage of Critical Organs at Risk Without Compromising Dosimetry Metrics in Proton Pencil Beam Scanning FLASH Radiation Therapy. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00735-1. [PMID: 38879087 DOI: 10.1016/j.ijrobp.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/12/2024] [Accepted: 06/09/2024] [Indexed: 07/10/2024]
Abstract
PURPOSE This study aimed to investigate a dose rate optimization framework based on the spot-scanning patterns to improve ultrahigh-dose-rate coverage of critical organs at risk (OARs) for proton pencil beam scanning (PBS) FLASH radiation therapy (ultrahigh dose-rate (often referred to as >40 Gy per second) delivery) and present implementation of a genetic algorithm (GA) method for spot sequence optimization to achieve PBS FLASH dose rate optimization under relatively low nozzle beam currents. METHODS AND MATERIALS First, a multifield FLASH plan was developed to meet all the dosimetric goals and optimal FLASH dose rate coverage by considering the deliverable minimum monitor unit constraint. Then, a GA method was implemented into the in-house treatment platform to maximize the dose rate by exploring the best spot delivery sequence. A phantom study was performed to evaluate the effectiveness of the dose rate optimization. Then, 10 consecutive plans for patients with lung cancer previously treated using PBS intensity-modulated proton therapy were optimized using 45 GyRBE in 3 fractions for both transmission and Bragg peak FLASH radiation therapy for further validation. The spot delivery sequence of each treatment field was optimized using this GA. The ultrahigh-dose-rate-volume histogram and dose rate coverage V40GyRBE/s were investigated to assess the efficacy of dose rate optimization quantitatively. RESULTS Using a relatively low monitor unit/spot of 150, corresponding to a nozzle beam current of 65 nA, the FLASH dose rate ratio V40GyRBE/s of the OAR contour of the core was increased from 0% to ∼60% in the phantom study. In the patients with lung cancer, the ultrahigh-dose-rate coverage V40GyRBE/s was improved from 15.2%, 15.5%, 17.6%, and 16.0% before the delivery sequence optimization to 31.8%, 43.5%, 47.6%, and 30.5% after delivery sequence optimization in the lungs-GTV (gross tumor volume), spinal cord, esophagus, and heart (for all, P < .001). When the beam current increased to 130 nA, V40GyRBE/s was improved from 45.1%, 47.1%, 51.2%, and 51.4% to 65.3%, 83.5%, 88.1%, and 69.4% (P < .05). The averaged V40GyRBE/s for the target and OARs increased from 12.9% to 41.6% and 46.3% to 77.5% for 65 and 130 nA, respectively, showing significant improvements based on a clinical proton system. After optimizing the dose rate for the Bragg peak FLASH technique with a beam current of 340 nA, the V40GyRBE/s values for the lung GTV, spinal cord, esophagus, and heart were increased by 8.9%, 15.8%, 22%, and 20.8%, respectively. CONCLUSIONS An optimal plan quality can be maintained as the spot delivery sequence optimization is a separate independent process after the plan optimization. Both the phantom and patient results demonstrated that novel spot delivery sequence optimization can effectively improve the ultrahigh-dose-rate coverage for critical OARs, which can potentially be applied in clinical practice for better OARs-sparing efficacy.
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Affiliation(s)
- Xingyi Zhao
- State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, Center for Applied Physics and Technology, Peking University, Beijing, China; New York Proton Center, New York, New York
| | - Sheng Huang
- Radiation Oncology, Tianjin Medical University Cancer Institute & Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Haibo Lin
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - J Isabelle Choi
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Kun Zhu
- State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, Center for Applied Physics and Technology, Peking University, Beijing, China
| | - Charles B Simone
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Xueqing Yan
- State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, Center for Applied Physics and Technology, Peking University, Beijing, China.
| | - Minglei Kang
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
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Chow JCL, Ruda HE. Mechanisms of Action in FLASH Radiotherapy: A Comprehensive Review of Physicochemical and Biological Processes on Cancerous and Normal Cells. Cells 2024; 13:835. [PMID: 38786057 PMCID: PMC11120005 DOI: 10.3390/cells13100835] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2024] [Revised: 05/09/2024] [Accepted: 05/11/2024] [Indexed: 05/25/2024] Open
Abstract
The advent of FLASH radiotherapy (FLASH-RT) has brought forth a paradigm shift in cancer treatment, showcasing remarkable normal cell sparing effects with ultra-high dose rates (>40 Gy/s). This review delves into the multifaceted mechanisms underpinning the efficacy of FLASH effect, examining both physicochemical and biological hypotheses in cell biophysics. The physicochemical process encompasses oxygen depletion, reactive oxygen species, and free radical recombination. In parallel, the biological process explores the FLASH effect on the immune system and on blood vessels in treatment sites such as the brain, lung, gastrointestinal tract, skin, and subcutaneous tissue. This review investigated the selective targeting of cancer cells and the modulation of the tumor microenvironment through FLASH-RT. Examining these mechanisms, we explore the implications and challenges of integrating FLASH-RT into cancer treatment. The potential to spare normal cells, boost the immune response, and modify the tumor vasculature offers new therapeutic strategies. Despite progress in understanding FLASH-RT, this review highlights knowledge gaps, emphasizing the need for further research to optimize its clinical applications. The synthesis of physicochemical and biological insights serves as a comprehensive resource for cell biology, molecular biology, and biophysics researchers and clinicians navigating the evolution of FLASH-RT in cancer therapy.
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Affiliation(s)
- James C. L. Chow
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON M5G 1X6, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, ON M5T 1P5, Canada
| | - Harry E. Ruda
- Centre of Advance Nanotechnology, Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON M5S 3E4, Canada;
- Department of Materials Science and Engineering, University of Toronto, Toronto, ON M5S 3E4, Canada
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Poulsen PR, Johansen JG, Sitarz MK, Kanouta E, Kristensen L, Grau C, Sørensen BS. Oxygen Enhancement Ratio-Weighted Dose Quantitatively Describes Acute Skin Toxicity Variations in Mice After Pencil Beam Scanning Proton FLASH Irradiation With Changing Doses and Time Structures. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00358-4. [PMID: 38462015 DOI: 10.1016/j.ijrobp.2024.02.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Revised: 02/12/2024] [Accepted: 02/24/2024] [Indexed: 03/12/2024]
Abstract
PURPOSE The aim of this work was to investigate the ability of a biological oxygen enhancement ratio-weighted dose, DOER, to describe acute skin toxicity variations observed in mice after proton pencil beam scanning irradiations with changing doses and beam time structures. METHODS AND MATERIALS In five independent experiments, the right hind leg of a total of 621 CDF1 mice was irradiated previously in the entrance plateau of a pencil beam scanning proton beam. The incidence of acute skin toxicity (of level 1.5-2.0-2.5-3.0-3.5) was scored for 47 different mouse groups that mapped toxicity as function of dose for conventional and FLASH dose rate, toxicity as function of field dose rate with and without repainting, and toxicity when splitting the treatment into 1 to 6 identical deliveries separated by 2 minutes. DOER was calculated for all mouse groups using a simple oxygen kinetics model to describe oxygen depletion. The three independent model parameters (oxygen-depletion rate, oxygen-recovery rate, oxygen level without irradiation) were fitted to the experimental data. The ability of DOER to describe the toxicity variations across all experiments was investigated by comparing DOER-response curves across the five independent experiments. RESULTS After conversion from the independent variable tested in each experiment to DOER, all five experiments had similar MDDOER50 (DOER giving 50% toxicity incidence) with standard deviations of 0.45 - 1.6 Gy for the five toxicity levels. DOER could thus describe the observed toxicity variations across all experiments. CONCLUSIONS DOER described the varying FLASH-sparing effect observed for a wide range of conditions. Calculation of DOER for other irradiation conditions can quantitatively estimate the FLASH-sparing effect for arbitrary irradiations for the investigated murine model. With appropriate fitting parameters DOER also may be able to describe FLASH effect variations with dose and dose rate for other assays and endpoints.
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Affiliation(s)
- Per Rugaard Poulsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark.
| | - Jacob Graversen Johansen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Mateusz Krzysztof Sitarz
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Eleni Kanouta
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Line Kristensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Cai Grau
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Brita Singers Sørensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Clinical Medicine, Aarhus University, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
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Shiraishi Y, Matsuya Y, Fukunaga H. Possible mechanisms and simulation modeling of FLASH radiotherapy. Radiol Phys Technol 2024; 17:11-23. [PMID: 38184508 DOI: 10.1007/s12194-023-00770-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 12/01/2023] [Accepted: 12/02/2023] [Indexed: 01/08/2024]
Abstract
FLASH radiotherapy (FLASH-RT) has great potential to improve patient outcomes. It delivers radiation doses at an ultra-high dose rate (UHDR: ≥ 40 Gy/s) in a single instant or a few pulses. Much higher irradiation doses can be administered to tumors with FLASH-RT than with conventional dose rate (0.01-0.40 Gy/s) radiotherapy. UHDR irradiation can suppress toxicity in normal tissues while sustaining antitumor efficiency, which is referred to as the FLASH effect. However, the mechanisms underlying the effects of the FLASH remain unclear. To clarify these mechanisms, the development of simulation models that can contribute to treatment planning for FLASH-RT is still underway. Previous studies indicated that transient oxygen depletion or augmented reactions between secondary reactive species produced by irradiation may be involved in this process. To discuss the possible mechanisms of the FLASH effect and its clinical potential, we summarized the physicochemical, chemical, and biological perspectives as well as the development of simulation modeling for FLASH-RT.
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Affiliation(s)
- Yuta Shiraishi
- Graduate School of Health Sciences, Hokkaido University, N12 W5 Kita-Ku, Sapporo, Hokkaido, 060-0812, Japan
- Faculty of Health Sciences, Japan Healthcare University, 3-11-1-50 Tsukisamu-Higashi, Toyohira-Ku, Sapporo, Hokkaido, 062-0053, Japan
| | - Yusuke Matsuya
- Faculty of Health Sciences, Hokkaido University, N12 W5 Kita-Ku, Sapporo, Hokkaido, 060-0812, Japan
| | - Hisanori Fukunaga
- Faculty of Health Sciences, Hokkaido University, N12 W5 Kita-Ku, Sapporo, Hokkaido, 060-0812, Japan.
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El Khatib M, Motlagh AO, Beyer JN, Troxler T, Allu SR, Sun Q, Burslem GM, Vinogradov SA. Direct Measurements of FLASH-Induced Changes in Intracellular Oxygenation. Int J Radiat Oncol Biol Phys 2024; 118:781-789. [PMID: 37729972 DOI: 10.1016/j.ijrobp.2023.09.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 08/01/2023] [Accepted: 09/13/2023] [Indexed: 09/22/2023]
Abstract
PURPOSE The goal of our study was to characterize the dynamics of intracellular oxygen during application of radiation at conventional (CONV) and FLASH dose rates and obtain evidence for or against the oxygen depletion hypothesis as a mechanism of the FLASH effect. METHODS AND MATERIALS The measurements were performed by the phosphorescence quenching method using probe Oxyphor PtG4, which was delivered into the cellular cytosol by electroporation. RESULTS Intracellular radiochemical oxygen depletion (ROD) g-value for a dose rate of 100 Gy/s in the normoxic range was found to be 0.58 ± 0.03 μM/Gy. Intracellular ROD g-values for FLASH and CONV dose rates in the normoxic range were found to be nearly equal. As in solution-based studies, intracellular ROD was found to exhibit strong dependence on oxygen concentration in the range of 0 to ∼40 μM [O2]. CONCLUSIONS Depletion of oxygen in cells in vitro by a clinical dose of proton radiation delivered as FLASH is unable to produce a transient state of hypoxia and, therefore, unable to induce radioprotection. The difference between ROD g-values for FLASH and CONV dose rates, detected previously in solutions-based experiments, disappears when measurements are conducted inside cells. Understanding this phenomenon should provide additional insight into the role of oxygen in FLASH radiation therapy and help to decipher the mechanism of the FLASH effect.
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Affiliation(s)
- Mirna El Khatib
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania.
| | - Azar O Motlagh
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Jenna N Beyer
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Thomas Troxler
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Srinivasa Rao Allu
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Qi Sun
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | - George M Burslem
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania.
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Clements N, Esplen N, Bateman J, Robertson C, Dosanjh M, Korysko P, Farabolini W, Corsini R, Bazalova-Carter M. Mini-GRID radiotherapy on the CLEAR very-high-energy electron beamline: collimator optimization, film dosimetry, and Monte Carlo simulations. Phys Med Biol 2024; 69:055003. [PMID: 38295408 DOI: 10.1088/1361-6560/ad247d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2023] [Accepted: 01/31/2024] [Indexed: 02/02/2024]
Abstract
Objective.Spatially-fractionated radiotherapy (SFRT) delivered with a very-high-energy electron (VHEE) beam and a mini-GRID collimator was investigated to achieve synergistic normal tissue-sparing through spatial fractionation and the FLASH effect.Approach.A tungsten mini-GRID collimator for delivering VHEE SFRT was optimized using Monte Carlo (MC) simulations. Peak-to-valley dose ratios (PVDRs), depths of convergence (DoCs, PVDR ≤ 1.1), and peak and valley doses in a water phantom from a simulated 150 MeV VHEE source were evaluated. Collimator thickness, hole width, and septal width were varied to determine an optimal value for each parameter that maximized PVDR and DoC. The optimized collimator (20 mm thick rectangular prism with a 15 mm × 15 mm face with a 7 × 7 array of 0.5 mm holes separated by 1.1 mm septa) was 3D-printed and used for VHEE irradiations with the CERN linear electron accelerator for research beam. Open beam and mini-GRID irradiations were performed at 140, 175, and 200 MeV and dose was recorded with radiochromic films in a water tank. PVDR, central-axis (CAX) and valley dose rates and DoCs were evaluated.Main results.Films demonstrated peak and valley dose rates on the order of 100 s of MGy/s, which could promote FLASH-sparing effects. Across the three energies, PVDRs of 2-4 at 13 mm depth and DoCs between 39 and 47 mm were achieved. Open beam and mini-GRID MC simulations were run to replicate the film results at 200 MeV. For the mini-GRID irradiations, the film CAX dose was on average 15% higher, the film valley dose was 28% higher, and the film PVDR was 15% lower than calculated by MC.Significance.Ultimately, the PVDRs and DoCs were determined to be too low for a significant potential for SFRT tissue-sparing effects to be present, particularly at depth. Further beam delivery optimization and investigations of new means of spatial fractionation are warranted.
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Affiliation(s)
- Nathan Clements
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Nolan Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
| | - Joseph Bateman
- Department of Physics, University of Oxford, Oxford, United Kingdom
| | | | - Manjit Dosanjh
- Department of Physics, University of Oxford, Oxford, United Kingdom
- CERN, Geneva, Switzerland
| | - Pierre Korysko
- Department of Physics, University of Oxford, Oxford, United Kingdom
- CERN, Geneva, Switzerland
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Portier L, Daira P, Fourmaux B, Heinrich S, Becerra M, Fouillade C, Berthault N, Dutreix M, Londoño-Vallejo A, Verrelle P, Bernoud-Hubac N, Favaudon V. Differential Remodeling of the Oxylipin Pool After FLASH Versus Conventional Dose-Rate Irradiation In Vitro and In Vivo. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00281-5. [PMID: 38340776 DOI: 10.1016/j.ijrobp.2024.01.210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2023] [Revised: 01/09/2024] [Accepted: 01/13/2024] [Indexed: 02/12/2024]
Abstract
PURPOSE The products of lipid peroxidation have been implicated in human diseases and aging. This prompted us to investigate the response to conventional (CONV) versus FLASH irradiation of oxylipins, a family of bioactive lipid metabolites derived from omega-3 or omega-6 polyunsaturated fatty acids through oxygen-dependent non-enzymatic as well as dioxygenase-mediated free radical reactions. METHODS AND MATERIALS Ultrahigh performance liquid chromatography coupled to tandem mass spectrometry was used to quantify the expression of 37 oxylipins derived from eicosatetraenoic, eicosapentaenoic and docosahexaenoic acid in mouse lung and in normal or cancer cells exposed to either radiation modality under precise monitoring of the temperature and oxygenation. Among the 37 isomers assayed, 14-16 were present in high enough amount to enable quantitative analysis. The endpoints were the expression of oxylipins as a function of the dose of radiation, normoxia versus hypoxia, temperature and post-irradiation time. RESULTS In normal, normoxic cells at 37°C radiation elicited destruction and neosynthesis of oxylipins acting antagonistically on a background subject to rapid remodeling by oxygenases. Neosynthesis was observed in the CONV mode only, in such a way that the level of oxylipins at 5 minutes after FLASH irradiation was 20-50% lower than in non-irradiated and CONV-irradiated cells. Hypoxia mitigated the differential CONV versus FLASH response in some oxylipins. These patterns were not reproduced in tumor cells. Depression of specific oxylipins following FLASH irradiation was observed in mouse lung at 5 min following irradiation, with near complete recovery in 24 hours and further remodeling at one week and two months post-irradiation. CONCLUSIONS Down-regulation of oxylipins was a hallmark of FLASH irradiation specific of normal cells. Temperature effects suggest that this process occurs via diffusion-controlled, bimolecular recombination of a primary radical species upstream from peroxyl radical formation and evoke a major role of the membrane composition and fluidity in response to the FLASH modality.
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Affiliation(s)
- Lucie Portier
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Patricia Daira
- Univ Lyon, INSA Lyon, CNRS, LaMCoS, UMR 5259, Villeurbanne, France
| | | | - Sophie Heinrich
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Margaux Becerra
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Charles Fouillade
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Nathalie Berthault
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Marie Dutreix
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Arturo Londoño-Vallejo
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | - Pierre Verrelle
- Institut Curie, Hospital Section, Department of Radiotherapy-Oncology, 26 rue d'Ulm, 75248 Paris Cedex 05, France; Institut Curie, Research Division, Inserm U 1196-CNRS UMR 9187, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France
| | | | - Vincent Favaudon
- Institut Curie, Research Division, Inserm U 1021-CNRS UMR 3347, Paris-Saclay University, PSL Research University, Centre Universitaire CS 90030, Orsay, France.
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Cordoni FG. A spatial measure-valued model for radiation-induced DNA damage kinetics and repair under protracted irradiation condition. J Math Biol 2024; 88:21. [PMID: 38285219 PMCID: PMC10824812 DOI: 10.1007/s00285-024-02046-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 10/01/2023] [Accepted: 12/27/2023] [Indexed: 01/30/2024]
Abstract
In the present work, we develop a general spatial stochastic model to describe the formation and repair of radiation-induced DNA damage. The model is described mathematically as a measure-valued particle-based stochastic system and extends in several directions the model developed in Cordoni et al. (Phys Rev E 103:012412, 2021; Int J Radiat Biol 1-16, 2022a; Radiat Res 197:218-232, 2022b). In this new spatial formulation, radiation-induced DNA damage in the cell nucleus can undergo different pathways to either repair or lead to cell inactivation. The main novelty of the work is to rigorously define a spatial model that considers the pairwise interaction of lesions and continuous protracted irradiation. The former is relevant from a biological point of view as clustered lesions are less likely to be repaired, leading to cell inactivation. The latter instead describes the effects of a continuous radiation field on biological tissue. We prove the existence and uniqueness of a solution to the above stochastic systems, characterizing its probabilistic properties. We further couple the model describing the biological system to a set of reaction-diffusion equations with random discontinuity that model the chemical environment. At last, we study the large system limit of the process. The developed model can be applied to different contexts, with radiotherapy and space radioprotection being the most relevant. Further, the biochemical system derived can play a crucial role in understanding an extremely promising novel radiotherapy treatment modality, named in the community FLASH radiotherapy, whose mechanism is today largely unknown.
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10
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Hu A, Zhou W, Qiu R, Wei S, Wu Z, Zhang H, Li J. Computational model of radiation oxygen effect with Monte Carlo simulation: effects of antioxidants and peroxyl radicals. Int J Radiat Biol 2024; 100:595-608. [PMID: 38166197 DOI: 10.1080/09553002.2023.2295292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 11/20/2023] [Indexed: 01/04/2024]
Abstract
PURPOSE Oxygen plays a crucial role in radiation biology. Antioxidants and peroxyl radicals affect the oxygen effect greatly. This study aims to establish a computational model of the oxygen effect and explore the effect attributed to antioxidants and peroxyl radicals. MATERIALS AND METHODS Oxygen-related reactions are added to our track-structure Monte Carlo code NASIC, including oxygen fixation, chemical repair by antioxidants and damage migration from base-derived peroxyl radicals. Then the code is used to simulate the DNA damage under various oxygen, antioxidant and damage migration rate conditions. The oxygen enhancement ratio(OER) is calculated quantifying by the number of double-strand breaks for each condition. The roles of antioxidants and peroxyl radicals are examined by manipulating the relevant parameters. RESULTS AND CONCLUSIONS Our results indicate that antioxidants are capable of rapidly restoring DNA radicals through chemical reactions, which compete with natural and oxygen fixation processes. Additionally, antioxidants can react with peroxyl radicals derived from bases, thereby preventing the damage from migrating to DNA strands. By quantitatively accounting for the impact of peroxyl radicals and antioxidants on the OER curves, our study establishes a more precise and comprehensive model of the radiation oxygen effect.
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Affiliation(s)
- Ankang Hu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Wanyi Zhou
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Rui Qiu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Shuoyang Wei
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Zhen Wu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Nuctech Company Limited, Beijing, China
| | - Hui Zhang
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Junli Li
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
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11
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Zhu H, Schuemann J, Zhang Q, Gerweck LE. Modeling the impact of tissue oxygen profiles and oxygen depletion parameter uncertainties on biological response and therapeutic benefit of FLASH. Med Phys 2024; 51:670-681. [PMID: 36939370 PMCID: PMC10509320 DOI: 10.1002/mp.16366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 02/22/2023] [Accepted: 03/06/2023] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND Ultra-high dose rate (FLASH) radiation has been reported to efficiently suppress tumor growth while sparing normal tissue; however, the mechanism of the differential tissue sparing effect is still not known. Oxygen has long been known to profoundly impact radiobiological responses, and radiolytic oxygen depletion has been considered to be a possible cause or contributor to the FLASH phenomenon. PURPOSE This work investigates the impact of tissue pO2 profiles, oxygen depletion per unit dose (g), and the oxygen concentration yielding half-maximum radiosensitization (the average of its maximum value and one) (k) in tumor and normal tissue. METHODS We developed a model that considers the dependent relationship between oxygen depletion and change of radiosensitivity by FLASH irradiation. The model assumed that FLASH irradiation depletes intracellular oxygen more rapidly than it diffuses into the cell from the extracellular environment. Cell survival was calculated based on the linear quadratic-linear model and the radiosensitivity related parameters were adjusted in 1 Gy increments of the administered dose. The model reproduced published experimental data that were obtained with different cell lines and oxygen concentrations, and was used to analyze the impact of parameter uncertainties on the radiobiological responses. This study expands the oxygen depletion analysis of FLASH to normal human tissue and tumor based on clinically determined aggregate and individual patient pO2 profiles. RESULTS The results show that the pO2 profile is the most essential factor that affects biological response and analyses based on the median pO2 rather than the full pO2 profile can be unreliable and misleading. Additionally, the presence of a small fraction of cells on the threshold of radiobiologic hypoxia substantially alters biological response due to FLASH oxygen depletion. We found that an increment in the k value is generally more protective of tumor than normal tissue due to a higher frequency of lower pO2 values in tumors. Variation in the g value affects the dose at which oxygen depletion impacts response, but does not alter the dose-dependent response trends, if the g value is identical in both tumor and normal tissue. CONCLUSIONS The therapeutic efficacy of FLASH oxygen depletion is likely patient and tissue-dependent. For breast cancer, FLASH is beneficial in a minority of cases; however, in a subset of well oxygenated tumors, a therapeutic gain may be realized due to induced normal tissue hypoxia.
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Affiliation(s)
- Hongyu Zhu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangzhou 510060, China
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Qixian Zhang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China
| | - Leo E Gerweck
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America
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12
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Shiraishi Y, Matsuya Y, Kusumoto T, Fukunaga H. Modeling for predicting survival fraction of cells after ultra-high dose rate irradiation. Phys Med Biol 2023; 69:015017. [PMID: 38056015 DOI: 10.1088/1361-6560/ad131b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 12/06/2023] [Indexed: 12/08/2023]
Abstract
Objective. FLASH radiotherapy (FLASH-RT) with ultra-high dose rate (UHDR) irradiation (i.e. > 40 Gy s-1) spares the function of normal tissues while preserving antitumor efficacy, known as the FLASH effect. The biological effects after conventional dose rate-radiotherapy (CONV-RT) with ≤0.1 Gy s-1have been well modeled by considering microdosimetry and DNA repair processes, meanwhile modeling of radiosensitivities under UHDR irradiation is insufficient. Here, we developed anintegrated microdosimetric-kinetic(IMK)model for UHDR-irradiationenabling the prediction of surviving fraction after UHDR irradiation.Approach.TheIMK model for UHDR-irradiationconsiders the initial DNA damage yields by the modification of indirect effects under UHDR compared to CONV dose rate. The developed model is based on the linear-quadratic (LQ) nature with the dose and dose square coefficients, considering the reduction of DNA damage yields as a function of dose rate.Main results.The estimate by the developed model could successfully reproduce thein vitroexperimental dose-response curve for various cell line types and dose rates.Significance.The developed model would be useful for predicting the biological effects under the UHDR irradiation.
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Affiliation(s)
- Yuta Shiraishi
- Graduate school of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan
- Faculty of Health Sciences, Japan Healthcare University, 3-11-1-50 Tsukisamu-higashi, Toyohira-ku, Sapporo, Hokkaido, 062-0053, Japan
| | - Yusuke Matsuya
- Faculty of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan
- Nuclear Science and Engineering Center, Japan Atomic Energy Agency, 2-4 Shirakata, Tokai, Ibaraki, 319-1195, Japan
| | - Tamon Kusumoto
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, Chiba, 263-8555, Japan
| | - Hisanori Fukunaga
- Faculty of Health Sciences, Hokkaido University, Kita-12, Nishi-5, Kita-ku, Sapporo, Hokkaido, 060-0812, Japan
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13
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Iturri L, Bertho A, Lamirault C, Brisebard E, Juchaux M, Gilbert C, Espenon J, Sébrié C, Jourdain L, de Marzi L, Pouzoulet F, Muret J, Verrelle P, Prezado Y. Oxygen supplementation in anesthesia can block FLASH effect and anti-tumor immunity in conventional proton therapy. COMMUNICATIONS MEDICINE 2023; 3:183. [PMID: 38102219 PMCID: PMC10724215 DOI: 10.1038/s43856-023-00411-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Accepted: 11/21/2023] [Indexed: 12/17/2023] Open
Abstract
BACKGROUND Radiation-induced neurocognitive dysfunction is a major adverse effect of brain radiation therapy and has specific relevance in pediatric oncology, where serious cognitive deficits have been reported in survivors of pediatric brain tumors. Moreover, many pediatric patients receive proton therapy under general anesthesia or sedation to guarantee precise ballistics with a high oxygen content for safety. The present study addresses the relevant question of the potential effect of supplemental oxygen administered during anesthesia on normal tissue toxicity and investigates the anti-tumor immune response generated following conventional and FLASH proton therapy. METHODS Rats (Fischer 344) were cranially irradiated with a single high dose of proton therapy (15 Gy or 25 Gy) using FLASH dose rate proton irradiation (257 ± 2 Gy/s) or conventional dose rate proton irradiation (4 ± 0.02 Gy/s), and the toxicities in the normal tissue were examined by histological, cytometric and behavioral analysis. Glioblastoma-bearing rats were irradiated in the same manner and tumor-infiltrating leukocytes were quantified by flow cytometry. RESULTS Our findings indicate that supplemental oxygen has an adverse impact on both functional and anatomical evaluations of normal brain following conventional and FLASH proton therapy. In addition, oxygen supplementation in anesthesia is particularly detrimental for anti-tumor immune response by preventing a strong immune cell infiltration into tumoral tissues following conventional proton therapy. CONCLUSIONS These results demonstrate the need to further optimize anesthesia protocols used in radiotherapy with the goal of preserving normal tissues and achieving tumor control, specifically in combination with immunotherapy agents.
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Affiliation(s)
- Lorea Iturri
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Annaïg Bertho
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Charlotte Lamirault
- Translational Research Department, Institut Curie, Experimental Radiotherapy Platform, Université Paris Saclay, Orsay, France
| | | | - Marjorie Juchaux
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Cristèle Gilbert
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Julie Espenon
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Catherine Sébrié
- Service Hospitalier Frederic Joliot, CEA, CNRS, Inserm, BIOMAPS Universite Paris-Saclay, Orsay, France
| | - Laurène Jourdain
- Service Hospitalier Frederic Joliot, CEA, CNRS, Inserm, BIOMAPS Universite Paris-Saclay, Orsay, France
| | - Ludovic de Marzi
- Institut Curie, Université PSL, Université Paris-Saclay, Inserm U1288, Laboratoire de Recherche Translationnelle en Oncologie (LITO), Orsay, France
- Institut Curie, Radiation Oncology Department, Campus universitaire, Orsay, France
| | - Frédéric Pouzoulet
- Translational Research Department, Institut Curie, Experimental Radiotherapy Platform, Université Paris Saclay, Orsay, France
- Institut Curie, Université PSL, Université Paris-Saclay, Inserm U1288, Laboratoire de Recherche Translationnelle en Oncologie (LITO), Orsay, France
| | - Jane Muret
- Institut Curie, Université PSL, Department of Anesthesia and Intensive Care, Paris, France
| | - Pierre Verrelle
- Institut Curie, Radiation Oncology Department, Campus universitaire, Orsay, France
- Institut Curie, Université Paris-Saclay, Inserm U1196, CNRS UMR9187, Chimie et Modélisation pour la Biologie du Cancer (CMBC), Orsay, France
| | - Yolanda Prezado
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France.
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France.
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Gupta S, Inman JL, De Chant J, Obst-Huebl L, Nakamura K, Costello SM, Marqusee S, Mao JH, Kunz L, Paisley R, Vozenin MC, Snijders AM, Ralston CY. A Novel Platform for Evaluating Dose Rate Effects on Oxidative Damage to Peptides: Toward a High-Throughput Method to Characterize the Mechanisms Underlying the FLASH Effect. Radiat Res 2023; 200:523-530. [PMID: 38014573 PMCID: PMC10754258 DOI: 10.1667/rade-23-00131.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/05/2023] [Indexed: 11/29/2023]
Abstract
High dose rate radiation has gained considerable interest recently as a possible avenue for increasing the therapeutic window in cancer radiation treatment. The sparing of healthy tissue at high dose rates relative to conventional dose rates, while maintaining tumor control, has been termed the FLASH effect. Although the effect has been validated in animal models using multiple radiation sources, it is not yet well understood. Here, we demonstrate a new experimental platform for quantifying oxidative damage to protein sidechains in solution as a function of radiation dose rate and oxygen availability using liquid chromatography mass spectrometry. Using this reductionist approach, we show that for both X-ray and electron sources, isolated peptides in solution are oxidatively modified to different extents as a function of both dose rate and oxygen availability. Our method provides an experimental platform for exploring the parameter space of the dose rate effect on oxidative changes to proteins in solution.
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Affiliation(s)
- Sayan Gupta
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Jamie L. Inman
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Jared De Chant
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Lieselotte Obst-Huebl
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Kei Nakamura
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Shawn M. Costello
- Biophysics Graduate Program, Department of Chemistry; California Institute for Quantitative Biosciences, University of California, Berkeley, Califormia; Chan Zuckerberg Biohub, San Francisco, California
| | - Susan Marqusee
- Department of Molecular and Cell Biology, Department of Chemistry; California Institute for Quantitative Biosciences, University of California, Berkeley, Califormia; Chan Zuckerberg Biohub, San Francisco, California
| | - Jian-Hua Mao
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Louis Kunz
- University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ryan Paisley
- University Hospital and University of Lausanne, Lausanne, Switzerland
| | | | - Antoine M. Snijders
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Corie Y. Ralston
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
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15
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Ma J, Gao H, Shen X, Bai X, Tang M. A FLASH model of radiolytic oxygen depletion and reactive oxygen species for differential tumor and normal-tissue response. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.10.20.23297337. [PMID: 37961572 PMCID: PMC10635166 DOI: 10.1101/2023.10.20.23297337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Objective FLASH-RT can potentially improve the sparing of normal tissues while preserving the tumoricidal efficiency, owing to the radiation with ultra-high dose rate. However, the FLASH mechanism remains to be solved. A popular FLASH model is based on radiolytic oxygen depletion (ROD), which explains for radiation protection of normal tissues under FLASH-RT. However, ROD does not explain the preservation of tumoricidal efficiency for tumors. This work will develop a ROS+ROD FLASH model that can explain the differential tumor and normal-tissue response. Approach The new FLASH model utilizes reactive oxygen species (ROS) in addition to ROD, and takes into account that ROS level decreases during FLASH-RT. Specifically, the differential-equation model takes into account that the basic ROS level is lower during FLASH-RT and the degeneration rates of ROS are different in tumor cells and healthy cells. Based on this ROS+ROD FLASH model, the surviving fractions of tumor and normal cells are respectively compared between conventional radiotherapy (CONV-RT) and FLASH-RT. Main results While ROD alone does not distinguish the response of tumors and normal tissues to FLASH-RT, the proposed new FLASH model based on ROD and ROS successfully explained the differential response of tumors and normal tissues to FLASH-RT, i.e., the preserved tumoricidal capability, which cannot be explained by ROD alone, and the extra normal-tissue protection owing to the ultra-high dose rate. Significance Since the ROS level decreases slower in tumors than in normal tissues, during FLASH-RT, ROS decreases more in normal tissue, thus can get more protection. By incorporating ROS in addition to ROD, the new FLASH model can not only recover all results by previous FLASH model with ROD alone, but also explain the differential response: preserved lethality of FLASH-RT to tumors and improved protection to normal tissues.
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Affiliation(s)
- Jiangjun Ma
- Institute of Natural Sciences and School of Mathematics, Shanghai Jiao Tong University, Shanghai, China
| | - Hao Gao
- Department of Radiation Oncology, University of Kansas Medical Center, Kansas City, USA
| | - Xing Shen
- Ruijin hospital proton therapy center Shanghai Jiaotong University School of Medicine
| | - Xuemin Bai
- Mevion Medical Systems, Inc., Kunshan, Jiangsu, China
| | - Min Tang
- Institute of Natural Sciences and School of Mathematics, Shanghai Jiao Tong University, Shanghai, China
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16
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Lyu ZQ, Xie YZ, Zhou Y, Cheng YH, Jiang M. Development of a compact high-current repetitive pulsed x-ray system. THE REVIEW OF SCIENTIFIC INSTRUMENTS 2023; 94:103311. [PMID: 37882669 DOI: 10.1063/5.0159227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/04/2023] [Indexed: 10/27/2023]
Abstract
Pulsed x-rays are crucial for various applications such as radiography, biological effects, and the system-generated electromagnetic pulse effect. X rays with a higher dose rate and a higher total dose can generate more significant radiation effects and more effective radiography. However, most pulsed sub-100 keV x-ray systems with high dose rates operate in the single pulse mode with limited total dose, and most repetitive pulsed x-ray systems have a low dose rate. This paper develops a compact high-current repetitive pulsed x-ray system with a low-impedance diode to generate high dose rate pulsed x-rays with an average energy below 100 keV. A diode with a double-ring cathode is designed and tested to produce uniform pulsed x-rays. In order to investigate the x-ray intensity and the pulse number of repetitions for different anode thicknesses, five typical thicknesses are tested. The experimental results show that this system can operate stably at a repetitive rate of 0.2 Hz with a peak voltage of about 200 kV and a peak current of about 100 kA. The dose rate is about 2.4 × 105 Gy(LiF)/s, and the average x-ray energy is about 55 keV with the 40 µm thick tantalum anode. The x-ray uniformity is better than 2:1 over the measuring plane.
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Affiliation(s)
- Ze-Qi Lyu
- State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, 710049 Xi'an, Shaanxi, China
| | - Yan-Zhao Xie
- State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, 710049 Xi'an, Shaanxi, China
| | - Yi Zhou
- State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, 710049 Xi'an, Shaanxi, China
| | - Yin-Hui Cheng
- State Key Laboratory of Electrical Insulation and Power Equipment, School of Electrical Engineering, Xi'an Jiaotong University, 710049 Xi'an, Shaanxi, China
| | - Ming Jiang
- Key Laboratory of Physical Electronics and Devices of the Ministry of Education, Faculty of Electronic and Information Engineering, Xi'an Jiaotong University, 710049 Xi'an, Shaanxi, China
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17
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Hu S, Lan X, Zheng J, Bi Y, Ye Y, Si M, Fang Y, Wang J, Liu J, Chen Y, Chen Y, Xiang P, Niu T, Huang Y. The dose-related plateau effect of surviving fraction in normal tissue during the ultra-high-dose-rate radiotherapy. Phys Med Biol 2023; 68:185004. [PMID: 37586385 DOI: 10.1088/1361-6560/acf112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/16/2023] [Indexed: 08/18/2023]
Abstract
Objective.Ultra-high-dose-rate radiotherapy, referred to as FLASH therapy, has been demonstrated to reduce the damage of normal tissue as well as inhibiting tumor growth compared with conventional dose-rate radiotherapy. The transient hypoxia may be a vital explanation for sparing the normal tissue. The heterogeneity of oxygen distribution for different doses and dose rates in the different radiotherapy schemes are analyzed. With these results, the influence of doses and dose rates on cell survival are evaluated in this work.Approach.The two-dimensional reaction-diffusion equations are used to describe the heterogeneity of the oxygen distribution in capillaries and tissue. A modified linear quadratic model is employed to characterize the surviving fraction at different doses and dose rates.Main results.The reduction of the damage to the normal tissue can be observed if the doses exceeds a minimum dose threshold under the ultra-high-dose-rate radiation. Also, the surviving fraction exhibits the 'plateau effect' under the ultra-high dose rates radiation, which signifies that within a specific range of doses, the surviving fraction either exhibits minimal variation or increases with the dose. For a given dose, the surviving fraction increases with the dose rate until tending to a stable value, which means that the protection in normal tissue reaches saturation.Significance.The emergence of the 'plateau effect' allows delivering the higher doses while minimizing damage to normal tissue. It is necessary to develop appropriate program of doses and dose rates for different irradiated tissue to achieve more efficient protection.
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Affiliation(s)
- Shuai Hu
- School of Physics and Astronomy, China West Normal University, Nanchong 637009, People's Republic of China
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
| | - Xiaofei Lan
- School of Physics and Astronomy, China West Normal University, Nanchong 637009, People's Republic of China
| | - Jinfen Zheng
- Dermatology, Center for Chronic Disease Prevention of Shenzhen, Guangdong Shenzhen 518020, People's Republic of China
| | - Yuanjie Bi
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
| | - Yuanchun Ye
- Department of Hematology, Oncology and Cancer Immunology Campus Benjamin Franklin Charité-Universitätsmedizin Berlin Corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin Hindenburgdamm, 30,12203, Berlin Germany
| | - Meiyu Si
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
- University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China
| | - Yuhong Fang
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
| | - Jinghui Wang
- Varian Medical Systems, Palo Alto, CA 94304, United States of America
| | - Junyan Liu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA 94304, United States of America
| | - Yuan Chen
- The Institute for Advanced Studies of Wuhan University, 299, Bayi Road, Wuhan, 430072, People's Republic of China
| | - Yuling Chen
- Department of Rheumatology and Immunology, The Seventh Affiliated Hospital Sun Yat-sen University, Shenzhen 518107, People's Republic of China
| | - Pai Xiang
- The Institute for Advanced Studies of Wuhan University, 299, Bayi Road, Wuhan, 430072, People's Republic of China
| | - Tianye Niu
- Shenzhen Bay Laboratory, Shenzhen 518107, People's Republic of China
| | - Yongsheng Huang
- School of Science, Sun Yat-Sen University, Shenzhen 518107, People's Republic of China
- Institute of High Energy Physics, Chinese Academy of Sciences, Beijing 100049, People's Republic of China
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18
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Deffet S, Hamaide V, Sterpin E. Definition of dose rate for FLASH pencil-beam scanning proton therapy: A comparative study. Med Phys 2023; 50:5784-5792. [PMID: 37439504 DOI: 10.1002/mp.16607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/28/2023] [Accepted: 06/20/2023] [Indexed: 07/14/2023] Open
Abstract
BACKGROUND FLASH proton therapy has the potential to reduce side effects of conventional proton therapy by delivering a high dose of radiation in a very short period of time. However, significant progress is needed in the development of FLASH proton therapy. Increasing the dose rate while maintaining dose conformality may involve the use of advanced beam-shaping technologies and specialized equipment such as 3D patient-specific range modulators, to take advantage of the higher transmission efficiency at the highest energy available. The dose rate is an important factor in FLASH proton therapy, but its definition can vary because of the uneven distribution of the dose over time in pencil-beam scanning (PBS). PURPOSE Highlight the distinctions, both in terms of concept and numerical values, of the various definitions that can be established for the dose rate in PBS proton therapy. METHODS In an in silico study, five definitions of the dose rate, namely the PBS dose rate, the percentile dose rate, the maximum percentile dose rate, the average dose rate, and the dose averaged dose rate (DADR) were analyzed first through theoretical comparison, and then applied to a head and neck case. To carry out this study, a treatment plan utilizing a single energy level and requiring the use of a patient-specific range modulator was employed. The dose rate values were compared both locally and by means of dose rate volume histograms (DRVHs). RESULTS The PBS dose rate, the percentile dose rate, and the maximum percentile dose are definitions that are specifically designed to take into account the time structure of the delivery of a PBS treatment plan. Although they may appear similar, our study shows that they can vary locally by up to 10%. On the other hand, the DADR values were approximately twice as high as those of the PBS, percentile, and maximum percentile dose rates, since the DADR disregards the periods when a voxel does not receive any dose. Finally, the average dose rate can be defined in various ways, as discussed in this paper. The average dose rate is found to be lower by a factor of approximately 1/2 than the PBS, percentile, and maximum percentile dose rates. CONCLUSIONS We have shown that using different definitions for the dose rate in FLASH proton therapy can lead to variations in calculated values ranging from a few percent to a factor of two. Since the dose rate is a critical parameter in FLASH radiation therapy, it is essential to carefully consider the choice of definition. However, to make an informed decision, additional biological data and models are needed.
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Affiliation(s)
- Sylvain Deffet
- Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Louvain-La-Neuve, Belgium
| | | | - Edmond Sterpin
- Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Louvain-La-Neuve, Belgium
- Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven, Leuven, Belgium
- Particle Therapy Interuniversity Center Leuven-PARTICLE, Leuven, Belgium
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19
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Clements N, Esplen N, Bazalova-Carter M. A feasibility study of ultra-high dose rate mini-GRID therapy using very-high-energy electron beams for a simulated pediatric brain case. Phys Med 2023; 112:102637. [PMID: 37454482 DOI: 10.1016/j.ejmp.2023.102637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 05/09/2023] [Accepted: 07/04/2023] [Indexed: 07/18/2023] Open
Abstract
Ultra-high dose rate (UHDR, >40 Gy/s), spatially-fractionated minibeam GRID (mini-GRID) therapy using very-high-energy electrons (VHEE) was investigated using Monte Carlo simulations. Multi-directional VHEE treatments with and without mini-GRID-fractionation were compared to a clinical 6 MV volumetric modulated arc therapy (VMAT) plan for a pediatric glioblastoma patient using dose-volume histograms, volume-averaged dose rates in critical patient structures, and planning target volume D98s. Peak-to-valley dose ratios (PVDRs) and dose rates in organs at risk (OARs) were evaluated due to their relevance for normal-tissue sparing in FLASH and spatially-fractionated techniques. Depths of convergence, defined where the PVDR is first ≤1.1, and depths at which dose rates fall below the UHDR threshold were also evaluated. In a water phantom, the VHEE mini-GRID treatments presented a surface (5 mm depth) PVDR of (51±2) and a depth of convergence of 42 mm at 150 MeV and a surface PVDR of (33±1) with a depth of convergence of 57 mm at 250 MeV. For a pediatric GBM case, VHEE treatments without mini-GRID-fractionation produced 25% and 22% lower volume-averaged doses to OARs compared to the 6 MV VMAT plan and 8/9 and 9/9 of the patient structures were exposed to volume-averaged dose rates >40 Gy/s for the 150 MeV and 250 MeV plans, respectively. The 150 MeV and 250 MeV mini-GRID treatments produced 17% and 38% higher volume-averaged doses to OARs and 3/9 patient structures had volume-averaged dose rates above 40 Gy/s. VHEE mini-GRID plans produced many comparable dose metrics to the clinical VMAT plan, encouraging further optimization.
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Affiliation(s)
- Nathan Clements
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada.
| | - Nolan Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
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20
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Pennock M, Wei S, Cheng C, Lin H, Hasan S, Chhabra AM, Choi JI, Bakst RL, Kabarriti R, Simone II CB, Lee NY, Kang M, Press RH. Proton Bragg Peak FLASH Enables Organ Sparing and Ultra-High Dose-Rate Delivery: Proof of Principle in Recurrent Head and Neck Cancer. Cancers (Basel) 2023; 15:3828. [PMID: 37568644 PMCID: PMC10417542 DOI: 10.3390/cancers15153828] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 07/21/2023] [Accepted: 07/25/2023] [Indexed: 08/13/2023] Open
Abstract
Proton pencil-beam scanning (PBS) Bragg peak FLASH combines ultra-high dose rate delivery and organ-at-risk (OAR) sparing. This proof-of-principle study compared dosimetry and dose rate coverage between PBS Bragg peak FLASH and PBS transmission FLASH in head and neck reirradiation. PBS Bragg peak FLASH plans were created via the highest beam single energy, range shifter, and range compensator, and were compared to PBS transmission FLASH plans for 6 GyE/fraction and 10 GyE/fraction in eight recurrent head and neck patients originally treated with quad shot reirradiation (14.8/3.7 CGE). The 6 GyE/fraction and 10 GyE/fraction plans were also created using conventional-rate intensity-modulated proton therapy techniques. PBS Bragg peak FLASH, PBS transmission FLASH, and conventional plans were compared for OAR sparing, FLASH dose rate coverage, and target coverage. All FLASH OAR V40 Gy/s dose rate coverage was 90-100% at 6 GyE and 10 GyE for both FLASH modalities. PBS Bragg peak FLASH generated dose volume histograms (DVHs) like those of conventional therapy and demonstrated improved OAR dose sparing over PBS transmission FLASH. All the modalities had similar CTV coverage. PBS Bragg peak FLASH can deliver conformal, ultra-high dose rate FLASH with a two-millisecond delivery of the minimum MU per spot. PBS Bragg peak FLASH demonstrated similar dose rate coverage to PBS transmission FLASH with improved OAR dose-sparing, which was more pronounced in the 10 GyE/fraction than in the 6 GyE/fraction. This feasibility study generates hypotheses for the benefits of FLASH in head and neck reirradiation and developing biological models.
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Affiliation(s)
- Michael Pennock
- Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, New York, NY 10461, USA;
| | - Shouyi Wei
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Chingyun Cheng
- Department of Radiation Oncology, Rutgers Cancer Institute of New Jersey, New Brunswick, NJ 08901, USA;
| | - Haibo Lin
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Shaakir Hasan
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Arpit M. Chhabra
- Department of Radiation Oncology, New York Proton Center, New York, NY 10035, USA; (A.M.C.); (J.I.C.); (C.B.S.II)
| | - J. Isabelle Choi
- Department of Radiation Oncology, New York Proton Center, New York, NY 10035, USA; (A.M.C.); (J.I.C.); (C.B.S.II)
| | - Richard L. Bakst
- Department of Radiation Oncology—Radiation Oncology Associates, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;
| | - Rafi Kabarriti
- Department of Radiation Oncology, Albert Einstein College of Medicine, Montefiore Medical Center, New York, NY 10461, USA;
| | - Charles B. Simone II
- Department of Radiation Oncology, New York Proton Center, New York, NY 10035, USA; (A.M.C.); (J.I.C.); (C.B.S.II)
| | - Nancy Y. Lee
- Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
| | - Minglei Kang
- Department of Physics, New York Proton Center, New York, NY 10035, USA; (S.W.); (H.L.); (S.H.); (M.K.)
| | - Robert H. Press
- Department of Radiation Oncology, Baptist Health South Florida, Miami Cancer Institute, Miami, FL 33176, USA;
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21
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Tan HS, Teo KBK, Dong L, Friberg A, Koumenis C, Diffenderfer E, Zou JW. Modeling ultra-high dose rate electron and proton FLASH effect with the physicochemical approach. Phys Med Biol 2023; 68:10.1088/1361-6560/ace14d. [PMID: 37352867 PMCID: PMC10472835 DOI: 10.1088/1361-6560/ace14d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/23/2023] [Indexed: 06/25/2023]
Abstract
Objective. A physicochemical model built on the radiochemical kinetic theory was recently proposed in (Labarbeet al2020) to explain the FLASH effect. We performed extensive simulations to scrutinize its applicability for oxygen depletion studies and FLASH-related experiments involving both proton and electron beams.Approach. Using the dose and beam delivery parameters for each FLASH experiment, we numerically solved the radiochemical rate equations comprised of a set of coupled nonlinear ordinary differential equations to obtain the area under the curve (AUC) of radical concentrations.Main results. The modeled differences in AUC induced by ultra-high dose rates appeared to correlate well with the FLASH effect. (i) For the whole brain irradiation of mice performed in (Montay-Gruelet al2017), the threshold dose rate values for memory preservation coincided with those at which AUC started to decrease much less rapidly. (ii) For the proton pencil beam scanning FLASH of (Cunninghamet al2021), we found linear correlations between radicals' AUC and the biological endpoints: TGF-β1, leg contracture and plasma level of cytokine IL-6. (iii) Compatible with the findings of the proton FLASH experiment in (Kimet al2021), we found that radicals' AUC at the entrance and mid-Spread-Out Bragg peak regions were highly similar. In addition, our model also predicted ratios of oxygen depletionG-values between normal and UHDR irradiation similar to those observed in (Caoet al2021) and (El Khatibet al2022).Significance. Collectively, our results suggest that the normal tissue sparing conferred by UHDR irradiation may be due to the lower degree of exposure to peroxyl and superoxide radicals. We also found that the differential effect of dose rate on the radicals' AUC was less pronounced at lower initial oxygen levels, a trait that appears to align with the FLASH differential effect on normal versus tumor tissues.
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Affiliation(s)
- Hai Siong Tan
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Kevin Boon Keng Teo
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Lei Dong
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Andrew Friberg
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Constantinos Koumenis
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Eric Diffenderfer
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Jennifer Wei Zou
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
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22
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D-Kondo JN, Garcia-Garcia OR, LaVerne JA, Faddegon B, Schuemann J, Shin WG, Ramos-Méndez J. An integrated Monte Carlo track-structure simulation framework for modeling inter and intra-track effects on homogenous chemistry. Phys Med Biol 2023; 68:10.1088/1361-6560/acd6d0. [PMID: 37201533 PMCID: PMC10355172 DOI: 10.1088/1361-6560/acd6d0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 05/18/2023] [Indexed: 05/20/2023]
Abstract
Objective. The TOPAS-nBio Monte Carlo track structure simulation code, a wrapper of Geant4-DNA, was extended for its use in pulsed and longtime homogeneous chemistry simulations using the Gillespie algorithm.Approach. Three different tests were used to assess the reliability of the implementation and its ability to accurately reproduce published experimental results: (1) a simple model with a known analytical solution, (2) the temporal evolution of chemical yields during the homogeneous chemistry stage, and (3) radiolysis simulations conducted in pure water with dissolved oxygen at concentrations ranging from 10μM to 1 mM with [H2O2] yields calculated for 100 MeV protons at conventional and FLASH dose rates of 0.286 Gy s-1and 500 Gy s-1, respectively. Simulated chemical yield results were compared closely with data calculated using the Kinetiscope software which also employs the Gillespie algorithm.Main results. Validation results in the third test agreed with experimental data of similar dose rates and oxygen concentrations within one standard deviation, with a maximum of 1% difference for both conventional and FLASH dose rates. In conclusion, the new implementation of TOPAS-nBio for the homogeneous long time chemistry simulation was capable of recreating the chemical evolution of the reactive intermediates that follow water radiolysis.Significance. Thus, TOPAS-nBio provides a reliable all-in-one chemistry simulation of the physical, physico-chemical, non-homogeneous, and homogeneous chemistry and could be of use for the study of FLASH dose rate effects on radiation chemistry.
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Affiliation(s)
- J. Naoki D-Kondo
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94115, United States of America
| | - Omar R. Garcia-Garcia
- Faculty of Mathematics and Physics Sciences, Benemérita Universidad Autónoma de Puebla, Puebla 72000, Mexico
| | - Jay A. LaVerne
- Radiation Laboratory and Department of Physics, University of Notre Dame, Notre Dame, IN 46556, United States of America
| | - Bruce Faddegon
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94115, United States of America
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - Wook-Geun Shin
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States of America
| | - José Ramos-Méndez
- Department of Radiation Oncology, University of California San Francisco, San Francisco, CA 94115, United States of America
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23
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Camazzola G, Boscolo D, Scifoni E, Dorn A, Durante M, Krämer M, Abram V, Fuss MC. TRAX-CHEMxt: Towards the Homogeneous Chemical Stage of Radiation Damage. Int J Mol Sci 2023; 24:ijms24119398. [PMID: 37298351 DOI: 10.3390/ijms24119398] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/18/2023] [Accepted: 05/24/2023] [Indexed: 06/12/2023] Open
Abstract
The indirect effect of radiation plays an important role in radio-induced biological damages. Monte Carlo codes have been widely used in recent years to study the chemical evolution of particle tracks. However, due to the large computational efforts required, their applicability is typically limited to simulations in pure water targets and to temporal scales up to the µs. In this work, a new extension of TRAX-CHEM is presented, namely TRAX-CHEMxt, able to predict the chemical yields at longer times, with the capability of exploring the homogeneous biochemical stage. Based on the species coordinates produced around one track, the set of reaction-diffusion equations is solved numerically with a computationally light approach based on concentration distributions. In the overlapping time scale (500 ns-1 µs), a very good agreement to standard TRAX-CHEM is found, with deviations below 6% for different beam qualities and oxygenations. Moreover, an improvement in the computational speed by more than three orders of magnitude is achieved. The results of this work are also compared with those from another Monte Carlo-based algorithm and a fully homogeneous code (Kinetiscope). TRAX-CHEMxt will allow for studying the variation in chemical endpoints at longer timescales with the introduction, as the next step, of biomolecules, for more realistic assessments of biological response under different radiation and environmental conditions.
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Affiliation(s)
- Gianmarco Camazzola
- Biophysics Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291 Darmstadt, Germany
- Quantum Dynamics and Control Division, Max Planck Institute for Nuclear Physics, 69117 Heidelberg, Germany
- Department of Physics and Astronomy, Heidelberg University, 69120 Heidelberg, Germany
| | - Daria Boscolo
- Biophysics Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291 Darmstadt, Germany
| | - Emanuele Scifoni
- Trento Institute for Fundamental Physics and Applications (TIFPA), National Institute for Nuclear Physics (INFN), 38123 Povo, Italy
| | - Alexander Dorn
- Quantum Dynamics and Control Division, Max Planck Institute for Nuclear Physics, 69117 Heidelberg, Germany
| | - Marco Durante
- Biophysics Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291 Darmstadt, Germany
- Institute for Condensed Matter Physics, Technical University of Darmstadt, 64289 Darmstadt, Germany
| | - Michael Krämer
- Biophysics Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291 Darmstadt, Germany
| | - Valentino Abram
- Department of Mathematics, University of Trento, 38123 Povo, Italy
| | - Martina C Fuss
- Biophysics Department, GSI Helmholtz Centre for Heavy Ion Research GmbH, 64291 Darmstadt, Germany
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24
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Chappuis F, Tran HN, Zein SA, Bailat C, Incerti S, Bochud F, Desorgher L. The general-purpose Geant4 Monte Carlo toolkit and its Geant4-DNA extension to investigate mechanisms underlying the FLASH effect in radiotherapy: Current status and challenges. Phys Med 2023; 110:102601. [PMID: 37201453 DOI: 10.1016/j.ejmp.2023.102601] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/06/2023] [Accepted: 05/01/2023] [Indexed: 05/20/2023] Open
Abstract
FLASH radiotherapy is a promising approach to cancer treatment that offers several advantages over conventional radiotherapy. With this novel technique, high doses of radiation are delivered in a short period of time, inducing the so-called FLASH effect - a phenomenon characterized by healthy tissue sparing without alteration of tumor control. The mechanisms behind the FLASH effect remain unknown. One way to approach this problem is to gain insight into the initial parameters that can distinguish FLASH from conventional irradiation by simulating particle transport in aqueous media using the general-purpose Geant4 Monte Carlo toolkit and its Geant4-DNA extension. This review article discusses the current status of Geant4 and Geant4-DNA simulations to investigate mechanisms underlying the FLASH effect, as well as the challenges faced in this research field. One of the primary challenges is to accurately simulate the experimental irradiation parameters. Another challenge is the temporal extension of the simulations. This review also focuses on two hypotheses to explain the FLASH effect - namely the oxygen depletion hypothesis and the inter-track interactions hypothesis - and discusses how the Geant4 toolkit can be used to investigate them. The aim of this review is to provide an overview of Geant4 and Geant4-DNA simulations for FLASH radiotherapy and to highlight the challenges that need to be overcome in order to better study the FLASH effect.
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Affiliation(s)
- Flore Chappuis
- Institute of Radiation Physics (IRA), Lausanne University Hospital and University of Lausanne, CH-1007 Lausanne, Switzerland
| | - Hoang Ngoc Tran
- Univ. Bordeaux, CNRS, LP2I Bordeaux, UMR 5797, F-33170 Gradignan, France
| | - Sara A Zein
- Univ. Bordeaux, CNRS, LP2I Bordeaux, UMR 5797, F-33170 Gradignan, France
| | - Claude Bailat
- Institute of Radiation Physics (IRA), Lausanne University Hospital and University of Lausanne, CH-1007 Lausanne, Switzerland
| | - Sébastien Incerti
- Univ. Bordeaux, CNRS, LP2I Bordeaux, UMR 5797, F-33170 Gradignan, France
| | - François Bochud
- Institute of Radiation Physics (IRA), Lausanne University Hospital and University of Lausanne, CH-1007 Lausanne, Switzerland
| | - Laurent Desorgher
- Institute of Radiation Physics (IRA), Lausanne University Hospital and University of Lausanne, CH-1007 Lausanne, Switzerland.
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25
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Atkinson J, Bezak E, Le H, Kempson I. The current status of FLASH particle therapy: a systematic review. Phys Eng Sci Med 2023; 46:529-560. [PMID: 37160539 DOI: 10.1007/s13246-023-01266-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 04/20/2023] [Indexed: 05/11/2023]
Abstract
Particle therapies are becoming increasingly available clinically due to their beneficial energy deposition profile, sparing healthy tissues. This may be further promoted with ultra-high dose rates, termed FLASH. This review comprehensively summarises current knowledge based on studies relevant to proton- and carbon-FLASH therapy. As electron-FLASH literature presents important radiobiological findings that form the basis of proton and carbon-based FLASH studies, a summary of key electron-FLASH papers is also included. Preclinical data suggest three key mechanisms by which proton and carbon-FLASH are able to reduce normal tissue toxicities compared to conventional dose rates, with equipotent, or enhanced, tumour kill efficacy. However, a degree of caution is needed in clinically translating these findings as: most studies use transmission and do not conform the Bragg peak to tumour volume; mechanistic understanding is still in its infancy; stringent verification of dosimetry is rarely provided; biological assays are prone to limitations which need greater acknowledgement.
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Affiliation(s)
- Jake Atkinson
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, 5095, Australia
| | - Eva Bezak
- Cancer Research Institute, University of South Australia, Adelaide, South Australia, 5000, Australia
- Department of Physics, University of Adelaide, North Terrace, Adelaide, South Australia, 5000, Australia
| | - Hien Le
- Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide, 5000, Australia
| | - Ivan Kempson
- Future Industries Institute, University of South Australia, Mawson Lakes, South Australia, 5095, Australia.
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26
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Zhang Q, Gerweck LE, Cascio E, Gu L, Yang Q, Dong X, Huang P, Bertolet A, Nesteruk KP, Sung W, McNamara AL, Schuemann J. Absence of Tissue-Sparing Effects in Partial Proton FLASH Irradiation in Murine Intestine. Cancers (Basel) 2023; 15:cancers15082269. [PMID: 37190197 DOI: 10.3390/cancers15082269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 05/17/2023] Open
Abstract
Ultra-high dose rate irradiation has been reported to protect normal tissues more than conventional dose rate irradiation. This tissue sparing has been termed the FLASH effect. We investigated the FLASH effect of proton irradiation on the intestine as well as the hypothesis that lymphocyte depletion is a cause of the FLASH effect. A 16 × 12 mm2 elliptical field with a dose rate of ~120 Gy/s was provided by a 228 MeV proton pencil beam. Partial abdominal irradiation was delivered to C57BL/6j and immunodeficient Rag1-/-/C57 mice. Proliferating crypt cells were counted at 2 days post exposure, and the thickness of the muscularis externa was measured at 280 days following irradiation. FLASH irradiation did not reduce the morbidity or mortality of conventional irradiation in either strain of mice; in fact, a tendency for worse survival in FLASH-irradiated mice was observed. There were no significant differences in lymphocyte numbers between FLASH and conventional-dose-rate mice. A similar number of proliferating crypt cells and a similar thickness of the muscularis externa following FLASH and conventional dose rate irradiation were observed. Partial abdominal FLASH proton irradiation at 120 Gy/s did not spare normal intestinal tissue, and no difference in lymphocyte depletion was observed. This study suggests that the effect of FLASH irradiation may depend on multiple factors, and in some cases dose rates of over 100 Gy/s do not induce a FLASH effect and can even result in worse outcomes.
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Affiliation(s)
- Qixian Zhang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Leo E Gerweck
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Ethan Cascio
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Liqun Gu
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Qingyuan Yang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Xinyue Dong
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Peigen Huang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Alejandro Bertolet
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Konrad Pawel Nesteruk
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Wonmo Sung
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Aimee L McNamara
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Jan Schuemann
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
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27
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Cooper CR, Jones DJL, Jones GDD, Petersson K. Comet Assay Profiling of FLASH-Induced Damage: Mechanistic Insights into the Effects of FLASH Irradiation. Int J Mol Sci 2023; 24:7195. [PMID: 37108360 PMCID: PMC10138874 DOI: 10.3390/ijms24087195] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 04/06/2023] [Accepted: 04/10/2023] [Indexed: 04/29/2023] Open
Abstract
Numerous studies have demonstrated the normal tissue-sparing effects of ultra-high dose rate 'FLASH' irradiation in vivo, with an associated reduction in damage burden being reported in vitro. Towards this, two key radiochemical mechanisms have been proposed: radical-radical recombination (RRR) and transient oxygen depletion (TOD), with both being proposed to lead to reduced levels of induced damage. Previously, we reported that FLASH induces lower levels of DNA strand break damage in whole-blood peripheral blood lymphocytes (WB-PBL) ex vivo, but our study failed to distinguish the mechanism(s) involved. A potential outcome of RRR is the formation of crosslink damage (particularly, if any organic radicals recombine), whilst a possible outcome of TOD is a more anoxic profile of induced damage resulting from FLASH. Therefore, the aim of the current study was to profile FLASH-induced damage via the Comet assay, assessing any DNA crosslink formation as a putative marker of RRR and/or anoxic DNA damage formation as an indicative marker of TOD, to determine the extent to which either mechanism contributes to the "FLASH effect". Following FLASH irradiation, we see no evidence of any crosslink formation; however, FLASH irradiation induces a more anoxic profile of induced damage, supporting the TOD mechanism. Furthermore, treatment of WB-PBLs pre-irradiation with BSO abrogates the reduced strand break damage burden mediated by FLASH exposures. In summary, we do not see any experimental evidence to support the RRR mechanism contributing to the reduced damage burden induced by FLASH. However, the observation of a greater anoxic profile of damage following FLASH irradiation, together with the BSO abrogation of the reduced strand break damage burden mediated by FLASH, lends further support to TOD being a driver of the reduced damage burden plus a change in the damage profile mediated by FLASH.
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Affiliation(s)
- Christian R. Cooper
- Leicester Cancer Research Centre, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester LE2 7LX, UK; (D.J.L.J.); (G.D.D.J.)
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
| | - Donald J. L. Jones
- Leicester Cancer Research Centre, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester LE2 7LX, UK; (D.J.L.J.); (G.D.D.J.)
| | - George D. D. Jones
- Leicester Cancer Research Centre, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester LE2 7LX, UK; (D.J.L.J.); (G.D.D.J.)
| | - Kristoffer Petersson
- MRC Oxford Institute for Radiation Oncology, University of Oxford, Old Road Campus Research Building, Oxford OX3 7DQ, UK
- Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital Lund University, 221 85 Lund, Sweden
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Klett KC, Martin-Villa BC, Villarreal VS, Melemenidis S, Viswanathan V, Manjappa R, Ashraf MR, Soto L, Lau B, Dutt S, Rankin EB, Loo BW, Heilshorn SC. Human enteroids as a tool to study conventional and ultra-high dose rate radiation. Integr Biol (Camb) 2023; 15:zyad013. [PMID: 37874173 PMCID: PMC10594601 DOI: 10.1093/intbio/zyad013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/25/2023]
Abstract
Radiation therapy, one of the most effective therapies to treat cancer, is highly toxic to healthy tissue. The delivery of radiation at ultra-high dose rates, FLASH radiation therapy (FLASH), has been shown to maintain therapeutic anti-tumor efficacy while sparing normal tissues compared to conventional dose rate irradiation (CONV). Though promising, these studies have been limited mainly to murine models. Here, we leveraged enteroids, three-dimensional cell clusters that mimic the intestine, to study human-specific tissue response to radiation. We observed enteroids have a greater colony growth potential following FLASH compared with CONV. In addition, the enteroids that reformed following FLASH more frequently exhibited proper intestinal polarity. While we did not observe differences in enteroid damage across groups, we did see distinct transcriptomic changes. Specifically, the FLASH enteroids upregulated the expression of genes associated with the WNT-family, cell-cell adhesion, and hypoxia response. These studies validate human enteroids as a model to investigate FLASH and provide further evidence supporting clinical study of this therapy. Insight Box Promising work has been done to demonstrate the potential of ultra-high dose rate radiation (FLASH) to ablate cancerous tissue, while preserving healthy tissue. While encouraging, these findings have been primarily observed using pre-clinical murine and traditional two-dimensional cell culture. This study validates the use of human enteroids as a tool to investigate human-specific tissue response to FLASH. Specifically, the work described demonstrates the ability of enteroids to recapitulate previous in vivo findings, while also providing a lens through which to probe cellular and molecular-level responses to FLASH. The human enteroids described herein offer a powerful model that can be used to probe the underlying mechanisms of FLASH in future studies.
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Affiliation(s)
- Katarina C Klett
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Victoria S Villarreal
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Luis Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Erinn B Rankin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Sarah C Heilshorn
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
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Froidevaux P, Grilj V, Bailat C, Geyer WR, Bochud F, Vozenin MC. FLASH irradiation does not induce lipid peroxidation in lipids micelles and liposomes. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2022.110733] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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30
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Liew H, Mein S, Tessonnier T, Abdollahi A, Debus J, Dokic I, Mairani A. Do We Preserve Tumor Control Probability (TCP) in FLASH Radiotherapy? A Model-Based Analysis. Int J Mol Sci 2023; 24:5118. [PMID: 36982185 PMCID: PMC10049554 DOI: 10.3390/ijms24065118] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2023] [Revised: 03/01/2023] [Accepted: 03/02/2023] [Indexed: 03/30/2023] Open
Abstract
Reports of concurrent sparing of normal tissue and iso-effective treatment of tumors at ultra-high dose-rates (uHDR) have fueled the growing field of FLASH radiotherapy. However, iso-effectiveness in tumors is often deduced from the absence of a significant difference in their growth kinetics. In a model-based analysis, we investigate the meaningfulness of these indications for the clinical treatment outcome. The predictions of a previously benchmarked model of uHDR sparing in the "UNIfied and VERSatile bio response Engine" (UNIVERSE) are combined with existing models of tumor volume kinetics as well as tumor control probability (TCP) and compared to experimental data. The potential TCP of FLASH radiotherapy is investigated by varying the assumed dose-rate, fractionation schemes and oxygen concentration in the target. The developed framework describes the reported tumor growth kinetics appropriately, indicating that sparing effects could be present in the tumor but might be too small to be detected with the number of animals used. The TCP predictions show the possibility of substantial loss of treatment efficacy for FLASH radiotherapy depending on several variables, including the fractionation scheme, oxygen level, and DNA repair kinetics. The possible loss of TCP should be seriously considered when assessing the clinical viability of FLASH treatments.
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Affiliation(s)
- Hans Liew
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Heidelberg University Hospital (UKHD), Heidelberg Ion-Beam Therapy Center (HIT), 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Stewart Mein
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Heidelberg University Hospital (UKHD), Heidelberg Ion-Beam Therapy Center (HIT), 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA 19104-6303, USA
| | - Thomas Tessonnier
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
| | - Amir Abdollahi
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Heidelberg University Hospital (UKHD), Heidelberg Ion-Beam Therapy Center (HIT), 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Jürgen Debus
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Heidelberg University Hospital (UKHD), Heidelberg Ion-Beam Therapy Center (HIT), 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Department of Radiation Oncology, Heidelberg Institute of Radiation Oncology (HIRO), University Hospital Heidelberg, National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
- Clinical Cooperation Unit Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Ivana Dokic
- Clinical Cooperation Unit Translational Radiation Oncology, German Cancer Consortium (DKTK) Core-Center Heidelberg, National Center for Tumor Diseases (NCT), Heidelberg University Hospital (UKHD) and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
- Division of Molecular and Translational Radiation Oncology, Heidelberg Faculty of Medicine (MFHD) and Heidelberg University Hospital (UKHD), Heidelberg Ion-Beam Therapy Center (HIT), 69120 Heidelberg, Germany
- Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Oncology (NCRO), Heidelberg University Hospital and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Andrea Mairani
- Heidelberg Ion-Beam Therapy Center (HIT), Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- Medical Physics Unit, National Centre of Oncological Hadrontherapy (CNAO), 27100 Pavia, Italy
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Zhang Q, Gerweck LE, Cascio E, Yang Q, Huang P, Niemierko A, Bertolet A, Nesteruk KP, McNamara A, Schuemann J. Proton FLASH effects on mouse skin at different oxygen tensions. Phys Med Biol 2023; 68:10.1088/1361-6560/acb888. [PMID: 36731139 PMCID: PMC11164666 DOI: 10.1088/1361-6560/acb888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 02/02/2023] [Indexed: 02/04/2023]
Abstract
Objective. Irradiation at FLASH dose rates (>40 Gy s-1) has received great attention due to its reported normal tissue sparing effect. The FLASH effect was originally observed in electron irradiations but has since been shown to also occur with both photon and proton beams. Several mechanisms have been proposed to explain the tissue sparing at high dose rates, including effects involving oxygen, such as depletion of oxygen within the irradiated cells. In this study, we investigated the protective role of FLASH proton irradiation on the skin when varying the oxygen concentration.Approach. Our double scattering proton system provided a 1.2 × 1.6 cm2elliptical field at a dose rate of ∼130 Gy s-1. The conventional dose rate was ∼0.4 Gy s-1. The legs of the FVB/N mice were marked with two tattooed dots and fixed in a holder for exposure. To alter the skin oxygen concentration, the mice were breathing pure oxygen or had their legs tied to restrict blood flow. The distance between the two dots was measured to analyze skin contraction over time.Main results. FLASH irradiation mitigated skin contraction by 15% compared to conventional dose rate irradiation. The epidermis thickness and collagen deposition at 75 d following 25 to 30 Gy exposure suggested a long-term protective function in the skin from FLASH irradiation. Providing the mice with oxygen or reducing the skin oxygen concentration removed the dose-rate-dependent difference in response.Significance. FLASH proton irradiation decreased skin contraction, epidermis thickness and collagen deposition compared to standard dose rate irradiations. The observed oxygen-dependence of the FLASH effect is consistent with, but not conclusive of, fast oxygen depletion during the exposure.
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Affiliation(s)
- Qixian Zhang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Leo E Gerweck
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Ethan Cascio
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Qingyuan Yang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Peigen Huang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Andrzej Niemierko
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Alejandro Bertolet
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Konrad Pawel Nesteruk
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Aimee McNamara
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
| | - Jan Schuemann
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA, United States of America
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Konishi T, Kusumoto T, Hiroyama Y, Kobayashi A, Mamiya T, Kodaira S. Induction of DNA strand breaks and oxidative base damages in plasmid DNA by ultra-high dose rate proton irradiation. Int J Radiat Biol 2023; 99:1405-1412. [PMID: 36731459 DOI: 10.1080/09553002.2023.2176562] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Revised: 12/30/2022] [Accepted: 01/26/2023] [Indexed: 02/04/2023]
Abstract
PURPOSE Radiation cancer therapy with ultra-high dose rate (UHDR) exposure, so-called FLASH radiotherapy, appears to reduce normal tissue damage without compromising tumor response to therapy. The aim of this study was to clarify whether a 59.5 MeV proton beam at an UHDR of 48.6 Gy/s could effectively reduce the DNA damage of pBR322 plasmid DNA in solution compared to the conventional dose rate (CONV) of 0.057 Gy/s. MATERIALS AND METHODS A simple system, consisting of pBR322 plasmid DNA in 1× Tris-EDTA buffer, was initially employed for proton beam exposure. We then used formamidopyrimidine-DNA glycosylase (Fpg) enzymes. which convert oxidative base damages of oxidized purines to DNA strand breaks, to quantify DNA single strand breaks (SSBs) and double strand breaks (DSBs) by agarose gel electrophoresis. RESULTS Our findings showed that the SSB induction rate (SSB per plasmid DNA/Gy) at UHDR and the induction of Fpg enzyme sensitive sites (ESS) were significantly reduced in UHDR compared to CONV. However, there was no significant difference in DSB induction and non-DSB cluster damages. CONCLUSIONS UHDR of a 59.5 MeV proton beam could reduce non-clustered, non-DSB damages, such as SSB and sparsely distributed ESS. However, this effect may not be significant in reducing lethal DNA damage that becomes apparent only in acute radiation effects of mammalian cells and in vivo studies.
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Affiliation(s)
- Teruaki Konishi
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Inageku, Japan
- Graduate School of Health Science, Hirosaki University, Hirosaki City, Japan
- Department of Physics, Rikkyo (St. Paul's) University, Tokyo, Japan
| | - Tamon Kusumoto
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Inageku, Japan
| | - Yota Hiroyama
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Inageku, Japan
- Graduate School of Health Science, Hirosaki University, Hirosaki City, Japan
| | - Alisa Kobayashi
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Inageku, Japan
| | - Taisei Mamiya
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Inageku, Japan
- Department of Physics, Rikkyo (St. Paul's) University, Tokyo, Japan
| | - Satoshi Kodaira
- Quantum Life and Medical Science Directorate, National Institutes for Quantum Science and Technology, Inageku, Japan
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Espinosa-Rodriguez A, Villa-Abaunza A, Díaz N, Pérez-Díaz M, Sánchez-Parcerisa D, Udías J, Ibáñez P. Design of an X-ray irradiator based on a standard imaging X-ray tube with FLASH dose-rate capabilities for preclinical research. Radiat Phys Chem Oxf Engl 1993 2023. [DOI: 10.1016/j.radphyschem.2023.110760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Minami K. [2.The Biological Effects of Electron and Current Research Trend]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2023; 79:857-862. [PMID: 37599071 DOI: 10.6009/jjrt.2023-2242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Affiliation(s)
- Kazumasa Minami
- Department of radiation oncology, Osaka University graduate school of medicine
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Wancura J, Egan J, Sajo E, Sudhyadhom A. MRI of radiation chemistry: First images and investigation of potential mechanisms. Med Phys 2023; 50:495-505. [PMID: 36201151 PMCID: PMC9930196 DOI: 10.1002/mp.16011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 08/25/2022] [Accepted: 09/17/2022] [Indexed: 01/25/2023] Open
Abstract
BACKGROUND Paramagnetic species such as O2 and free radicals can enhance T1 and T2 relaxation times. If the change in relaxation time is sufficiently large, the contrast will be generated in magnetic resonance images. Since radiation is known to be capable of altering the concentration of O2 and free radicals during water radiolysis, it may be possible for radiation to induce MR signal change. PURPOSE We present the first reported instance of x-ray-induced MR signal changes in water phantoms and investigate potential paramagnetic relaxation enhancement mechanisms associated with radiation chemistry changes in oxygen and free radical concentrations. METHODS Images of water and 10 mM coumarin phantoms were acquired on a 0.35 T MR-linac before, during, and after a dose delivery of 80 Gy using an inversion-recovery dual-echo sequence with water nullified. Radiation chemistry simulations of these conditions were performed to calculate changes in oxygen and free radical concentrations. Published relaxivity values were then applied to calculate the resulting T1 change, and analytical MR signal equations were used to calculate the associated signal change. RESULTS Compared to pre-irradiation reference images, water phantom images taken during and after irradiation showed little to no change, while coumarin phantom images showed a small signal loss in the irradiated region with a contrast-to-noise ratio (CNR) of 1.0-2.5. Radiation chemistry simulations found oxygen depletion of -11 µM in water and -31 µM in coumarin, resulting in a T1 lengthening of 24 ms and 68 ms respectively, and a simulated CNR of 1.0 and 2.8 respectively. This change was consistent with observations in both direction and magnitude. Steady-state superoxide, hydroxyl, hydroperoxyl, and hydrogen radical concentrations were found to contribute less than 1 ms of T1 change. CONCLUSION Observed radiation-induced MR signal changes were dominated by an oxygen depletion mechanism. Free radicals were concluded to play a minor secondary role under steady-state conditions. Future applications may include in vivo FLASH treatment verification but would require an MR sequence with a better signal-to-noise ratio and higher temporal resolution than the one used in this study.
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Affiliation(s)
- Joshua Wancura
- Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - James Egan
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Erno Sajo
- Department of Physics and Applied Physics, University of Massachusetts Lowell, Lowell, MA 01854, USA
| | - Atchar Sudhyadhom
- Department of Radiation Oncology, Brigham and Women’s Hospital, Dana-Farber Cancer Institute and Harvard Medical School, Boston, MA 02115, USA
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Lv Y, Lv Y, Wang Z, Lan T, Feng X, Chen H, Zhu J, Ma X, Du J, Hou G, Liao W, Yuan K, Wu H. FLASH radiotherapy: A promising new method for radiotherapy. Oncol Lett 2022; 24:419. [PMID: 36284652 PMCID: PMC9580247 DOI: 10.3892/ol.2022.13539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2022] [Accepted: 08/10/2022] [Indexed: 11/06/2022] Open
Abstract
Among the treatments for malignant tumors, radiotherapy is of great significance both as a main treatment and as an adjuvant treatment. Radiation therapy damages cancer cells with ionizing radiation, leading to their death. However, radiation-induced toxicity limits the dose delivered to the tumor, thereby constraining the control effect of radiotherapy on tumor growth. In addition, the delayed toxicity caused by radiotherapy significantly harms the physical and mental health of patients. FLASH-RT, an emerging class of radiotherapy, causes a phenomenon known as the 'FLASH effect', which delivers radiotherapy at an ultra-high dose rate with lower toxicity to normal tissue than conventional radiotherapy to achieve local tumor control. Although its mechanism remains to be fully elucidated, this modality constitutes a potential new approach to treating malignant tumors. In the present review, the current research progress of FLASH-RT and its various particular effects are described, including the status of research on FLASH-RT and its influencing factors. The hypothetic mechanism of action of FLASH-RT is also summarized, providing insight into future tumor treatments.
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Affiliation(s)
- Yinghao Lv
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Yue Lv
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Zhen Wang
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Tian Lan
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Xuping Feng
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Hao Chen
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Jiang Zhu
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Xiao Ma
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Jinpeng Du
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Guimin Hou
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Wenwei Liao
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
| | - Kefei Yuan
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
| | - Hong Wu
- Department of Liver Surgery and Liver Transplantation, State Key Laboratory of Biotherapy and Cancer Center, Sichuan University and Collaborative Innovation Center of Biotherapy, West China Hospital, Chengdu, Sichuan 610000, P.R. China
- Laboratory of Liver Surgery, West China Hospital, Sichuan University, Chengdu, Sichuan 610000, P.R. China
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Zou W, Kim H, Diffenderfer ES, Carlson DJ, Koch CJ, Xiao Y, Teo BK, Kim MM, Metz JM, Fan Y, Maity A, Koumenis C, Busch TM, Wiersma R, Cengel KA, Dong L. A phenomenological model of proton FLASH oxygen depletion effects depending on tissue vasculature and oxygen supply. Front Oncol 2022; 12:1004121. [PMID: 36518319 PMCID: PMC9742361 DOI: 10.3389/fonc.2022.1004121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/11/2022] [Indexed: 11/29/2022] Open
Abstract
Introduction Radiation-induced oxygen depletion in tissue is assumed as a contributor to the FLASH sparing effects. In this study, we simulated the heterogeneous oxygen depletion in the tissue surrounding the vessels and calculated the proton FLASH effective-dose-modifying factor (FEDMF), which could be used for biology-based treatment planning. Methods The dose and dose-weighted linear energy transfer (LET) of a small animal proton irradiator was simulated with Monte Carlo simulation. We deployed a parabolic partial differential equation to account for the generalized radiation oxygen depletion, tissue oxygen diffusion, and metabolic processes to investigate oxygen distribution in 1D, 2D, and 3D solution space. Dose and dose rates, particle LET, vasculature spacing, and blood oxygen supplies were considered. Using a similar framework for the hypoxic reduction factor (HRF) developed previously, the FEDMF was derived as the ratio of the cumulative normoxic-equivalent dose (CNED) between CONV and UHDR deliveries. Results Dynamic equilibrium between oxygen diffusion and tissue metabolism can result in tissue hypoxia. The hypoxic region displayed enhanced radio-resistance and resulted in lower CNED under UHDR deliveries. In 1D solution, comparing 15 Gy proton dose delivered at CONV 0.5 and UHDR 125 Gy/s, 61.5% of the tissue exhibited ≥20% FEDMF at 175 μm vasculature spacing and 18.9 μM boundary condition. This percentage reduced to 34.5% and 0% for 8 and 2 Gy deliveries, respectively. Similar trends were observed in the 3D solution space. The FLASH versus CONV differential effect remained at larger vasculature spacings. A higher FLASH dose rate showed an increased region with ≥20% FEDMF. A higher LET near the proton Bragg peak region did not appear to alter the FLASH effect. Conclusion We developed 1D, 2D, and 3D oxygen depletion simulation process to obtain the dynamic HRF and derive the proton FEDMF related to the dose delivery parameters and the local tissue vasculature information. The phenomenological model can be used to simulate or predict FLASH effects based on tissue vasculature and oxygen concentration data obtained from other experiments.
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Vozenin MC, Bourhis J, Durante M. Towards clinical translation of FLASH radiotherapy. Nat Rev Clin Oncol 2022; 19:791-803. [DOI: 10.1038/s41571-022-00697-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2022] [Indexed: 11/09/2022]
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Potential Molecular Mechanisms behind the Ultra-High Dose Rate "FLASH" Effect. Int J Mol Sci 2022; 23:ijms232012109. [PMID: 36292961 PMCID: PMC9602825 DOI: 10.3390/ijms232012109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/26/2022] [Accepted: 10/08/2022] [Indexed: 11/17/2022] Open
Abstract
FLASH radiotherapy, or the delivery of a dose at an ultra-high dose rate (>40 Gy/s), has recently emerged as a promising tool to enhance the therapeutic index in cancer treatment. The remarkable sparing of normal tissues and equivalent tumor control by FLASH irradiation compared to conventional dose rate irradiation—the FLASH effect—has already been demonstrated in several preclinical models and even in a first patient with T-cell cutaneous lymphoma. However, the biological mechanisms responsible for the differential effect produced by FLASH irradiation in normal and cancer cells remain to be elucidated. This is of great importance because a good understanding of the underlying radiobiological mechanisms and characterization of the specific beam parameters is required for a successful clinical translation of FLASH radiotherapy. In this review, we summarize the FLASH investigations performed so far and critically evaluate the current hypotheses explaining the FLASH effect, including oxygen depletion, the production of reactive oxygen species, and an altered immune response. We also propose a new theory that assumes an important role of mitochondria in mediating the normal tissue and tumor response to FLASH dose rates.
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Gao Y, Liu R, Chang C, Charyyev S, Zhou J, Bradley JD, Liu T, Yang X. A potential revolution in cancer treatment: A topical review of FLASH radiotherapy. J Appl Clin Med Phys 2022; 23:e13790. [PMID: 36168677 PMCID: PMC9588273 DOI: 10.1002/acm2.13790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2022] [Revised: 07/08/2022] [Accepted: 09/01/2022] [Indexed: 11/26/2022] Open
Abstract
FLASH radiotherapy (RT) is a novel technique in which the ultrahigh dose rate (UHDR) (≥40 Gy/s) is delivered to the entire treatment volume. Recent outcomes of in vivo studies show that the UHDR RT has the potential to spare normal tissue without sacrificing tumor control. There is a growing interest in the application of FLASH RT, and the ultrahigh dose irradiation delivery has been achieved by a few experimental and modified linear accelerators. The underlying mechanism of FLASH effect is yet to be fully understood, but the oxygen depletion in normal tissue providing extra protection during FLASH irradiation is a hypothesis that attracts most attention currently. Monte Carlo simulation is playing an important role in FLASH, enabling the understanding of its dosimetry calculations and hardware design. More advanced Monte Carlo simulation tools are under development to fulfill the challenge of reproducing the radiolysis and radiobiology processes in FLASH irradiation. FLASH RT may become one of standard treatment modalities for tumor treatment in the future. This paper presents the history and status of FLASH RT studies with a focus on FLASH irradiation delivery modalities, underlying mechanism of FLASH effect, in vivo and vitro experiments, and simulation studies. Existing challenges and prospects of this novel technique are discussed in this manuscript.
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Affiliation(s)
- Yuan Gao
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - Ruirui Liu
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - Chih‐Wei Chang
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - Serdar Charyyev
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - Jun Zhou
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - Jeffrey D. Bradley
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - Tian Liu
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer InstituteEmory UniversityAtlantaGeorgiaUSA
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Hageman E, Che PP, Dahele M, Slotman BJ, Sminia P. Radiobiological Aspects of FLASH Radiotherapy. Biomolecules 2022; 12:biom12101376. [PMID: 36291585 PMCID: PMC9599153 DOI: 10.3390/biom12101376] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 09/21/2022] [Accepted: 09/22/2022] [Indexed: 11/16/2022] Open
Abstract
Radiotherapy (RT) is one of the primary treatment modalities for cancer patients. The clinical use of RT requires a balance to be struck between tumor effect and the risk of toxicity. Sparing normal tissue is the cornerstone of reducing toxicity. Advances in physical targeting and dose-shaping technology have helped to achieve this. FLASH RT is a promising, novel treatment technique that seeks to exploit a potential normal tissue-sparing effect of ultra-high dose rate irradiation. A significant body of in vitro and in vivo data has highlighted a decrease in acute and late radiation toxicities, while preserving the radiation effect in tumor cells. The underlying biological mechanisms of FLASH RT, however, remain unclear. Three main mechanisms have been hypothesized to account for this differential FLASH RT effect between the tumor and healthy tissue: the oxygen depletion, the DNA damage, and the immune-mediated hypothesis. These hypotheses and molecular mechanisms have been evaluated both in vitro and in vivo. Furthermore, the effect of ultra-high dose rate radiation with extremely short delivery times on the dynamic tumor microenvironment involving circulating blood cells and immune cells in humans is essentially unknown. Therefore, while there is great interest in FLASH RT as a means of targeting tumors with the promise of an increased therapeutic ratio, evidence of a generalized FLASH effect in humans and data to show that FLASH in humans is safe and at least effective against tumors as standard photon RT is currently lacking. FLASH RT needs further preclinical investigation and well-designed in-human studies before it can be introduced into clinical practice.
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Affiliation(s)
- Eline Hageman
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Radiation Oncology, Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Cancer Center Amsterdam, Cancer Biology and Immunology, 1081 HV Amsterdam, The Netherlands
| | - Pei-Pei Che
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Radiation Oncology, Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Cancer Center Amsterdam, Cancer Biology and Immunology, 1081 HV Amsterdam, The Netherlands
| | - Max Dahele
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Radiation Oncology, Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Ben J. Slotman
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Radiation Oncology, Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
| | - Peter Sminia
- Amsterdam UMC Location Vrije Universiteit Amsterdam, Radiation Oncology, Boelelaan 1117, 1081 HV Amsterdam, The Netherlands
- Cancer Center Amsterdam, Cancer Biology and Immunology, 1081 HV Amsterdam, The Netherlands
- Correspondence:
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Lin B, Huang D, Gao F, Yang Y, Wu D, Zhang Y, Feng G, Dai T, Du X. Mechanisms of FLASH effect. Front Oncol 2022; 12:995612. [PMID: 36212435 PMCID: PMC9537695 DOI: 10.3389/fonc.2022.995612] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
FLASH radiotherapy (FLASH-RT) is a novel radiotherapy technology defined as ultra-high dose rate (≥ 40 Gy/s) radiotherapy. The biological effects of FLASH-RT include two aspects: first, compared with conventional dose rate radiotherapy, FLASH-RT can reduce radiation-induced damage in healthy tissue, and second, FLASH-RT can retain antitumor effectiveness. Current research shows that mechanisms of the biological effects of FLASH-RT are related to oxygen. However, due to the short time of FLASH-RT, evidences related to the mechanisms are indirect, and the exact mechanisms of the biological effects of FLASH-RT are not completely clear and some are even contradictory. This review focuses on the mechanisms of the biological effects of FLASH-RT and proposes future research directions.
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Affiliation(s)
- Binwei Lin
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, China
| | - Dan Huang
- Department of Radiology Mianyang Central Hospital, Mianyang, China
| | - Feng Gao
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Yiwei Yang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Dai Wu
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Yu Zhang
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Gang Feng
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Tangzhi Dai
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Xiaobo Du
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
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Jansen J, Beyreuther E, García-Calderón D, Karsch L, Knoll J, Pawelke J, Schürer M, Seco J. oChanges in Radical Levels as a Cause for the FLASH effect: Impact of beam structure parameters at ultra-high dose rates on oxygen depletion in water. Radiother Oncol 2022; 175:193-196. [PMID: 36030933 DOI: 10.1016/j.radonc.2022.08.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 01/15/2023]
Abstract
The influence of different average and bunch dose rates in electron beams on the FLASH effect was investigated. The present study measures O2 content in water at different beam pulse patterns and finds strong correlation with biological data, strengthening the hypothesis of radical-related mechanisms as a reason for the FLASH effect.
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Affiliation(s)
- Jeannette Jansen
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Elke Beyreuther
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiation Physics, Dresden, Germany
| | - Daniel García-Calderón
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Ruprecht-Karls-University, Heidelberg, Germany
| | - Leonhard Karsch
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Jan Knoll
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Ruprecht-Karls-University, Heidelberg, Germany
| | - Jörg Pawelke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Michael Schürer
- National Center for Tumor Diseases Dresden (NCT/UCC), Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Joao Seco
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Ruprecht-Karls-University, Heidelberg, Germany.
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Braşoveanu M, Nemţanu MR. Dual Modification of Starch by Physical Methods Based on Corona Electrical Discharge and Ionizing Radiation: Synergistic Impact on Rheological Behavior. Foods 2022; 11:foods11162479. [PMID: 36010483 PMCID: PMC9407343 DOI: 10.3390/foods11162479] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 08/09/2022] [Accepted: 08/15/2022] [Indexed: 11/26/2022] Open
Abstract
The present paper focuses on evaluating the synergistic effects of dual modification with corona electric discharge (CED) and electron beam irradiation (EBI) on the rheological behavior of starch. Combined treatments were applied successively (CED/EBI and EBI/CED) and compared with single treatments. The outcomes showed that the rheological features of starch were altered by the dual modification in correlation with the irradiation dose mainly as a result of radiation-induced degradation. Decreases in apparent viscosity were described by exponential-like-models according to the order of application of the treatment sequences. The mathematical models allowed the estimation of the irradiation doses for which the viscosity decreased by e times for the dual modified starches (3.3 ± 1.3 kGy for CED/EBI and 5.6 ± 0.5 kGy for EBI/CED, respectively) and the fraction (f) of 0.47 ± 0.10 corresponding to starch granule considered to be affected by plasma. Both dual treatments yielded a synergistic effect, regardless of the order of application of the treatment sequences, being more effective in decreasing starch apparent viscosity than single EBI. However, synergism evaluation proved that the use of plasma as a pre-treatment to irradiation processing could provide benefits up to 20 kGy. These findings support the practical goals of technologists with valuable information that may facilitate or simplify the experimental design of starch dual modification with plasma and ionizing radiation.
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Wei S, Lin H, Isabelle Choi J, Shi C, Simone CB, Kang M. Advanced pencil beam scanning Bragg peak FLASH-RT delivery technique can enhance lung cancer planning treatment outcomes compared to conventional multiple-energy proton PBS techniques. Radiother Oncol 2022; 175:238-247. [PMID: 35961583 DOI: 10.1016/j.radonc.2022.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/01/2022] [Accepted: 08/01/2022] [Indexed: 12/25/2022]
Abstract
PURPOSE To investigate the dosimetric characteristics between an advanced proton pencil beam scanning (PBS) Bragg peak FLASH technique and conventional PBS planning technique in lung tumors. To evaluate the "FLASHness" of single-field in a multiple-field delivery scheme for a hypofractionation regimen and move a step forward to clinical application. METHODS Single-energy PBS Bragg peak FLASH treatment plans were optimized based on a novel Bragg peak tracking technique to enable Bragg peaks to stop at the distal edge of the target. Inverse treatment planning using multiple-field optimization (MFO) can achieve sufficient FLASH dose rate and intensity-modulated proton therapy (IMPT)-equivalent dosimetric quality. The dose rate of organs-at-risk (OARs) and the target were calculated under FLASH machine parameters. A group of 10 consecutive lung SBRT patients was optimized to 34 Gy/fraction using a standard treatment of PBS technique with multiple energy layers as references to the Bragg peak plans. The dosimetric quality was compared between Bragg peak FLASH and conventional plans based on RTOG0915 dose metrics. FLASH dose rate ratios (V40Gy/s) were calculated as a metric of the FLASH-sparing effect. RESULTS For higher dose thresholds, the Bragg peak plans achieved greater V40Gy/s FLASH coverage for all major OARs. The V40Gy/s was close to 100% for all OARs when the dose thresholds were > 5 Gy for full plan and single beam evaluations. The less "FLASHness" region was associated with a low dose distribution, mainly occurring in the PBS field penumbra region. The conventional IMPT treatment plans yielded slightly superior target dose uniformity with a D2%(%) of 108.02% versus that of Bragg peak 300 MU plans of 111.81% (p < 0.01) and that of Bragg peak 1200 MU plans of 115.95% (p < 0.01). No significant difference in dose metrics was found between Bragg peak and IMPT treatment plans for the spinal cord, esophagus, heart, or lung-GTV (all p > 0.05). CONCLUSION Hypofractionated lung Bragg peak plans can maintain comparable plan quality to conventional PBS while achieving sufficient FLASH dose rate coverage for major OARs for each field under the multiple-field delivery scheme. The novel Bragg peak FLASH technique has the potential to enhance lung cancer planning treatment outcomes compared to standard PBS treatment techniques.
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Affiliation(s)
- Shouyi Wei
- New York Proton Center, New York, NY 10035, USA
| | - Haibo Lin
- New York Proton Center, New York, NY 10035, USA.
| | | | - Chengyu Shi
- City of Hope, Orange County, Irvine, CA 92618, USA
| | | | - Minglei Kang
- New York Proton Center, New York, NY 10035, USA.
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Rothwell B, Lowe M, Traneus E, Krieger M, Schuemann J. Treatment planning considerations for the development of FLASH proton therapy. Radiother Oncol 2022; 175:222-230. [PMID: 35963397 DOI: 10.1016/j.radonc.2022.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/21/2022] [Accepted: 08/01/2022] [Indexed: 10/15/2022]
Abstract
With increasing focus on the translation of the observed FLASH effect into clinical practice, this paper presents treatment planning considerations for its development using proton therapy. Potential requirements to induce a FLASH effect are discussed along with the properties of existing proton therapy delivery systems and the changes in planning and delivery approaches required to satisfy these prerequisites. For the exploration of treatment planning approaches for FLASH, developments in treatment planning systems are needed. Flexibility in adapting to new information will be important in such an evolving area. Variations in definitions, threshold values and assumptions can make it difficult to compare different published studies and to interpret previous studies in the context of new information. Together with the fact that much is left to be understood about the underlying mechanism behind the FLASH effect, a systematic and comprehensive approach to information storage is encouraged. Collecting and retaining more detailed information on planned and realised dose delivery as well as reporting the assumptions made in planning studies creates the potential for research to be revisited and re-evaluated in the light of future improvements in understanding. Forward thinking at the time of study development can help facilitate retrospective analysis. This, we hope, will increase the available evidence and accelerate the translation of the FLASH effect into clinical benefit.
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Affiliation(s)
- Bethany Rothwell
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.
| | - Matthew Lowe
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom; Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | | | - Miriam Krieger
- Varian Medical Systems Particle Therapy GmbH & Co. KG, Troisdorf, Germany
| | - Jan Schuemann
- Division of Physics, Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Böhlen TT, Germond JF, Bourhis J, Vozenin MC, Ozsahin EM, Bochud F, Bailat C, Moeckli R. Normal tissue sparing by FLASH as a function of single fraction dose: A quantitative analysis. Int J Radiat Oncol Biol Phys 2022; 114:1032-1044. [PMID: 35810988 DOI: 10.1016/j.ijrobp.2022.05.038] [Citation(s) in RCA: 29] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/26/2022] [Accepted: 05/24/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE The FLASH effect designates normal tissue sparing by ultra-high dose rate (UHDR) compared to conventional dose rate (CONV) irradiation without compromising tumor control. Understanding the magnitude of this effect and its dependency on dose are essential requirements for an optimized clinical translation of FLASH radiation therapy. In this context, we evaluated available experimental data on the magnitudes of normal tissue sparing provided by the FLASH effect as a function of dose, and followed a phenomenological data-driven approach for its parameterization. METHODS We gathered available in vivo data of the normal tissue sparing of CONV compared to UHDR single fraction doses and converted it to a common scale using isoeffect dose ratios, hereafter referred to as FLASH modifying factors (FMF). We then evaluated the suitability of a piecewise linear function with two pieces to parametrize FMF × D as a function of dose D. RESULTS We found that the magnitude of FMF generally decreases (i.e., sparing increases) as function of single fraction dose and that individual data series can be described by the piecewise linear function. The sparing magnitude appears organ specific. Pooled skin reaction data followed a consistent trend as a function of dose. Average FMF values and their standard deviations were 0.95±0.11 for all data below 10 Gy, 0.92±0.06 for mouse gut data between 10-25 Gy, and 0.96±0.07 and 0.71±0.06 for mammalian skin reaction data between 10-25 Gy and >25 Gy, respectively. CONCLUSIONS The magnitude of normal tissue sparing by FLASH is increasing with dose and is dependent on the irradiated tissue. A piecewise linear function can parameterize currently available individual data series.
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Affiliation(s)
- Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Esat Mahmut Ozsahin
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland..
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Blain G, Vandenborre J, Villoing D, Fiegel V, Fois GR, Haddad F, Koumeir C, Maigne L, Métivier V, Poirier F, Potiron V, Supiot S, Servagent N, Delpon G, Chiavassa S. Proton Irradiations at Ultra-High Dose Rate vs. Conventional Dose Rate: Strong Impact on Hydrogen Peroxide Yield. Radiat Res 2022; 198:318-324. [PMID: 35675499 DOI: 10.1667/rade-22-00021.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 05/25/2022] [Indexed: 11/03/2022]
Abstract
During ultra-high dose rate (UHDR) external radiation therapy, healthy tissues appear to be spared while tumor control remains the same compared to conventional dose rate. However, the understanding of radiochemical and biological mechanisms involved are still to be discussed. This study shows how the hydrogen peroxide (H2O2) production, one of the reactive oxygen species (ROS), could be controlled by early heterogenous radiolysis processes in water during UHDR proton-beam irradiations. Pure water was irradiated in the plateau region (track-segment) with 68 MeV protons under conventional (0.2 Gy/s) and several UHDR conditions (40 Gy/s to 60 kGy/s) at the ARRONAX cyclotron. Production of H2O2 was then monitored using the Ghormley triiodide method. New values of GTS(H2O2) were added in conventional dose rate. A substantial decrease in H2O2 production was observed from 0.2 to 1.5 kGy/s with a more dramatic decrease below 100 Gy/s. At higher dose rate, up to 60 kGy/s, the H2O2 production stayed stable with a mean decrease of 38% ± 4%. This finding, associated to the decrease in the production of hydroxyl radical (•OH) already observed in other studies in similar conditions can be explained by the well-known spur theory in radiation chemistry. Thus, a two-step FLASH-RT mechanism can be envisioned: an early step at the microsecond scale mainly controlled by heterogenous radiolysis, and a second, slower, dominated by O2 depletion and biochemical processes. To validate this hypothesis, more measurements of radiolytic species will soon be performed, including radicals and associated lifetimes.
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Affiliation(s)
- Guillaume Blain
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | - Johan Vandenborre
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | | | - Vincent Fiegel
- Institut de Cancérologie de l'Ouest, Saint-Herblain, France
| | - Giovanna Rosa Fois
- Université Clermont Auvergne, CNRS/IN2P3, LPC, 63000 Clermont-Ferrand, France
| | - Ferid Haddad
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France.,GIP ARRONAX, Saint-Herblain, France
| | | | - Lydia Maigne
- Université Clermont Auvergne, CNRS/IN2P3, LPC, 63000 Clermont-Ferrand, France
| | - Vincent Métivier
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | | | | | | | - Noël Servagent
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | - Grégory Delpon
- Institut de Cancérologie de l'Ouest, Saint-Herblain, France
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Van den Heuvel F, Vella A, Fiorini F, Brooke M, Hill M, Ryan A, Maughan T, Giaccia A. Using oxygen dose histograms to quantify voxelised ultra-high dose rate (FLASH) effects in multiple radiation modalities. Phys Med Biol 2022; 67:125001. [PMID: 35594854 PMCID: PMC9174700 DOI: 10.1088/1361-6560/ac71ef] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 05/20/2022] [Indexed: 11/12/2022]
Abstract
Purpose.To introduce a methodology to predict tissue sparing effects in pulsed ultra-high dose rate radiation exposures which could be included in a dose-effect prediction system or treatment planning system and to illustrate it by using three published experiments.Methods and materials.The proposed system formalises the variability of oxygen levels as an oxygen dose histogram (ODH), which provides an instantaneous oxygen level at a delivered dose. The histogram concept alleviates the need for a mechanistic approach. At each given oxygen level the oxygen fixation concept is used to calculate the change in DNA-damage induction compared to the fully hypoxic case. Using the ODH concept it is possible to estimate the effect even in the case of multiple pulses, partial oxygen depletion, and spatial oxygen depletion. The system is illustrated by applying it to the seminal results by Town (Nat. 1967) on cell cultures and the pre-clinical experiment on cognitive effects by Montay-Gruelet al(2017Radiother. Oncol.124365-9).Results.The proposed system predicts that a possible FLASH-effect depends on the initial oxygenation level in tissue, the total dose delivered, pulse length and pulse repetition rate. The magnitude of the FLASH-effect is the result of a redundant system, in that it will have the same specific value for a different combination of these dependencies. The cell culture data are well represented, while a correlation between the pre-clinical experiments and the calculated values is highly significant (p < 0.01).Conclusions. A system based only on oxygen related effects is able to quantify most of the effects currently observed in FLASH-radiation.
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Affiliation(s)
- Frank Van den Heuvel
- University of Oxford, Department of Oncology, Oxford, United Kingdom
- Radiation Oncology, Zuidwest Radiotherapeutic Institute, Vlissingen (Flushing), Zeeland, The Netherlands
| | - Anna Vella
- University of Oxford, Department of Oncology, Oxford, United Kingdom
- Oxford University Hospitals, Department of Hæmatology & Oncology, Oxford, United Kingdom
| | - Francesca Fiorini
- University of Oxford, Department of Oncology, Oxford, United Kingdom
- Rutherford Cancer Centre Thames Valley, Reading, United Kingdom
| | - Mark Brooke
- University of Oxford, Department of Oncology, Oxford, United Kingdom
| | - Mark Hill
- University of Oxford, Department of Oncology, Oxford, United Kingdom
| | - Anderson Ryan
- University of Oxford, Department of Oncology, Oxford, United Kingdom
| | - Tim Maughan
- University of Oxford, Department of Oncology, Oxford, United Kingdom
- Oxford University Hospitals, Department of Hæmatology & Oncology, Oxford, United Kingdom
| | - Amato Giaccia
- University of Oxford, Department of Oncology, Oxford, United Kingdom
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Cooper CR, Jones D, Jones GDD, Petersson K. FLASH irradiation induces lower levels of DNA damage ex vivo, an effect modulated by oxygen tension, dose, and dose rate. Br J Radiol 2022; 95:20211150. [PMID: 35171701 PMCID: PMC10993968 DOI: 10.1259/bjr.20211150] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/07/2022] [Accepted: 01/31/2022] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE FLASH irradiation reportedly produces less normal tissue toxicity, while maintaining tumour response. To investigate oxygen's role in the 'FLASH effect', we assessed DNA damage levels following irradiation at different oxygen tensions, doses and dose rates. METHODS Samples of whole blood were irradiated (20 Gy) at various oxygen tensions (0.25-21%) with 6 MeV electrons at dose rates of either 2 kGy/s (FLASH) or 0.1 Gy/s (CONV), and subsequently with various doses (0-40 Gy) and intermediate dose rates (0.3-1000 Gy/s). DNA damage of peripheral blood lymphocytes (PBL) were assessed by the alkaline comet assay. RESULTS Following 20 Gy irradiation, lower levels of DNA damage were induced for FLASH, the difference being significant at 0.25% (p < 0.05) and 0.5% O2 (p < 0.01). The differential in DNA damage at 0.5% O2 was found to increase with total dose and dose rate, becoming significant for doses ≥20 Gy and dose rates ≥30 Gy/s. CONCLUSION This study shows, using the alkaline comet assay, that lower levels of DNA damage are induced following FLASH irradiation, an effect that is modulated by the oxygen tension, and increases with the total dose and dose rate of irradiation, indicating that an oxygen related mechanism, e.g. transient radiation-induced oxygen depletion, may contribute to the tissue sparing effect of FLASH irradiation. ADVANCES IN KNOWLEDGE This paper is first to directly show that FLASH-induced DNA damage is modulated by oxygen tension, total dose and dose rate, with FLASH inducing significantly lower levels of DNA damage for doses ≥20 Gy and dose rates ≥30 Gy/s, at 0.5% O2.
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Affiliation(s)
- Christian R Cooper
- Leicester Cancer Research Centre, University of Leicester,
Robert Kilpatrick Clinical Sciences Building, Leicester Royal
Infirmary, Leicester,
UK
| | - Donald Jones
- Leicester Cancer Research Centre, University of Leicester,
Robert Kilpatrick Clinical Sciences Building, Leicester Royal
Infirmary, Leicester,
UK
| | - George DD Jones
- Leicester Cancer Research Centre, University of Leicester,
Robert Kilpatrick Clinical Sciences Building, Leicester Royal
Infirmary, Leicester,
UK
| | - Kristoffer Petersson
- MRC Oxford Institute for Radiation Oncology, University of
Oxford, Old Road Campus Research Building,
Oxford, UK
- Department of Haematology, Oncology and Radiation Physics,
Skåne University Hospital Lund University,
Lund, Sweden
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