1
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McGarrigle JM, Long KR, Prezado Y. The FLASH effect-an evaluation of preclinical studies of ultra-high dose rate radiotherapy. Front Oncol 2024; 14:1340190. [PMID: 38711846 PMCID: PMC11071325 DOI: 10.3389/fonc.2024.1340190] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 03/20/2024] [Indexed: 05/08/2024] Open
Abstract
FLASH radiotherapy (FLASH-RT) is a novel radiotherapy approach based on the use of ultra-high dose radiation to treat malignant cells. Although tumours can be reduced or eradicated using radiotherapy, toxicities induced by radiation can compromise healthy tissues. The FLASH effect is the observation that treatment delivered at an ultra-high dose rate is able to reduce adverse toxicities present at conventional dose rates. While this novel technique may provide a turning point for clinical practice, the exact mechanisms underlying the causes or influences of the FLASH effect are not fully understood. The study presented here uses data collected from 41 experimental investigations (published before March 2024) of the FLASH effect. Searchable databases were constructed to contain the outcomes of the various experiments in addition to values of beam parameters that may have a bearing on the FLASH effect. An in-depth review of the impact of the key beam parameters on the results of the experiments was carried out. Correlations between parameter values and experimental outcomes were studied. Pulse Dose Rate had positive correlations with almost all end points, suggesting viability of FLASH-RT as a new modality of radiotherapy. The collective results of this systematic review study suggest that beam parameter qualities from both FLASH and conventional radiotherapy can be valuable for tissue sparing and effective tumour treatment.
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Affiliation(s)
| | - Kenneth Richard Long
- Department of Physics, Imperial College London, London, United Kingdom
- Science and Technology Facilities Council (STFC), Rutherford Appleton Laboratory, Oxford, United Kingdom
| | - Yolanda Prezado
- Institut Curie, Universite Paris-Saclay, Centre national de la recherche scientifique (CNRS) UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
- Universite Paris-Saclay, Centre national de la recherche scientifique (CNRS) UMR3347, Inserm U1021, Signalisation radiobiologie et cancer, Orsay, France
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2
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Tang R, Yin J, Liu Y, Xue J. FLASH radiotherapy: A new milestone in the field of cancer radiotherapy. Cancer Lett 2024; 587:216651. [PMID: 38342233 DOI: 10.1016/j.canlet.2024.216651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 11/03/2023] [Accepted: 01/13/2024] [Indexed: 02/13/2024]
Abstract
Radiotherapy plays a pivotal role in the control and eradication of tumors, but it can also induce radiation injury to surrounding normal tissues while targeting tumor cells. In recent years, FLASH-Radiotherapy (FLASH-RT) has emerged as a cutting-edge research focus in the field of radiation therapy. By delivering high radiation doses to the treatment target in an ultra-short time, FLASH-RT produces the FLASH effect, which reduces the toxicity to normal tissues while achieving comparable tumor control efficacy to conventional radiotherapy. This review provides a brief overview of the development history of FLASH-RT and its impact on tumor control. Additionally, it focuses on introducing the protective effects and molecular mechanisms of this technology on various normal tissues, as well as exploring its synergistic effects when combined with other tumor therapies. Importantly, this review discusses the challenges faced in translating FLASH-RT into clinical practice and outlines its promising future applications.
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Affiliation(s)
- Rui Tang
- Hospital of Chengdu University of Traditional Chinese Medicine, Chengdu, 610072, Sichuan, China; Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jianqiong Yin
- Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Yuanxin Liu
- Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
| | - Jianxin Xue
- Division of Thoracic Tumor Multimodality Treatment, Cancer Center, The National Clinical Research Center for Geriatrics, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Department of Radiation Oncology, Cancer Center, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Laboratory of Clinical Cell Therapy, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China; Disaster Medical Center, Sichuan University, Chengdu, 610041, Sichuan, China.
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3
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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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4
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Oesterle R, Bailat C, Buhlmann D, Bochud F, Grilj V. Construction and dosimetric characterization of a motorized scanning-slit system for electron FLASH experiments. Med Phys 2024; 51:1396-1404. [PMID: 37439505 PMCID: PMC10787038 DOI: 10.1002/mp.16610] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 07/14/2023] Open
Abstract
BACKGROUND Beam scanning is a useful technique for the treatment of large tumors when the primary beam size is limited, which is the case with radiation beams used in FLASH radiotherapy. PURPOSE To optimize beam scanning as a dose delivery method for FLASH radiotherapy, it is necessary to first understand the effects of beam scanning on the FLASH effect. To do so, biological FLASH experiments need to be done using defined beam parameters with beam scanning and compared to the situation without beam scanning. In this regard, we propose implementation of a simple slit scanning system with an electron FLASH beam to obtain a scanned radiation field that closely resembles a static field. METHODS A pulsed electron linear accelerator (linac) was used in combination with a scanning slit system in order to simulate a scanned electron beam. Three configurations that produced homogeneous lateral profiles and high enough doses per pulse for FLASH experiments were established. The optimal scanning parameters were found for each configuration by examining the flatness of the obtained lateral dose profiles. Using the optimal scanning parameters, the scanned FLASH beams were dosimetrically characterized and compared to non-scanned open field beam. RESULTS A final electron FLASH beam scanning configuration was found for a 1 mm wide slit at a distance of 350 mm from the linac and a 2 mm wide slit at distances of 350 and 490 mm from the linac. The lateral profiles for these final configurations were found to have a homogeneity that is comparable to the open field profiles. The percentage depth dose (PDD) values found for these final configurations closely matched (by a few percentage) the PDD of the open field beam. CONCLUSIONS Three electron FLASH beam scanning configurations achieved by the motorized slit system were found to produce radiation fields similar to a non-scanned open field electron beam. These final configurations can therefore be used in future biological FLASH experiments to compare to non-scanned beam experiments in order to optimize beam scanning as a technique permitting the treatment of larger tumors with FLASH radiotherapy.
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Affiliation(s)
- Roxane Oesterle
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Damien Buhlmann
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Francois Bochud
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
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5
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Rudigkeit S, Schmid TE, Dombrowsky AC, Stolz J, Bartzsch S, Chen CB, Matejka N, Sammer M, Bergmaier A, Dollinger G, Reindl J. Proton-FLASH: effects of ultra-high dose rate irradiation on an in-vivo mouse ear model. Sci Rep 2024; 14:1418. [PMID: 38228747 PMCID: PMC10791610 DOI: 10.1038/s41598-024-51951-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 01/11/2024] [Indexed: 01/18/2024] Open
Abstract
FLASH-radiotherapy may provide significant sparing of healthy tissue through ultra-high dose rates in protons, electrons, and x-rays while maintaining the tumor control. Key factors for the FLASH effect might be oxygen depletion, the immune system, and the irradiated blood volume, but none could be fully confirmed yet. Therefore, further investigations are necessary. We investigated the protective (tissue sparing) effect of FLASH in proton treatment using an in-vivo mouse ear model. The right ears of Balb/c mice were irradiated with 20 MeV protons at the ion microprobe SNAKE in Garching near Munich by using three dose rates (Conv = 0.06 Gy/s, Flash9 = 9.3 Gy/s and Flash930 = 930 Gy/s) at a total dose of 23 Gy or 33 Gy. The ear thickness, desquamation, and erythema combined in an inflammation score were measured for 180 days. The cytokines TGF-β1, TNF-α, IL1α, and IL1β were analyzed in the blood sampled in the first 4 weeks and at termination day. No differences in inflammation reactions were visible in the 23 Gy group for the different dose rates. In the 33 Gy group, the ear swelling and the inflammation score for Flash9 was reduced by (57 ± 12) % and (67 ± 17) % and for Flash930 by (40 ± 13) % and (50 ± 17) % compared to the Conv dose rate. No changes in the cytokines in the blood could be measured. However, an estimation of the irradiated blood volume demonstrates, that 100-times more blood is irradiated when using Conv compared to using Flash9 or Flash930. This indicates that blood might play a role in the underlying mechanisms in the protective effect of FLASH.
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Affiliation(s)
- Sarah Rudigkeit
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Thomas E Schmid
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
- Department of Radiooncology, School of Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Annique C Dombrowsky
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
| | - Jessica Stolz
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
| | - Stefan Bartzsch
- Institute of Radiation Medicine (IRM), Helmholtz Zentrum München, Neuherberg, Germany
- Department of Radiooncology, School of Medicine, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Ce-Belle Chen
- Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore, Singapore
- Singapore Synchrotron Light Source, National University of Singapore, Singapore, Singapore
| | - Nicole Matejka
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Matthias Sammer
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Andreas Bergmaier
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Günther Dollinger
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany
| | - Judith Reindl
- Institute of Applied Physics and Measurement Technologies, Universität der Bundeswehr München, Neubiberg, Germany.
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6
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Shukla S, Saha T, Rama N, Acharya A, Le T, Bian F, Donovan J, Tan LA, Vatner R, Kalinichenko V, Mascia A, Perentesis JP, Kalin TV. Ultra-high dose-rate proton FLASH improves tumor control. Radiother Oncol 2023; 186:109741. [PMID: 37315577 PMCID: PMC10527231 DOI: 10.1016/j.radonc.2023.109741] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2022] [Revised: 06/04/2023] [Accepted: 06/05/2023] [Indexed: 06/16/2023]
Abstract
BACKGROUND AND PURPOSE Proton radiotherapy (PRT) offers potential benefits over other radiation modalities, including photon and electron radiotherapy. Increasing the rate at which proton radiation is delivered may provide a therapeutic advantage. Here, we compared the efficacy of conventional proton therapy (CONVpr) to ultrahigh dose-rate proton therapy, FLASHpr, in a mouse model of non-small cell lung cancers (NSCLC). MATERIALS AND METHODS Mice bearing orthotopic lung tumors received thoracic radiation therapy using CONVpr (<0.05 Gy/s) and FLASHpr (>60 Gy/s) dose rates. RESULTS Compared to CONVpr, FLASHpr was more effective in reducing tumor burden and decreasing tumor cell proliferation. Furthermore, FLASHpr was more efficient in increasing the infiltration of cytotoxic CD8+ T-lymphocytes inside the tumor while simultaneously reducing the percentage of immunosuppressive regulatory T-cells (Tregs) among T-lymphocytes. Also, compared to CONVpr, FLASHpr was more effective in decreasing pro-tumorigenic M2-like macrophages in lung tumors, while increasing infiltration of anti-tumor M1-like macrophages. Finally, FLASHpr treatment reduced expression of checkpoint inhibitors in lung tumors, indicating reduced immune tolerance. CONCLUSIONS Our results suggest that FLASH dose-rate proton delivery modulates the immune system to improve tumor control and might thus be a promising new alternative to conventional dose rates for NSCLC treatment.
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Affiliation(s)
- Samriddhi Shukla
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Taniya Saha
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Nihar Rama
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Anusha Acharya
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Tien Le
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Fenghua Bian
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Johnny Donovan
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Lin Abigail Tan
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Ralph Vatner
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, USA, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Vladimir Kalinichenko
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States; Neonatology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States; Center for Lung Regenerative Medicine, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States
| | - Anthony Mascia
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, USA, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - John P Perentesis
- Cincinnati Children's Hospital Medical Center, Division of Oncology, Division of Experimental Hematology, Division of Biomedical Informatics, Cincinnati, OH 45229, USA
| | - Tanya V Kalin
- Division of Pulmonary Biology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States; Neonatology, the Perinatal Institute of Cincinnati Children's Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, United States.
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7
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Flannigan DJ, VandenBussche EJ. Pulsed-beam transmission electron microscopy and radiation damage. Micron 2023; 172:103501. [PMID: 37390662 DOI: 10.1016/j.micron.2023.103501] [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: 05/22/2023] [Revised: 06/20/2023] [Accepted: 06/21/2023] [Indexed: 07/02/2023]
Abstract
We review the use of pulsed electron-beams in transmission electron microscopes (TEMs) for the purpose of mitigating specimen damage. We begin by placing the importance of TEMs with respect to materials characterization into proper context, and we provide a brief overview of established methods for reducing or eliminating the deleterious effects of beam-induced damage. We then introduce the concept of pulsed-beam TEM, and we briefly describe the basic methods and instrument configurations used to create so-called temporally structured electron beams. Following a brief overview of the use of high-dose-rate pulsed-electron beams in cancer radiation therapy, we review historical speculations and more recent compelling but mostly anecdotal findings of a pulsed-beam TEM damage effect. This is followed by an in-depth technical review of recent works seeking to establish cause-and-effect relationships, to conclusively uncover the presence of an effect, and to explore the practicality of the approach. These studies, in particular, provide the most compelling evidence to date that using a pulsed electron beam in the TEM is indeed a viable way to mitigate damage. Throughout, we point out current gaps in understanding, and we conclude with a brief perspective of current needs and future directions.
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Affiliation(s)
- David J Flannigan
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, MN 55455, USA; Minnesota Institute for Ultrafast Science, University of Minnesota, Minneapolis, MN 55455, USA.
| | - Elisah J VandenBussche
- Department of Chemical Engineering and Materials Science, University of Minnesota, 421 Washington Avenue SE, Minneapolis, MN 55455, USA; Minnesota Institute for Ultrafast Science, University of Minnesota, Minneapolis, MN 55455, USA
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8
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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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9
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Su C, Himes JE, Kirsch DG. Relationship between the tumor microenvironment and the efficacy of the combination of radiotherapy and immunotherapy. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 378:201-232. [PMID: 37438018 DOI: 10.1016/bs.ircmb.2023.03.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/14/2023]
Abstract
Activating and recruiting the immune system is critical for successful cancer treatment. Since the discovery of immune checkpoint inhibitors, immunotherapy has become the standard of care for many types of cancers. However, many patients fail to respond to immunotherapy. Further research is needed to understand the mechanisms of resistance and adjuvant therapies that can help sensitize patients to immunotherapies. Here, we will discuss how radiotherapy can change the tumor microenvironment and work synergistically with immunotherapy. We will examine different pre-clinical models focusing on their limitations and their unique advantages in studying the efficacy of treatments and the tumor microenvironment. We will also describe emerging findings from clinical trials testing the combination of immunotherapy and radiotherapy.
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Affiliation(s)
- Chang Su
- Molecular Cancer Biology Program and Medical Scientist Training Program, Duke University School of Medicine, Durham, NC, United States
| | - Jonathon E Himes
- Molecular Cancer Biology Program and Medical Scientist Training Program, Duke University School of Medicine, Durham, NC, United States
| | - David G Kirsch
- Department of Radiation Oncology, Duke University School of Medicine, Durham, NC, United States; Department of Pharmacology & Cancer Biology, Duke University School of Medicine, Durham, NC, United States.
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10
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Mali SB, Dahivelkar S. Flash radiotherapy-gateway to promised land or another mirage. Oral Oncol 2023; 139:106342. [PMID: 36821983 DOI: 10.1016/j.oraloncology.2023.106342] [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: 02/14/2023] [Accepted: 02/15/2023] [Indexed: 02/23/2023]
Abstract
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 n 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.
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Affiliation(s)
- Shrikant B Mali
- MDS Oral and Maxillofacial Surgery Mahatma Gandhi Vidya Mandir's Dental College and Hospital Nashik, India.
| | - Sachinkumar Dahivelkar
- MDS Oral and Maxillofacial Surgery Mahatma Gandhi Vidya Mandir's Dental College and Hospital Nashik, India.
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11
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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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12
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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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13
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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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14
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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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15
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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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16
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Tinganelli W, Weber U, Puspitasari A, Simoniello P, Abdollahi A, Oppermann J, Schuy C, Horst F, Helm A, Fournier C, Durante M. FLASH with carbon ions: tumor control, normal tissue sparing, and distal metastasis in a mouse osteosarcoma model. Radiother Oncol 2022; 175:185-190. [DOI: 10.1016/j.radonc.2022.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/30/2022] [Accepted: 05/02/2022] [Indexed: 12/30/2022]
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17
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Gao H, Liu J, Lin Y, Gan GN, Pratx G, Wang F, Langen K, Bradley JD, Rotondo RL, Li HH, Chen RC. Simultaneous dose and dose rate optimization (SDDRO) of the FLASH effect for pencil-beam-scanning proton therapy. Med Phys 2022; 49:2014-2025. [PMID: 34800301 PMCID: PMC8917068 DOI: 10.1002/mp.15356] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 09/29/2021] [Accepted: 10/25/2021] [Indexed: 11/06/2022] Open
Abstract
PURPOSE Compared to CONV-RT (with conventional dose rate), FLASH-RT (with ultra-high dose rate) can provide biological dose sparing for organs-at-risk (OARs) via the so-called FLASH effect, in addition to physical dose sparing. However, the FLASH effect only occurs, when both dose and dose rate meet certain minimum thresholds. This work will develop a simultaneous dose and dose rate optimization (SDDRO) method accounting for both FLASH dose and dose rate constraints during treatment planning for pencil-beam-scanning proton therapy. METHODS SDDRO optimizes the FLASH effect (specific to FLASH-RT) as well as the dose distribution (similar to CONV-RT). The nonlinear dose rate constraint is linearized, and the reformulated optimization problem is efficiently solved via iterative convex relaxation powered by alternating direction method of multipliers. To resolve and quantify the generic tradeoff of FLASH-RT between FLASH and dose optimization, we propose the use of FLASH effective dose based on dose modifying factor (DMF) owing to the FLASH effect. RESULTS FLASH-RT via transmission beams (TB) (IMPT-TB or SDDRO) and CONV-RT via Bragg peaks (BP) (IMPT-BP) were evaluated for clinical prostate, lung, head-and-neck (HN), and brain cases. Despite the use of TB, which is generally suboptimal to BP for normal tissue sparing, FLASH-RT via SDDRO considerably reduced FLASH effective dose for high-dose OAR adjacent to the target. For example, in the lung SBRT case, the max esophageal dose constraint 27 Gy was only met by SDDRO (24.8 Gy), compared to IMPT-BP (35.3 Gy) or IMPT-TB (36.6 Gy); in the brain SRS case, the brain constraint V12Gy≤15cc was also only met by SDDRO (13.7cc), compared to IMPT-BP (43.9cc) or IMPT-TB (18.4cc). In addition, SDDRO substantially improved the FLASH coverage from IMPT-TB, e.g., an increase from 37.2% to 67.1% for lung, from 39.1% to 58.3% for prostate, from 65.4% to 82.1% for HN, from 50.8% to 73.3% for the brain. CONCLUSIONS Both FLASH dose and dose rate constraints are incorporated into SDDRO for FLASH-RT that jointly optimizes the FLASH effect and physical dose distribution. FLASH effective dose via FLASH DMF is introduced to reconcile the tradeoff between physical dose sparing and FLASH sparing, and quantify the net effective gain from CONV-RT to FLASH-RT.
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Affiliation(s)
- Hao Gao
- Department of Radiation Oncology, University of Kansas Medical Center, USA
| | - Jiulong Liu
- LSEC, Institute of Computational Mathematics and Scientific/Engineering Computing, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, China
| | - Yuting Lin
- Department of Radiation Oncology, University of Kansas Medical Center, USA
| | - Gregory N Gan
- Department of Radiation Oncology, University of Kansas Medical Center, USA
| | - Guillem Pratx
- Department of Radiation Oncology, Stanford University, USA
| | - Fen Wang
- Department of Radiation Oncology, University of Kansas Medical Center, USA
| | - Katja Langen
- Department of Radiation Oncology, Emory University, USA
| | | | - Ronny L Rotondo
- Department of Radiation Oncology, University of Kansas Medical Center, USA
| | - Harold H Li
- Department of Radiation Oncology, University of Kansas Medical Center, USA
| | - Ronald C Chen
- Department of Radiation Oncology, University of Kansas Medical Center, USA
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18
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Friedl AA, Prise KM, Butterworth KT, Montay-Gruel P, Favaudon V. Radiobiology of the FLASH effect. Med Phys 2022; 49:1993-2013. [PMID: 34426981 DOI: 10.1002/mp.15184] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Revised: 08/03/2021] [Accepted: 08/09/2021] [Indexed: 12/17/2022] Open
Abstract
Radiation exposures at ultrahigh dose rates (UHDRs) at several orders of magnitude greater than in current clinical radiotherapy (RT) have been shown to manifest differential radiobiological responses compared to conventional (CONV) dose rates. This has led to studies investigating the application of UHDR for therapeutic advantage (FLASH-RT) that have gained significant interest since the initial discovery in 2014 that demonstrated reduced lung toxicity with equivalent levels of tumor control compared with conventional dose-rate RT. Many subsequent studies have demonstrated the potential protective role of FLASH-RT in normal tissues, yet the underlying molecular and cellular mechanisms of the FLASH effect remain to be fully elucidated. Here, we summarize the current evidence of the FLASH effect and review FLASH-RT studies performed in preclinical models of normal tissue response. To critically examine the underlying biological mechanisms of responses to UHDR radiation exposures, we evaluate in vitro studies performed with normal and tumor cells. Differential responses to UHDR versus CONV irradiation recurrently involve reduced inflammatory processes and differential expression of pro- and anti-inflammatory genes. In addition, frequently reduced levels of DNA damage or misrepair products are seen after UHDR irradiation. So far, it is not clear what signal elicits these differential responses, but there are indications for involvement of reactive species. Different susceptibility to FLASH effects observed between normal and tumor cells may result from altered metabolic and detoxification pathways and/or repair pathways used by tumor cells. We summarize the current theories that may explain the FLASH effect and highlight important research questions that are key to a better mechanistic understanding and, thus, the future implementation of FLASH-RT in the clinic.
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Affiliation(s)
- Anna A Friedl
- Department of Radiation Oncology, University Hospital, LMU Munich, Munich, Germany
| | - Kevin M Prise
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Karl T Butterworth
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, UK
| | - Pierre Montay-Gruel
- Department of Radiation Oncology, University of California at Irvine, Irvine, California, USA
| | - Vincent Favaudon
- Institut Curie, Inserm U 1021-CNRS UMR 3347, Université Paris-Saclay, PSL Research University, Centre Universitaire, Orsay, France
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19
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Okoro CM, Schüler E, Taniguchi CM. The Therapeutic Potential of FLASH-RT for Pancreatic Cancer. Cancers (Basel) 2022; 14:cancers14051167. [PMID: 35267474 PMCID: PMC8909276 DOI: 10.3390/cancers14051167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 02/21/2022] [Accepted: 02/22/2022] [Indexed: 11/21/2022] Open
Abstract
Simple Summary Ultra-high dose rate radiation, widely nicknamed FLASH-RT, kills tumors without significantly damaging nearby normal tissues. This selective sparing of normal tissue by FLASH-RT tissue is called the FLASH effect. This review explores some of the proposed mechanisms of the FLASH effect and the current data that might support its use in pancreatic cancer. Since radiation for pancreatic cancer treatment is limited by GI toxicity issues and is a disease with one of the lowest five-year survival rates, FLASH-RT could have a large impact in the treatment of this disease with further study. Abstract Recent preclinical evidence has shown that ionizing radiation given at an ultra-high dose rate (UHDR), also known as FLASH radiation therapy (FLASH-RT), can selectively reduce radiation injury to normal tissue while remaining isoeffective to conventional radiation therapy (CONV-RT) with respect to tumor killing. Unresectable pancreatic cancer is challenging to control without ablative doses of radiation, but this is difficult to achieve without significant gastrointestinal toxicity. In this review article, we explore the propsed mechanisms of FLASH-RT and its tissue-sparing effect, as well as its relevance and suitability for the treatment of pancreatic cancer. We also briefly discuss the challenges with regard to dosimetry, dose rate, and fractionation for using FLASH-RT to treat this disease.
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Affiliation(s)
- Chidi M. Okoro
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
| | - Emil Schüler
- Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Correspondence: (E.S.); (C.M.T.)
| | - Cullen M. Taniguchi
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA;
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX 77030, USA
- Correspondence: (E.S.); (C.M.T.)
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20
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Perstin A, Poirier Y, Sawant A, Tambasco M. Quantifying the DNA-damaging effects of FLASH irradiation with plasmid DNA. Int J Radiat Oncol Biol Phys 2022; 113:437-447. [PMID: 35124135 DOI: 10.1016/j.ijrobp.2022.01.049] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 01/19/2022] [Accepted: 01/26/2022] [Indexed: 11/15/2022]
Abstract
PURPOSE To investigate a plasmid DNA nicking assay approach for isolating and quantifying the DNA damaging effects of ultra-high dose rate (i.e., FLASH) irradiation relative to conventional dose rate irradiation. METHODS We constructed and irradiated phantoms containing plasmid DNA to nominal doses of 20 Gy and 30 Gy using 16 MeV electrons at conventional (0.167 Gy/s) and FLASH (46.6 Gy/s and 93.2 Gy/s) dose rates. We delivered conventional dose rates using a standard clinical Varian iX linac and FLASH dose rates (FDR) using a modified Varian 21EX C-series linac. We ran the irradiated DNA and controls (0 Gy) through an agarose gel electrophoresis procedure that sorted and localized the DNA into bands associated with single strand breaks (SSBs), double strand breaks (DSBs), and undamaged DNA. We quantitatively analyzed the gel images to compute the relative yields of SSBs and DSBs, and applied a mathematical model of plasmid DNA damage as a function of dose to compute relative biological effectiveness (RBE) of SSB and DSB (RBESSBandRBEDSB) damage for a given endpoint and FDR. RESULTS Both RBESSBandRBEDSB were less than unity with the FDR irradiations, indicating FLASH sparing. With regard to the more deleterious DNA DSB damage, RBEDSBs of FLASH beams at dose rates of 46.6 Gy/s and 93.2 Gy/s relative to the conventional 16 MeV beam dose rate were 0.54 ± 0.15 and 0.55 ± 0.17, respectively. CONCLUSION We have demonstrated the feasibility of using a DNA-based phantom to isolate and assess the FLASH sparing effect on DNA. We also found that FLASH irradiation causes less damage to DNA compared to a conventional dose rate. This result supports the notion that the protective effect of FLASH irradiation occurs at least partially via fundamental biochemical processes.
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Affiliation(s)
- Alan Perstin
- Physics Graduate Student, San Diego State University
| | - Yannick Poirier
- Assistant Professor, Oncology, Department of Radiation Oncology, University of Maryland
| | - Amit Sawant
- Professor and Vice Chair, Department of Radiation Oncology, University of Maryland
| | - Mauro Tambasco
- Associate Professor/Medical Physicist, Associate Program Director, Medical Physics Residency, Associate Director, Medical Physics , Department of Physics, San Diego State University.
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21
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Wang X, Luo H, Zheng X, Ge H. FLASH radiotherapy: Research process from basic experimentation to clinical application. PRECISION RADIATION ONCOLOGY 2021. [DOI: 10.1002/pro6.1140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Affiliation(s)
- Xiaohui Wang
- Department of Radiation Oncology Affiliated Cancer Hospital of Zhengzhou University Zhengzhou China
| | - Hui Luo
- Department of Radiation Oncology Affiliated Cancer Hospital of Zhengzhou University Zhengzhou China
| | - Xiaoli Zheng
- Department of Radiation Oncology Affiliated Cancer Hospital of Zhengzhou University Zhengzhou China
| | - Hong Ge
- Department of Radiation Oncology Affiliated Cancer Hospital of Zhengzhou University Zhengzhou China
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22
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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: 34] [Impact Index Per Article: 11.3] [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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23
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Quantitative Assessment of 3D Dose Rate for Proton Pencil Beam Scanning FLASH Radiotherapy and Its Application for Lung Hypofractionation Treatment Planning. Cancers (Basel) 2021; 13:cancers13143549. [PMID: 34298762 PMCID: PMC8303986 DOI: 10.3390/cancers13143549] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 07/12/2021] [Accepted: 07/13/2021] [Indexed: 12/24/2022] Open
Abstract
To quantitatively assess target and organs-at-risk (OAR) dose rate based on three proposed proton PBS dose rate metrics and study FLASH intensity-modulated proton therapy (IMPT) treatment planning using transmission beams. An in-house FLASH planning platform was developed to optimize transmission (shoot-through) plans for nine consecutive lung cancer patients previously planned with proton SBRT. Dose and dose rate calculation codes were developed to quantify three types of dose rate calculation methods (dose-averaged dose rate (DADR), average dose rate (ADR), and dose-threshold dose rate (DTDR)) based on both phantom and patient treatment plans. Two different minimum MU/spot settings were used to optimize two different dose regimes, 34-Gy in one fraction and 45-Gy in three fractions. The OAR sparing and target coverage can be optimized with good uniformity (hotspot < 110% of prescription dose). ADR, accounting for the spot dwelling and scanning time, gives the lowest dose rate; DTDR, not considering this time but a dose-threshold, gives an intermediate dose rate, whereas DADR gives the highest dose rate without considering any time or dose-threshold. All three dose rates attenuate along the beam direction, and the highest dose rate regions often occur on the field edge for ADR and DTDR, whereas DADR has a better dose rate uniformity. The differences in dose rate metrics have led a large variation for OARs dose rate assessment, posing challenges to FLASH clinical implementation. This is the first attempt to study the impact of the dose rate models, and more investigations and evidence for the details of proton PBS FLASH parameters are needed to explore the correlation between FLASH efficacy and the dose rate metrics.
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24
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Lin Y, Lin B, Fu S, Folkerts MM, Abel E, Bradley J, Gao H. SDDRO-joint: simultaneous dose and dose rate optimization with the joint use of transmission beams and Bragg peaks for FLASH proton therapy. Phys Med Biol 2021; 66. [PMID: 34010818 DOI: 10.1088/1361-6560/ac02d8] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Accepted: 05/19/2021] [Indexed: 11/12/2022]
Abstract
Cancer radiotherapy (RT) with the irradiation at ultra-high dose rates, namely FLASH-RT, can substantially reduce radiation-induced normal tissue toxicities while maintaining tumor response. Currently, clinical FLASH-RT on deep-seated tumors can only be performed with proton beams. One way to achieve ultra-high dose rates at depth is through the use of high-energy transmission beams (TB), where the Bragg peaks (BP) fall outside the body. However, planning with TB alone does not fully leverage the degrees of freedom for dose shaping as traditional intensity modulated proton therapy (IMPT) which uses the BP of multi-energy proton beams at the tumor target. This work will develop a simultaneous dose and dose rate optimization (SDDRO) method with the joint use of TB and BP, namely SDDRO-Joint. Specifically, BP are placed inside tumor targets to improve the target dose conformality and sparse the normal-tissue dose, while TB primarily cover the tumor boundary to achieve ultra-high dose rate coverage of organs-at-risk (OAR) close to tumor targets. The sparing of OAR and other normal tissues via SDDRO-Joint is jointly by TB and BP, i.e. the FLASH sparing by TB and the dose sparing by BP. The results suggest that the addition of BP substantially increased the target dose conformality for SDDRO. Noticeably SDDRO-Joint also provided slightly higher conformal index values than the conventional IMPT method with BP alone.
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Affiliation(s)
- Yuting Lin
- Department of Radiation Oncology, Emory University, Atlanta, GA, United States of America
| | - Bowen Lin
- Department of Radiation Oncology, Emory University, Atlanta, GA, United States of America.,School of Mathematics, Shandong University, Jinan, Shandong, People's Republic of China
| | - Shujun Fu
- School of Mathematics, Shandong University, Jinan, Shandong, People's Republic of China
| | | | - Eric Abel
- Varian Medical Systems, Inc., Palo Alto, CA, United States of America
| | - Jeffrey Bradley
- Department of Radiation Oncology, Emory University, Atlanta, GA, United States of America
| | - Hao Gao
- Department of Radiation Oncology, Emory University, Atlanta, GA, United States of America
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25
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De Martino M, Padilla O, Daviaud C, Wu CC, Gartrell RD, Vanpouille-Box C. Exploiting Radiation Therapy to Restore Immune Reactivity of Glioblastoma. Front Oncol 2021; 11:671044. [PMID: 34094969 PMCID: PMC8173136 DOI: 10.3389/fonc.2021.671044] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Accepted: 04/13/2021] [Indexed: 02/06/2023] Open
Abstract
Glioblastoma (GBM) is among the most aggressive of brain tumors and confers a dismal prognosis despite advances in surgical technique, radiation delivery methods, chemotherapy, and tumor-treating fields. While immunotherapy (IT) has improved the care of several adult cancers with previously dismal prognoses, monotherapy with IT in GBM has shown minimal response in first recurrence. Recent discoveries in lymphatics and evaluation of blood brain barrier offer insight to improve the use of ITs and determine the best combinations of therapies, including radiation. We highlight important features of the tumor immune microenvironment in GBM and potential for combining radiation and immunotherapy to improve prognosis in this devastating disease.
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Affiliation(s)
- Mara De Martino
- Department of Radiation Oncology, Weill Cornell Medicine, New York, NY, United States
| | - Oscar Padilla
- Department of Radiation Oncology, Columbia University Irving Medical Center, New York, NY, United States
| | - Camille Daviaud
- Department of Radiation Oncology, Weill Cornell Medicine, New York, NY, United States
| | - Cheng-Chia Wu
- Department of Radiation Oncology, Columbia University Irving Medical Center, New York, NY, United States.,Herbert Irving Comprehensive Cancer Center, New York, NY, United States
| | - Robyn D Gartrell
- Department of Pediatrics, Pediatric Hematology/Oncology/SCT, Columbia University Irving Medical Center, New York, NY, United States
| | - Claire Vanpouille-Box
- Department of Radiation Oncology, Weill Cornell Medicine, New York, NY, United States.,Sandra and Edward Meyer Cancer Center, New York, NY, United States
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26
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Yang G, Lu C, Mei Z, Sun X, Han J, Qian J, Liang Y, Pan Z, Kong D, Xu S, Liu Z, Gao Y, Qi G, Shou Y, Chen S, Cao Z, Zhao Y, Lin C, Zhao Y, Geng Y, Ma W, Yan X. Association of Cancer Stem Cell Radio-Resistance Under Ultra-High Dose Rate FLASH Irradiation With Lysosome-Mediated Autophagy. Front Cell Dev Biol 2021; 9:672693. [PMID: 33996830 PMCID: PMC8116574 DOI: 10.3389/fcell.2021.672693] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 04/06/2021] [Indexed: 12/03/2022] Open
Abstract
Cancer stem cell (CSC) is thought to be the major cause of radio-resistance and relapse post radiotherapy (RT). Recently ultra-high dose rate “FLASH-RT” evokes great interest for its decreasing normal tissue damages while maintaining tumor responses compared with conventional dose rate RT. However, the killing effect and mechanism of FLASH irradiation (FLASH-IR) on CSC and normal cancer cell are still unclear. Presently the radiation induced death profile of CSC and normal cancer cell were studied. Cells were irradiated with FLASH-IR (∼109 Gy/s) at the dose of 6–9 Gy via laser-accelerated nanosecond particles. Then the ratio of apoptosis, pyroptosis and necrosis were determined. The results showed that FLASH-IR can induce apoptosis, pyroptosis and necrosis in both CSC and normal cancer cell with different ratios. And CSC was more resistant to radiation than normal cancer cell under FLASH-IR. Further experiments tracing lysosome and autophagy showed that CSCs had higher levels of lysosome and autophagy. Taken together, our results suggested that the radio-resistance of CSC may associate with the increase of lysosome-mediated autophagy, and the decrease of apoptosis, necrosis and pyroptosis. To our limited knowledge, this is the first report shedding light on the killing effects and death pathways of CSC and normal cancer cell under FLASH-IR. By clarifying the death pathways of CSC and normal cancer cell under FLASH-IR, it may help us improve the understanding of the radio-resistance of CSC and thus help to optimize the future clinical FLASH treatment plan.
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Affiliation(s)
- Gen Yang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Chunyang Lu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Zhusong Mei
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Xiaoyi Sun
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Jintao Han
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Jing Qian
- Teaching and Research Section of Nuclear Medicine, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Yulan Liang
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Zhuo Pan
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Defeng Kong
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Shirui Xu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Zhipeng Liu
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Ying Gao
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Guijun Qi
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Yinren Shou
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Shiyou Chen
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Zhengxuan Cao
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Ye Zhao
- Teaching and Research Section of Nuclear Medicine, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Chen Lin
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Yanying Zhao
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Yixing Geng
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Wenjun Ma
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China
| | - Xueqing Yan
- State Key Laboratory of Nuclear Physics and Technology, School of Physics, CAPT, Peking University, Beijing, China.,Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, China
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27
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Cunningham S, McCauley S, Vairamani K, Speth J, Girdhani S, Abel E, Sharma RA, Perentesis JP, Wells SI, Mascia A, Sertorio M. FLASH Proton Pencil Beam Scanning Irradiation Minimizes Radiation-Induced Leg Contracture and Skin Toxicity in Mice. Cancers (Basel) 2021; 13:cancers13051012. [PMID: 33804336 PMCID: PMC7957631 DOI: 10.3390/cancers13051012] [Citation(s) in RCA: 109] [Impact Index Per Article: 36.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 02/18/2021] [Accepted: 02/22/2021] [Indexed: 02/07/2023] Open
Abstract
Simple Summary Dose and efficacy of radiation therapy are limited by the toxicity to normal tissue adjacent to the treated tumor region. Recently, ultra-high dose rate radiotherapy (FLASH radiotherapy) has shown beneficial reduction of normal tissue damage while preserving similar tumor efficacy with electron, photon and scattered proton beam irradiation in preclinical models. Proton therapy is increasingly delivered by pencil beam scanning (PBS) technology, and we therefore set out to test PBS FLASH radiotherapy on normal tissue toxicity and tumor control in vivo in mouse using a clinical proton delivery system. This validation of the FLASH normal tissue-sparing hypothesis with a clinical delivery system provides supporting data for PBS FLASH radiotherapy and its potential role in improving radiotherapy outcomes. Abstract Ultra-high dose rate radiation has been reported to produce a more favorable toxicity and tumor control profile compared to conventional dose rates that are used for patient treatment. So far, the so-called FLASH effect has been validated for electron, photon and scattered proton beam, but not yet for proton pencil beam scanning (PBS). Because PBS is the state-of-the-art delivery modality for proton therapy and constitutes a wide and growing installation base, we determined the benefit of FLASH PBS on skin and soft tissue toxicity. Using a pencil beam scanning nozzle and the plateau region of a 250 MeV proton beam, a uniform physical dose of 35 Gy (toxicity study) or 15 Gy (tumor control study) was delivered to the right hind leg of mice at various dose rates: Sham, Conventional (Conv, 1 Gy/s), Flash60 (57 Gy/s) and Flash115 (115 Gy/s). Acute radiation effects were quantified by measurements of plasma and skin levels of TGF-β1 and skin toxicity scoring. Delayed irradiation response was defined by hind leg contracture as a surrogate of irradiation-induced skin and soft tissue toxicity and by plasma levels of 13 different cytokines (CXCL1, CXCL10, Eotaxin, IL1-beta, IL-6, MCP-1, Mip1alpha, TNF-alpha, TNF-beta, VEGF, G-CSF, GM-CSF and TGF- β1). Plasma and skin levels of TGF-β1, skin toxicity and leg contracture were all significantly decreased in FLASH compared to Conv groups of mice. FLASH and Conv PBS had similar efficacy with regards to growth control of MOC1 and MOC2 head and neck cancer cells transplanted into syngeneic, immunocompetent mice. These results demonstrate consistent delivery of FLASH PBS radiation from 1 to 115 Gy/s in a clinical gantry. Radiation response following delivery of 35 Gy indicates potential benefits of FLASH versus conventional PBS that are related to skin and soft tissue toxicity.
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Affiliation(s)
- Shannon Cunningham
- Cincinnati Children’s Hospital Medical Center, Division of Oncology, Cincinnati, OH 45229, USA; (S.C.); (S.M.); (K.V.); (J.P.P.); (S.I.W.)
| | - Shelby McCauley
- Cincinnati Children’s Hospital Medical Center, Division of Oncology, Cincinnati, OH 45229, USA; (S.C.); (S.M.); (K.V.); (J.P.P.); (S.I.W.)
| | - Kanimozhi Vairamani
- Cincinnati Children’s Hospital Medical Center, Division of Oncology, Cincinnati, OH 45229, USA; (S.C.); (S.M.); (K.V.); (J.P.P.); (S.I.W.)
| | - Joseph Speth
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; (J.S.); (A.M.)
| | - Swati Girdhani
- Varian Medical Systems, Inc., Palo Alto, CA 94304, USA; (S.G.); (E.A.); (R.A.S.)
| | - Eric Abel
- Varian Medical Systems, Inc., Palo Alto, CA 94304, USA; (S.G.); (E.A.); (R.A.S.)
| | - Ricky A. Sharma
- Varian Medical Systems, Inc., Palo Alto, CA 94304, USA; (S.G.); (E.A.); (R.A.S.)
| | - John P. Perentesis
- Cincinnati Children’s Hospital Medical Center, Division of Oncology, Cincinnati, OH 45229, USA; (S.C.); (S.M.); (K.V.); (J.P.P.); (S.I.W.)
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Susanne I. Wells
- Cincinnati Children’s Hospital Medical Center, Division of Oncology, Cincinnati, OH 45229, USA; (S.C.); (S.M.); (K.V.); (J.P.P.); (S.I.W.)
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Anthony Mascia
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA; (J.S.); (A.M.)
| | - Mathieu Sertorio
- Cincinnati Children’s Hospital Medical Center, Division of Oncology, Cincinnati, OH 45229, USA; (S.C.); (S.M.); (K.V.); (J.P.P.); (S.I.W.)
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
- Correspondence:
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Mazal A, Vera Sanchez JA, Sanchez-Parcerisa D, Udias JM, España S, Sanchez-Tembleque V, Fraile LM, Bragado P, Gutierrez-Uzquiza A, Gordillo N, Garcia G, Castro Novais J, Perez Moreno JM, Mayorga Ortiz L, Ilundain Idoate A, Cremades Sendino M, Ares C, Miralbell R, Schreuder N. Biological and Mechanical Synergies to Deal With Proton Therapy Pitfalls: Minibeams, FLASH, Arcs, and Gantryless Rooms. Front Oncol 2021; 10:613669. [PMID: 33585238 PMCID: PMC7874206 DOI: 10.3389/fonc.2020.613669] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 12/02/2020] [Indexed: 12/28/2022] Open
Abstract
Proton therapy has advantages and pitfalls comparing with photon therapy in radiation therapy. Among the limitations of protons in clinical practice we can selectively mention: uncertainties in range, lateral penumbra, deposition of higher LET outside the target, entrance dose, dose in the beam path, dose constraints in critical organs close to the target volume, organ movements and cost. In this review, we combine proposals under study to mitigate those pitfalls by using individually or in combination: (a) biological approaches of beam management in time (very high dose rate “FLASH” irradiations in the order of 100 Gy/s) and (b) modulation in space (a combination of mini-beams of millimetric extent), together with mechanical approaches such as (c) rotational techniques (optimized in partial arcs) and, in an effort to reduce cost, (d) gantry-less delivery systems. In some cases, these proposals are synergic (e.g., FLASH and minibeams), in others they are hardly compatible (mini-beam and rotation). Fixed lines have been used in pioneer centers, or for specific indications (ophthalmic, radiosurgery,…), they logically evolved to isocentric gantries. The present proposals to produce fixed lines are somewhat controversial. Rotational techniques, minibeams and FLASH in proton therapy are making their way, with an increasing degree of complexity in these three approaches, but with a high interest in the basic science and clinical communities. All of them must be proven in clinical applications.
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Affiliation(s)
| | | | - Daniel Sanchez-Parcerisa
- Grupo de Física Nuclear and IPARCOS, U. Complutense Madrid, CEI Moncloa, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain.,Sedecal Molecular Imaging, Madrid, Spain
| | - Jose Manuel Udias
- Grupo de Física Nuclear and IPARCOS, U. Complutense Madrid, CEI Moncloa, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - Samuel España
- Grupo de Física Nuclear and IPARCOS, U. Complutense Madrid, CEI Moncloa, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - Victor Sanchez-Tembleque
- Grupo de Física Nuclear and IPARCOS, U. Complutense Madrid, CEI Moncloa, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - Luis Mario Fraile
- Grupo de Física Nuclear and IPARCOS, U. Complutense Madrid, CEI Moncloa, Madrid, Spain.,Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain
| | - Paloma Bragado
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain.,Department of Biochemistry and Molecular Biology. U. Complutense, Madrid, Spain
| | - Alvaro Gutierrez-Uzquiza
- Instituto de Investigación Sanitaria del Hospital Clínico San Carlos, Madrid, Spain.,Department of Biochemistry and Molecular Biology. U. Complutense, Madrid, Spain
| | - Nuria Gordillo
- Department of Applied Physics, U. Autonoma de Madrid, Madrid, Spain.,Center for Materials Microanalysis, (CMAM), U. Autonoma de Madrid, Madrid, Spain
| | - Gaston Garcia
- Center for Materials Microanalysis, (CMAM), U. Autonoma de Madrid, Madrid, Spain
| | | | | | | | | | | | - Carme Ares
- Centro de Protonterapia Quironsalud, Madrid, Spain
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29
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Esplen N, Mendonca MS, Bazalova-Carter M. Physics and biology of ultrahigh dose-rate (FLASH) radiotherapy: a topical review. Phys Med Biol 2020; 65:23TR03. [PMID: 32721941 DOI: 10.1088/1361-6560/abaa28] [Citation(s) in RCA: 114] [Impact Index Per Article: 28.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ultrahigh dose-rate radiotherapy (RT), or 'FLASH' therapy, has gained significant momentum following various in vivo studies published since 2014 which have demonstrated a reduction in normal tissue toxicity and similar tumor control for FLASH-RT when compared with conventional dose-rate RT. Subsequent studies have sought to investigate the potential for FLASH normal tissue protection and the literature has been since been inundated with publications on FLASH therapies. Today, FLASH-RT is considered by some as having the potential to 'revolutionize radiotherapy'. FLASH-RT is considered by some as having the potential to 'revolutionize radiotherapy'. The goal of this review article is to present the current state of this intriguing RT technique and to review existing publications on FLASH-RT in terms of its physical and biological aspects. In the physics section, the current landscape of ultrahigh dose-rate radiation delivery and dosimetry is presented. Specifically, electron, photon and proton radiation sources capable of delivering ultrahigh dose-rates along with their beam delivery parameters are thoroughly discussed. Additionally, the benefits and drawbacks of radiation detectors suitable for dosimetry in FLASH-RT are presented. The biology section comprises a summary of pioneering in vitro ultrahigh dose-rate studies performed in the 1960s and early 1970s and continues with a summary of the recent literature investigating normal and tumor tissue responses in electron, photon and proton beams. The section is concluded with possible mechanistic explanations of the FLASH normal-tissue protection effect (FLASH effect). Finally, challenges associated with clinical translation of FLASH-RT and its future prospects are critically discussed; specifically, proposed treatment machines and publications on treatment planning for FLASH-RT are reviewed.
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Affiliation(s)
- Nolan Esplen
- Department of Physics and Astronomy, University of Victoria, Victoria, BC, Canada
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30
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Kim YE, Gwak SH, Hong BJ, Oh JM, Choi HS, Kim MS, Oh D, Lartey FM, Rafat M, Schüler E, Kim HS, von Eyben R, Weissman IL, Koch CJ, Maxim PG, Loo BW, Ahn GO. Effects of Ultra-high doserate FLASH Irradiation on the Tumor Microenvironment in Lewis Lung Carcinoma: Role of Myosin Light Chain. Int J Radiat Oncol Biol Phys 2020; 109:1440-1453. [PMID: 33186615 DOI: 10.1016/j.ijrobp.2020.11.012] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/26/2020] [Accepted: 10/26/2020] [Indexed: 12/17/2022]
Abstract
PURPOSE To investigate whether the vascular collapse in tumors by conventional dose rate (CONV) irradiation (IR) would also occur by the ultra-high dose rate FLASH IR. METHODS AND MATERIALS Lewis lung carcinoma (LLC) cells were subcutaneously implanted in mice. This was followed by CONV or FLASH IR at 15 Gy. Tumors were harvested at 6 or 48 hours after IR and stained for CD31, phosphorylated myosin light chain (p-MLC), γH2AX (a surrogate marker for DNA double strand break), intracellular reactive oxygen species (ROS), or immune cells such as myeloid and CD8α T cells. Cell lines were irradiated with CONV IR for Western blot analyses. ML-7 was intraperitoneally administered daily to LLC-bearing mice for 7 days before 15 Gy CONV IR. Tumors were similarly harvested and analyzed. RESULTS By immunostaining, we observed that CONV IR at 6 hours resulted in constricted vessel morphology, increased expression of p-MLC, and much higher numbers of γH2AX-positive cells in tumors, which were not observed with FLASH IR. Mechanistically, MLC activation by ROS is unlikely, because FLASH IR produced significantly more ROS than CONV IR in tumors. In vitro studies demonstrated that ML-7, an inhibitor of MLC kinase, abrogated IR-induced γH2AX formation and disappearance kinetics. Lastly, we observed that CONV IR when combined with ML-7 produced some effects similar to FLASH IR, including reduction in the vasculature collapse, fewer γH2AX-positive cells, and increased immune cell influx to the tumors. CONCLUSIONS FLASH IR produced novel changes in the tumor microenvironment that were not observed with CONV IR. We believe that MLC activation in tumors may be responsible for some of the microenvironmental changes differentially regulated between CONV and FLASH IR.
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Affiliation(s)
- Young-Eun Kim
- Department of Life Science, Pohang University of Science and Technology, Gyeongbuk, Korea
| | - Seung-Hee Gwak
- Department of Life Science, Pohang University of Science and Technology, Gyeongbuk, Korea
| | - Beom-Ju Hong
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Gyeongbuk, Korea
| | - Jung-Min Oh
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology (POSTECH), Gyeongbuk, Korea
| | - Hyung-Seok Choi
- Department of Life Science, Pohang University of Science and Technology, Gyeongbuk, Korea
| | - Myeoung Su Kim
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Dawit Oh
- College of Veterinary Medicine, Seoul National University, Seoul, Korea
| | - Frederik M Lartey
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Marjan Rafat
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Emil Schüler
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Hyo-Soo Kim
- Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea
| | - Rie von Eyben
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Irving L Weissman
- Institute of Stem Cell and Regenerative Medicine, Stanford University School of Medicine, Stanford, California
| | - Cameron J Koch
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Peter G Maxim
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California.
| | - G-One Ahn
- College of Veterinary Medicine, Seoul National University, Seoul, Korea.
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31
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FLASH Radiotherapy: Current Knowledge and Future Insights Using Proton-Beam Therapy. Int J Mol Sci 2020; 21:ijms21186492. [PMID: 32899466 PMCID: PMC7556020 DOI: 10.3390/ijms21186492] [Citation(s) in RCA: 112] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 12/27/2022] Open
Abstract
FLASH radiotherapy is the delivery of ultra-high dose rate radiation several orders of magnitude higher than what is currently used in conventional clinical radiotherapy, and has the potential to revolutionize the future of cancer treatment. FLASH radiotherapy induces a phenomenon known as the FLASH effect, whereby the ultra-high dose rate radiation reduces the normal tissue toxicities commonly associated with conventional radiotherapy, while still maintaining local tumor control. The underlying mechanism(s) responsible for the FLASH effect are yet to be fully elucidated, but a prominent role for oxygen tension and reactive oxygen species production is the most current valid hypothesis. The FLASH effect has been confirmed in many studies in recent years, both in vitro and in vivo, with even the first patient with T-cell cutaneous lymphoma being treated using FLASH radiotherapy. However, most of the studies into FLASH radiotherapy have used electron beams that have low tissue penetration, which presents a limitation for translation into clinical practice. A promising alternate FLASH delivery method is via proton beam therapy, as the dose can be deposited deeper within the tissue. However, studies into FLASH protons are currently sparse. This review will summarize FLASH radiotherapy research conducted to date and the current theories explaining the FLASH effect, with an emphasis on the future potential for FLASH proton beam therapy.
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Could Protons and Carbon Ions Be the Silver Bullets Against Pancreatic Cancer? Int J Mol Sci 2020; 21:ijms21134767. [PMID: 32635552 PMCID: PMC7369903 DOI: 10.3390/ijms21134767] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/30/2020] [Accepted: 07/01/2020] [Indexed: 02/07/2023] Open
Abstract
Pancreatic cancer is a very aggressive cancer type associated with one of the poorest prognostics. Despite several clinical trials to combine different types of therapies, none of them resulted in significant improvements for patient survival. Pancreatic cancers demonstrate a very broad panel of resistance mechanisms due to their biological properties but also their ability to remodel the tumour microenvironment. Radiotherapy is one of the most widely used treatments against cancer but, up to now, its impact remains limited in the context of pancreatic cancer. The modern era of radiotherapy proposes new approaches with increasing conformation but also more efficient effects on tumours in the case of charged particles. In this review, we highlight the interest in using charged particles in the context of pancreatic cancer therapy and the impact of this alternative to counteract resistance mechanisms.
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Wilson JD, Hammond EM, Higgins GS, Petersson K. Ultra-High Dose Rate (FLASH) Radiotherapy: Silver Bullet or Fool's Gold? Front Oncol 2020; 9:1563. [PMID: 32010633 PMCID: PMC6979639 DOI: 10.3389/fonc.2019.01563] [Citation(s) in RCA: 247] [Impact Index Per Article: 61.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 12/24/2019] [Indexed: 12/12/2022] Open
Abstract
Radiotherapy is a cornerstone of both curative and palliative cancer care. However, radiotherapy is severely limited by radiation-induced toxicities. If these toxicities could be reduced, a greater dose of radiation could be given therefore facilitating a better tumor response. Initial pre-clinical studies have shown that irradiation at dose rates far exceeding those currently used in clinical contexts reduce radiation-induced toxicities whilst maintaining an equivalent tumor response. This is known as the FLASH effect. To date, a single patient has been subjected to FLASH radiotherapy for the treatment of subcutaneous T-cell lymphoma resulting in complete response and minimal toxicities. The mechanism responsible for reduced tissue toxicity following FLASH radiotherapy is yet to be elucidated, but the most prominent hypothesis so far proposed is that acute oxygen depletion occurs within the irradiated tissue. This review examines the tissue response to FLASH radiotherapy, critically evaluates the evidence supporting hypotheses surrounding the biological basis of the FLASH effect, and considers the potential for FLASH radiotherapy to be translated into clinical contexts.
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Affiliation(s)
- Joseph D. Wilson
- Department of Oncology, The Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Ester M. Hammond
- Department of Oncology, The Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Geoff S. Higgins
- Department of Oncology, The Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
| | - Kristoffer Petersson
- Department of Oncology, The Oxford Institute for Radiation Oncology, University of Oxford, Oxford, United Kingdom
- Radiation Physics, Department of Haematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
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