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Grams MP, Mateus CQ, Mashayekhi M, Mutter RW, Djonov V, Fazzari JM, Xiao H, Frechette KM, Wentworth AJ, Morris JM, Klebel B, Thull JC, Guenzel RM, Wismayer DJS, Lucien F, Park SS, Lester SC. Minibeam Radiation Therapy Treatment (MBRT): Commissioning and First Clinical Implementation. Int J Radiat Oncol Biol Phys 2024:S0360-3016(24)02948-1. [PMID: 39002850 DOI: 10.1016/j.ijrobp.2024.06.035] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2024] [Revised: 06/22/2024] [Accepted: 06/29/2024] [Indexed: 07/15/2024]
Abstract
PURPOSE Minibeam radiation therapy (MBRT) is characterized by the delivery of submillimeter-wide regions of high "peak" and low "valley" doses throughout a tumor. Preclinical studies have long shown the promise of this technique, and we report here the first clinical implementation of MBRT. METHODS AND MATERIALS A clinical orthovoltage unit was commissioned for MBRT patient treatments using 3-, 4-, 5-, 8-, and 10-cm diameter cones. The 180 kVp output was spatially separated into minibeams using a tungsten collimator with 0.5 mm wide slits spaced 1.1 mm on center. Percentage depth dose (PDD) measurements were obtained using film dosimetry and plastic water for both peak and valley doses. PDDs were measured on the central axis for offsets of 0, 0.5, and 1 cm. The peak-to-valley ratio was calculated at each depth for all cones and offsets. To mitigate the effects of patient motion on delivered dose, patient-specific 3-dimensional-printed collimator holders were created. These conformed to the unique anatomy of each patient and affixed the tungsten collimator directly to the body. Two patients were treated with MBRT; both received 2 fractions. RESULTS Peak PDDs decreased gradually with depth. Valley PDDs initially increased slightly with depth, then decreased gradually beyond 2 cm. The peak-to-valley ratios were highest at the surface for smaller cone sizes and offsets. In vivo film dosimetry confirmed a distinct delineation of peak and valley doses in both patients treated with MBRT with no dose blurring. Both patients experienced prompt improvement in symptoms and tumor response. CONCLUSIONS We report commissioning results, treatment processes, and the first 2 patients treated with MBRT using a clinical orthovoltage unit. While demonstrating the feasibility of this approach is a crucial first step toward wider translation, clinical trials are needed to further establish safety and efficacy.
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Affiliation(s)
- Michael P Grams
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota.
| | | | | | - Robert W Mutter
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota; Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, Minnesota
| | | | | | - Huaping Xiao
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | | | | | | | - Brandon Klebel
- Division of Engineering, Mayo Clinic, Rochester, Minnesota
| | - Jack C Thull
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | | | | | - Fabrice Lucien
- Department of Urology, Mayo Clinic, Rochester, Minnesota; Division of Immunology, Mayo Clinic, Rochester, Minnesota
| | - Sean S Park
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Scott C Lester
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
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Prezado Y, Grams M, Jouglar E, Martínez-Rovira I, Ortiz R, Seco J, Chang S. Spatially fractionated radiation therapy: a critical review on current status of clinical and preclinical studies and knowledge gaps. Phys Med Biol 2024; 69:10TR02. [PMID: 38648789 DOI: 10.1088/1361-6560/ad4192] [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: 11/27/2023] [Accepted: 04/22/2024] [Indexed: 04/25/2024]
Abstract
Spatially fractionated radiation therapy (SFRT) is a therapeutic approach with the potential to disrupt the classical paradigms of conventional radiation therapy. The high spatial dose modulation in SFRT activates distinct radiobiological mechanisms which lead to a remarkable increase in normal tissue tolerances. Several decades of clinical use and numerous preclinical experiments suggest that SFRT has the potential to increase the therapeutic index, especially in bulky and radioresistant tumors. To unleash the full potential of SFRT a deeper understanding of the underlying biology and its relationship with the complex dosimetry of SFRT is needed. This review provides a critical analysis of the field, discussing not only the main clinical and preclinical findings but also analyzing the main knowledge gaps in a holistic way.
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Affiliation(s)
- Yolanda Prezado
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, F-91400, Orsay, France
- Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, F-91400, Orsay, France
- New Approaches in Radiotherapy Lab, Center for Research in Molecular Medicine and Chronic Diseases (CIMUS), Instituto de investigación Sanitaria de Santiago de Compostela (IDIS), University of Santiago de Compostela, Santiago de Compostela, A Coruña, E-15706, Spain
- Oportunius Program, Galician Agency of Innovation (GAIN), Xunta de Galicia, Santiago de Compostela, A Coruña, Spain
| | - Michael Grams
- Department of Radiation Oncology, Mayo Clinic, 200 First St SW, Rochester, MN 55905, United States of America
| | - Emmanuel Jouglar
- Institut Curie, PSL Research University, Department of Radiation Oncology, F-75005, Paris and Orsay Protontherapy Center, F-91400, Orsay, France
| | - Immaculada Martínez-Rovira
- Physics Department, Universitat Auto`noma de Barcelona, E-08193, Cerdanyola del Valle`s (Barcelona), Spain
| | - Ramon Ortiz
- University of California San Francisco, Department of Radiation Oncology, 1600 Divisadero Street, San Francisco, CA 94143, United States of America
| | - Joao Seco
- Division of Biomedical physics in Radiation Oncology, DKFZ-German Cancer Research Center, Heidelberg, Germany
- Department of Physics and Astronomy, Heidelberg University, Heidelberg, Germany
| | - Sha Chang
- Dept of Radiation Oncology and Department of Biomedical Engineering, University of North Carolina School of Medicine, United States of America
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolin State University, United States of America
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Lu Q, Yan W, Zhu A, Tubin S, Mourad WF, Yang J. Combining spatially fractionated radiation therapy (SFRT) and immunotherapy opens new rays of hope for enhancing therapeutic ratio. Clin Transl Radiat Oncol 2024; 44:100691. [PMID: 38033759 PMCID: PMC10684810 DOI: 10.1016/j.ctro.2023.100691] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Revised: 10/04/2023] [Accepted: 10/15/2023] [Indexed: 12/02/2023] Open
Abstract
Spatially Fractionated Radiation Therapy (SFRT) is a form of radiotherapy that delivers a single large dose of radiation within the target volume in a heterogeneous pattern with regions of peak dosage and regions of under dosage. SFRT types can be defined by how the heterogeneous pattern of radiation is obtained. Immune checkpoint inhibitors (ICIs) have been approved for various malignant tumors and are widely used to treat patients with metastatic cancer. The efficacy of ICI monotherapy is limited due to the "cold" tumor microenvironment. Fractionated radiotherapy can achieve higher doses per fraction to the target tumor, and induce immune activation (immodulate tumor immunogenicity and microenvironment). Therefore, coupling ICI therapy and fractionated radiation therapy could significantly improve the outcome of metastatic cancer. This review focuses on both preclinical and clinical studies that use a combination of radiotherapy and ICI therapy in cancer.
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Affiliation(s)
- Qiuxia Lu
- Foshan Fosun Chancheng Hospital, P.R. China
- Junxin Precision Oncology Group, P.R. China
| | - Weisi Yan
- Baptist Health System, Lexington, KY, United States
- Junxin Precision Oncology Group, P.R. China
| | - Alan Zhu
- Mayo Clinic Alix School of Medicine, Scottsdale, AZ, United States
| | - Slavisa Tubin
- Albert Einstein Collage of Medicine New York, Center for Ion Therapy, Medaustron, Austria
| | - Waleed F. Mourad
- Department of Radiation Medicine Markey Cancer Center, University of Kentucky - College of Medicine, United States
| | - Jun Yang
- Foshan Fosun Chancheng Hospital, P.R. China
- Junxin Precision Oncology Group, P.R. China
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Lukas L, Zhang H, Cheng K, Epstein A. Immune Priming with Spatially Fractionated Radiation Therapy. Curr Oncol Rep 2023; 25:1483-1496. [PMID: 37979032 PMCID: PMC10728252 DOI: 10.1007/s11912-023-01473-7] [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] [Accepted: 10/30/2023] [Indexed: 11/19/2023]
Abstract
PURPOSE OF REVIEW This review aims to summarize the current preclinical and clinical evidence of nontargeted immune effects of spatially fractionated radiation therapy (SFRT). We then highlight strategies to augment the immunomodulatory potential of SFRT in combination with immunotherapy (IT). RECENT FINDINGS The response of cancer to IT is limited by primary and acquired immune resistance, and strategies are needed to prime the immune system to increase the efficacy of IT. Radiation therapy can induce immunologic effects and can potentially be used to synergize the effects of IT, although the optimal combination of radiation and IT is largely unknown. SFRT is a novel radiation technique that limits ablative doses to tumor subvolumes, and this highly heterogeneous dose deposition may increase the immune-rich infiltrate within the targeted tumor with enhanced antigen presentation and activated T cells in nonirradiated tumors. The understanding of nontargeted effects of SFRT can contribute to future translational strategies to combine SFRT and IT. Integration of SFRT and IT is an innovative approach to address immune resistance to IT with the overall goal of improving the therapeutic ratio of radiation therapy and increasing the efficacy of IT.
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Affiliation(s)
- Lauren Lukas
- Department of Radiation Oncology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
| | - Hualin Zhang
- Department of Radiation Oncology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Karen Cheng
- Department of Radiation Oncology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Alan Epstein
- Department of Pathology, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
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Iliadi C, Verset L, Bouchart C, Martinive P, Van Gestel D, Krayem M. The current understanding of the immune landscape relative to radiotherapy across tumor types. Front Immunol 2023; 14:1148692. [PMID: 37006319 PMCID: PMC10060828 DOI: 10.3389/fimmu.2023.1148692] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 03/03/2023] [Indexed: 03/18/2023] Open
Abstract
Radiotherapy is part of the standard of care treatment for a great majority of cancer patients. As a result of radiation, both tumor cells and the environment around them are affected directly by radiation, which mainly primes but also might limit the immune response. Multiple immune factors play a role in cancer progression and response to radiotherapy, including the immune tumor microenvironment and systemic immunity referred to as the immune landscape. A heterogeneous tumor microenvironment and the varying patient characteristics complicate the dynamic relationship between radiotherapy and this immune landscape. In this review, we will present the current overview of the immunological landscape in relation to radiotherapy in order to provide insight and encourage research to further improve cancer treatment. An investigation into the impact of radiation therapy on the immune landscape showed in several cancers a common pattern of immunological responses after radiation. Radiation leads to an upsurge in infiltrating T lymphocytes and the expression of programmed death ligand 1 (PD-L1) which can hint at a benefit for the patient when combined with immunotherapy. In spite of this, lymphopenia in the tumor microenvironment of 'cold' tumors or caused by radiation is considered to be an important obstacle to the patient's survival. In several cancers, a rise in the immunosuppressive populations is seen after radiation, mainly pro-tumoral M2 macrophages and myeloid-derived suppressor cells (MDSCs). As a final point, we will highlight how the radiation parameters themselves can influence the immune system and, therefore, be exploited to the advantage of the patient.
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Affiliation(s)
- Chrysanthi Iliadi
- Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
- Laboratory of Clinical and Experimental Oncology (LOCE), Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
| | - Laurine Verset
- Department of Pathology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
| | - Christelle Bouchart
- Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
| | - Philippe Martinive
- Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
| | - Dirk Van Gestel
- Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
| | - Mohammad Krayem
- Department of Radiation Oncology, Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
- Laboratory of Clinical and Experimental Oncology (LOCE), Institut Jules Bordet, Université Libre de Bruxelles (ULB), Hôpital Universitaire de Bruxelles (H.U.B), Brussels, Belgium
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Bertho A, Iturri L, Brisebard E, Juchaux M, Gilbert C, Ortiz R, Sebrie C, Jourdain L, Lamirault C, Ramasamy G, Pouzoulet F, Prezado Y. Evaluation of the Role of the Immune System Response After Minibeam Radiation Therapy. Int J Radiat Oncol Biol Phys 2023; 115:426-439. [PMID: 35985455 DOI: 10.1016/j.ijrobp.2022.08.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Revised: 07/23/2022] [Accepted: 08/05/2022] [Indexed: 01/11/2023]
Abstract
PURPOSE Minibeam radiation therapy (MBRT) is an innovative technique that uses a spatial dose modulation. The dose distribution consists of high doses (peaks) in the path of the minibeam and low doses (valleys). The underlying biological mechanism associated with MBRT efficacy remains currently unclear and thus we investigated the potential role of the immune system after treatment with MBRT. METHODS AND MATERIALS Rats bearing an orthotopic glioblastoma cell line were treated with 1 fraction of high dose conventional radiation therapy (30 Gy) or 1 fraction of the same mean dose in MBRT. Both immunocompetent (F344) and immunodeficient (Nude) rats were analyzed in survival studies. Systemic and intratumoral immune cell population changes were studied with flow cytometry and immunohistochemistry (IHC) 2 and 7 days after the irradiation. RESULTS The absence of response of Nude rats after MBRT suggested that T cells were key in the mode of action of MBRT. An inflammatory phenotype was observed in the blood 1 week after irradiation compared with conventional irradiation. Tumor immune cell analysis by flow cytometry showed a substantial infiltration of lymphocytes, specifically of CD8 T cells and B cells in both conventional and MBRT-treated animals. IHC revealed that MBRT induced a faster recruitment of CD8 and CD4 T cells. Animals that were cured by radiation therapy did not suffer tumor growth after reimplantation of tumoral cells, proving the long-term immunity response generated after a high dose of radiation. CONCLUSIONS Our findings show that MBRT can elicit a robust antitumor immune response in glioblastoma while avoiding the high toxicity of a high dose of conventional radiation therapy.
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Affiliation(s)
- Annaig Bertho
- CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Institut Curie, Université PSL, Orsay, France; CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Université Paris-Saclay, Orsay, France.
| | - Lorea Iturri
- CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Institut Curie, Université PSL, Orsay, France; CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Université Paris-Saclay, Orsay, France
| | | | - Marjorie Juchaux
- CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Institut Curie, Université PSL, Orsay, France; CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Université Paris-Saclay, Orsay, France
| | - Cristèle Gilbert
- CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Institut Curie, Université PSL, Orsay, France; CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Université Paris-Saclay, Orsay, France
| | - Ramon Ortiz
- CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Institut Curie, Université PSL, Orsay, France; CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Université Paris-Saclay, Orsay, France
| | - Catherine Sebrie
- Service Hospitalier Frédéric Joliot, CEA, CNRS, Inserm, BIOMAPS Université Paris-Saclay, Orsay, France
| | - Laurene Jourdain
- Service Hospitalier Frédéric Joliot, CEA, CNRS, Inserm, BIOMAPS Université Paris-Saclay, Orsay, France
| | - Charlotte Lamirault
- Département de Recherche Translationnelle, CurieCoreTech-Experimental Radiotherapy (RadeXp), Institut Curie, PSL University, Paris, France
| | - Gabriel Ramasamy
- Département de Recherche Translationnelle, CurieCoreTech-Experimental Radiotherapy (RadeXp), Institut Curie, PSL University, Paris, France
| | - Frédéric Pouzoulet
- Département de Recherche Translationnelle, CurieCoreTech-Experimental Radiotherapy (RadeXp), Institut Curie, PSL University, Paris, France; Inserm U1288, Laboratoire de Recherche Translationnelle en Oncologie, Institut Curie, PSL University, Université Paris-Saclay, Orsay, France
| | - Yolanda Prezado
- CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Institut Curie, Université PSL, Orsay, France; CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Université Paris-Saclay, Orsay, France
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Schneider T, Fernandez-Palomo C, Bertho A, Fazzari J, Iturri L, Martin OA, Trappetti V, Djonov V, Prezado Y. Combining FLASH and spatially fractionated radiation therapy: The best of both worlds. Radiother Oncol 2022; 175:169-177. [PMID: 35952978 DOI: 10.1016/j.radonc.2022.08.004] [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: 04/14/2022] [Revised: 07/23/2022] [Accepted: 08/03/2022] [Indexed: 11/16/2022]
Abstract
FLASH radiotherapy (FLASH-RT) and spatially fractionated radiation therapy (SFRT) are two new therapeutical strategies that use non-standard dose delivery methods to reduce normal tissue toxicity and increase the therapeutic index. Although likely based on different mechanisms, both FLASH-RT and SFRT have shown to elicit radiobiological effects that significantly differ from those induced by conventional radiotherapy. With the therapeutic potential having been established separately for each technique, the combination of FLASH-RT and SFRT could therefore represent a winning alliance. In this review, we discuss the state of the art, advantages and current limitations, potential synergies, and where a combination of these two techniques could be implemented today or in the near future.
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Affiliation(s)
- Tim Schneider
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France
| | | | - Annaïg Bertho
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France
| | - Jennifer Fazzari
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland
| | - Lorea Iturri
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France
| | - Olga A Martin
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland; Division of Radiation Oncology, Peter MacCallum Cancer Centre, 305 Grattan St, Melbourne, VIC 3000, Australia; University of Melbourne, Parkville, VIC 3010, Australia
| | - Verdiana Trappetti
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland
| | - Valentin Djonov
- Institute of Anatomy, University of Bern, Baltzerstrasse 2, 3012 Bern, Switzerland
| | - Yolanda Prezado
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France; Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, 91400 Orsay, France.
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Moghaddasi L, Reid P, Bezak E, Marcu LG. Radiobiological and Treatment-Related Aspects of Spatially Fractionated Radiotherapy. Int J Mol Sci 2022; 23:3366. [PMID: 35328787 PMCID: PMC8954016 DOI: 10.3390/ijms23063366] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Revised: 03/13/2022] [Accepted: 03/17/2022] [Indexed: 11/17/2022] Open
Abstract
The continuously evolving field of radiotherapy aims to devise and implement techniques that allow for greater tumour control and better sparing of critical organs. Investigations into the complexity of tumour radiobiology confirmed the high heterogeneity of tumours as being responsible for the often poor treatment outcome. Hypoxic subvolumes, a subpopulation of cancer stem cells, as well as the inherent or acquired radioresistance define tumour aggressiveness and metastatic potential, which remain a therapeutic challenge. Non-conventional irradiation techniques, such as spatially fractionated radiotherapy, have been developed to tackle some of these challenges and to offer a high therapeutic index when treating radioresistant tumours. The goal of this article was to highlight the current knowledge on the molecular and radiobiological mechanisms behind spatially fractionated radiotherapy and to present the up-to-date preclinical and clinical evidence towards the therapeutic potential of this technique involving both photon and proton beams.
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Affiliation(s)
- Leyla Moghaddasi
- Department of Medical Physics, Austin Health, Ballarat, VIC 3350, Australia;
- School of Physical Sciences, University of Adelaide, Adelaide, SA 5001, Australia;
| | - Paul Reid
- Radiation Health, Environment Protection Authority, Adelaide, SA 5000, Australia;
| | - Eva Bezak
- School of Physical Sciences, University of Adelaide, Adelaide, SA 5001, Australia;
- Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia
| | - Loredana G. Marcu
- Cancer Research Institute, University of South Australia, Adelaide, SA 5001, Australia
- Faculty of Informatics and Science, University of Oradea, 1 Universitatii Str., 410087 Oradea, Romania
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Bertho A, Iturri L, Prezado Y. Radiation-induced immune response in novel radiotherapy approaches FLASH and spatially fractionated radiotherapies. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2022; 376:37-68. [PMID: 36997269 DOI: 10.1016/bs.ircmb.2022.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The last several years have revealed increasing evidence of the immunomodulatory role of radiation therapy. Radiotherapy reshapes the tumoral microenvironment can shift the balance toward a more immunostimulatory or immunosuppressive microenvironment. The immune response to radiation therapy appears to depend on the irradiation configuration (dose, particle, fractionation) and delivery modes (dose rate, spatial distributions). Although an optimal irradiation configuration (dose, temporal fractionation, spatial dose distribution, etc.) has not yet been determined, temporal schemes employing high doses per fraction appear to favor radiation-induced immune response through immunogenic cell death. Through the release of damage-associated molecular patterns and the sensing of double-stranded DNA and RNA breaks, immunogenic cell death activates the innate and adaptive immune response, leading to tumor infiltration by effector T cells and the abscopal effect. Novel radiotherapy approaches such as FLASH and spatially fractionated radiotherapies (SFRT) strongly modulate the dose delivery method. FLASH-RT and SFRT have the potential to trigger the immune system effectively while preserving healthy surrounding tissues. This manuscript reviews the current state of knowledge on the immunomodulation effects of these two new radiotherapy techniques in the tumor, healthy immune cells and non-targeted regions, as well as their therapeutic potential in combination with immunotherapy.
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