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Srinivasan D, Subbarayan R, Srivastava N, Radhakrishnan A, Adtani PN, Chauhan A, Krishnamoorthy L. A comprehensive overview of radiation therapy impacts of various cancer treatments and pivotal role in the immune system. Cell Biochem Funct 2024; 42:e4103. [PMID: 39073207 DOI: 10.1002/cbf.4103] [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: 05/13/2024] [Revised: 06/25/2024] [Accepted: 07/17/2024] [Indexed: 07/30/2024]
Abstract
The cancer treatment landscape is significantly evolving, focusing on advanced radiation therapy methods to maximize effectiveness and minimize the adverse effects. Recognized as a pivotal component in cancer and disease treatment, radiation therapy (RT) has drawn attention in recent research that delves into its intricate interplay with inflammation and the immune response. This exploration unveils the underlying processes that significantly influence treatment outcomes. In this context, the potential advantages of combining bronchoscopy with RT across diverse clinical scenarios, alongside the targeted impact of brachytherapy, are explored. Concurrently, radiation treatments serve multifaceted roles such as DNA repair, cell elimination, and generating immune stress signaling molecules known as damage-associated molecular patterns, elucidating their effectiveness in treating various diseases. External beam RT introduces versatility by utilizing particles such as photons, electrons, protons, or carbon ions, each offering distinct advantages. Advanced RT techniques contribute to the evolving landscape, with emerging technologies like FLASH, spatially fractionated RT, and others poised to revolutionize the field. The comprehension of RT, striving for improved treatment outcomes, reduced side effects, and facilitating personalized and innovative treatments for cancer and noncancer patients. After navigating these advancements, the goal is fixed to usher in a new era in which RT is a cornerstone of precision and effectiveness in medical interventions. In summarizing the myriad findings, the review underscores the significance of understanding the differential impacts of radiation approaches on inflammation and immune modulation, offering valuable insights for developing innovative therapeutic interventions that harness the immune system in conjunction with RT.
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Affiliation(s)
- Dhasarathdev Srinivasan
- Centre for Advanced Biotherapeutics and Regenerative Medicine, Faculty of Research, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, India
| | - Rajasekaran Subbarayan
- Centre for Advanced Biotherapeutics and Regenerative Medicine, Faculty of Research, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, India
| | - Nityanand Srivastava
- Department of Cell Biology, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Arunkumar Radhakrishnan
- Department of Pharmacology, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, India
| | - Pooja Narain Adtani
- Department of Basic Medical and Dental Sciences, College of Dentistry, Gulf Medical University, Ajman, United Arab Emirates
| | - Ankush Chauhan
- Centre for Herbal Pharmacology and Environmental Sustainability, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, India
| | - Loganathan Krishnamoorthy
- Department of Allied Health Sciences-FAHS, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, India
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Diepeveen MH, Lathouwers D, José Santo R, Hoogeman MS, Habraken SJM. Two-dimensional oxygen-diffusion modelling for FLASH proton therapy with pencil beam scanning-Impact of diffusive tissue properties, dose, dose rate and scan patterns. Phys Med Biol 2024; 69:155020. [PMID: 38959905 DOI: 10.1088/1361-6560/ad5eee] [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: 12/22/2023] [Accepted: 07/03/2024] [Indexed: 07/05/2024]
Abstract
Objective.Oxygen depletion is generally believed to play an important role in the FLASH effect-a differential reduction of the radiosensitivity of healthy tissues, relative to that of the tumour under ultra-high dose-rate (UHDR) irradiation conditions. In proton therapy (PT) with pencil-beam scanning (PBS), the deposition of dose, and, hence, the degree of (radiolytic) oxygen depletion varies both spatially and temporally. Therefore, the resulting oxygen concentration and the healthy-tissue sparing effect through radiation-induced hypoxia varies both spatially and temporally as well.Approach.We propose and numerically solve a physical oxygen diffusion model to study these effects and their dependence on tissue parameters and the scan pattern in pencil-beam delivery. Since current clinical FLASH PT (FLASH-PT) is based on 250 MeV shoot-through (transmission) beams, for which dose and dose rate (DR) hardly vary with depth compared to the variation transverse to the beam axis, we focus on the two-dimensional case. We numerically integrate the model to obtain the oxygen concentration in each voxel as a function of time and extract voxel-based and spatially and temporarily integrated metrics for oxygen (FLASH) enhanced dose. Furthermore, we evaluate the impact on oxygen enhancement of standard pencil-beam delivery patterns and patterns that were optimised on dose-rate. Our model can contribute to the identification of tissue properties and pencil-beam delivery parameters that are critical for FLASH-PT and it may be used for the optimisation of FLASH-PT treatment plans and their delivery.Main results.(i) the diffusive properties of oxygen are critical for the steady state concentration and therefore the FLASH effect, even more so in two dimensions when compared to one dimension. (ii) The FLASH effect through oxygen depletion depends primarily on dose and less on other parameters. (iii) At a fixed fraction dose there is a slight dependence on DR. (iv) Scan patterns optimised on DR slightly increase the oxygen induced FLASH effect.Significance.To our best knowledge, this is the first study assessing the impact of scan-pattern optimization (SPO) in FLASH-PT with PBS on a biological FLASH model. While the observed impact of SPO is relatively small, a larger effect is expected for larger target volumes. A better understanding of the FLASH effect and the role of oxygen (depletion) therein is essential for the further development of FLASH-PT with PBS, and SPO.
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Affiliation(s)
- Maarten H Diepeveen
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, The Netherlands
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
| | - Danny Lathouwers
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
- Holland Proton Therapy Center, Department of Medical Physics and Informatics, Delft, The Netherlands
| | - Rodrigo José Santo
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, The Netherlands
- Holland Proton Therapy Center, Department of Medical Physics and Informatics, Delft, The Netherlands
| | - Mischa S Hoogeman
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, The Netherlands
- Delft University of Technology, Department of Radiation Science and Technology, Delft, The Netherlands
- Holland Proton Therapy Center, Department of Medical Physics and Informatics, Delft, The Netherlands
| | - Steven J M Habraken
- Erasmus MC Cancer Institute, University Medical Center Rotterdam, Department of Radiotherapy, Rotterdam, The Netherlands
- Holland Proton Therapy Center, Department of Medical Physics and Informatics, Delft, The Netherlands
- Leiden University Medical Center, Department of Radiotherapy,Leiden, The Netherlands
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Wanstall HC, Korysko P, Farabolini W, Corsini R, Bateman JJ, Rieker V, Hemming A, Henthorn NT, Merchant MJ, Santina E, Chadwick AL, Robertson C, Malyzhenkov A, Jones RM. VHEE FLASH sparing effect measured at CLEAR, CERN with DNA damage of pBR322 plasmid as a biological endpoint. Sci Rep 2024; 14:14803. [PMID: 38926450 PMCID: PMC11208499 DOI: 10.1038/s41598-024-65055-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 06/17/2024] [Indexed: 06/28/2024] Open
Abstract
Ultra-high dose rate (UHDR) irradiation has been shown to have a sparing effect on healthy tissue, an effect known as 'FLASH'. This effect has been studied across several radiation modalities, including photons, protons and clinical energy electrons, however, very little data is available for the effect of FLASH with Very High Energy Electrons (VHEE). pBR322 plasmid DNA was used as a biological model to measure DNA damage in response to Very High Energy Electron (VHEE) irradiation at conventional (0.08 Gy/s), intermediate (96 Gy/s) and ultra-high dose rates (UHDR, (2 × 109 Gy/s) at the CERN Linear Electron Accelerator (CLEAR) user facility. UHDRs were used to determine if the biological FLASH effect could be measured in the plasmid model, within a hydroxyl scavenging environment. Two different concentrations of the hydroxyl radical scavenger Tris were used in the plasmid environment to alter the proportions of indirect damage, and to replicate a cellular scavenging capacity. Indirect damage refers to the interaction of ionising radiation with molecules and species to generate reactive species which can then attack DNA. UHDR irradiated plasmid was shown to have significantly reduced amounts of damage in comparison to conventionally irradiated, where single strand breaks (SSBs) was used as the biological endpoint. This was the case for both hydroxyl scavenging capacities. A reduced electron energy within the VHEE range was also determined to increase the DNA damage to pBR322 plasmid. Results indicate that the pBR322 plasmid model can be successfully used to explore and test the effect of UHDR regimes on DNA damage. This is the first study to report FLASH sparing with VHEE, with induced damage to pBR322 plasmid DNA as the biological endpoint. UHDR irradiated plasmid had reduced amounts of DNA single-strand breaks (SSBs) in comparison with conventional dose rates. The magnitude of the FLASH sparing was a 27% reduction in SSB frequency in a 10 mM Tris environment and a 16% reduction in a 100 mM Tris environment.
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Affiliation(s)
- Hannah C Wanstall
- Department of Physics and Astronomy, Faculty of Science and Engineering, University of Manchester, Schuster Building, Oxford Road, Manchester, M13 9PL, UK.
- Manchester Academic Health Science Centre, Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK.
- Daresbury Laboratory, The Cockcroft Institute, Daresbury, Warrington, WA4 4AD, UK.
| | - Pierre Korysko
- University of Oxford, Oxford, OX1 2JD, UK
- CERN, Geneva, 1211, Geneva 23, Switzerland
| | | | | | | | - Vilde Rieker
- CERN, Geneva, 1211, Geneva 23, Switzerland
- University of Oslo, 0316, Oslo, Norway
| | - Abigail Hemming
- Manchester Academic Health Science Centre, Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK
| | - Nicholas T Henthorn
- Manchester Academic Health Science Centre, Christie NHS Foundation Trust, Wilmslow Road, Manchester, M20 4BX, UK
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Michael J Merchant
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Elham Santina
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | - Amy L Chadwick
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, School of Medical Sciences, The University of Manchester, Oxford Road, Manchester, M13 9PL, UK
| | | | | | - Roger M Jones
- Department of Physics and Astronomy, Faculty of Science and Engineering, University of Manchester, Schuster Building, Oxford Road, Manchester, M13 9PL, UK
- Daresbury Laboratory, The Cockcroft Institute, Daresbury, Warrington, WA4 4AD, UK
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Zhao X, Huang S, Lin H, Choi JI, Zhu K, Simone CB, Yan X, Kang M. A Novel Dose Rate Optimization Method to Maximize Ultrahigh-Dose-Rate Coverage of Critical Organs at Risk Without Compromising Dosimetry Metrics in Proton Pencil Beam Scanning FLASH Radiation Therapy. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)00735-1. [PMID: 38879087 DOI: 10.1016/j.ijrobp.2024.06.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 05/12/2024] [Accepted: 06/09/2024] [Indexed: 07/10/2024]
Abstract
PURPOSE This study aimed to investigate a dose rate optimization framework based on the spot-scanning patterns to improve ultrahigh-dose-rate coverage of critical organs at risk (OARs) for proton pencil beam scanning (PBS) FLASH radiation therapy (ultrahigh dose-rate (often referred to as >40 Gy per second) delivery) and present implementation of a genetic algorithm (GA) method for spot sequence optimization to achieve PBS FLASH dose rate optimization under relatively low nozzle beam currents. METHODS AND MATERIALS First, a multifield FLASH plan was developed to meet all the dosimetric goals and optimal FLASH dose rate coverage by considering the deliverable minimum monitor unit constraint. Then, a GA method was implemented into the in-house treatment platform to maximize the dose rate by exploring the best spot delivery sequence. A phantom study was performed to evaluate the effectiveness of the dose rate optimization. Then, 10 consecutive plans for patients with lung cancer previously treated using PBS intensity-modulated proton therapy were optimized using 45 GyRBE in 3 fractions for both transmission and Bragg peak FLASH radiation therapy for further validation. The spot delivery sequence of each treatment field was optimized using this GA. The ultrahigh-dose-rate-volume histogram and dose rate coverage V40GyRBE/s were investigated to assess the efficacy of dose rate optimization quantitatively. RESULTS Using a relatively low monitor unit/spot of 150, corresponding to a nozzle beam current of 65 nA, the FLASH dose rate ratio V40GyRBE/s of the OAR contour of the core was increased from 0% to ∼60% in the phantom study. In the patients with lung cancer, the ultrahigh-dose-rate coverage V40GyRBE/s was improved from 15.2%, 15.5%, 17.6%, and 16.0% before the delivery sequence optimization to 31.8%, 43.5%, 47.6%, and 30.5% after delivery sequence optimization in the lungs-GTV (gross tumor volume), spinal cord, esophagus, and heart (for all, P < .001). When the beam current increased to 130 nA, V40GyRBE/s was improved from 45.1%, 47.1%, 51.2%, and 51.4% to 65.3%, 83.5%, 88.1%, and 69.4% (P < .05). The averaged V40GyRBE/s for the target and OARs increased from 12.9% to 41.6% and 46.3% to 77.5% for 65 and 130 nA, respectively, showing significant improvements based on a clinical proton system. After optimizing the dose rate for the Bragg peak FLASH technique with a beam current of 340 nA, the V40GyRBE/s values for the lung GTV, spinal cord, esophagus, and heart were increased by 8.9%, 15.8%, 22%, and 20.8%, respectively. CONCLUSIONS An optimal plan quality can be maintained as the spot delivery sequence optimization is a separate independent process after the plan optimization. Both the phantom and patient results demonstrated that novel spot delivery sequence optimization can effectively improve the ultrahigh-dose-rate coverage for critical OARs, which can potentially be applied in clinical practice for better OARs-sparing efficacy.
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Affiliation(s)
- Xingyi Zhao
- State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, Center for Applied Physics and Technology, Peking University, Beijing, China; New York Proton Center, New York, New York
| | - Sheng Huang
- Radiation Oncology, Tianjin Medical University Cancer Institute & Hospital, National Clinical Research Center for Cancer, Tianjin's Clinical Research Center for Cancer, Tianjin, China
| | - Haibo Lin
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - J Isabelle Choi
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Kun Zhu
- State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, Center for Applied Physics and Technology, Peking University, Beijing, China
| | - Charles B Simone
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Xueqing Yan
- State Key Laboratory of Nuclear Physics and Technology, and Key Laboratory of HEDP of the Ministry of Education, Center for Applied Physics and Technology, Peking University, Beijing, China.
| | - Minglei Kang
- New York Proton Center, New York, New York; Departments of Radiation Oncology and Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York.
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5
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Morel D, Robert C, Paragios N, Grégoire V, Deutsch E. Translational Frontiers and Clinical Opportunities of Immunologically Fitted Radiotherapy. Clin Cancer Res 2024; 30:2317-2332. [PMID: 38477824 PMCID: PMC11145173 DOI: 10.1158/1078-0432.ccr-23-3632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 01/09/2024] [Accepted: 02/13/2024] [Indexed: 03/14/2024]
Abstract
Ionizing radiation can have a wide range of impacts on tumor-immune interactions, which are being studied with the greatest interest and at an accelerating pace by the medical community. Despite its undeniable immunostimulatory potential, it clearly appears that radiotherapy as it is prescribed and delivered nowadays often alters the host's immunity toward a suboptimal state. This may impair the full recovery of a sustained and efficient antitumor immunosurveillance posttreatment. An emerging concept is arising from this awareness and consists of reconsidering the way of designing radiation treatment planning, notably by taking into account the individualized risks of deleterious radio-induced immune alteration that can be deciphered from the planned beam trajectory through lymphocyte-rich organs. In this review, we critically appraise key aspects to consider while planning immunologically fitted radiotherapy, including the challenges linked to the identification of new dose constraints to immune-rich structures. We also discuss how pharmacologic immunomodulation could be advantageously used in combination with radiotherapy to compensate for the radio-induced loss, for example, with (i) agonists of interleukin (IL)2, IL4, IL7, IL9, IL15, or IL21, similarly to G-CSF being used for the prophylaxis of severe chemo-induced neutropenia, or with (ii) myeloid-derived suppressive cell blockers.
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Affiliation(s)
- Daphné Morel
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
- INSERM U1030, Molecular Radiotherapy, Villejuif, France
| | - Charlotte Robert
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
- INSERM U1030, Molecular Radiotherapy, Villejuif, France
- Paris-Saclay University, School of Medicine, Le Kremlin Bicêtre, France
| | - Nikos Paragios
- Therapanacea, Paris, France
- CentraleSupélec, Gif-sur-Yvette, France
| | - Vincent Grégoire
- Department of Radiation Oncology, Centre Léon Bérard, Lyon, France
| | - Eric Deutsch
- Department of Radiation Oncology, Gustave Roussy, Villejuif, France
- INSERM U1030, Molecular Radiotherapy, Villejuif, France
- Paris-Saclay University, School of Medicine, Le Kremlin Bicêtre, France
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Pageot C, Zerouali K, Guillet D, Muir B, Renaud J, Lalonde A. The effect of electron backscatter and charge build up in media on beam current transformer signal for ultra-high dose rate (FLASH) electron beam monitoring. Phys Med Biol 2024; 69:105016. [PMID: 38640916 DOI: 10.1088/1361-6560/ad40f7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2023] [Accepted: 04/19/2024] [Indexed: 04/21/2024]
Abstract
Objective.Beam current transformers (BCT) are promising detectors for real-time beam monitoring in ultra-high dose rate (UHDR) electron radiotherapy. However, previous studies have reported a significant sensitivity of the BCT signal to changes in source-to-surface distance (SSD), field size, and phantom material which have until now been attributed to the fluctuating levels of electrons backscattered within the BCT. The purpose of this study is to evaluate this hypothesis, with the goal of understanding and mitigating the variations in BCT signal due to changes in irradiation conditions.Approach.Monte Carlo simulations and experimental measurements were conducted with a UHDR-capable intra-operative electron linear accelerator to analyze the impact of backscattered electrons on BCT signal. The potential influence of charge accumulation in media as a mechanism affecting BCT signal perturbation was further investigated by examining the effects of phantom conductivity and electrical grounding. Finally, the effectiveness of Faraday shielding to mitigate BCT signal variations is evaluated.Main Results.Monte Carlo simulations indicated that the fraction of electrons backscattered in water and on the collimator plastic at 6 and 9 MeV is lower than 1%, suggesting that backscattered electrons alone cannot account for the observed BCT signal variations. However, our experimental measurements confirmed previous findings of BCT response variation up to 15% for different field diameters. A significant impact of phantom type on BCT response was also observed, with variations in BCT signal as high as 14.1% when comparing measurements in water and solid water. The introduction of a Faraday shield to our applicators effectively mitigated the dependencies of BCT signal on SSD, field size, and phantom material.Significance.Our results indicate that variations in BCT signal as a function of SSD, field size, and phantom material are likely driven by an electric field originating in dielectric materials exposed to the UHDR electron beam. Strategies such as Faraday shielding were shown to effectively prevent these electric fields from affecting BCT signal, enabling reliable BCT-based electron UHDR beam monitoring.
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Affiliation(s)
- Charles Pageot
- École Polytechnique de Montréal, Montreal, QC, Canada
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
| | - Karim Zerouali
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
| | - Dominique Guillet
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
| | - Bryan Muir
- National Research Council, Ottawa, ON, Canada
| | | | - Arthur Lalonde
- Centre Hospitalier de l'Université de Montreal (CHUM), Montreal, QC, Canada
- Université de Montréal , Montreal, QC, Canada
- Centre de Recherche du Centre Hospitalier de l'Université de Montreal (CRCHUM), Montreal, QC, Canada
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7
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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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8
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Almeida A, Godfroid C, Leavitt RJ, Montay-Gruel P, Petit B, Romero J, Ollivier J, Meziani L, Sprengers K, Paisley R, Grilj V, Limoli CL, Romero P, Vozenin MC. Antitumor Effect by Either FLASH or Conventional Dose Rate Irradiation Involves Equivalent Immune Responses. Int J Radiat Oncol Biol Phys 2024; 118:1110-1122. [PMID: 37951550 PMCID: PMC11093276 DOI: 10.1016/j.ijrobp.2023.10.031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 10/05/2023] [Accepted: 10/14/2023] [Indexed: 11/14/2023]
Abstract
PURPOSE The capability of ultrahigh dose rate FLASH radiation therapy to generate the FLASH effect has opened the possibility to enhance the therapeutic index of radiation therapy. The contribution of the immune response has frequently been hypothesized to account for a certain fraction of the antitumor efficacy and tumor kill of FLASH but has yet to be rigorously evaluated. METHODS AND MATERIALS To investigate the immune response as a potentially important mechanism of the antitumor effect of FLASH, various murine tumor models were grafted either subcutaneously or orthotopically into immunocompetent mice or in moderately and severely immunocompromised mice. Mice were locally irradiated with single dose (20 Gy) or hypofractionated regimens (3 × 8 or 2 × 6 Gy) using FLASH (≥2000 Gy/s) and conventional (CONV) dose rates (0.1 Gy/s), with/without anti-CTLA-4. Tumor growth was monitored over time and immune profiling performed. RESULTS FLASH and CONV 20 Gy were isoeffective in delaying tumor growth in immunocompetent and moderately immunodeficient hosts and increased tumor doubling time to >14 days versus >7 days in control animals. Similar observations were obtained with a hypofractionated scheme, regardless of the microenvironment (subcutaneous flank vs ortho lungs). Interestingly, in profoundly immunocompromised mice, 20 Gy FLASH retained antitumor activity and significantly increased tumor doubling time to >14 days versus >8 days in control animals, suggesting a possible antitumor mechanism independent of the immune response. Analysis of the tumor microenvironment showed similar immune profiles after both irradiation modalities with significant decrease of lymphoid cells by ∼40% and a corresponding increase of myeloid cells. In addition, FLASH and CONV did not increase transforming growth factor-β1 levels in tumors compared with unirradiated control animals. Furthermore, when a complete and long-lasting antitumor response was obtained (>140 days), both modalities of irradiation were able to generate a long-term immunologic memory response. CONCLUSIONS The present results clearly document that the tumor responses across multiple immunocompetent and immunodeficient mouse models are largely dose rate independent and simultaneously contradict a major role of the immune response in the antitumor efficacy of FLASH. Therefore, our study indicates that FLASH is as potent as CONV in modulating antitumor immune response and can be used as an immunomodulatory agent.
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Affiliation(s)
- Aymeric Almeida
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Céline Godfroid
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland; Department of Oncology UNIL CHUV, University of Lausanne, Épalinges, Switzerland
| | - Ron J Leavitt
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Pierre Montay-Gruel
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland; Radiation Oncology Department, Iridium Netwerk, Wilrijk (Antwerp), Belgium; Antwerp Research in Radiation Oncology (AReRO), Centre for Oncological Research (CORE), University of Antwerp, Antwerp, Belgium
| | - Benoit Petit
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jackeline Romero
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Jonathan Ollivier
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Lydia Meziani
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Kevin Sprengers
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Ryan Paisley
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Charles L Limoli
- Department of Radiation Oncology, University of California, Irvine, California
| | - Pedro Romero
- Department of Oncology UNIL CHUV, University of Lausanne, Épalinges, Switzerland
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology/Radiation Oncology Service/Department of Oncology/CHUV, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
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9
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Pham TN, Coupey J, Toutain J, Candéias SM, Simonin G, Rousseau M, Touzani O, Thariat J, Valable S. Early effects of different brain radiotherapy modalities on circulating leucocyte subpopulations in rodents. Int J Radiat Biol 2024; 100:744-755. [PMID: 38466699 DOI: 10.1080/09553002.2024.2324471] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Accepted: 02/09/2024] [Indexed: 03/13/2024]
Abstract
PURPOSES Lymphopenia is extensively studied, but not circulating leucocyte subpopulations, which however have distinct roles in tumor tolerance. Proton therapy has been shown to have a lesser impact on the immune system than conventional X-ray radiotherapy through lower dose exposure to healthy tissues. We explored the differential effects of brain X-ray and proton irradiation on circulating leucocyte subpopulations. MATERIALS AND METHODS Leucocyte subpopulation counts from tumor-free mice were obtained 12 hours after 4 fractions of 2.5 Gy. The relationships between irradiation type (X-rays or protons), irradiated volume (whole-brain/hemi-brain) and dose rate (1 or 2 Gy/min) with circulating leucocyte subpopulations (T-CD4+, T-CD8+, B, and NK-cells, neutrophils, and monocytes) were investigated using linear regression and tree-based modeling approaches. Relationships between dose maps (brain, vessels, lymph nodes (LNs)) and leucocyte subpopulations were analyzed and applied to construct the blood dose model, assessing the hypothesis of a direct lymphocyte-killing effect in radiation-induced lymphopenia. RESULTS Radiation-induced lymphopenia occurred after X-ray but not proton brain irradiation in lymphoid subpopulations (T-CD4+, T-CD8+, B, and NK-cells). There was an increase in neutrophil counts following protons but not X-rays. Monocytes remained unchanged under both X-rays and protons. Besides irradiation type, irradiated volume and dose rate had a significant impact on NK-cell, neutrophil and monocyte levels but not T-CD4+, T-CD8+, and B-cells. The dose to the blood had a heterogeneous impact on leucocyte subpopulations: neutrophil counts remained stable with increasing dose to the blood, while lymphocyte counts decreased with increasing dose (T-CD8+-cells > T-CD4+-cells > B-cells > NK-cells). Direct cell-killing effect of the dose to the blood mildly contributed to radiation-induced lymphopenia. LN exposure significantly contributed to lymphopenia and partially explained the distinct impact of irradiation type on circulating lymphocytes. CONCLUSIONS Leucocyte subpopulations reacted differently to X-ray or proton brain irradiation. This difference could be partly explained by LN exposure to radiation dose. Further researches and analyses on other biological processes and interactions between leucocyte subpopulations are ongoing. The various mechanisms underlying leucocyte subpopulation changes under different irradiation modalities may have implications for the choice of radiotherapy modalities and their combination with immunotherapy in brain cancer treatment.
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Affiliation(s)
- Thao-Nguyen Pham
- Normandie Univ, UNICAEN, CNRS, ISTCT, GIP Cyceron, Caen, France
- Laboratoire de physique corpusculaire UMR6534 IN2P3/ENSICAEN, France - Normandie Université, France
| | - Julie Coupey
- Normandie Univ, UNICAEN, CNRS, ISTCT, GIP Cyceron, Caen, France
| | - Jérôme Toutain
- Normandie Univ, UNICAEN, CNRS, ISTCT, GIP Cyceron, Caen, France
| | - Serge M Candéias
- Univ. Grenoble Alpes, CEA, CNRS, IRIG-LCBM-UMR5249, Grenoble, France
| | - Gaël Simonin
- CNRS, IPHC, UMR 7178, Strasbourg University, Strasbourg, France
| | - Marc Rousseau
- CNRS, IPHC, UMR 7178, Strasbourg University, Strasbourg, France
| | - Omar Touzani
- Normandie Univ, UNICAEN, CNRS, ISTCT, GIP Cyceron, Caen, France
| | - Juliette Thariat
- Laboratoire de physique corpusculaire UMR6534 IN2P3/ENSICAEN, France - Normandie Université, France
- Department of Radiation Oncology, Centre François Baclesse, Caen, Normandy, France
| | - Samuel Valable
- Normandie Univ, UNICAEN, CNRS, ISTCT, GIP Cyceron, Caen, France
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10
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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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11
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Borghini A, Labate L, Piccinini S, Panaino CMV, Andreassi MG, Gizzi LA. FLASH Radiotherapy: Expectations, Challenges, and Current Knowledge. Int J Mol Sci 2024; 25:2546. [PMID: 38473799 DOI: 10.3390/ijms25052546] [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: 11/18/2023] [Revised: 02/12/2024] [Accepted: 02/19/2024] [Indexed: 03/14/2024] Open
Abstract
Major strides have been made in the development of FLASH radiotherapy (FLASH RT) in the last ten years, but there are still many obstacles to overcome for transfer to the clinic to become a reality. Although preclinical and first-in-human clinical evidence suggests that ultra-high dose rates (UHDRs) induce a sparing effect in normal tissue without modifying the therapeutic effect on the tumor, successful clinical translation of FLASH-RT depends on a better understanding of the biological mechanisms underpinning the sparing effect. Suitable in vitro studies are required to fully understand the radiobiological mechanisms associated with UHDRs. From a technical point of view, it is also crucial to develop optimal technologies in terms of beam irradiation parameters for producing FLASH conditions. This review provides an overview of the research progress of FLASH RT and discusses the potential challenges to be faced before its clinical application. We critically summarize the preclinical evidence and in vitro studies on DNA damage following UHDR irradiation. We also highlight the ongoing developments of technologies for delivering FLASH-compliant beams, with a focus on laser-driven plasma accelerators suitable for performing basic radiobiological research on the UHDR effects.
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Affiliation(s)
| | - Luca Labate
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
| | - Simona Piccinini
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
| | | | | | - Leonida Antonio Gizzi
- Intense Laser Irradiation Laboratory (ILIL), CNR Istituto Nazionale di Ottica, 56124 Pisa, Italy
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12
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Zhu H, Schuemann J, Zhang Q, Gerweck LE. Modeling the impact of tissue oxygen profiles and oxygen depletion parameter uncertainties on biological response and therapeutic benefit of FLASH. Med Phys 2024; 51:670-681. [PMID: 36939370 PMCID: PMC10509320 DOI: 10.1002/mp.16366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 02/22/2023] [Accepted: 03/06/2023] [Indexed: 03/21/2023] Open
Abstract
BACKGROUND Ultra-high dose rate (FLASH) radiation has been reported to efficiently suppress tumor growth while sparing normal tissue; however, the mechanism of the differential tissue sparing effect is still not known. Oxygen has long been known to profoundly impact radiobiological responses, and radiolytic oxygen depletion has been considered to be a possible cause or contributor to the FLASH phenomenon. PURPOSE This work investigates the impact of tissue pO2 profiles, oxygen depletion per unit dose (g), and the oxygen concentration yielding half-maximum radiosensitization (the average of its maximum value and one) (k) in tumor and normal tissue. METHODS We developed a model that considers the dependent relationship between oxygen depletion and change of radiosensitivity by FLASH irradiation. The model assumed that FLASH irradiation depletes intracellular oxygen more rapidly than it diffuses into the cell from the extracellular environment. Cell survival was calculated based on the linear quadratic-linear model and the radiosensitivity related parameters were adjusted in 1 Gy increments of the administered dose. The model reproduced published experimental data that were obtained with different cell lines and oxygen concentrations, and was used to analyze the impact of parameter uncertainties on the radiobiological responses. This study expands the oxygen depletion analysis of FLASH to normal human tissue and tumor based on clinically determined aggregate and individual patient pO2 profiles. RESULTS The results show that the pO2 profile is the most essential factor that affects biological response and analyses based on the median pO2 rather than the full pO2 profile can be unreliable and misleading. Additionally, the presence of a small fraction of cells on the threshold of radiobiologic hypoxia substantially alters biological response due to FLASH oxygen depletion. We found that an increment in the k value is generally more protective of tumor than normal tissue due to a higher frequency of lower pO2 values in tumors. Variation in the g value affects the dose at which oxygen depletion impacts response, but does not alter the dose-dependent response trends, if the g value is identical in both tumor and normal tissue. CONCLUSIONS The therapeutic efficacy of FLASH oxygen depletion is likely patient and tissue-dependent. For breast cancer, FLASH is beneficial in a minority of cases; however, in a subset of well oxygenated tumors, a therapeutic gain may be realized due to induced normal tissue hypoxia.
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Affiliation(s)
- Hongyu Zhu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Guangzhou 510060, China
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America
| | - Qixian Zhang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China
| | - Leo E Gerweck
- Department of Radiation Oncology, Massachusetts General Hospital, Boston, MA 02114, United States of America
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13
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Beckers C, Pruschy M, Vetrugno I. Tumor hypoxia and radiotherapy: A major driver of resistance even for novel radiotherapy modalities. Semin Cancer Biol 2024; 98:19-30. [PMID: 38040401 DOI: 10.1016/j.semcancer.2023.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2023] [Revised: 11/16/2023] [Accepted: 11/22/2023] [Indexed: 12/03/2023]
Abstract
Hypoxia in solid tumors is an important predictor of poor clinical outcome to radiotherapy. Both physicochemical and biological processes contribute to a reduced sensitivity of hypoxic tumor cells to ionizing radiation and hypoxia-related treatment resistances. A conventional low-dose fractionated radiotherapy regimen exploits iterative reoxygenation in between the individual fractions, nevertheless tumor hypoxia still remains a major hurdle for successful treatment outcome. The technological advances achieved in image guidance and highly conformal dose delivery make it nowadays possible to prescribe larger doses to the tumor as part of single high-dose or hypofractionated radiotherapy, while keeping an acceptable level of normal tissue complication in the co-irradiated organs at risk. However, we insufficiently understand the impact of tumor hypoxia to single high-doses of RT and hypofractionated RT. So-called FLASH radiotherapy, which delivers ionizing radiation at ultrahigh dose rates (> 40 Gy/sec), has recently emerged as an important breakthrough in the radiotherapy field to reduce normal tissue toxicity compared to irradiation at conventional dose rates (few Gy/min). Not surprisingly, oxygen consumption and tumor hypoxia also seem to play an intriguing role for FLASH radiotherapy. Here we will discuss the role of tumor hypoxia for radiotherapy in general and in the context of novel radiotherapy treatment approaches.
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Affiliation(s)
- Claire Beckers
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Martin Pruschy
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
| | - Irene Vetrugno
- Laboratory for Applied Radiobiology, Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
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14
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Ku E, Harada G, Chiao E, Rao P, Hosseinian S, Seyedin S, Healy E, Maxim P, Chow W, Stitzlein R, Limoli C, Harris J. The Correlation Between Lymphocyte Nadir and Radiation Therapy for Soft Tissue Sarcoma: Defining Key Dosimetric Parameters and Outlining Clinical Significance. Adv Radiat Oncol 2024; 9:101309. [PMID: 38260229 PMCID: PMC10801664 DOI: 10.1016/j.adro.2023.101309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 06/28/2023] [Indexed: 01/24/2024] Open
Abstract
Purpose The objectives of this study were to identify key dosimetric parameters associated with postradiation therapy lymphopenia and uncover any effect on clinical outcomes. Methods and Materials This was a retrospective review of 69 patients (between April 2010 and January 2023) who underwent radiation therapy (RT) as a part of curative intent for soft tissue sarcoma (STS) at a single academic institution. All patients with treatment plans available to review and measurable absolute lymphocyte count (ALC) nadir within a year after completion of RT were included. Results Median follow-up was 22 months after the start of RT. A decrease in lymphocyte count was noted as early as during treatment and persisted at least 3 months after the completion of RT. On multivariable linear regression, the strongest correlations with ALC nadir were mean body dose, body V10 Gy, mean bone dose, bone V10 Gy, and bone V20 Gy. Five-year overall survival was 60% and 5-year disease-free survival was 44%. Advanced T-stage, chemotherapy use, use of intensity-modulated RT, lower ALC nadir, and the development of grade ≥2 lymphopenia at nadir were associated with worse overall survival and disease-free survival. Conclusions Post-RT lymphopenia was associated with worse outcomes in STS. There were associations between higher body V10 Gy and bone V10 Gy and lower post-RT ALC nadir, despite the varying sites of STS presentation, which aligns with the well-known radiosensitivity of lymphocyte cell lines. These findings support efforts to reduce treatment-related hematopoietic toxicity as a way to improve oncologic outcomes. Additionally, this study supports the idea that the effect of radiation on lymphocyte progenitors in the bone marrow is more significant than that on circulating lymphocytes in treatments with limited involvement of the heart and lung.
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Affiliation(s)
- Eric Ku
- Department of Radiation Oncology, University of California, Irvine, Orange, California
| | - Garrett Harada
- Department of Radiation Oncology, University of California, Irvine, Orange, California
| | - Elaine Chiao
- School of Medicine, University of California, Irvine, Irvine, California
| | - Pranathi Rao
- School of Medicine, University of California, Irvine, Irvine, California
| | - Sina Hosseinian
- School of Medicine, University of California, Irvine, Irvine, California
| | - Steven Seyedin
- Department of Radiation Oncology, University of California, Irvine, Orange, California
| | - Erin Healy
- Department of Radiation Oncology, University of California, Irvine, Orange, California
| | - Peter Maxim
- Department of Radiation Oncology, University of California, Irvine, Orange, California
| | - Warren Chow
- Department of Hematology/Oncology, University of California, Irvine, Orange, California
| | - Russell Stitzlein
- Orthopedic Surgery, University of California, Irvine, Orange, California
| | - Charles Limoli
- Department of Radiation Oncology, University of California, Irvine, Orange, California
| | - Jeremy Harris
- Department of Radiation Oncology, University of California, Irvine, Orange, California
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15
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Friedes C, Iocolano M, Lee SH, Duan L, Li B, Doucette A, Cohen RB, Aggarwal C, Sun LL, Levin WP, Cengel KA, Kao G, Teo BKK, Langer CJ, Xiao Y, Bradley J, Feigenberg SJ, Yegya-Raman N. The effective radiation dose to immune cells predicts lymphopenia and inferior cancer control in locally advanced NSCLC. Radiother Oncol 2024; 190:110030. [PMID: 38008414 DOI: 10.1016/j.radonc.2023.110030] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 11/14/2023] [Accepted: 11/19/2023] [Indexed: 11/28/2023]
Abstract
PURPOSE To explore the association of the effective dose to immune cells (EDIC) with disease control, lymphopenia, and toxicity in patients with non-small cell lung cancer (NSCLC) and identify methods to reduce EDIC. METHODS We abstracted data from all patients with locally advanced NSCLC treated with chemoradiation with or without consolidative immunotherapy over a ten-year period. Associations between EDIC and progression-free survival (PFS) and overall survival (OS) were modeled with Cox proportional hazards and Kaplan-Meier method. Logistic regression was used to model predictors of lymphopenia and higher EDIC. Analyses were performed with EDIC as a continuous and categorical variable. Lymphopenia was graded per CTCAE v5.0. RESULTS Overall, 786 patients were included (228 of which received consolidative immunotherapy); median EDIC was 4.7 Gy. Patients with EDIC < 4.7 Gy had a longer median PFS (15.3 vs. 9.0 months; p < 0.001) and OS (34.2 vs. 22.4 months; p < 0.001). On multivariable modeling, EDIC correlated with inferior PFS (HR 1.08, 95 % CI 1.01-1.14, p = 0.014) and OS (HR 1.10, 95 % CI 1.04-1.18, p = 0.002). EDIC was predictive of grade 4 lymphopenia (OR 1.16, 95 % CI 1.02-1.33, p = 0.026). EDIC ≥ 4.7 Gy was associated with increased grade 2 + pneumonitis (6-month incidence: 26 % vs 20 %, p = 0.04) and unplanned hospitalizations (90-day incidence: 40 % vs 30 %, p = 0.002). Compared to protons, photon therapy was associated with EDIC ≥ 4.7 Gy (OR 5.26, 95 % CI 3.71-7.69, p < 0.001) in multivariable modeling. CONCLUSIONS EDIC is associated with inferior disease outcomes, treatment-related toxicity, and the development of severe lymphopenia. Proton therapy is associated with lower EDIC. Further investigations to limit radiation dose to the immune system appear warranted.
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Affiliation(s)
- Cole Friedes
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States.
| | - Michelle Iocolano
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Sang Ho Lee
- Department of Radiation Oncology, Division of Physics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Lian Duan
- Department of Radiation Oncology, Division of Physics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Bolin Li
- Department of Radiation Oncology, Division of Physics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Abigail Doucette
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Roger B Cohen
- Division of Hematology/Oncology University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Charu Aggarwal
- Division of Hematology/Oncology University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Lova L Sun
- Division of Hematology/Oncology University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - William P Levin
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Keith A Cengel
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Gary Kao
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Boon-Keng Kevin Teo
- Department of Radiation Oncology, Division of Physics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Corey J Langer
- Division of Hematology/Oncology University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Ying Xiao
- Department of Radiation Oncology, Division of Physics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Jeffrey Bradley
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Steven J Feigenberg
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States
| | - Nikhil Yegya-Raman
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, United States.
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16
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Gupta S, Inman JL, De Chant J, Obst-Huebl L, Nakamura K, Costello SM, Marqusee S, Mao JH, Kunz L, Paisley R, Vozenin MC, Snijders AM, Ralston CY. A Novel Platform for Evaluating Dose Rate Effects on Oxidative Damage to Peptides: Toward a High-Throughput Method to Characterize the Mechanisms Underlying the FLASH Effect. Radiat Res 2023; 200:523-530. [PMID: 38014573 PMCID: PMC10754258 DOI: 10.1667/rade-23-00131.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2023] [Accepted: 10/05/2023] [Indexed: 11/29/2023]
Abstract
High dose rate radiation has gained considerable interest recently as a possible avenue for increasing the therapeutic window in cancer radiation treatment. The sparing of healthy tissue at high dose rates relative to conventional dose rates, while maintaining tumor control, has been termed the FLASH effect. Although the effect has been validated in animal models using multiple radiation sources, it is not yet well understood. Here, we demonstrate a new experimental platform for quantifying oxidative damage to protein sidechains in solution as a function of radiation dose rate and oxygen availability using liquid chromatography mass spectrometry. Using this reductionist approach, we show that for both X-ray and electron sources, isolated peptides in solution are oxidatively modified to different extents as a function of both dose rate and oxygen availability. Our method provides an experimental platform for exploring the parameter space of the dose rate effect on oxidative changes to proteins in solution.
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Affiliation(s)
- Sayan Gupta
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Jamie L. Inman
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Jared De Chant
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Lieselotte Obst-Huebl
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Kei Nakamura
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Shawn M. Costello
- Biophysics Graduate Program, Department of Chemistry; California Institute for Quantitative Biosciences, University of California, Berkeley, Califormia; Chan Zuckerberg Biohub, San Francisco, California
| | - Susan Marqusee
- Department of Molecular and Cell Biology, Department of Chemistry; California Institute for Quantitative Biosciences, University of California, Berkeley, Califormia; Chan Zuckerberg Biohub, San Francisco, California
| | - Jian-Hua Mao
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Louis Kunz
- University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ryan Paisley
- University Hospital and University of Lausanne, Lausanne, Switzerland
| | | | - Antoine M. Snijders
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
| | - Corie Y. Ralston
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720
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17
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Lin B, Fan M, Niu T, Liang Y, Xu H, Tang W, Du X. Key changes in the future clinical application of ultra-high dose rate radiotherapy. Front Oncol 2023; 13:1244488. [PMID: 37941555 PMCID: PMC10628486 DOI: 10.3389/fonc.2023.1244488] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Accepted: 10/09/2023] [Indexed: 11/10/2023] Open
Abstract
Ultra-high dose rate radiotherapy (FLASH-RT) is an external beam radiotherapy strategy that uses an extremely high dose rate (≥40 Gy/s). Compared with conventional dose rate radiotherapy (≤0.1 Gy/s), the main advantage of FLASH-RT is that it can reduce damage of organs at risk surrounding the cancer and retain the anti-tumor effect. An important feature of FLASH-RT is that an extremely high dose rate leads to an extremely short treatment time; therefore, in clinical applications, the steps of radiotherapy may need to be adjusted. In this review, we discuss the selection of indications, simulations, target delineation, selection of radiotherapy technologies, and treatment plan evaluation for FLASH-RT to provide a theoretical basis for future research.
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Affiliation(s)
- Binwei Lin
- Department of Oncology, National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital), Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology, Mianyang, China
| | - Mi Fan
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Tingting Niu
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Yuwen Liang
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Haonan Xu
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Wenqiang Tang
- Department of Oncology, Affiliated Hospital of North Sichuan Medical College, Nanchong, China
| | - Xiaobo Du
- Department of Oncology, National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation (Mianyang Central Hospital), Mianyang Central Hospital, School of Medicine, University of Electronic Science and Technology, Mianyang, China
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18
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Polevoy GG, Kumar DS, Daripelli S, Prasanna M. Flash Therapy for Cancer: A Potentially New Radiotherapy Methodology. Cureus 2023; 15:e46928. [PMID: 38021805 PMCID: PMC10640654 DOI: 10.7759/cureus.46928] [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] [Accepted: 10/11/2023] [Indexed: 12/01/2023] Open
Abstract
In traditional treatment modalities and standard clinical practices, FLASH radiotherapy (FL-RT) administers radiation therapy at an exceptionally high dosage rate. When compared to standard dose rate radiation therapy, numerous preclinical investigations have demonstrated that FL-RT provides similar benefits in conserving normal tissue while maintaining equal antitumor efficacy, a phenomenon possible due to the 'FLASH effect' (FE) of FL-RT. The methodologies involve proton radiotherapy, intensity-modulated radiation treatment, and managing high-throughput damage by radiation to solid tissues. Recent results from animal studies indicate that FL-RT can reduce radiation-induced tissue damage, significantly enhancing anticancer potency. Focusing on the potential benefits of FL proton beam treatment in the years to come, this review details the FL-RT research that has been done so far and the existing theories illuminating the FL effects. This subject remains of interest, with many issues still needing to be answered. We offer a brief review to emphasize a few of the key efforts and difficulties in moving FL radiation research forward. The existing research state of FL-RT, its affecting variables, and its different specific impacts are presented in this current review. Key topics discussed include the biochemical mechanism during FL therapy, beam sources for FL therapy, the FL effect on immunity, clinical and preclinical studies on the protective effect of FL therapy, and parameters for effective FL therapy.
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Affiliation(s)
| | - Devika S Kumar
- Department of Research and Development, Saveetha Institute of Medical and Technical Sciences (SIMATS), Chennai, IND
| | - Sushma Daripelli
- Department of Anatomy, Government Medical College (GMC) Jangaon, Jangaon, IND
| | - Muthu Prasanna
- Department of Pharmaceutical Biotechnology, Surya Group of Institutions, Tamil Nadu, IND
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19
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Laurent PA, Deutsch É. [Radiation-induced lymphopenia: Lymphocytes as a new organ at risk]. Cancer Radiother 2023; 27:511-518. [PMID: 37661506 DOI: 10.1016/j.canrad.2023.06.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Accepted: 06/22/2023] [Indexed: 09/05/2023]
Abstract
Taking the immune system into account in the fight against tumors has upset the cancer treatment paradigm in the 21st century. Combination treatment strategies associating radiotherapy with immunotherapy are being increasingly implemented in clinical practice. In this context, lymphocytes, whether lymphocytes infiltrating the tumour, circulating blood lymphocytes or lymphocytes residing within the lymph nodes, are key players in cellular and humoral anti-tumor immunity. The significant radiosensitivity of lymphocytes was demonstrated in the early 1990s. Along with the cells of the digestive mucosa, lymphocytes are thus among the most radiosensitive cell types in the body. Compared to the old practices of external radiotherapy, current intensity modulated treatments have allowed a considerable improvement in acute and late toxicity, at the cost of a significant increase in the volume irradiated at low doses. This is not without consequence on the incidence of radiation-induced lymphopenia, with prognostic implications for many tumor types. Thus, in order not to hinder the action of antitumor immunity and the efficacy of immunotherapy, it is essential to consider lymphocytes as a new organ at risk in its own right. In this development, based on current data from the literature, we will begin by justifying the necessary prevention of radiation-induced lymphopenia, before providing the tools currently known to apprehend lymphocytes as a new multicompartments. Finally, we will broaden the perspective by outlining ways to develop research in this area.
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Affiliation(s)
- P A Laurent
- Service de radiothérapie oncologique, Gustave-Roussy Cancer Campus, Villejuif, France; Inserm, U1030 Molecular Radiation Therapy and Therapeutic Innovation, Gustave-Roussy Cancer Campus, université Paris-Saclay, Villejuif, France
| | - É Deutsch
- Service de radiothérapie oncologique, Gustave-Roussy Cancer Campus, Villejuif, France; Inserm, U1030 Molecular Radiation Therapy and Therapeutic Innovation, Gustave-Roussy Cancer Campus, université Paris-Saclay, Villejuif, France.
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20
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Wang X, Bai H, Gao M, Guan Y, Yu L, Li J, Dong Y, Song Y, Tao Z, Meng M, Wu Z, Zhao L, Yuan Z. Impact of radiation dose to the immune system on disease progression and survival for early-stage non-small cell lung cancer treated with stereotactic body radiation therapy. Radiother Oncol 2023; 186:109804. [PMID: 37437605 DOI: 10.1016/j.radonc.2023.109804] [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: 01/11/2023] [Revised: 06/23/2023] [Accepted: 07/04/2023] [Indexed: 07/14/2023]
Abstract
OBJECTIVES Although the effects of estimated dose of radiation to immune cells (EDRIC) in stage III NSCLC, LA-NSCLC, LS-SCLC and esophageal cancer on clinical outcomes have been studied, its impact in early-stage non-small cell lung cancer (ES-NSCLC) is unknown. In this study, we evaluated the role of EDRIC and identified the factors influencing EDRIC in this population. METHODS AND MATERIALS We retrospectively analyzed 211 pathologically confirmed ES-NSCLC patients who were treated with SBRT between 2007 and 2020. EDRIC was calculated based on the model developed by Jin et al. and improved by Ladbury et al. Kaplan-Meier method and Cox proportional hazards regression were adopted to estimate CSS, PFS, LPFS, and DMFS. Pearson correlation was used to assess the correlation between variables. We further validated our findings in an independent cohort of 119 patients with ES-NSCLC. RESULTS A total of 211 patients were included with median follow-up of 48 months in the training cohort. The median EDRIC was 2.178 Gy (range: 0.426-6.015). GTV showed a positive correlation with EDRIC (r = 0.707, P = 0.000). In multivariate analysis, higher EDRIC was significantly associated with worse CSS (HR = 1.468, P = 0.009) and DMFS (HR = 1.491, P = 0.016). Considering each EDRIC quartile, there was a significant difference in CSS between 1st and 4th and 1st and 3rd quartile (P = 0.000, P = 0.004, respectively); and DMFS between 1st and 4th,1st and 3rd, and 1st and 2nd quartile (P = 0.000, P = 0.000, P = 0.008, respectively). In the subgroup and validation cohort, EDRIC was also the important prognostic predictor of CSS and DMFS using multivariate analysis. CONCLUSION EDRIC was an independent predictor of CSS and DMFS in ES-NSCLC, and it was affected by GTV and tumor location. Though EDRIC is a critical determinant of treatment outcomes, it is quantifiable and potentially modifiable. Additional researches exploring the feasibility of achieving lower EDRIC while maintaining adequate tumor coverage during radiotherapy are warranted.
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Affiliation(s)
- Xiaofeng Wang
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Hui Bai
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Miaomiao Gao
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Yong Guan
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Lu Yu
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Junyi Li
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Yang Dong
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Yongchun Song
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Zhen Tao
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Maobin Meng
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Zhiqiang Wu
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Lujun Zhao
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China
| | - Zhiyong Yuan
- Department of Radiation Oncology, Tianjin Medical University Cancer Institute and Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China.
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21
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Deffet S, Hamaide V, Sterpin E. Definition of dose rate for FLASH pencil-beam scanning proton therapy: A comparative study. Med Phys 2023; 50:5784-5792. [PMID: 37439504 DOI: 10.1002/mp.16607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 05/28/2023] [Accepted: 06/20/2023] [Indexed: 07/14/2023] Open
Abstract
BACKGROUND FLASH proton therapy has the potential to reduce side effects of conventional proton therapy by delivering a high dose of radiation in a very short period of time. However, significant progress is needed in the development of FLASH proton therapy. Increasing the dose rate while maintaining dose conformality may involve the use of advanced beam-shaping technologies and specialized equipment such as 3D patient-specific range modulators, to take advantage of the higher transmission efficiency at the highest energy available. The dose rate is an important factor in FLASH proton therapy, but its definition can vary because of the uneven distribution of the dose over time in pencil-beam scanning (PBS). PURPOSE Highlight the distinctions, both in terms of concept and numerical values, of the various definitions that can be established for the dose rate in PBS proton therapy. METHODS In an in silico study, five definitions of the dose rate, namely the PBS dose rate, the percentile dose rate, the maximum percentile dose rate, the average dose rate, and the dose averaged dose rate (DADR) were analyzed first through theoretical comparison, and then applied to a head and neck case. To carry out this study, a treatment plan utilizing a single energy level and requiring the use of a patient-specific range modulator was employed. The dose rate values were compared both locally and by means of dose rate volume histograms (DRVHs). RESULTS The PBS dose rate, the percentile dose rate, and the maximum percentile dose are definitions that are specifically designed to take into account the time structure of the delivery of a PBS treatment plan. Although they may appear similar, our study shows that they can vary locally by up to 10%. On the other hand, the DADR values were approximately twice as high as those of the PBS, percentile, and maximum percentile dose rates, since the DADR disregards the periods when a voxel does not receive any dose. Finally, the average dose rate can be defined in various ways, as discussed in this paper. The average dose rate is found to be lower by a factor of approximately 1/2 than the PBS, percentile, and maximum percentile dose rates. CONCLUSIONS We have shown that using different definitions for the dose rate in FLASH proton therapy can lead to variations in calculated values ranging from a few percent to a factor of two. Since the dose rate is a critical parameter in FLASH radiation therapy, it is essential to carefully consider the choice of definition. However, to make an informed decision, additional biological data and models are needed.
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Affiliation(s)
- Sylvain Deffet
- Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Louvain-La-Neuve, Belgium
| | | | - Edmond Sterpin
- Center of Molecular Imaging, Radiotherapy and Oncology (MIRO), Institut de Recherche Expérimentale et Clinique (IREC), Université catholique de Louvain, Louvain-La-Neuve, Belgium
- Laboratory of Experimental Radiotherapy, Department of Oncology, KU Leuven, Leuven, Belgium
- Particle Therapy Interuniversity Center Leuven-PARTICLE, Leuven, Belgium
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22
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Duval KEA, Aulwes E, Zhang R, Rahman M, Ashraf MR, Sloop A, Sunnerberg J, Williams BB, Cao X, Bruza P, Kheirollah A, Tavakkoli A, Jarvis LA, Schaner PE, Swartz HM, Gladstone DJ, Pogue BW, Hoopes PJ. Comparison of Tumor Control and Skin Damage in a Mouse Model after Ultra-High Dose Rate Irradiation and Conventional Irradiation. Radiat Res 2023; 200:223-231. [PMID: 37590482 PMCID: PMC10551764 DOI: 10.1667/rade-23-00057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 07/07/2023] [Indexed: 08/19/2023]
Abstract
Recent studies suggest ultra-high dose rate radiation treatment (UHDR-RT) reduces normal tissue damage compared to conventional radiation treatment (CONV-RT) at the same dose. In this study, we compared first, the kinetics and degree of skin damage in wild-type C57BL/6 mice, and second, tumor treatment efficacy in GL261 and B16F10 dermal tumor models, at the same UHDR-RT and CONV-RT doses. Flank skin of wild-type mice received UHDR-RT or CONV-RT at 25 Gy and 30 Gy. Normal skin damage was tracked by clinical observation to determine the time to moist desquamation, an endpoint which was verified by histopathology. Tumors were inoculated on the right flank of the mice, then received UHDR-RT or CONV-RT at 1 × 11 Gy, 1 × 15, 1 × 25, 3 × 6 and 3 × 8 Gy, and time to tumor tripling volume was determined. Tumors also received 1 × 11, 1 × 15, 3 × 6 and 3 × 8 Gy doses for assessment of CD8+/CD4+ tumor infiltrate and genetic expression 96 h postirradiation. All irradiations of the mouse tumor or flank skin were performed with megavoltage electron beams (10 MeV, 270 Gy/s for UHDR-RT and 9 MeV, 0.12 Gy/s for CONV-RT) delivered via a clinical linear accelerator. Tumor control was statistically equal for similar doses of UHDR-RT and CONV-RT in B16F10 and GL261 murine tumors. There were variable qualitative differences in genetic expression of immune and cell damage-associated pathways between UHDR and CONV irradiated B16F10 tumors. Compared to CONV-RT, UHDR-RT resulted in an increased latent period to skin desquamation after a single 25 Gy dose (7 days longer). Time to moist skin desquamation did not significantly differ between UHDR-RT and CONV-RT after a 30 Gy dose. The histomorphological characteristics of skin damage were similar for UHDR-RT and CONV-RT. These studies demonstrated similar tumor control responses for equivalent single and fractionated radiation doses, with variable difference in expression of tumor progression and immune related gene pathways. There was a modest UHDR-RT skin sparing effect after a 1 × 25 Gy dose but not after a 1 × 30 Gy dose.
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Affiliation(s)
- Kayla E. A. Duval
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - Ethan Aulwes
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - Rongxiao Zhang
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Mahbubur Rahman
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - M. Ramish Ashraf
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Austin Sloop
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Jacob Sunnerberg
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Benjamin B. Williams
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Xu Cao
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | - Petr Bruza
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
| | | | - Armin Tavakkoli
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - Lesley A. Jarvis
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Philip E. Schaner
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Harold M. Swartz
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
| | - David J. Gladstone
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
| | - Brian W. Pogue
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
- Department of Medical Physics, University of Wisconsin, Madison, Wisconsin
| | - P. Jack Hoopes
- Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Dartmouth Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire
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23
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McCullum L, Shin J, Xing S, Beekman C, Schuemann J, Hong T, Duda D, Mohan R, Lin SH, Correa-Alfonso CM, Domal S, Withrow J, Bolch W, Paganetti H, Grassberger C. Predicting Severity of Radiation Induced Lymphopenia in Individual Proton Therapy Patients for Varying Dose Rate and Fractionation Using Dynamic 4-Dimensional Blood Flow Simulations. Int J Radiat Oncol Biol Phys 2023; 116:1226-1233. [PMID: 36739919 PMCID: PMC10363211 DOI: 10.1016/j.ijrobp.2023.01.054] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 01/11/2023] [Accepted: 01/27/2023] [Indexed: 02/05/2023]
Abstract
PURPOSE Radiation-induced lymphopenia has gained attention recently as the result of its correlation with survival in a range of indications, particularly when combining radiation therapy (RT) with immunotherapy. The purpose of this study is to use a dynamic blood circulation model combined with observed lymphocyte depletion in patients to derive the in vivo radiosensitivity of circulating lymphocytes and study the effect of RT delivery parameters. METHODS AND MATERIALS We assembled a cohort of 17 patients with hepatocellular carcinoma treated with proton RT alone in 15 fractions (fx) using conventional dose rates (beam-on time [BOT], 120 seconds) for whom weekly absolute lymphocyte counts (ALCs) during RT and follow-up were available. We used HEDOS, a time-dependent, whole-body, blood flow computational framework, in combination with explicit liver blood flow modeling, to calculate the dose volume histograms for circulating lymphocytes for changing BOTs (1 second-300 seconds) and fractionations (5 fx, 15 fx). From this, we used the linear cell survival model and an exponential model to determine patient-specific lymphocyte radiation sensitivity, α, and recovery, σ, respectively. RESULTS The in vivo-derived patient-specific α had a median of 0.65 Gy-1 (range, 0.30-1.38). Decreasing BOT to 1 second led to an increased average end-of-treatment ALC of 27.5%, increasing to 60.3% when combined with the 5-fx regimen. Decreasing to 5 fx at the conventional dose rate led to an increase of 17.0% on average. The benefit of both increasing dose rate and reducing the number of fractions was patient specificࣧpatients with highly sensitive lymphocytes benefited most from decreasing BOT, whereas patients with slow lymphocyte recovery benefited most from the shorter fractionation regimen. CONCLUSIONS We observed that increasing dose rate at the same fractionation reduced ALC depletion more significantly than reducing the number of fractions. High-dose-rates led to an increased sparing of lymphocytes when shortening the fractionation regimen, particularly for patients with radiosensitive lymphocytes at elevated risk.
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Affiliation(s)
- Lucas McCullum
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts.
| | - Jungwook Shin
- Radiation Epidemiology Branch, National Cancer Institute, Rockville, Maryland
| | - Stella Xing
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Chris Beekman
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Jan Schuemann
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Theodore Hong
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Dan Duda
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Radhe Mohan
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Steven H Lin
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Camilo M Correa-Alfonso
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Sean Domal
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Julia Withrow
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Wesley Bolch
- J. Crayton Pruitt Family Department of Biomedical Engineering, University of Florida, Gainesville, Florida
| | - Harald Paganetti
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
| | - Clemens Grassberger
- Department of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts
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24
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Tan HS, Teo KBK, Dong L, Friberg A, Koumenis C, Diffenderfer E, Zou JW. Modeling ultra-high dose rate electron and proton FLASH effect with the physicochemical approach. Phys Med Biol 2023; 68:10.1088/1361-6560/ace14d. [PMID: 37352867 PMCID: PMC10472835 DOI: 10.1088/1361-6560/ace14d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 06/23/2023] [Indexed: 06/25/2023]
Abstract
Objective. A physicochemical model built on the radiochemical kinetic theory was recently proposed in (Labarbeet al2020) to explain the FLASH effect. We performed extensive simulations to scrutinize its applicability for oxygen depletion studies and FLASH-related experiments involving both proton and electron beams.Approach. Using the dose and beam delivery parameters for each FLASH experiment, we numerically solved the radiochemical rate equations comprised of a set of coupled nonlinear ordinary differential equations to obtain the area under the curve (AUC) of radical concentrations.Main results. The modeled differences in AUC induced by ultra-high dose rates appeared to correlate well with the FLASH effect. (i) For the whole brain irradiation of mice performed in (Montay-Gruelet al2017), the threshold dose rate values for memory preservation coincided with those at which AUC started to decrease much less rapidly. (ii) For the proton pencil beam scanning FLASH of (Cunninghamet al2021), we found linear correlations between radicals' AUC and the biological endpoints: TGF-β1, leg contracture and plasma level of cytokine IL-6. (iii) Compatible with the findings of the proton FLASH experiment in (Kimet al2021), we found that radicals' AUC at the entrance and mid-Spread-Out Bragg peak regions were highly similar. In addition, our model also predicted ratios of oxygen depletionG-values between normal and UHDR irradiation similar to those observed in (Caoet al2021) and (El Khatibet al2022).Significance. Collectively, our results suggest that the normal tissue sparing conferred by UHDR irradiation may be due to the lower degree of exposure to peroxyl and superoxide radicals. We also found that the differential effect of dose rate on the radicals' AUC was less pronounced at lower initial oxygen levels, a trait that appears to align with the FLASH differential effect on normal versus tumor tissues.
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Affiliation(s)
- Hai Siong Tan
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Kevin Boon Keng Teo
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Lei Dong
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Andrew Friberg
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Constantinos Koumenis
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Eric Diffenderfer
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
| | - Jennifer Wei Zou
- University of Pennsylvania, Perelman School of Medicine, Department of Radiation Oncology, Philadelphia, United States of America
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25
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Wang CX, Hunt J, Feinstein S, Kim SK, Monjazeb AM. Advances in Radiotherapy Immune Modulation: From Bench-to-Bedside and Back Again. Surg Oncol Clin N Am 2023; 32:617-629. [PMID: 37182996 DOI: 10.1016/j.soc.2023.02.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Pre-clinical and clinical data clearly demonstrate the immune modulatory effects of radiotherapy (RT) but clinical trials testing RT + immunotherapy have been equivocal. An improved understanding of the immune modulatory effects of RT and how practical parameters of RT delivery (site and number of lesions, dose, fractionation, timing) influence these effects are needed to optimally combine RT with immunotherapy. Additionally, increased exploration of immunotherapy combinations with RT, beyond immune checkpoint inhibitors, are needed. A "bench-to-bedside and back again" approach will improve our understanding of RT immune modulation and allow for the implementation of more effective RT + immunotherapy strategies.
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Affiliation(s)
- Charles X Wang
- UC Davis Health, Department of Radiation Oncology, 4501 X-Street, Sacramento, CA 95817, USA
| | - Jared Hunt
- UC Davis Health, Department of Radiation Oncology, 4501 X-Street, Sacramento, CA 95817, USA
| | - Shera Feinstein
- UC Davis Health, Department of Radiation Oncology, 4501 X-Street, Sacramento, CA 95817, USA
| | - Soo Kyoung Kim
- UC Davis Health, Department of Radiation Oncology, 4501 X-Street, Sacramento, CA 95817, USA
| | - Arta M Monjazeb
- UC Davis Health, Department of Radiation Oncology, 4501 X-Street, Sacramento, CA 95817, USA.
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26
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Qiu J, Lin H, Ke D, Yu Y, Xu J, Qiu H, Zheng Q, Li H, Zheng H, Liu L, Wang Z, Yao Q, Li J. Higher radiation dose on immune cells is associated with radiation-induced lymphopenia and worse prognosis in patients with locally advanced esophageal squamous cell carcinoma. Front Immunol 2023; 14:1066255. [PMID: 37223094 PMCID: PMC10200938 DOI: 10.3389/fimmu.2023.1066255] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2022] [Accepted: 04/24/2023] [Indexed: 05/25/2023] Open
Abstract
Background To explore the effective dose to immune cells (EDIC) for better prognosis while avoiding radiation-induced lymphopenia (RIL) in patients with locally advanced esophageal squamous cell carcinoma (ESCC). Materials and methods Overall, 381 patients with locally advanced ESCC receiving definitive radiotherapy with or without chemotherapy (dRT ± CT) between 2014 and 2020 were included in this study. The EDIC model was calculated by radiation fraction number and mean doses to the heart, lung, and integral body. The correlation between EDIC and clinical outcomes was analyzed using Cox proportional hazards regression, and risk factors for RIL were determined by logistic regression analysis. Results The median EDIC was 4.38 Gy. Multivariate analysis revealed that low-EDIC significantly improved the OS of patients when compared with high-EDIC (HR = 1.614, P = 0.003) and PFS (HR = 1.401, P = 0.022). Moreover, high-EDIC was associated with a higher incidence of grade 4 RIL (OR = 2.053, P = 0.007) than low-EDIC. In addition, we identified body mass index (BMI), tumor thickness, and nodal stage as independent prognostic factors of OS and PFS, while BMI (OR = 0.576, P = 0.046) and weight loss (OR = 2.214, P = 0.005) as independent risk factors of grade 4 RIL. In subgroup analyses, the good group had better clinical outcomes than the remaining two groups (P< 0.001). Conclusion This study demonstrated that EDIC significantly correlates with poor clinical outcomes and severe RIL. Optimizing treatment plans to decrease the radiation doses to immune cells is critical for improving the outcomes.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Zhiping Wang
- *Correspondence: Zhiping Wang, ; Qiwei Yao, ; Jiancheng Li,
| | - Qiwei Yao
- *Correspondence: Zhiping Wang, ; Qiwei Yao, ; Jiancheng Li,
| | - Jiancheng Li
- *Correspondence: Zhiping Wang, ; Qiwei Yao, ; Jiancheng Li,
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27
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Zhang Q, Gerweck LE, Cascio E, Gu L, Yang Q, Dong X, Huang P, Bertolet A, Nesteruk KP, Sung W, McNamara AL, Schuemann J. Absence of Tissue-Sparing Effects in Partial Proton FLASH Irradiation in Murine Intestine. Cancers (Basel) 2023; 15:cancers15082269. [PMID: 37190197 DOI: 10.3390/cancers15082269] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/07/2023] [Accepted: 04/11/2023] [Indexed: 05/17/2023] Open
Abstract
Ultra-high dose rate irradiation has been reported to protect normal tissues more than conventional dose rate irradiation. This tissue sparing has been termed the FLASH effect. We investigated the FLASH effect of proton irradiation on the intestine as well as the hypothesis that lymphocyte depletion is a cause of the FLASH effect. A 16 × 12 mm2 elliptical field with a dose rate of ~120 Gy/s was provided by a 228 MeV proton pencil beam. Partial abdominal irradiation was delivered to C57BL/6j and immunodeficient Rag1-/-/C57 mice. Proliferating crypt cells were counted at 2 days post exposure, and the thickness of the muscularis externa was measured at 280 days following irradiation. FLASH irradiation did not reduce the morbidity or mortality of conventional irradiation in either strain of mice; in fact, a tendency for worse survival in FLASH-irradiated mice was observed. There were no significant differences in lymphocyte numbers between FLASH and conventional-dose-rate mice. A similar number of proliferating crypt cells and a similar thickness of the muscularis externa following FLASH and conventional dose rate irradiation were observed. Partial abdominal FLASH proton irradiation at 120 Gy/s did not spare normal intestinal tissue, and no difference in lymphocyte depletion was observed. This study suggests that the effect of FLASH irradiation may depend on multiple factors, and in some cases dose rates of over 100 Gy/s do not induce a FLASH effect and can even result in worse outcomes.
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Affiliation(s)
- Qixian Zhang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Leo E Gerweck
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Ethan Cascio
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Liqun Gu
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Qingyuan Yang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Xinyue Dong
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Peigen Huang
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Alejandro Bertolet
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Konrad Pawel Nesteruk
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Wonmo Sung
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Aimee L McNamara
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
| | - Jan Schuemann
- Physics Division, Department of Radiation Oncology, Massachusetts General Hospital & Harvard Medical School, Boston, MA 02129, USA
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Klett KC, Martin-Villa BC, Villarreal VS, Melemenidis S, Viswanathan V, Manjappa R, Ashraf MR, Soto L, Lau B, Dutt S, Rankin EB, Loo BW, Heilshorn SC. Human enteroids as a tool to study conventional and ultra-high dose rate radiation. Integr Biol (Camb) 2023; 15:zyad013. [PMID: 37874173 PMCID: PMC10594601 DOI: 10.1093/intbio/zyad013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 09/22/2023] [Accepted: 09/26/2023] [Indexed: 10/25/2023]
Abstract
Radiation therapy, one of the most effective therapies to treat cancer, is highly toxic to healthy tissue. The delivery of radiation at ultra-high dose rates, FLASH radiation therapy (FLASH), has been shown to maintain therapeutic anti-tumor efficacy while sparing normal tissues compared to conventional dose rate irradiation (CONV). Though promising, these studies have been limited mainly to murine models. Here, we leveraged enteroids, three-dimensional cell clusters that mimic the intestine, to study human-specific tissue response to radiation. We observed enteroids have a greater colony growth potential following FLASH compared with CONV. In addition, the enteroids that reformed following FLASH more frequently exhibited proper intestinal polarity. While we did not observe differences in enteroid damage across groups, we did see distinct transcriptomic changes. Specifically, the FLASH enteroids upregulated the expression of genes associated with the WNT-family, cell-cell adhesion, and hypoxia response. These studies validate human enteroids as a model to investigate FLASH and provide further evidence supporting clinical study of this therapy. Insight Box Promising work has been done to demonstrate the potential of ultra-high dose rate radiation (FLASH) to ablate cancerous tissue, while preserving healthy tissue. While encouraging, these findings have been primarily observed using pre-clinical murine and traditional two-dimensional cell culture. This study validates the use of human enteroids as a tool to investigate human-specific tissue response to FLASH. Specifically, the work described demonstrates the ability of enteroids to recapitulate previous in vivo findings, while also providing a lens through which to probe cellular and molecular-level responses to FLASH. The human enteroids described herein offer a powerful model that can be used to probe the underlying mechanisms of FLASH in future studies.
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Affiliation(s)
- Katarina C Klett
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Victoria S Villarreal
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Vignesh Viswanathan
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Luis Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
| | - Erinn B Rankin
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
- Department of Obstetrics and Gynecology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Sarah C Heilshorn
- Department of Materials Science and Engineering, Stanford University, Stanford, CA, USA
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Dai Y, Liang R, Wang J, Zhang J, Wu D, Zhao R, Liu Z, Chen F. Fractionated FLASH radiation in xenografted lung tumors induced FLASH effect at a split dose of 2 Gy. Int J Radiat Biol 2023; 99:1542-1549. [PMID: 36952604 DOI: 10.1080/09553002.2023.2194403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 03/16/2023] [Indexed: 03/25/2023]
Abstract
PURPOSE To explore the minimum split dose of FLASH radiotherapy (FLASH). MATERIAL AND METHODS Lungs of nude mice were used to verify the capacity of normal tissue sparing of FLASH, while tumor-bearing nude mice were used to evaluate the curative power. Xenografted tumor models were established in Balb/c-nu mice using A549 cells at a concentration of 5 × 10 6 / 100 μ L . With the same total dose (20 Gy), the dose rate of FLASH was 200 Gy/s when conventional radiotherapy(CONV) was 0.033 Gy/s. Two schemes of FLASH irradiations were applied: single pulse (FLASH1) and ten pulses (FLASH10). Then, according to the different tissue types and irradiation schemes, mice were divided into eight groups: Control-T, CONV-T, FLASH1-T, FLASH10-T (T for tumor) and Control-L, CONV-L, FLASH1-L, FLASH10-L (L for lung). Evaluation of FLASH effect was based on the changes in tumor volume and pathological analysis of tumor and lung tissues before and after irradiation. RESULTS Compared to control group, the mean volume of tumors in nude mice increased slowly or decreased after irradiation with both FLASH and CONV (Control-T: 233.6± 55.19 mm3, CONV-T: 146.1± 50.62 mm3, FLASH1-T: 148± 18.83 mm3, FLASH10-T: 119.1± 50.62 mm3, p ≤ . 05) . Tumor cells of irradiated groups had similar degrees of dissolution damage and inflammation, while the acute radiation pneumonia induced by FLASH was less severe. The pulmonary pathology of FLASH1-L and FLASH10-L were similar, and only a few neutrophils were observed. In addition to inflammatory cells, slight thickening of alveolar septum and obvious interstitial hemorrhage were also observed in the CONV-L group. CONCLUSION The FLASH effect was successfully reproduced in both single and fractionated irradiation, with 2 Gy being the minimum split dose to achieve the FLASH effect in existing experiments. It is suggested that the transient oxygen depletion might not be the only mechanism behind the FLASH effect.
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Affiliation(s)
- Yuling Dai
- Nuclear and Radiation Frontier Technology Research Center, China Institute for Radiation Protection, Taiyuan, China
- Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
| | - Runcheng Liang
- Nuclear and Radiation Frontier Technology Research Center, China Institute for Radiation Protection, Taiyuan, China
- Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
| | - Jianxin Wang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Jing Zhang
- Nuclear and Radiation Frontier Technology Research Center, China Institute for Radiation Protection, Taiyuan, China
- Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
| | - Dai Wu
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Ri Zhao
- Nuclear and Radiation Frontier Technology Research Center, China Institute for Radiation Protection, Taiyuan, China
- Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
| | - Zhaoxing Liu
- Nuclear and Radiation Frontier Technology Research Center, China Institute for Radiation Protection, Taiyuan, China
- Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
| | - Faguo Chen
- Nuclear and Radiation Frontier Technology Research Center, China Institute for Radiation Protection, Taiyuan, China
- Shanxi Provincial Key Laboratory for Translational Nuclear Medicine and Precision Protection, Taiyuan, China
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Cucinotta FA, Smirnova OA. Effects of Flash Radiotherapy on Blood Lymphocytes in Humans and Small Laboratory Animals. Radiat Res 2023; 199:240-251. [PMID: 36693147 DOI: 10.1667/rade-22-00093.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2022] [Accepted: 12/21/2022] [Indexed: 01/26/2023]
Abstract
A mathematical model, which describes the level of surviving lymphocytes in the blood after ultra-high (FLASH) and lower dose rates of partial-body irradiation, is developed. The model is represented by simple analytic formulae that involve a few parameters, namely, physiologic parameters (characteristics of the blood flow through the blood circulatory system and its irradiated part), a biophysical parameter (a characteristic of the blood lymphocytes radiosensitivity), and the physical parameters (characteristics of irradiation). The model predicts that the level of surviving blood lymphocytes increases as the dose rate increases and approaches the limiting level of (1 - vR), where vR is the fraction of the blood volume in the irradiated part of the blood circulatory system. The model also predicts that the level of surviving blood lymphocytes after the same exposure is higher for lower vR. It is found that FLASH irradiation in humans with doses of 10 to 40 Gy and with exposure times significantly less (<1 s) than the blood circulation time (∼60 s) leads to the maximal blood lymphocyte sparing. Simple formula, which determines effective dose rates for optimal blood lymphocyte sparing, is derived in the framework of the developed model. For the dose range specified above, the obtained modeling prediction of the range of effective dose rates for optimal blood lymphocyte sparing in humans (namely, N ≥40 Gy/s) coincides with the dose rate range in FLASH radiation therapy. It is revealed that the respective effective dose rates for mice are higher than those for humans (for the same dose range) due to the shorter blood circulation time in mice than in humans. Proceeding from the findings obtained in this paper, a hypothesis elucidating the mechanisms of the abscopal effect of FLASH radiation therapy (namely, an antitumor response on metastases located outside of irradiated part of a body) is proposed.
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31
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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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32
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Xu M, Qiu X, Chen Q, Yang T, Xu J, Chen L, Shuai L, Xu Z, Cheng X, Zhang Y, Cao Z. Changes of gut microbiome and metabolome in the AOM/DSS mouse model of colorectal cancer with FLASH radiation. RADIATION MEDICINE AND PROTECTION 2023. [DOI: 10.1016/j.radmp.2023.02.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
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Yuan H, Gui R, Wang Z, Fang F, Zhao H. Gut microbiota: A novel and potential target for radioimmunotherapy in colorectal cancer. Front Immunol 2023; 14:1128774. [PMID: 36798129 PMCID: PMC9927011 DOI: 10.3389/fimmu.2023.1128774] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 01/17/2023] [Indexed: 02/04/2023] Open
Abstract
Colorectal cancer (CRC) is one of the most common cancers, with a high mortality rate, and is a major burden on human health worldwide. Gut microbiota regulate human immunity and metabolism through producing numerous metabolites, which act as signaling molecules and substrates for metabolic reactions in various biological processes. The importance of host-gut microbiota interactions in immunometabolic mechanisms in CRC is increasingly recognized, and interest in modulating the microbiota to improve patient's response to therapy has been raising. However, the specific mechanisms by which gut microbiota interact with immunotherapy and radiotherapy remain incongruent. Here we review recent advances and discuss the feasibility of gut microbiota as a regulatory target to enhance the immunogenicity of CRC, improve the radiosensitivity of colorectal tumor cells and ameliorate complications such as radiotoxicity. Currently, great breakthroughs in the treatment of non-small cell lung cancer and others have been achieved by radioimmunotherapy, but radioimmunotherapy alone has not been effective in CRC patients. By summarizing the recent preclinical and clinical evidence and considering regulatory roles played by microflora in the gut, such as anti-tumor immunity, we discuss the potential of targeting gut microbiota to enhance the efficacy of radioimmunotherapy in CRC and expect this review can provide references and fresh ideas for the clinical application of this novel strategy.
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Affiliation(s)
- Hanghang Yuan
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China,National Health Commission (NHC) Key laboratory of Radiobiology, School of Public Health, Jilin University, Changchun, China
| | - Ruirui Gui
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China,National Health Commission (NHC) Key laboratory of Radiobiology, School of Public Health, Jilin University, Changchun, China
| | - Zhicheng Wang
- National Health Commission (NHC) Key laboratory of Radiobiology, School of Public Health, Jilin University, Changchun, China
| | - Fang Fang
- National Health Commission (NHC) Key laboratory of Radiobiology, School of Public Health, Jilin University, Changchun, China,*Correspondence: Fang Fang, ; Hongguang Zhao,
| | - Hongguang Zhao
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China,*Correspondence: Fang Fang, ; Hongguang Zhao,
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Minami K. [2.The Biological Effects of Electron and Current Research Trend]. Nihon Hoshasen Gijutsu Gakkai Zasshi 2023; 79:857-862. [PMID: 37599071 DOI: 10.6009/jjrt.2023-2242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/22/2023]
Affiliation(s)
- Kazumasa Minami
- Department of radiation oncology, Osaka University graduate school of medicine
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35
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Helm A, Totis C, Durante M, Fournier C. Are charged particles a good match for combination with immunotherapy? Current knowledge and perspectives. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023; 376:1-36. [PMID: 36997266 DOI: 10.1016/bs.ircmb.2023.01.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
Charged particle radiotherapy, mainly using protons and carbon ions, provides physical characteristics allowing for a volume conformal irradiation and a reduction of the integral dose to normal tissue. Carbon ion therapy additionally features an increased biological effectiveness resulting in peculiar molecular effects. Immunotherapy, mostly performed with immune checkpoint inhibitors, is nowadays considered a pillar in cancer therapy. Based on the advantageous features of charged particle radiotherapy, we review pre-clinical evidence revealing a strong potential of its combination with immunotherapy. We argue that the combination therapy deserves further investigation with the aim of translation in clinics, where a few studies have been set up already.
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Affiliation(s)
- A Helm
- Biophysics Department, GSI, Darmstadt, Germany
| | - C Totis
- Biophysics Department, GSI, Darmstadt, Germany
| | - M Durante
- Biophysics Department, GSI, Darmstadt, Germany.
| | - C Fournier
- Biophysics Department, GSI, Darmstadt, Germany
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de Kermenguy F, Meziani L, Mondini M, Clémenson C, Morel D, Deutsch E, Robert C. Radio-induced lymphopenia in the era of anti-cancer immunotherapy. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2023. [DOI: 10.1016/bs.ircmb.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
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Hu A, Qiu R, Li WB, Zhou W, Wu Z, Zhang H, Li J. Radical recombination and antioxidants: a hypothesis on the FLASH effect mechanism. Int J Radiat Biol 2023; 99:620-628. [PMID: 35938944 DOI: 10.1080/09553002.2022.2110307] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
PURPOSE FLASH (ultra-high dose rate) radiotherapy spares normal tissue while keeping tumor control. However, the mechanism of the FLASH effect remains unclear and may have consequences beyond the irradiated area. MATERIALS AND METHODS We reanalyze the available results of ultra-high-dose-rate-related experiments to find out the key points of the mechanism of the FLASH effect. Then, we present a hypothesis on the mechanism of the FLASH effect: FLASH beams generate a high transient concentration of peroxyl radicals leading to a high fraction of radical recombination, which results in less oxidation damage to normal tissue. For the cells containing higher concentrations of antioxidants, the fractions of radical recombination are smaller because the antioxidants compete to react with peroxyl radicals. Therefore the damages by different dose rate beams differ slightly in this condition. Since some tumors contain a higher level of antioxidants, this may be the reason for the loss of the protective effect in tumors irradiated by FLASH beams. The high concentration of antioxidants in tumors results in slight radiolytic oxygen consumption, and consequently the protective effect observed in in vitro experiment cannot be observed in in vivo experiment. To quantitatively elaborate our hypothesis, a kinetic model is implemented to simulate the reactions induced by irradiation. Two parameters are defined to abstractly study the factors affecting the reaction, such as dose rate, antioxidants, total dose and reaction rate constants. RESULTS AND CONCLUSIONS We find that the explanation of the difference between in vivo and in vitro experiments is crucial to understanding the mechanism of the FLASH effect. Our hypothesis agrees with the results of related experiments. Based on the kinetic model, the effects of these factors on the FLASH effect are quantitatively investigated.
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Affiliation(s)
- Ankang Hu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Rui Qiu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Wei Bo Li
- Institute of Radiation Medicine, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Neuherberg, Germany
| | - Wanyi Zhou
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Zhen Wu
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Nuctech Company Limited, Beijing, China
| | - Hui Zhang
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
| | - Junli Li
- Department of Engineering Physics, Tsinghua University, Beijing, China
- Key Laboratory of Particle & Radiation Imaging, Tsinghua University, Ministry of Education, Beijing, China
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Iturri L, Bertho A, Lamirault C, Juchaux M, Gilbert C, Espenon J, Sebrie C, Jourdain L, Pouzoulet F, Verrelle P, De Marzi L, Prezado Y. Proton FLASH Radiation Therapy and Immune Infiltration: Evaluation in an Orthotopic Glioma Rat Model. Int J Radiat Oncol Biol Phys 2022:S0360-3016(22)03639-2. [PMID: 36563907 DOI: 10.1016/j.ijrobp.2022.12.018] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Revised: 12/02/2022] [Accepted: 12/10/2022] [Indexed: 12/24/2022]
Abstract
PURPOSE FLASH radiation therapy (FLASH-RT) is a promising radiation technique that uses ultrahigh doses of radiation to increase the therapeutic window of the treatment. FLASH-RT has been observed to provide normal tissue sparing at high dose rates and similar tumor control compared with conventional RT, yet the biological processes governing these radiobiological effects are still unknown. In this study, we sought to investigate the potential immune response generated by FLASH-RT in a high dose of proton therapy in an orthotopic glioma rat model. METHODS AND MATERIALS We cranially irradiated rats with a single high dose (25 Gy) using FLASH dose rate proton irradiation (257 ± 2 Gy/s) or conventional dose rate proton irradiation (4 ± 0.02 Gy/s). We first assessed the protective FLASH effect that resulted in our setup through behavioral studies in naïve rats. This was followed by a comprehensive analysis of immune cells in blood, healthy tissue of the brain, and tumor microenvironment by flow cytometry. RESULTS Proton FLASH-RT spared memory impairment produced by conventional high-dose proton therapy and induced a similar tumor infiltrating lymphocyte recruitment. Additionally, a general neuroinflammation that was similar in both dose rates was observed. CONCLUSIONS Overall, this study demonstrated that FLASH proton therapy offers a neuro-protective effect even at high doses while mounting an effective lymphoid immune response in the tumor.
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Affiliation(s)
- Lorea Iturri
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France.
| | - Annaïg Bertho
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Charlotte Lamirault
- Institut Curie, PSL University, Département de Recherche Translationnelle, CurieCoreTech-Experimental Radiotherapy (RadeXp), Paris, France
| | - Marjorie Juchaux
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Cristèle Gilbert
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Julie Espenon
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
| | - Catherine Sebrie
- CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, BIOMAPS Université Paris-Saclay, Orsay, France
| | - Laurène Jourdain
- CEA, CNRS, Inserm, Service Hospitalier Frédéric Joliot, BIOMAPS Université Paris-Saclay, Orsay, France
| | - Frédéric Pouzoulet
- Institut Curie, PSL University, Département de Recherche Translationnelle, CurieCoreTech-Experimental Radiotherapy (RadeXp), Paris, France
| | - Pierre Verrelle
- Institut Curie, Campus Universitaire, PSL Research University, University Paris Saclay, INSERM LITO (U1288), Orsay, 91898 France; Centre de Protonthérapie d'Orsay, Radiation Oncology Department, Campus Universitaire, Institut Curie, PSL Research University, Orsay, 91898 France
| | - Ludovic De Marzi
- Institut Curie, Campus Universitaire, PSL Research University, University Paris Saclay, INSERM LITO (U1288), Orsay, 91898 France; Centre de Protonthérapie d'Orsay, Radiation Oncology Department, Campus Universitaire, Institut Curie, PSL Research University, Orsay, 91898 France
| | - Yolanda Prezado
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, France
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Konradsson E, Liljedahl E, Gustafsson E, Adrian G, Beyer S, Ilaahi SE, Petersson K, Ceberg C, Nittby Redebrandt H. Comparable Long-Term Tumor Control for Hypofractionated FLASH Versus Conventional Radiation Therapy in an Immunocompetent Rat Glioma Model. Adv Radiat Oncol 2022; 7:101011. [PMID: 36092986 PMCID: PMC9449779 DOI: 10.1016/j.adro.2022.101011] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 06/20/2022] [Indexed: 11/29/2022] Open
Abstract
Purpose To ensure a clinical translation of FLASH radiation therapy (FLASH-RT) for a specific tumor type, studies on tumor control and toxicity within the same biological system are needed. In this study, our objective was to evaluate tumor control and toxicity for hypofractionated FLASH-RT and conventional radiation therapy (CONV-RT) in an immunocompetent rat glioma model. Methods and Materials Fisher 344 rats (N = 68) were inoculated subcutaneously with NS1 glioma cells and randomized into groups (n = 9-10 per group). CONV-RT (∼8 Gy/min) or FLASH-RT (70-90 Gy/s) was administered in 3 fractions of either 8 Gy, 12.5 Gy, or 15 Gy using a 10-MeV electron beam. The maximum tumor diameter was measured weekly, and overall survival was determined until day 100. Long-term tumor control was defined as no evident tumor on day 100. Animals were evaluated for acute dermal side effects at 2 to 5 weeks after completed RT and for late dermal side effects at 3 months after initiation of treatment. Results Survival was significantly increased in all irradiated groups compared with control animals (P < .001). In general, irradiated tumors started to shrink at 1 week post-completed RT. In 40% (23 of 58) of the irradiated animals, long-term tumor control was achieved. Radiation-induced skin toxic effects were mild and consisted of hair loss, erythema, and dry desquamation. No severe toxic effect was observed. There was no significant difference between FLASH-RT and CONV-RT in overall survival, acute side effects, or late side effects for any of the dose levels. Conclusions This study shows that hypofractionated FLASH-RT results in long-term tumor control rates similar to those of CONV-RT for the treatment of large subcutaneous glioblastomas in immunocompetent rats. Neither treatment technique induced severe skin toxic effects. Consequently, no significant difference in toxicity could be resolved, suggesting that higher doses may be required to detect a FLASH sparing of skin.
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Affiliation(s)
- Elise Konradsson
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Emma Liljedahl
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Emma Gustafsson
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Gabriel Adrian
- Division of Oncology and Pathology, Department of Clinical Sciences, Skåne University Hospital, Lund University, Lund, Sweden
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
| | - Sarah Beyer
- Division of Oncology and Pathology, Department of Clinical Sciences, Skåne University Hospital, Lund University, Lund, Sweden
| | - Suhayb Ehsaan Ilaahi
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Kristoffer Petersson
- Department of Hematology, Oncology and Radiation Physics, Skåne University Hospital, Lund, Sweden
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, Oxford, United Kingdom
| | - Crister Ceberg
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Henrietta Nittby Redebrandt
- Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
- Department of Neurosurgery, Skåne University Hospital, Lund, Sweden
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Comparison of intratumor and local immune response between MV X-ray FLASH and conventional radiotherapies. Clin Transl Radiat Oncol 2022; 38:138-146. [DOI: 10.1016/j.ctro.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/06/2022] [Accepted: 11/07/2022] [Indexed: 11/10/2022] Open
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Vozenin MC, Bourhis J, Durante M. Towards clinical translation of FLASH radiotherapy. Nat Rev Clin Oncol 2022; 19:791-803. [DOI: 10.1038/s41571-022-00697-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2022] [Indexed: 11/09/2022]
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Potential Molecular Mechanisms behind the Ultra-High Dose Rate "FLASH" Effect. Int J Mol Sci 2022; 23:ijms232012109. [PMID: 36292961 PMCID: PMC9602825 DOI: 10.3390/ijms232012109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/26/2022] [Accepted: 10/08/2022] [Indexed: 11/17/2022] Open
Abstract
FLASH radiotherapy, or the delivery of a dose at an ultra-high dose rate (>40 Gy/s), has recently emerged as a promising tool to enhance the therapeutic index in cancer treatment. The remarkable sparing of normal tissues and equivalent tumor control by FLASH irradiation compared to conventional dose rate irradiation—the FLASH effect—has already been demonstrated in several preclinical models and even in a first patient with T-cell cutaneous lymphoma. However, the biological mechanisms responsible for the differential effect produced by FLASH irradiation in normal and cancer cells remain to be elucidated. This is of great importance because a good understanding of the underlying radiobiological mechanisms and characterization of the specific beam parameters is required for a successful clinical translation of FLASH radiotherapy. In this review, we summarize the FLASH investigations performed so far and critically evaluate the current hypotheses explaining the FLASH effect, including oxygen depletion, the production of reactive oxygen species, and an altered immune response. We also propose a new theory that assumes an important role of mitochondria in mediating the normal tissue and tumor response to FLASH dose rates.
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Li L, Yuan Y, Zuo Y. A review of the impact of FLASH radiotherapy on the central nervous system and glioma. RADIATION MEDICINE AND PROTECTION 2022. [DOI: 10.1016/j.radmp.2022.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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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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Lin B, Huang D, Gao F, Yang Y, Wu D, Zhang Y, Feng G, Dai T, Du X. Mechanisms of FLASH effect. Front Oncol 2022; 12:995612. [PMID: 36212435 PMCID: PMC9537695 DOI: 10.3389/fonc.2022.995612] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 08/22/2022] [Indexed: 11/13/2022] Open
Abstract
FLASH radiotherapy (FLASH-RT) is a novel radiotherapy technology defined as ultra-high dose rate (≥ 40 Gy/s) radiotherapy. The biological effects of FLASH-RT include two aspects: first, compared with conventional dose rate radiotherapy, FLASH-RT can reduce radiation-induced damage in healthy tissue, and second, FLASH-RT can retain antitumor effectiveness. Current research shows that mechanisms of the biological effects of FLASH-RT are related to oxygen. However, due to the short time of FLASH-RT, evidences related to the mechanisms are indirect, and the exact mechanisms of the biological effects of FLASH-RT are not completely clear and some are even contradictory. This review focuses on the mechanisms of the biological effects of FLASH-RT and proposes future research directions.
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Affiliation(s)
- Binwei Lin
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
- State Key Laboratory of Ultrasound in Medicine and Engineering, College of Biomedical Engineering, Chongqing Medical University, Chongqing, China
| | - Dan Huang
- Department of Radiology Mianyang Central Hospital, Mianyang, China
| | - Feng Gao
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Yiwei Yang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Dai Wu
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, China
| | - Yu Zhang
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Gang Feng
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Tangzhi Dai
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
| | - Xiaobo Du
- National Health Commission (NHC) Key Laboratory of Nuclear Technology Medical Transformation, Mianyang Central Hospital, Department of Oncology, Mianyang Central Hospital, Mianyang, China
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Telarovic I, Yong CSM, Guckenberger M, Unkelbach J, Pruschy M. Radiation-induced lymphopenia does not impact treatment efficacy in a mouse tumor model. Neoplasia 2022; 31:100812. [PMID: 35667149 PMCID: PMC9168138 DOI: 10.1016/j.neo.2022.100812] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2022] [Revised: 05/18/2022] [Accepted: 05/23/2022] [Indexed: 12/03/2022]
Abstract
Radiation-induced lymphopenia is a common occurrence in radiation oncology and an established negative prognostic factor, however the mechanisms underlying the relationship between lymphopenia and inferior survival remain elusive. The relevance of lymphocyte co-irradiation as critical normal tissue component at risk is an emerging topic of high clinical relevance, even more so in the context of potentially synergistic radiotherapy-immunotherapy combinations. The impact of the radiotherapy treatment volume on the lymphocytes of healthy and tumor-bearing mice was investigated in a novel mouse model of radiation-induced lymphopenia. Using an image-guided small-animal radiotherapy treatment platform, translationally relevant tumor-oriented volumes of irradiation with an anatomically defined increasing amount of normal tissue were irradiated, with a focus on the circulating blood and lymph nodes. In healthy mice, the influence of irradiation with increasing radiotherapy treatment volumes was quantified on the level of circulating blood cells and in the spleen. A significant decrease in the lymphocytes was observed in response to irradiation, including the minimally irradiated putative tumor area. The extent of lymphopenia correlated with the increasing volumes of irradiation. In tumor-bearing mice, differential radiotherapy treatment volumes did not influence the overall therapeutic response to radiotherapy alone. Intriguingly, an improved treatment efficacy in mice treated with draining-lymph node co-irradiation was observed in combination with an immune checkpoint inhibitor. Taken together, our study reveals compelling data on the importance of radiotherapy treatment volume in the context of lymphocytes as critical components of normal tissue co-irradiation and highlights emerging challenges at the interface of radiotherapy and immunotherapy.
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Affiliation(s)
- Irma Telarovic
- Laboratory for Applied Radiobiology, Dept. Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Carmen S M Yong
- Laboratory for Applied Radiobiology, Dept. Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland; Dept. Immunology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Matthias Guckenberger
- Dept. Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Jan Unkelbach
- Dept. Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Martin Pruschy
- Laboratory for Applied Radiobiology, Dept. Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland.
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Jansen J, Beyreuther E, García-Calderón D, Karsch L, Knoll J, Pawelke J, Schürer M, Seco J. oChanges in Radical Levels as a Cause for the FLASH effect: Impact of beam structure parameters at ultra-high dose rates on oxygen depletion in water. Radiother Oncol 2022; 175:193-196. [PMID: 36030933 DOI: 10.1016/j.radonc.2022.08.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 08/19/2022] [Accepted: 08/22/2022] [Indexed: 01/15/2023]
Abstract
The influence of different average and bunch dose rates in electron beams on the FLASH effect was investigated. The present study measures O2 content in water at different beam pulse patterns and finds strong correlation with biological data, strengthening the hypothesis of radical-related mechanisms as a reason for the FLASH effect.
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Affiliation(s)
- Jeannette Jansen
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Elke Beyreuther
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiation Physics, Dresden, Germany
| | - Daniel García-Calderón
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Ruprecht-Karls-University, Heidelberg, Germany
| | - Leonhard Karsch
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Jan Knoll
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Ruprecht-Karls-University, Heidelberg, Germany
| | - Jörg Pawelke
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, TU Dresden and Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Michael Schürer
- National Center for Tumor Diseases Dresden (NCT/UCC), Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, Helmholtz-Zentrum Dresden-Rossendorf (HZDR), Dresden, Germany
| | - Joao Seco
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Ruprecht-Karls-University, Heidelberg, Germany.
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Wei S, Lin H, Isabelle Choi J, Shi C, Simone CB, Kang M. Advanced pencil beam scanning Bragg peak FLASH-RT delivery technique can enhance lung cancer planning treatment outcomes compared to conventional multiple-energy proton PBS techniques. Radiother Oncol 2022; 175:238-247. [PMID: 35961583 DOI: 10.1016/j.radonc.2022.08.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Revised: 08/01/2022] [Accepted: 08/01/2022] [Indexed: 12/25/2022]
Abstract
PURPOSE To investigate the dosimetric characteristics between an advanced proton pencil beam scanning (PBS) Bragg peak FLASH technique and conventional PBS planning technique in lung tumors. To evaluate the "FLASHness" of single-field in a multiple-field delivery scheme for a hypofractionation regimen and move a step forward to clinical application. METHODS Single-energy PBS Bragg peak FLASH treatment plans were optimized based on a novel Bragg peak tracking technique to enable Bragg peaks to stop at the distal edge of the target. Inverse treatment planning using multiple-field optimization (MFO) can achieve sufficient FLASH dose rate and intensity-modulated proton therapy (IMPT)-equivalent dosimetric quality. The dose rate of organs-at-risk (OARs) and the target were calculated under FLASH machine parameters. A group of 10 consecutive lung SBRT patients was optimized to 34 Gy/fraction using a standard treatment of PBS technique with multiple energy layers as references to the Bragg peak plans. The dosimetric quality was compared between Bragg peak FLASH and conventional plans based on RTOG0915 dose metrics. FLASH dose rate ratios (V40Gy/s) were calculated as a metric of the FLASH-sparing effect. RESULTS For higher dose thresholds, the Bragg peak plans achieved greater V40Gy/s FLASH coverage for all major OARs. The V40Gy/s was close to 100% for all OARs when the dose thresholds were > 5 Gy for full plan and single beam evaluations. The less "FLASHness" region was associated with a low dose distribution, mainly occurring in the PBS field penumbra region. The conventional IMPT treatment plans yielded slightly superior target dose uniformity with a D2%(%) of 108.02% versus that of Bragg peak 300 MU plans of 111.81% (p < 0.01) and that of Bragg peak 1200 MU plans of 115.95% (p < 0.01). No significant difference in dose metrics was found between Bragg peak and IMPT treatment plans for the spinal cord, esophagus, heart, or lung-GTV (all p > 0.05). CONCLUSION Hypofractionated lung Bragg peak plans can maintain comparable plan quality to conventional PBS while achieving sufficient FLASH dose rate coverage for major OARs for each field under the multiple-field delivery scheme. The novel Bragg peak FLASH technique has the potential to enhance lung cancer planning treatment outcomes compared to standard PBS treatment techniques.
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Affiliation(s)
- Shouyi Wei
- New York Proton Center, New York, NY 10035, USA
| | - Haibo Lin
- New York Proton Center, New York, NY 10035, USA.
| | | | - Chengyu Shi
- City of Hope, Orange County, Irvine, CA 92618, USA
| | | | - Minglei Kang
- New York Proton Center, New York, NY 10035, USA.
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Rothwell B, Lowe M, Traneus E, Krieger M, Schuemann J. Treatment planning considerations for the development of FLASH proton therapy. Radiother Oncol 2022; 175:222-230. [PMID: 35963397 DOI: 10.1016/j.radonc.2022.08.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/21/2022] [Accepted: 08/01/2022] [Indexed: 10/15/2022]
Abstract
With increasing focus on the translation of the observed FLASH effect into clinical practice, this paper presents treatment planning considerations for its development using proton therapy. Potential requirements to induce a FLASH effect are discussed along with the properties of existing proton therapy delivery systems and the changes in planning and delivery approaches required to satisfy these prerequisites. For the exploration of treatment planning approaches for FLASH, developments in treatment planning systems are needed. Flexibility in adapting to new information will be important in such an evolving area. Variations in definitions, threshold values and assumptions can make it difficult to compare different published studies and to interpret previous studies in the context of new information. Together with the fact that much is left to be understood about the underlying mechanism behind the FLASH effect, a systematic and comprehensive approach to information storage is encouraged. Collecting and retaining more detailed information on planned and realised dose delivery as well as reporting the assumptions made in planning studies creates the potential for research to be revisited and re-evaluated in the light of future improvements in understanding. Forward thinking at the time of study development can help facilitate retrospective analysis. This, we hope, will increase the available evidence and accelerate the translation of the FLASH effect into clinical benefit.
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Affiliation(s)
- Bethany Rothwell
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom.
| | - Matthew Lowe
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom; Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
| | | | - Miriam Krieger
- Varian Medical Systems Particle Therapy GmbH & Co. KG, Troisdorf, Germany
| | - Jan Schuemann
- Division of Physics, Dept. of Radiation Oncology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
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Sung W, Cho B. Modeling of radiation effects to immune system: a review. THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY 2022; 81:1013-1019. [PMID: 35966936 PMCID: PMC9358382 DOI: 10.1007/s40042-022-00574-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 03/17/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
Cancer metastasis is the major cause of cancer mortality and accounts for about 90% of cancer death. Although radiation therapy has been considered to reduce the localized cancer burden, emerging evidence that radiation can potentially turn tumors into an in situ vaccine has raised significant interest in combining radiation with immunotherapy. However, the combination approach might be limited by the radiation-induced immunosuppression. Assessment of radiation effects on the immune system at the patient level is critical to maximize the systemic antitumor response of radiation. In this review, we summarize the developed solutions in three different categories for systemic radiation therapy: blood dose, radiation-induced lymphopenia, and tumor control. Furthermore, we address how they could be combined to optimize radiotherapy regimens and maximize their synergy with immunotherapy.
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Affiliation(s)
- Wonmo Sung
- Department of Biomedical Engineering and of Biomedicine & Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Byungchul Cho
- Department of Radiation Oncology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea
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