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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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Rohrer Bley C, Wolf F, Gonçalves Jorge P, Grilj V, Petridis I, Petit B, Böhlen TT, Moeckli R, Limoli C, Bourhis J, Meier V, Vozenin MC. Dose- and Volume-Limiting Late Toxicity of FLASH Radiotherapy in Cats with Squamous Cell Carcinoma of the Nasal Planum and in Mini Pigs. Clin Cancer Res 2022; 28:3814-3823. [PMID: 35421221 PMCID: PMC9433962 DOI: 10.1158/1078-0432.ccr-22-0262] [Citation(s) in RCA: 44] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/02/2022] [Accepted: 04/12/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE The FLASH effect is characterized by normal tissue sparing without compromising tumor control. Although demonstrated in various preclinical models, safe translation of FLASH-radiotherapy stands to benefit from larger vertebrate animal models. Based on prior results, we designed a randomized phase III trial to investigate the FLASH effect in cat patients with spontaneous tumors. In parallel, the sparing capacity of FLASH-radiotherapy was studied on mini pigs by using large field irradiation. EXPERIMENTAL DESIGN Cats with T1-T2, N0 carcinomas of the nasal planum were randomly assigned to two arms of electron irradiation: arm 1 was the standard of care (SoC) and used 10 × 4.8 Gy (90% isodose); arm 2 used 1 × 30 Gy (90% isodose) FLASH. Mini pigs were irradiated using applicators of increasing size and a single surface dose of 31 Gy FLASH. RESULTS In cats, acute side effects were mild and similar in both arms. The trial was prematurely interrupted due to maxillary bone necrosis, which occurred 9 to 15 months after radiotherapy in 3 of 7 cats treated with FLASH-radiotherapy (43%), as compared with 0 of 9 cats treated with SoC. All cats were tumor-free at 1 year in both arms, with one cat progressing later in each arm. In pigs, no acute toxicity was recorded, but severe late skin necrosis occurred in a volume-dependent manner (7-9 months), which later resolved. CONCLUSIONS The reported outcomes point to the caveats of translating single-high-dose FLASH-radiotherapy and emphasizes the need for caution and further investigations. See related commentary by Maity and Koumenis, p. 3636.
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Affiliation(s)
- Carla Rohrer Bley
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Friederike Wolf
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Patrik Gonçalves Jorge
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Veljko Grilj
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ioannis Petridis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Benoit Petit
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Till T Böhlen
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Raphael Moeckli
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles Limoli
- Department of Radiation Oncology, School of Medicine, University of California at Irvine, Irvine, California
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Valeria Meier
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
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Maity A, Koumenis C. Shining a FLASHlight on Ultrahigh Dose-Rate Radiation and Possible Late Toxicity. Clin Cancer Res 2022; 28:3636-3638. [PMID: 35736814 PMCID: PMC9444945 DOI: 10.1158/1078-0432.ccr-22-1255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/25/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022]
Abstract
A recent study reported results from a clinical trial in cats and from experiments in mini-pigs in which a single dose of radiotherapy was delivered at ultrahigh dose rates (FLASH). There was acceptable acute toxicity; however, some animals suffered severe late toxicity, raising caution in the design of future trials. See related article by Rohrer Bley et al., p. 3814.
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Affiliation(s)
- Amit Maity
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104,Department of Radiation Oncology, Spencer Fox Eccles School of Medicine at the University of Utah, Salt Lake City, UT,Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT,Correspondence: Amit Maity, MD, PhD, Department of Radiation Oncology, 1950 City of Hope Drive, Rm 1570, Salt Lake City, UT 84112, Phone: 801-581-2396, Fax: 801-585-2666,
| | - Constantinos Koumenis
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
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Rahman M, Trigilio A, Franciosini G, Moeckli R, Zhang R, Böhlen TT. FLASH radiotherapy treatment planning and models for electron beams. Radiother Oncol 2022; 175:210-221. [PMID: 35964763 DOI: 10.1016/j.radonc.2022.08.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2022] [Revised: 08/04/2022] [Accepted: 08/04/2022] [Indexed: 12/18/2022]
Abstract
The FLASH effect designates normal tissue sparing at ultra-high dose rate (UHDR, >40 Gy/s) compared to conventional dose rate (∼0.1 Gy/s) irradiation while maintaining tumour control and has the potential to improve the therapeutic ratio of radiotherapy (RT). UHDR high-energy electron (HEE, 4-20 MeV) beams are currently a mainstay for investigating the clinical potential of FLASH RT for superficial tumours. In the future very-high energy electron (VHEE, 50-250 MeV) UHDR beams may be used to treat deep-seated tumours. UHDR HEE treatment planning focused at its initial stage on accurate dosimetric modelling of converted and dedicated UHDR electron RT devices for the clinical transfer of FLASH RT. VHEE treatment planning demonstrated promising dosimetric performance compared to clinical photon RT techniques in silico and was used to evaluate and optimise the design of novel VHEE RT devices. Multiple metrics and models have been proposed for a quantitative description of the FLASH effect in treatment planning, but an improved experimental characterization and understanding of the FLASH effect is needed to allow for an accurate and validated modelling of the effect in treatment planning. The importance of treatment planning for electron FLASH RT will augment as the field moves forward to treat more complex clinical indications and target sites. In this review, TPS developments in HEE and VHEE are presented considering beam models, characteristics, and future FLASH applications.
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Affiliation(s)
- Mahbubur Rahman
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA
| | - Antonio Trigilio
- Physics Department, "La Sapienza" University of Rome, Rome, Italy; INFN National Institute of Nuclear Physics, Rome Section, Rome, Italy
| | - Gaia Franciosini
- Physics Department, "La Sapienza" University of Rome, Rome, Italy; INFN National Institute of Nuclear Physics, Rome Section, Rome, Italy
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland.
| | - Rongxiao Zhang
- Thayer School of Engineering, Dartmouth College, Hanover, NH, USA; Dartmouth Hitchcock Medical Center, Lebanon, NH, USA
| | - Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
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Comparing radiolytic production of H 2O 2 and development of Zebrafish embryos after ultra high dose rate exposure with electron and transmission proton beams. Radiother Oncol 2022; 175:197-202. [PMID: 35868604 DOI: 10.1016/j.radonc.2022.07.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 06/30/2022] [Accepted: 07/13/2022] [Indexed: 11/21/2022]
Abstract
The physico-chemical and biological response to conventional and UHDR electron and proton beams was investigated, along with conventional photons. The temporal structure and nature of the beam affected both, with electron beam at ≥1400 Gy/s and proton beam at 0.1 and 1260 Gy/s found to be isoefficient at sparing zebrafish embryos.
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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: 36] [Impact Index Per Article: 18.0] [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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van Marlen P, Verbakel WF, Slotman BJ, Dahele M. Single-fraction 34 Gy Lung Stereotactic Body Radiation Therapy Using Proton Transmission Beams: FLASH-dose Calculations and the Influence of Different Dose-rate Methods and Dose/Dose-rate Thresholds. Adv Radiat Oncol 2022; 7:100954. [PMID: 35634574 PMCID: PMC9130077 DOI: 10.1016/j.adro.2022.100954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 03/21/2022] [Indexed: 11/17/2022] Open
Abstract
Purpose Research suggests that in addition to the dose-rate, a dose threshold is also important for the reduction in normal tissue toxicity with similar tumor control after ultrahigh dose-rate radiation therapy (UHDR-RT). In this analysis we aimed to identify factors that might limit the ability to achieve this "FLASH"-effect in a scenario attractive for UHDR-RT (high fractional beam dose, small target, few organs-at-risk): single-fraction 34 Gy lung stereotactic body radiation therapy. Methods and Materials Clinical volumetric-modulated arc therapy (VMAT) plans, intensity modulated proton therapy (IMPT) plans and transmission beam (TB) plans were compared for 6 small and 1 large lung lesion. The TB-plan dose-rate was calculated using 4 methods and the FLASH-percentage (percentage of dose delivered at dose-rates ≥40/100 Gy/s and ≥4/8 Gy) was determined for various variables: a minimum spot time (minST) of 0.5/2 ms, maximum nozzle current (maxN) of 200/40 0nA, and 2 gantry current (GC) techniques (energy-layer based, spot-based [SB]). Results Based on absolute doses 5-beam TB and VMAT-plans are similar, but TB-plans have higher rib, skin, and ipsilateral lung dose than IMPT. Dose-rate calculation methods not considering scanning achieve FLASH-percentages between ∼30% to 80%, while methods considering scanning often achieve <30%. FLASH-percentages increase for lower minST/higher maxN and when using SB GC instead of energy-layer based GC, often approaching the percentage of dose exceeding the dose-threshold. For the small lesions average beam irradiation times (including scanning) varied between 0.06 to 0.31 seconds and total irradiation times between 0.28 to 1.57 seconds, for the large lesion beam times were between 0.16 to 1.47 seconds with total irradiation times of 1.09 to 5.89 seconds. Conclusions In a theoretically advantageous scenario for FLASH we found that TB-plan dosimetry was similar to that of VMAT, but inferior to that of IMPT, and that decreasing minST or using SB GC increase the estimated amount of FLASH. For the appropriate machine/delivery parameters high enough dose-rates can be achieved regardless of calculation method, meaning that a possible FLASH dose-threshold will likely be the primary limiting factor.
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Affiliation(s)
- Patricia van Marlen
- Department of Radiation Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Amsterdam, the Netherlands
| | - Wilko F.A.R. Verbakel
- Department of Radiation Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Amsterdam, the Netherlands
| | - Ben J. Slotman
- Department of Radiation Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Amsterdam, the Netherlands
| | - Max Dahele
- Department of Radiation Oncology, Amsterdam UMC, Vrije Universiteit Amsterdam, Cancer Center Amsterdam, Amsterdam, the Netherlands
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Karsch L, Pawelke J, Brand M, Hans S, Hideghéty K, Jansen J, Lessmann E, Löck S, Schürer M, Schurig R, Seco J, Szabó ER, Beyreuther E. Beam pulse structure and dose rate as determinants for the flash effect observed in zebrafish embryo. Radiother Oncol 2022; 173:49-54. [PMID: 35661675 DOI: 10.1016/j.radonc.2022.05.025] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/20/2022] [Accepted: 05/26/2022] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND PURPOSE Continuing recent experiments at the research electron accelerator ELBE at the Helmholtz-Zentrum Dresden-Rossendorf the influence of beam pulse structure on the Flash effect was investigated. MATERIALS AND METHODS The proton beam pulse structure of an isochronous cyclotron (UHDRiso) and a synchrocyclotron (UHDRsynchro) was mimicked at ELBE by quasi-continuous electron bunches at 13 MHz delivering mean dose rates of 287 Gy/s and 177 Gy/s and bunch dose rates of 106Gy/s and 109 Gy/s, respectively. For UHDRsynchro, 40 ms macro pulses at a frequency of 25 Hz superimposed the bunch delivery. For comparison, a maximum beam intensity (2.5 x 105 Gy/s mean and ∼109 Gy/s bunch dose rate) and a reference irradiation (of ∼8 Gy/min mean dose rate) were applied. Radiation induced changes were assessed in zebrafish embryos over four days post irradiation. RESULTS Relative to the reference a significant protecting Flash effect was observed for all electron beam pulse regimes with less severe damage the higher the mean dose rate of the electron beam. Accordingly, the macro pulsing induced prolongation of treatment time at UHDRsynchro regime reduces the protecting effect compared to the maximum regime delivered at same bunch but higher mean dose rate. The Flash effect of the UHDRiso regime was confirmed at a clinical isochronous cyclotron comparing the damage induced by proton beams delivered at 300 Gy/s and ∼9 Gy/min. CONCLUSION The recent findings indicate that the mean dose rate or treatment time are decisive for the normal tissue protecting Flash effect in zebrafish embryo.
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Affiliation(s)
- Leonhard Karsch
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Jörg Pawelke
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Michael Brand
- Center for Regenerative Therapies TU Dresden (CRTD), and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Stefan Hans
- Center for Regenerative Therapies TU Dresden (CRTD), and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Katalin Hideghéty
- ELI-ALPS, ELI-HU Non-Profit Ltd., Szeged, Hungary; Oncotherapy Department, University of Szeged, Szeged, Hungary
| | - Jeannette Jansen
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Elisabeth Lessmann
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Steffen Löck
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Schürer
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; National Center for Tumor Diseases Dresden (NCT/UCC), Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Rico Schurig
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Joao Seco
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Germany
| | | | - Elke Beyreuther
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany.
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Sørensen BS, Sitarz MK, Ankjærgaard C, Johansen JG, Andersen CE, Kanouta E, Grau C, Poulsen P. Pencil beam scanning proton FLASH maintains tumor control while normal tissue damage is reduced in a mouse model. Radiother Oncol 2022; 175:178-184. [PMID: 35595175 DOI: 10.1016/j.radonc.2022.05.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 01/16/2023]
Abstract
PURPOSE Preclinical studies indicate a normal tissue sparing effect when ultra-high dose rate (FLASH) radiation is used, while tumor response is maintained. This differential response has promising perspectives for improved clinical outcome. This study investigates tumor control and normal tissue toxicity of pencil beam scanning (PBS) proton FLASH in a mouse model. METHODS AND MATERIALS Tumor bearing hind limbs of non-anaesthetized CDF1 mice were irradiated in a single fraction with a PBS proton beam using either conventional (CONV) dose rate (0.33-0.63 Gy/s field dose rate, 244 MeV) or FLASH (71-89 Gy/s field dose rate, 250 MeV). 162 mice with a C3H mouse mammary carcinoma subcutaneously implanted in the foot were irradiated with physical doses of 40-60 Gy (8-14 mice per dose point). The endpoints were tumor control (TC) assessed as no recurrent tumor at 90 days after treatment, the level of acute moist desquamation (MD) to the skin of the foot within 25 days post irradiation, and radiation induced fibrosis (RIF) within 24 weeks post irradiation. RESULTS TCD50 (dose for 50% tumor control) was similar for CONV and FLASH with values (and 95% confidence intervals) of 49.1 (47.0-51.4) Gy for CONV and 51.3 (48.6-54.2) Gy for FLASH. RIF analysis was restricted to mice with tumor control. Both endpoints showed distinct normal tissue sparing effect of proton FLASH with MDD50 (dose for 50% of mice displaying moist desquamation) of <40.1 Gy for CONV and 52.3 (50.0-54.6) Gy for FLASH, (dose modifying factor at least 1.3) and FD50 (dose for 50% of mice displaying fibrosis) of 48.6 (43.2-50.8) Gy for CONV and 55.6 (52.5-60.1) Gy for FLASH (dose modifying factor of 1.14). CONCLUSIONS FLASH had the same tumor control as CONV, but reduced normal tissue damage assessed as acute skin damage and radiation induced fibrosis.
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Affiliation(s)
- Brita Singers Sørensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark.
| | | | | | - Jacob G Johansen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | - Eleni Kanouta
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Cai Grau
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Per Poulsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
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60
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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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Zhu H, Xie D, Yang Y, Huang S, Gao X, Peng Y, Wang B, Wang J, Xiao D, Wu D, Li C, Li C, Qian CN, Deng X. Radioprotective effect of X-ray abdominal FLASH irradiation: Adaptation to oxidative damage and inflammatory response may be benefiting factors. Med Phys 2022; 49:4812-4822. [PMID: 35451077 DOI: 10.1002/mp.15680] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Ultrahigh dose-rate irradiation (FLASH-IR) was reported to be efficient in tumor control while reducing normal tissue radiotoxicity. However, the mechanism of such phenomenon is still unclear. Besides, the FLASH experiments using high energy X-ray, the most common modality in clinical radiotherapy, is rarely reported. This study aims to investigate the radiobiological response using 6 MV X-ray FLASH-IR or conventional dose-rate IR (CONV-IR). METHODS The superconducting linac of Chengdu THz Free Electron Laser (CTFEL) facility was used for FLASH-IR, a diamond radiation detector and a CeBr3 scintillation detector were used to monitor the time structure and dose rate of FLASH pulses. BALB/c nude mice received whole abdominal 6 MV X-ray FLASH-IR or CONV-IR, the prescribed dose was 15 Gy or 10 Gy and the delivered absolute dose was monitored with EBT3 films. The mice were either euthanized 24 h post-IR to evaluate acute tissue responses or followed up for 6 weeks to observe late-stage responses and survival probability. Complete blood count, histological analyses, and measurement of cytokine expression and redox status were performed. RESULTS The mean dose rate of >150 Gy/s and instantaneous dose rate of >5.5×105 Gy/s was reached in FLASH-IR at the center of mice body. After 6 weeks' follow-up of mice that received 15 Gy IR, the FLASH group showed faster body weight recovery and higher survival probability than the CONV group. Histological analysis showed that FLASH-IR induced less acute intestinal damage than CONV-IR. Complete blood count and cytokine concentration measurement found that the inflammatory blood cell counts and pro-inflammatory cytokine concentrations were elevated at the acute stage after both FLASH-IR and CONV-IR. However, FLASH irradiated mice had significantly fewer inflammatory blood cells and diminished pro-inflammatory cytokine at the late stage. Moreover, higher reactive oxygen species (ROS) signal intensities but significantly reduced lipid peroxidation were found in the FLASH group than in the CONV group in the acute stage. CONCLUSIONS The radioprotective effect of 6 MV X-ray FLASH-IR was observed. The differences in inflammatory responses and redox status between the two groups may be the factors responsible for reduced radiotoxicities following FLASH-IR. Further studies are required to thoroughly evaluate the impact of ROS on FLASH effect. This article is protected by copyright. All rights reserved.
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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, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Dehuan Xie
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Yiwei Yang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Shaomin Huang
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Xingwang Gao
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Yinglin Peng
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Bin Wang
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Jianxin Wang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Dexin Xiao
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Dai Wu
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Changzhi Li
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Chenghua Li
- Center of Growth, Metabolism and Aging, Key Laboratory of Biological Resources and Ecological Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Chao-Nan Qian
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China.,Department of Radiation Oncology, Guangzhou Concord Cancer Center, Guangzhou, 510799, China
| | - Xiaowu Deng
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
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Bourgouin A, Knyziak A, Marinelli M, Kranzer R, Schüller A, Kapsch RP. Characterization of the PTB ultra-high pulse dose rate reference electron beam. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac5de8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/15/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Purpose. This investigation aims to present the characterisation and optimisation of an ultra-high pulse dose rate (UHPDR) electron beam at the PTB facility in Germany. A Monte Carlo beam model has been developed for dosimetry study for future investigation in FLASH radiotherapy and will be presented. Material and methods. The 20 MeV electron beams generated by the research linear accelerator has been characterised both in-beamline with profile monitors and magnet spectrometer, and in-water with a diamond detector prototype. The Monte Carlo model has been used to investigate six different setups to enable different dose per pulse (DPP) ranges and beam sizes in water. The properties of the electron radiation field in water have also been characterised in terms of beam size, quality specifier R
50 and flatness. The beam stability has also been studied. Results. The difference between the Monte-Carlo simulated and measured R
50 was smaller than 0.5 mm. The simulated beam sizes agreed with the measured ones within 2 mm. Two suitable setups have been identified for delivering reference UHPDR electron beams. The first one is characterised by a SSD of 70 cm, while in the second one an SSD of 90 cm is used in combination with a 2 mm aluminium scattering plates. The two set-ups are quick and simple to install and enable an expected overall DPP range from 0.13 Gy up to 6.7 Gy per pulse. Conclusion. The electron beams generated by the PTB research accelerator have shown to be stable throughout the four-months length of this investigation. The Monte Carlo models have shown to be in good agreement for beam size and depth dose and within 1% for the beam flatness. The diamond detector prototype has shown to be a promising tool to be used for relative measurements in UHPDR electron beams.
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Abstract
FLASH radiotherapy is a novel technique that has been shown in numerous preclinical in vivo studies to have the potential to be the next important improvement in cancer treatment. However, the biological mechanisms responsible for the selective FLASH sparing effect of normal tissues are not yet known. An optimal translation of FLASH radiotherapy into the clinic would require a good understanding of the specific beam parameters that induces a FLASH effect, environmental conditions affecting the response, and the radiobiological mechanisms involved. Even though the FLASH effect has generally been considered as an in vivo effect, studies finding these answers would be difficult and ethically challenging to carry out solely in animals. Hence, suitable in vitro studies aimed towards finding these answers are needed. In this review, we describe and summarise several in vitro assays that have been used or could be used to finally elucidate the mechanisms behind the FLASH effect.
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64
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Eggold JT, Chow S, Melemenidis S, Wang J, Natarajan S, Loo PE, Manjappa R, Viswanathan V, Kidd EA, Engleman E, Dorigo O, Loo BW, Rankin EB. Abdominopelvic FLASH Irradiation Improves PD-1 Immune Checkpoint Inhibition in Preclinical Models of Ovarian Cancer. Mol Cancer Ther 2021; 21:371-381. [PMID: 34866044 DOI: 10.1158/1535-7163.mct-21-0358] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Revised: 09/20/2021] [Accepted: 11/11/2021] [Indexed: 11/16/2022]
Abstract
Treatment of advanced ovarian cancer using PD-1/PD-L1 immune checkpoint blockade shows promise, however current clinical trials are limited by modest response rates. Radiation therapy has been shown to synergize with PD-1/PD-L1 blockade in some cancers but has not been utilized in advanced ovarian cancer due to toxicity associated with conventional abdominopelvic irradiation. While ultra-high dose rate (FLASH) irradiation has emerged as a strategy to reduce radiation-induced toxicity, the immunomodulatory properties of FLASH irradiation remain unknown. Here we demonstrate that single high dose abdominopelvic FLASH irradiation promoted intestinal regeneration and maintained tumor control in a preclinical mouse model of ovarian cancer. Reduced tumor burden in conventional and FLASH treated mice was associated with an early decrease in intratumoral regulatory T cells and a late increase in cytolytic CD8+ T cells. Compared to conventional irradiation, FLASH irradiation increased intratumoral T cell infiltration at early timepoints. Moreover, FLASH irradiation maintained the ability to increase intratumoral CD8+ T cell infiltration and enhance the efficacy of αPD-1 therapy in preclinical models of ovarian cancer. These data highlight the potential for FLASH irradiation to improve the therapeutic efficacy of checkpoint inhibition in the treatment of ovarian cancer.
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Affiliation(s)
| | - Stephanie Chow
- Radiation Oncology and Obstetrics & Gynecology, Stanford University
| | | | | | | | | | | | | | | | - Edgar Engleman
- Department of Pathology, Stanford University School of Medicine
| | - Oliver Dorigo
- Obstetrics and Gynecology/Gynecologic Oncology, Stanford University
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University
| | - Erinn B Rankin
- Radiation Oncology and Obstetrics & Gynecology, Stanford University
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65
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Kacem H, Almeida A, Cherbuin N, Vozenin MC. Understanding the FLASH effect to unravel the potential of ultra-high dose rate irradiation. Int J Radiat Biol 2021; 98:506-516. [PMID: 34788193 DOI: 10.1080/09553002.2021.2004328] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
A reemergence of research implementing radiation delivery at ultra-high dose rates (UHDRs) has triggered intense interest in the radiation sciences and has opened a new field of investigation in radiobiology. Much of the promise of UHDR irradiation involves the FLASH effect, an in vivo biological response observed to maintain anti-tumor efficacy without the normal tissue complications associated with standard dose rates. The FLASH effect has been validated primarily, using intermediate energy electron beams able to deliver high doses (>7 Gy) in a very short period of time (<200 ms), but has also been found with photon and proton beams. The clinical implications of this new area of research are highly significant, as FLASH radiotherapy (FLASH-RT) has the potential to enhance the therapeutic index, opening new possibilities for eradicating radio-resistant tumors without toxicity. As pioneers in this field, our group has developed a multidisciplinary research team focused on investigating the mechanisms and clinical translation of the FLASH effect. Here, we review the field of UHDR, from the physico-chemical to the biological mechanisms.
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Affiliation(s)
- Houda Kacem
- Department of Oncology, Laboratory of Radiation Oncology, Radiation Oncology Service, CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Aymeric Almeida
- Department of Oncology, Laboratory of Radiation Oncology, Radiation Oncology Service, CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Nicolas Cherbuin
- Department of Medical Radiology, Institute of Radiation Physics, CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Department of Oncology, Laboratory of Radiation Oncology, Radiation Oncology Service, CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
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Gao F, Yang Y, Zhu H, Wang J, Xiao D, Zhou Z, Dai T, Zhang Y, Feng G, Li J, Lin B, Xie G, Ke Q, Zhou K, Li P, Shen X, Wang H, Yan L, Lao C, Shan L, Li M, Lu Y, Chen M, Feng S, Zhao J, Wu D, Du X. First demonstration of the FLASH effect with ultrahigh dose rate high-energy X-rays. Radiother Oncol 2021; 166:44-50. [PMID: 34774651 DOI: 10.1016/j.radonc.2021.11.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 10/02/2021] [Accepted: 11/01/2021] [Indexed: 12/12/2022]
Abstract
PURPOSE This study aimed to evaluate whether high-energy X-rays (HEXs) of the PARTER (platform for advanced radiotherapy research) platform built on CTFEL (Chengdu THz Free Electron Laser facility) can produce ultrahigh dose rate (FLASH) X-rays and trigger the FLASH effect. MATERIALS AND METHODS EBT3 radiochromic film and fast current transformer (FCT) devices were used to measure absolute dose and pulsed beam current of HEXs. Subcutaneous tumor-bearing mice and healthy mice were treated with sham, FLASH, and conventional dose rate radiotherapy (CONV), respectively to observe the tumor control efficiency and normal tissue damage. RESULTS The maximum dose rate of HEXs of PARTER was up to over 1000 Gy/s. Tumor-bearing mice experiment showed a good result on tumor control (p < 0.0001) and significant difference in survival curves (p < 0.005) among the three groups. In the thorax-irradiated healthy mice experiment, there was a significant difference (p = 0.038) in survival among the three groups, with the risk of death decreased by 81% in the FLASH group compared to that in the CONV group. The survival time of healthy mice irradiated in the abdomen in the FLASH group was undoubtedly higher (62.5% of mice were still alive when we stopped observation) than that in the CONV group (7 days). CONCLUSION This study confirmed that HEXs of the PARTER system can produce ultrahigh dose rate X-rays and trigger a FLASH effect, which provides a basis for future scientific research and clinical application of HEX in FLASH radiotherapy.
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Affiliation(s)
- Feng Gao
- Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Yiwei Yang
- Institute of Nuclear Physics and Chemistry, China Academy of Engineering Physics, Mianyang, China
| | - Hongyu Zhu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, China
| | - Jianxin Wang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Dexin Xiao
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Zheng Zhou
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Tangzhi Dai
- Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Yu Zhang
- Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Gang Feng
- Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Jie Li
- Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Binwei Lin
- Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Gang Xie
- Department of Pathology, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Qi Ke
- Department of Pathology, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China
| | - Kui Zhou
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Peng Li
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Xuming Shen
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Hanbin Wang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Longgang Yan
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Chenglong Lao
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Lijun Shan
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Ming Li
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Yanhua Lu
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Menxue Chen
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Song Feng
- School of Nuclear Science and Technology, University of South China, Hengyang, China
| | - Jianheng Zhao
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Dai Wu
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China.
| | - Xiaobo Du
- Departmant of Oncology, Nuclear Medicine Laboratory of Mianyang Central Hospital, Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology of China, Mianyang, China.
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