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Biological Mechanisms to Reduce Radioresistance and Increase the Efficacy of Radiotherapy: State of the Art. Int J Mol Sci 2022; 23:ijms231810211. [PMID: 36142122 PMCID: PMC9499172 DOI: 10.3390/ijms231810211] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 08/25/2022] [Accepted: 09/02/2022] [Indexed: 12/02/2022] Open
Abstract
Cancer treatment with ionizing radiation (IR) is a well-established and effective clinical method to fight different types of tumors and is a palliative treatment to cure metastatic stages. Approximately half of all cancer patients undergo radiotherapy (RT) according to clinical protocols that employ two types of ionizing radiation: sparsely IR (i.e., X-rays) and densely IR (i.e., protons). Most cancer cells irradiated with therapeutic doses exhibit radio-induced cytotoxicity in terms of cell proliferation arrest and cell death by apoptosis. Nevertheless, despite the more tailored advances in RT protocols in the last few years, several tumors show a relatively high percentage of RT failure and tumor relapse due to their radioresistance. To counteract this extremely complex phenomenon and improve clinical protocols, several factors associated with radioresistance, of both a molecular and cellular nature, must be considered. Tumor genetics/epigenetics, tumor microenvironment, tumor metabolism, and the presence of non-malignant cells (i.e., fibroblast-associated cancer cells, macrophage-associated cancer cells, tumor-infiltrating lymphocytes, endothelial cells, cancer stem cells) are the main factors important in determining the tumor response to IR. Here, we attempt to provide an overview of how such factors can be taken advantage of in clinical strategies targeting radioresistant tumors.
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Rohrer Bley C, Wolf F, Gonçalves Jorge P, Grilj V, Petridis I, Petit B, Böhlen TT, Moeckli R, Limoli C, Bourhis J, Meier V, Vozenin MC. Dose- and Volume-Limiting Late Toxicity of FLASH Radiotherapy in Cats with Squamous Cell Carcinoma of the Nasal Planum and in Mini Pigs. Clin Cancer Res 2022; 28:3814-3823. [PMID: 35421221 PMCID: PMC9433962 DOI: 10.1158/1078-0432.ccr-22-0262] [Citation(s) in RCA: 39] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 02/02/2022] [Accepted: 04/12/2022] [Indexed: 01/07/2023]
Abstract
PURPOSE The FLASH effect is characterized by normal tissue sparing without compromising tumor control. Although demonstrated in various preclinical models, safe translation of FLASH-radiotherapy stands to benefit from larger vertebrate animal models. Based on prior results, we designed a randomized phase III trial to investigate the FLASH effect in cat patients with spontaneous tumors. In parallel, the sparing capacity of FLASH-radiotherapy was studied on mini pigs by using large field irradiation. EXPERIMENTAL DESIGN Cats with T1-T2, N0 carcinomas of the nasal planum were randomly assigned to two arms of electron irradiation: arm 1 was the standard of care (SoC) and used 10 × 4.8 Gy (90% isodose); arm 2 used 1 × 30 Gy (90% isodose) FLASH. Mini pigs were irradiated using applicators of increasing size and a single surface dose of 31 Gy FLASH. RESULTS In cats, acute side effects were mild and similar in both arms. The trial was prematurely interrupted due to maxillary bone necrosis, which occurred 9 to 15 months after radiotherapy in 3 of 7 cats treated with FLASH-radiotherapy (43%), as compared with 0 of 9 cats treated with SoC. All cats were tumor-free at 1 year in both arms, with one cat progressing later in each arm. In pigs, no acute toxicity was recorded, but severe late skin necrosis occurred in a volume-dependent manner (7-9 months), which later resolved. CONCLUSIONS The reported outcomes point to the caveats of translating single-high-dose FLASH-radiotherapy and emphasizes the need for caution and further investigations. See related commentary by Maity and Koumenis, p. 3636.
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Affiliation(s)
- Carla Rohrer Bley
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Friederike Wolf
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Patrik Gonçalves Jorge
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Veljko Grilj
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ioannis Petridis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Benoit Petit
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Till T Böhlen
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Raphael Moeckli
- Institute of Radiation Physics, Department of Radiology, University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles Limoli
- Department of Radiation Oncology, School of Medicine, University of California at Irvine, Irvine, California
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Valeria Meier
- Division of Radiation Oncology, Vetsuisse Faculty, University of Zurich, Zurich, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Lausanne, Switzerland
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Maity A, Koumenis C. Shining a FLASHlight on Ultrahigh Dose-Rate Radiation and Possible Late Toxicity. Clin Cancer Res 2022; 28:3636-3638. [PMID: 35736814 PMCID: PMC9444945 DOI: 10.1158/1078-0432.ccr-22-1255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/25/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022]
Abstract
A recent study reported results from a clinical trial in cats and from experiments in mini-pigs in which a single dose of radiotherapy was delivered at ultrahigh dose rates (FLASH). There was acceptable acute toxicity; however, some animals suffered severe late toxicity, raising caution in the design of future trials. See related article by Rohrer Bley et al., p. 3814.
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Affiliation(s)
- Amit Maity
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104,Department of Radiation Oncology, Spencer Fox Eccles School of Medicine at the University of Utah, Salt Lake City, UT,Huntsman Cancer Institute at the University of Utah, Salt Lake City, UT,Correspondence: Amit Maity, MD, PhD, Department of Radiation Oncology, 1950 City of Hope Drive, Rm 1570, Salt Lake City, UT 84112, Phone: 801-581-2396, Fax: 801-585-2666,
| | - Constantinos Koumenis
- Department of Radiation Oncology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104
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254
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Validation of Monte Carlo-based calculations for megavolt electron beams for IORT and FLASH-IORT. Heliyon 2022; 8:e10682. [PMID: 36185136 PMCID: PMC9519483 DOI: 10.1016/j.heliyon.2022.e10682] [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: 03/23/2022] [Revised: 05/18/2022] [Accepted: 09/13/2022] [Indexed: 11/20/2022] Open
Abstract
In Intra-Operative Radiation Therapy (IORT) the tumour site is surgically exposed and normal tissue located around the tumour may be avoided. Electron applicators would require large surgical incisions; therefore, the preferred mechanism for beam collimation is the IORT cone system. FLASH radiotherapy (FLASH-RT) involves the treatment of tumours at ultra-high dose rates and the IORT cone system can also be used. This study validates the Monte Carlo-based calculations for these small electron beams to accurately determine the dose characteristics of each possible cone-energy combination as well as custom-built alloy cutouts attached to the end of the IORT cone. This will contribute to accurate dose distribution and output factor calculations that are essential to all radiation therapy treatments. A Monte Carlo (MC) model was modelled for electron beams produced by a Siemens Primus LINAC and the IORT cones. The accelerator was built with the component modules available in the BEAMnrc code. The phase-space file generated by the BEAM simulation was used as the source input for the subsequent DOSXYZnrc simulations. Percentage Depth Dose (PDD) data and profiles were extracted from the dose distributions obtained with the DOSXYZnrc simulations. These beam characteristics were compared with measured data for 6, 12, and 18 MeV electron beams for the IORT open cones of diameters 19, 45, and 64 mm and irregularly shaped cutouts. The MC simulations could replicate electron beams within a criterion of 3%/3 mm. Applicator factors were within 0.7%, and cone factors showed good agreement, except for the 9 mm cone size. Based on the successful comparisons between measurement and MC-calculated dose distributions, output factors for the open cones and for small irregularly shaped IORT beams, it may be concluded that the Monte Carlo based dose calculation could replicate electron beams used for IORT and FLASH-IORT.
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Al-Zeer MA, Prehn F, Fiedler S, Lienert U, Krisch M, Berg J, Kurreck J, Hildebrandt G, Schültke E. Evaluating the Suitability of 3D Bioprinted Samples for Experimental Radiotherapy: A Pilot Study. Int J Mol Sci 2022; 23:ijms23179951. [PMID: 36077349 PMCID: PMC9456381 DOI: 10.3390/ijms23179951] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 08/29/2022] [Accepted: 08/29/2022] [Indexed: 12/22/2022] Open
Abstract
Radiotherapy is an important component in the treatment of lung cancer, one of the most common cancers worldwide, frequently resulting in death within only a few years of diagnosis. In order to evaluate new therapeutic approaches and compare their efficiency with regard to tumour control at a pre-clinical stage, it is important to develop standardized samples which can serve as inter-institutional outcome controls, independent of differences in local technical parameters or specific techniques. Recent developments in 3D bioprinting techniques could provide a sophisticated solution to this challenge. We have conducted a pilot project to evaluate the suitability of standardized samples generated from 3D printed human lung cancer cells in radiotherapy studies. The samples were irradiated at high dose rates using both broad beam and microbeam techniques. We found the 3D printed constructs to be sufficiently mechanically stable for use in microbeam studies with peak doses up to 400 Gy to test for cytotoxicity, DNA damage, and cancer cell death in vitro. The results of this study show how 3D structures generated from human lung cancer cells in an additive printing process can be used to study the effects of radiotherapy in a standardized manner.
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Affiliation(s)
- Munir A. Al-Zeer
- Department of Applied Biochemistry, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
- Correspondence: or (M.A.A.-Z.); (E.S.)
| | - Franziska Prehn
- Department of Radiooncology, Rostock University Medical Center, 18059 Rostock, Germany
| | - Stefan Fiedler
- European Molecular Biology Laboratory (EMBL), Hamburg Outstation/DESY, 22607 Hamburg, Germany
| | | | - Michael Krisch
- European Synchrotron Radiation Facility (ESRF), 38043 Grenoble, France
| | - Johanna Berg
- Department of Applied Biochemistry, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Jens Kurreck
- Department of Applied Biochemistry, Institute of Biotechnology, Technische Universität Berlin, 13355 Berlin, Germany
| | - Guido Hildebrandt
- Department of Radiooncology, Rostock University Medical Center, 18059 Rostock, Germany
| | - Elisabeth Schültke
- Department of Radiooncology, Rostock University Medical Center, 18059 Rostock, Germany
- Correspondence: or (M.A.A.-Z.); (E.S.)
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256
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Lai Y, Chi Y, Jia X. Mechanistic modelling of oxygen enhancement ratio of radiation via Monte Carlo simulation-based DNA damage calculation. Phys Med Biol 2022; 67:10.1088/1361-6560/ac8853. [PMID: 35944522 PMCID: PMC10152552 DOI: 10.1088/1361-6560/ac8853] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2022] [Accepted: 08/09/2022] [Indexed: 11/12/2022]
Abstract
Objective.Oxygen plays an important role in affecting the cellular radio-sensitivity to ionizing radiation. The objective of this study is to build a mechanistic model to compute oxygen enhancement ratio (OER) using a GPU-based Monte Carlo (MC) simulation package gMicroMC for microscopic radiation transport simulation and DNA damage calculation.Approach.We first simulated the water radiolysis process in the presence of DNA and oxygen for 1 ns and recorded the produced DNA damages. In this process, chemical reactions among oxygen, water radiolysis free radicals and DNA molecules were considered. We then applied a probabilistic approach to model the reactions between oxygen and indirect DNA damages for a maximal reaction time oft0. Finally, we defined two parametersP0andP1, representing probabilities for DNA damages without and with oxygen fixation effect not being restored in the repair process, to compute the final DNA double strand breaks (DSBs). As cell survival fraction is mainly determined by the number of DSBs, we assumed that the same numbers of DSBs resulted in the same cell survival rates, which enabled us to compute the OER as the ratio of doses producing the same number of DSBs without and with oxygen. We determined the three parameters (t0,P0andP1) by fitting the OERs obtained in our computation to a set of published experimental data under x-ray irradiation. We then validated the model by performing OER studies under proton irradiation and studied model sensitivity to parameter values.Main results.We obtained the model parameters ast0= 3.8 ms,P0= 0.08, andP1= 0.28 with a mean difference of 3.8% between the OERs computed by our model and that obtained from experimental measurements under x-ray irradiation. Applying the established model to proton irradiation, we obtained OERs as functions of oxygen concentration, LET, and dose values, which generally agreed with published experimental data. The parameter sensitivity analysis revealed that the absolute magnitude of the OER curve relied on the values ofP0andP1, while the curve was subject to a horizontal shift when adjustingt0.Significance.This study developed a mechanistic model that fully relies on microscopic MC simulations to compute OER.
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Affiliation(s)
- Youfang Lai
- Innovative Technology of Radiotherapy Computations and Hardware (iTORCH) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75287, United States of America
- Department of Physics, University of Texas at Arlington, Arlington, TX 76019, United States of America
| | - Yujie Chi
- Department of Physics, University of Texas at Arlington, Arlington, TX 76019, United States of America
| | - Xun Jia
- Innovative Technology of Radiotherapy Computations and Hardware (iTORCH) Laboratory, Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, TX 75287, United States of America
- Now at Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, MD, United States of America
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257
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Di Martino F, Del Sarto D, Giuseppina Bisogni M, Capaccioli S, Galante F, Gasperini A, Linsalata S, Mariani G, Pacitti M, Paiar F, Ursino S, Vanreusel V, Verellen D, Felici G. A new solution for UHDP and UHDR (Flash) measurements: Theory and conceptual design of ALLS chamber. Phys Med 2022; 102:9-18. [PMID: 36030665 DOI: 10.1016/j.ejmp.2022.08.010] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 07/27/2022] [Accepted: 08/10/2022] [Indexed: 10/15/2022] Open
Abstract
Ultra-High dose-per-pulse regimens (UHDP), necessary to trigger the "FLASH" effect, still pose serious challenges to dosimetry. Dosimetry plays a crucial role, both to significantly improve the accuracy of the radiobiological experiments necessary to fully understand the mechanisms underlying the effect and its dependencies on the beam parameters, and to be able to translate such effect into clinical practice. The standard ionization chamber in UHDP region is significantly affected by the effects of the electric field generated by the enormous density of charges produced by the dose pulse. This work describes the theory and the conceptual design of a gas chamber (the ALLS chamber) which overcomes the above-mentioned problems.
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Affiliation(s)
- Fabio Di Martino
- Fisica Sanitaria, Azienda Ospedaliero Universitaria Pisa AOUP, ed.18 via Roma 67, Pisa, Italy; Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Presidio S. Chiara, ed. 18 via Roma 67, Pisa, Italy; INFN, Sezione di Pisa, Largo B. Pontecorvo 3, I-57127 Pisa, Italy.
| | - Damiano Del Sarto
- Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Presidio S. Chiara, ed. 18 via Roma 67, Pisa, Italy
| | - Maria Giuseppina Bisogni
- Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Presidio S. Chiara, ed. 18 via Roma 67, Pisa, Italy; Department of Physics, University of Pisa, Largo B. Pontecorvo 3, I-57127 Pisa, Italy; INFN, Sezione di Pisa, Largo B. Pontecorvo 3, I-57127 Pisa, Italy
| | - Simone Capaccioli
- Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Presidio S. Chiara, ed. 18 via Roma 67, Pisa, Italy; Department of Physics, University of Pisa, Largo B. Pontecorvo 3, I-57127 Pisa, Italy
| | | | - Alessia Gasperini
- Iridium Kankernetwerk, 2610 Antwerp, Belgium; Antwerp University, Faculty of Medicine and Health Sciences, 2610 Antwerp, Belgium
| | - Stefania Linsalata
- Fisica Sanitaria, Azienda Ospedaliero Universitaria Pisa AOUP, ed.18 via Roma 67, Pisa, Italy
| | | | | | - Fabiola Paiar
- Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Presidio S. Chiara, ed. 18 via Roma 67, Pisa, Italy; INFN, Sezione di Pisa, Largo B. Pontecorvo 3, I-57127 Pisa, Italy; Radiation Oncology Unit, Department of Translational Research, University of Pisa, Pisa, Italy
| | - Stefano Ursino
- Centro Pisano ricerca e implementazione clinica Flash Radiotherapy (CPFR@CISUP), Presidio S. Chiara, ed. 18 via Roma 67, Pisa, Italy; INFN, Sezione di Pisa, Largo B. Pontecorvo 3, I-57127 Pisa, Italy; Radiation Oncology Unit, Department of Translational Research, University of Pisa, Pisa, Italy
| | - Verdi Vanreusel
- Iridium Kankernetwerk, 2610 Antwerp, Belgium; Antwerp University, Faculty of Medicine and Health Sciences, 2610 Antwerp, Belgium
| | - Dirk Verellen
- Iridium Kankernetwerk, 2610 Antwerp, Belgium; Antwerp University, Faculty of Medicine and Health Sciences, 2610 Antwerp, Belgium
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258
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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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259
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Cimmino A, Ambrožová I, Motta S, Versaci R, Olšovcová V, Chvátil D, Olšanský V, Truneček R, Velyhan A, Stránský V, Šolc J. COMPARISON OF OSL AND TL DOSEMETERS WITH DATA COLLECTED AT THE MT25 CYCLIC ELECTRON ACCELERATOR. RADIATION PROTECTION DOSIMETRY 2022; 198:670-674. [PMID: 36005969 DOI: 10.1093/rpd/ncac117] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2022] [Accepted: 05/18/2022] [Indexed: 06/15/2023]
Abstract
The Microtron MT25 is a cyclic electron accelerator with a Kapitza resonator, maximum beam energy of 25 MeV, standard repetition frequency of 423 Hz, pulse length of 3.5 μs and mean current of 30 μA. Studies at conventional particle accelerators allow to understand the response of dosemeters in known and controllable radiation fields. Subsequently, it is possible to develop models and predict their behavior in complex radiation fields, such as those generated at laser and FLASH facilities. Therefore, response of thermally and optically stimulated luminescence detectors outside of the beam was studied at the Microtron MT25. The detectors were placed on a Plexiglas phantom inside a lead and iron bunker to shield-off background radiation. In addition, GAFChromic™ films and track detectors were used. Two irradiations were performed: with and without an 8-cm thick polyethylene moderator. This paper presents a comparison of the responses of the different detection systems.
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Affiliation(s)
- Anna Cimmino
- Safety Group, ELI Beamlines Centre, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 25241, Czech Republic
| | - Iva Ambrožová
- Department of Radiation Dosimetry, Nuclear Physics Institute, Czech Academy of Sciences, Na Truhlářce 39/64, Prague 8 18000, Czech Republic
| | - Silvia Motta
- Safety Group, ELI Beamlines Centre, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 25241, Czech Republic
- Dosimetry Group, Paul Scherrer Institut, Forschungsstrasse 111, Villigen PSI 5232, Switzerland
| | - Roberto Versaci
- Safety Group, ELI Beamlines Centre, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 25241, Czech Republic
| | - Veronika Olšovcová
- Safety Group, ELI Beamlines Centre, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 25241, Czech Republic
| | - David Chvátil
- Department of Accelerators, Nuclear Physics Institute, Czech Academy of Sciences, Husinec-Řež 130, Řež 25068, Czech Republic
| | - Václav Olšanský
- Department of Accelerators, Nuclear Physics Institute, Czech Academy of Sciences, Husinec-Řež 130, Řež 25068, Czech Republic
| | - Roman Truneček
- Safety Group, ELI Beamlines Centre, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 25241, Czech Republic
| | - Andriy Velyhan
- Safety Group, ELI Beamlines Centre, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 25241, Czech Republic
| | - Vojtěch Stránský
- Safety Group, ELI Beamlines Centre, Institute of Physics, Czech Academy of Sciences, Za Radnicí 835, Dolní Břežany 25241, Czech Republic
| | - Jaroslav Šolc
- Unit of Primary Metrology of Ionizing Radiation, Czech Metrology Institute, Photon Dosimetry Laboratory, Radiová 1a, Praha 10 102 00, Czech Republic
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260
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Habraken S, Breedveld S, Groen J, Nuyttens J, Hoogeman M. Trade-off in healthy tissue sparing of FLASH and fractionation in stereotactic proton therapy of lung lesions with transmission beams. Radiother Oncol 2022; 175:231-237. [PMID: 35988773 DOI: 10.1016/j.radonc.2022.08.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Revised: 08/12/2022] [Accepted: 08/14/2022] [Indexed: 10/15/2022]
Abstract
PURPOSE AND OBJECTIVE Besides a dose-rate threshold of 40-100 Gy/s, the FLASH effect may require a dose >3.5-7 Gy. Even in hypofractioned treatments, with all beams delivered in each fraction (ABEF), most healthy tissue is irradiated to a lower fraction dose. This can be circumvented by single-beam-per-fraction (SBPF) delivery, with a loss of healthy tissue sparing by fractionation. We investigated the trade-off between FLASH and loss of fractionation in SBPF stereotactic proton therapy of lung cancer and determined break-even FLASH-enhancement ratios (FERs). MATERIALS AND METHODS Treatment plans for 12 patients were generated. GTV delineations were available and a 5 mm GTV-PTV margin was applied. Equiangular arrangements of 3, 5, 7, and 9 244 MeV proton transmission beams were used. To facilitate SBPF, the number of fractions was equal to the number of beams. Iso-effective fractionation schedules with a single field uniform dose prescription were used: D95%,PTV = 100%Dpres per beam. All plans were evaluated in terms of dose to lung and conformity of dose to target of FLASH-enhanced biologically equivalent dose (EQD2). RESULTS Compared to ABEF, SBPF resulted in a median increase of EQD2mean to healthy lung of 56%, 58%, 55% and 54% in plans with 3, 5, 7 and 9 fractions respectively and of 90%, 108%, 106% and 102% in V100% EQD2, quantifying conformity. This can be compensated for by FERs of at least 1.28, 1.32, 1.30 and 1.23 respectively for EQD2mean and 1.29, 1.18, 1.28 and 1.15 for V100%,EQD2. CONCLUSION A FLASH effect outweighing the loss of fractionation in SBPF may be achieved in stereotactic lung treatments. The trade-off with fractionation depends on the conditions under which the FLASH effect occurs. Better understanding of the underlying biology and the impact of delivery conditions is needed.
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Affiliation(s)
- Steven Habraken
- Erasmus University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands; Holland Proton Therapy Center, Department of Medical Physics & Informatics, Delft, The Netherlands.
| | - Sebastiaan Breedveld
- Erasmus University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands
| | - Jort Groen
- Erasmus University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands
| | - Joost Nuyttens
- Erasmus University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands; Holland Proton Therapy Center, Department Radiation Oncology, Delft, The Netherlands
| | - Mischa Hoogeman
- Erasmus University Medical Center, Department of Radiotherapy, Rotterdam, The Netherlands; Holland Proton Therapy Center, Department of Medical Physics & Informatics, Delft, The Netherlands
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261
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Wei S, Lin H, Huang S, Shi C, Xiong W, Zhai H, Hu L, Yu G, Press RH, Hasan S, Chhabra AM, Choi JI, Simone CB, Kang M. Dose rate and dose robustness for proton transmission FLASH-RT treatment in lung cancer. Front Oncol 2022; 12:970602. [PMID: 36059710 PMCID: PMC9435957 DOI: 10.3389/fonc.2022.970602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 07/27/2022] [Indexed: 11/13/2022] Open
Abstract
Purposes To evaluate the plan quality and robustness of both dose and dose rate of proton pencil beam scanning (PBS) transmission FLASH delivery in lung cancer treatment. Methods and materials An in-house FLASH planning platform was used to optimize 10 lung cancer patients previously consecutively treated with proton stereotactic body radiation therapy (SBRT) to receive 3 and 5 transmission beams (Trx-3fds and Trx-5fds, respectively) to 34 Gy in a single fraction. Perturbation scenarios (n=12) for setup and range uncertainties (5 mm and 3.5%) were introduced, and dose-volume histogram and dose-rate-volume histogram bands were generated. Conventional proton SBRT clinical plans were used as a reference. RTOG 0915 dose metrics and 40 Gy/s dose rate coverage (V40Gy/s) were used to assess the dose and dose rate robustness. Results Trx-5fds yields a comparable iCTV D2% of 105.3%, whereas Trx-3fds resulted in inferior D2% of 111.9% to the clinical SBRT plans with D2% of 105.6% (p<0.05). Both Trx-5fds and Trx-3fds plans had slightly worse dose metrics to organs at risk than SBRT plans. Trx-5fds achieved superior dosimetry robustness for iCTV, esophagus, and spinal cord doses than both Trx-3fds and conventional SBRT plans. There was no significant difference in dose rate robustness for V40Gy/s coverage between Trx-3fds and Trx-5fds. Dose rate distribution has similar distributions to the dose when perturbation exists. Conclusion Transmission plans yield overall modestly inferior plan quality compared to the conventional proton SBRT plans but provide improved robustness and the potential for a toxicity-sparing FLASH effect. By using more beams (5- versus 3-field), both dose and dose rate robustness for transmission plans can be achieved.
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Affiliation(s)
- Shouyi Wei
- New York Proton Center, New York, NY, United States
| | - Haibo Lin
- New York Proton Center, New York, NY, United States
| | - Sheng Huang
- New York Proton Center, New York, NY, United States
| | - Chengyu Shi
- City of Hope, Orange County, Irvine, CA, United States
| | - Weijun Xiong
- New York Proton Center, New York, NY, United States
| | - Huifang Zhai
- New York Proton Center, New York, NY, United States
| | - Lei Hu
- New York Proton Center, New York, NY, United States
| | - Gang Yu
- New York Proton Center, New York, NY, United States
| | | | | | | | | | | | - Minglei Kang
- New York Proton Center, New York, NY, United States
- *Correspondence: Minglei Kang,
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262
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Xie DH, Li YC, Ma S, Yang X, Lan RM, Chen AQ, Zhu HY, Mei Y, Peng LX, Li ZF, Huang BJ, Chen Y, Huang XY, Qian CN. Electron Ultra-High Dose Rate FLASH irradiation Study Using a Clinical Linac: Linac Modification, Dosimetry and Radiobiological outcome. Med Phys 2022; 49:6728-6738. [PMID: 35959736 DOI: 10.1002/mp.15920] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2021] [Revised: 05/24/2022] [Accepted: 08/02/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Ultra-high dose rate FLASH irradiation (FLASH-IR) has been shown to cause less normal tissue damage compared with conventional irradiation (CONV-IR), this is known as the "FLASH effect". It has attracted immense research interest because its underlying mechanism is scarcely known. The purpose of this study was to determine whether FLASH-IR and CONV-IR induce differential inflammatory cytokine expression using a modified clinical linac. MATERIALS AND METHODS An Elekta Synergy linac was used to deliver 6 MeV CONV-IR and modified to deliver FLASH-IR. Female FvB mice were randomly assigned to three different groups: a non-irradiated control, CONV-IR, or FLASH-IR. The FLASH-IR beam was produced by single pulses repeated manually with a 20-second interval (Strategy 1), or single-trigger multiple pulses with a 10 millisecond (ms) interval (Strategy 2). Mice were immobilized in the prone position in a custom-designed applicator with Gafchromic films positioned under the body. The prescribed doses for the mice were 6 to 18 Gy and verified using Gafchromic films. Cytokine expression of three pro-inflammatory cytokines [tumor necrosis factor-α (TNF-α), interferon-γ (IFN-γ), interleukin-6 (IL-6)] and one anti-inflammatory cytokine (IL-10) in serum samples and skin tissue were examined within 1- month post-IR. RESULTS The modified linac delivered radiation at an intra-pulse dose rate of around 1×106 Gy/s and a dose per pulse over 2 Gy at a source-to-surface distance (SSD) of 13 to 15 cms. The achieved dose coverage was 90 - 105% of the maximum dose within -20 ∼ 20 mm in the X direction and 95% within -30 ∼ 30 mm in the Y direction. The absolute deviations between the prescribed dose and the actual dose were 2.21, 6.04, 2.09 and 2.73% for 6, 9, 12 and 15 Gy as measured by EBT3 films, respectively; and 4.00, 4.49 and 2.30% for 10, 14 and 18 Gy as measured by the EBT XD films, respectively. The reductions in the CONV-IR versus the FLASH-IR group were 4.89, 10.28, -7.8 and -22.17 % for TNF-α, IFN-γ, IL-6 and IL-10 in the serum on D6, respectively; 37.26, 67.16, 56.68 and -18.95% in the serum on D31, respectively; and 62.67, 35.65, 37.75 and -12.20% for TNF-α, IFN-γ, IL-6 and IL-10 in the skin tissue, respectively. CONCLUSIONS Ultra-high dose rate electron FLASH caused lower pro-inflammatory cytokine levels in serum and skin tissue which might mediate differential tissue damage between FLASH-IR and CONV-IR. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- De-Huan Xie
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | | | - Sai Ma
- Elekta Instrument Ltd. Beijing Branch
| | - Xin Yang
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Ruo-Ming Lan
- School of Physics and Electronics, Shandong Normal University
| | - Ao-Qiang Chen
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Hong-Yu Zhu
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Yan Mei
- Department of Pathology, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences
| | - Li-Xia Peng
- Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | | | - Bi-Jun Huang
- Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Yan Chen
- Elekta Instrument Ltd. Beijing Branch
| | - Xiao-Yan Huang
- Department of Radiation Oncology, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine
| | - Chao-Nan Qian
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in Southern China, Collaborative Innovation Center for Cancer Medicine.,Guangzhou Concord Cancer Center
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263
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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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265
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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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266
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Wei S, Lin H, Shi C, Xiong W, Chen CC, Huang S, Press RH, Hasan S, Chhabra AM, Choi JI, Simone CB, Kang M. Use of single-energy proton pencil beam scanning Bragg peak for intensity-modulated proton therapy FLASH treatment planning in liver hypofractionated radiation therapy. Med Phys 2022; 49:6560-6574. [PMID: 35929404 DOI: 10.1002/mp.15894] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 06/09/2022] [Accepted: 07/20/2022] [Indexed: 11/11/2022] Open
Abstract
PURPOSE The transmission proton FLASH technique delivers high doses to the normal tissue distal to the target, which is less conformal compared to the Bragg peak technique. To investigate FLASH RT planning using single-energy Bragg peak beams with a similar beam arrangement as clinical intensity-modulated proton therapy (IMPT) in liver stereotactic body radiation therapy (SBRT) and to characterize the plan quality, dose sparing of organs-at-risk (OARs), and FLASH dose rate percentage. MATERIALS AND METHODS An in-house platform was developed to enable inverse IMPT-FLASH planning using single-energy Bragg peaks. A universal range shifter and range compensators were utilized to effectively align the Bragg peak to the distal edge of the target. Two different minimum MU settings of 400 and 800 MU/spot (Bragg-400MU and Bragg-800MU) plans were investigated on 10 consecutive hepatocellular carcinoma patients previously treated by IMPT-SBRT to evaluate the FLASH dose and dose rate coverage for OARs. The IMPT-FLASH using single-energy Bragg peaks delivered 50 Gy in 5 fractions with similar or identical beam arrangement to the clinical IMPT-SBRT plans. NRG GI003 dose constraint metrics were used. Three dose rate calculation methods, including average dose rate (ADR), dose threshold dose rate (DTDR), and dose-averaged dose rate (DADR), were all studied. RESULTS The novel spot map optimization can fulfill the inverse planning using single-energy Bragg peaks. All the Bragg peak FLASH plans achieved similar results for the liver-GTV Dmean and heart D0.5cc , compared to SBRT-IMPT. The Bragg-800MU plans resulted in 18.3% higher CTV D2cc compared with SBRT (p < 0.05), and no significant difference was found between Bragg-400MU and SBRT plans. For the CTV Dmax , SBRT plans resulted in 10.3% (p<0.01) less than Bragg-400MU plans and 16.6% (p<0.01) less than Bragg-800MU plans. The Bragg-800MU plans generally achieved higher ADR, DADR, and DTDR dose rates than Bragg-400MU plans, and DADR mostly led to the highest V40Gy/s compared to other dose rate calculation methods, whereas ADR led to the lowest. The lower dose rate portions in certain OARs are related to the lower dose deposited due to the farther distances from targets, especially in the penumbra of the beams. CONCLUSION Single-energy Bragg peak IMPT-FLASH plans eliminate the exit dose in normal tissues, maintaining comparable dose metrics to the conventional IMPT-SBRT plans while achieving a sufficient FLASH dose rate for liver cancers. This study demonstrates the feasibility of and sufficiently high dose rate when applying Bragg peak FLASH treatment for liver cancer hypofractionated FLASH therapy. The advancement of this novel method has the potential to optimize treatment for liver cancer patients. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Shouyi Wei
- New York Proton Center, New York, NY, USA
| | - Haibo Lin
- New York Proton Center, New York, NY, USA
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Intra-Operative Electron Radiation Therapy: An Update of the Evidence Collected in 40 Years to Search for Models for Electron-FLASH Studies. Cancers (Basel) 2022; 14:cancers14153693. [PMID: 35954357 PMCID: PMC9367249 DOI: 10.3390/cancers14153693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 07/13/2022] [Accepted: 07/22/2022] [Indexed: 12/10/2022] Open
Abstract
Simple Summary Four decades ago, intraoperative electron radiation therapy (IOeRT) was developed to improve precision in local cancer treatment by combining real-time surgical exploration and resection with high-energy electron irradiation. The technology of ultra-high dose rate electron and other radiation beams known as FLASH irradiation sharply increases its interests, as data from preclinical experiments have proven a marked favorable effect on the therapeutic index: similar cancer control with a clearly improved tolerance of many normal tissues to high doses of irradiation. The knowledge and tools regarding technology, physics, biology, and preclinical results in heterogeneous cancers opens great opportunities towards the path of developing the first clinical applications of the emerging FLASH technology via clinical trials based on state-of-the-art medical practice with IOeRT. Abstract Introduction: The clinical practice and outcome results of intraoperative electron radiation therapy (IOeRT) in cancer patients have been extensively reported over 4 decades. Electron beams can be delivered in the promising FLASH dose rate. Methods and Materials: Several cancer models were approached by two alternative radiobiological strategies to optimize local cancer control: boost versus exclusive IOeRT. Clinical outcomes are revisited via a bibliometric search performed for the elaboration of ESTRO/ACROP IORT guidelines. Results: In the period 1982 to 2020, a total of 19,148 patients were registered in 116 publications concerning soft tissue sarcomas (9% of patients), unresected and borderline-resected pancreatic cancer (22%), locally recurrent and locally advanced rectal cancer (22%), and breast cancer (45%). Clinical outcomes following IOeRT doses in the range of 10 to 25 Gy (with or without external beam fractionated radiation therapy) show a wide range of local control from 40 to 100% depending upon cancer site, histology, stage, and treatment intensity. Constraints for normal tissue tolerance are important to maintain tumor control combined with acceptable levels of side effects. Conclusions: IOeRT represents an evidence-based approach for several tumor types. A specific risk analysis for local recurrences supports the identification of cancer models that are candidates for FLASH studies.
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268
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Wang Q, Titt U, Mohan R, Guan F, Zhao Y, Yang M, Yepes P. Optimization of FLASH Proton Beams Using a Track-Repeating Algorithm. Med Phys 2022; 49:6684-6698. [PMID: 35900902 DOI: 10.1002/mp.15849] [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: 02/11/2022] [Revised: 05/16/2022] [Accepted: 06/23/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Radiation with high dose rate (FLASH) has shown to reduce toxicities to normal tissues around the target and maintain tumor control with the same amount of dose compared to conventional radiation. This phenomenon has been widely studied in electron therapy, which is often used for shallow tumor treatment. Proton therapy is considered as a more suitable treatment modality for deep-seated tumors. The feasibility of FLASH proton therapy has recently been demonstrated by a series of pre- and clinical trials. One of the challenges is to efficiently generate wide enough dose distributions in both lateral and longitudinal directions to cover the entire tumor volume. The goal of this paper is to introduce a set of automatic FLASH proton beam optimization algorithms developed recently. PURPOSE To develop a fast and efficient optimizer for the design of a passive scattering proton FLASH radiotherapy delivery at The University of Texas M. D. Anderson Proton Therapy Center, based on the Fast Dose Calculator (FDC). METHODS A track repeating algorithm, FDC, was validated vs. Geant4 simulations and applied to calculate dose distributions in various beamline setups. The design of the components was optimized to deliver homogeneous fields with well-defined diameters between 11.0 mm and 20.5 mm, as well as a spread-out Bragg peak (SOBP) with modulations between 8.5 and 39.0 mm. A ridge filter, a high-Z material scatterer, and a collimator with range compensator were inserted in the beam path, and their shapes and sizes were optimized to spread out the Bragg peak, widen the beam, and reduce the penumbra. The optimizer was developed and tested using two proton energies (87.0 MeV and 159.5 MeV) in a variety of beam line arrangements. Dose rates of the optimized beams were estimated by scaling their doses to those of unmodified beams. RESULTS The optimized 87.0 MeV beams, with a distance from the beam pipe window to the phantom surface (window-to-surface distance) of 550 mm, produced an 8.5-mm-wide spread-out Bragg peak (proximal 90% to distal 90% of the maximum dose); 14.5 mm, 12.0 mm, and 11.0 mm lateral widths at the 50%, 80%, and 90% dose location, respectively; and a 2.5 mm penumbra from 80% to 20% in the lateral profile. The 159.5 MeV beam had a SOBP of 39.0 mm and lateral widths of 20.5 mm, 15.0 mm, and 12.5 mm at 50%, 80%, and 90% dose location, respectively, when the window-to-surface distance (WSD) was 550 mm. Wider lateral widths were obtained with increased WSD. The SOBP modulations changed when the ridge filters with different characteristics were inserted. Dose rates on the beam central axis for all optimized beams (other than the 87.0 MeV beam with 2000 mm-WSD) were above that needed for the FLASH effect threshold (40 Gy/s) except at the very end of the depth dose profile scaling with a dose rate of 1400 Gy/s at the Bragg peak in the unmodified beams. The optimizer was able to instantly design the individual beamline components for each of the beam line setups, without the need of time intensive iterative simulations. CONCLUSION An efficient system, consisting of an optimizer and a Fast Dose Calculator have been developed and validated in a variety of beam line setups, comprising two proton energies, several WSDs and SOBPs. The set of automatic optimization algorithms produces beam shaping element designs efficiently and with excellent quality. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Qianxia Wang
- Department of Physics and Astronomy, MS 315, Rice University, 6100 Main St., Houston, TX, 77005, United States.,Department of Radiation Physics, Unit 1420, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030, United States
| | - Uwe Titt
- Department of Radiation Physics, Unit 1420, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030, United States
| | - Radhe Mohan
- Department of Radiation Physics, Unit 1420, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030, United States
| | - Fada Guan
- Department of Radiation Physics, Unit 1420, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030, United States.,Department of Therapeutic Radiology, Yale School of Medicine, 35 Park St., New Haven, CT, 06511, United States
| | - Yao Zhao
- Department of Radiation Physics, Unit 1420, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030, United States.,The University of Texas MD Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX, 77030, United States
| | - Ming Yang
- Department of Radiation Physics, Unit 1420, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030, United States
| | - Pablo Yepes
- Department of Physics and Astronomy, MS 315, Rice University, 6100 Main St., Houston, TX, 77005, United States.,Department of Radiation Physics, Unit 1420, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd., Houston, TX, 77030, United States
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269
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Liljedahl E, Konradsson E, Gustafsson E, Jonsson KF, Olofsson JK, Ceberg C, Redebrandt HN. Long-term anti-tumor effects following both conventional radiotherapy and FLASH in fully immunocompetent animals with glioblastoma. Sci Rep 2022; 12:12285. [PMID: 35853933 PMCID: PMC9296533 DOI: 10.1038/s41598-022-16612-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 07/12/2022] [Indexed: 12/13/2022] Open
Abstract
Radiotherapy can induce an immunological response. One limiting factor is side effects on normal tissue. Using FLASH radiotherapy, side effects could possibly be reduced. The efficacy of FLASH in relation to conventional radiotherapy (CONV-RT) has not been extensively explored in fully immunocompetent animals. Fully immunocompetent Fischer 344 rats were inoculated with NS1 glioblastoma cells subcutaneously or intracranially. Radiotherapy was delivered with FLASH or CONV-RT at 8 Gy × 2 (subcutaneous tumors) and 12.5 Gy × 2 (intracranial tumors). Cured animals were re-challenged in order to explore long-term anti-tumor immunity. Serum analytes and gene expression were explored. The majority of animals with subcutaneous tumors were cured when treated with FLASH or CONV-RT at 8 Gy × 2. Cured animals could reject tumor re-challenge. TIMP-1 in serum was reduced in animals treated with FLASH 8 Gy × 2 compared to control animals. Animals with intracranial tumors survived longer when treated with FLASH or CONV-RT at 12.5 Gy × 2, but cure was not reached. CONV-RT and FLASH were equally effective in fully immunocompetent animals with glioblastoma. Radiotherapy was highly efficient in the subcutaneous setting, leading to cure and long-term immunity in the majority of the animals.
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Affiliation(s)
- Emma Liljedahl
- The Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Elise Konradsson
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Emma Gustafsson
- The Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Karolina Förnvik Jonsson
- The Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Jill K Olofsson
- Department for Geosciences and Natural Resource Management, University of Copenhagen, Copenhagen, Denmark
| | - Crister Ceberg
- Medical Radiation Physics, Department of Clinical Sciences, Lund University, Lund, Sweden
| | - Henrietta Nittby Redebrandt
- The Rausing Laboratory, Division of Neurosurgery, Department of Clinical Sciences, Lund University, Lund, Sweden. .,Department of Neurosurgery, Skåne University Hospital, Rausing Laboratory, Lund University, BMC D10, 221 84, Lund, Sweden.
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270
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Böhlen TT, Germond JF, Bourhis J, Vozenin MC, Ozsahin EM, Bochud F, Bailat C, Moeckli R. Normal tissue sparing by FLASH as a function of single fraction dose: A quantitative analysis. Int J Radiat Oncol Biol Phys 2022; 114:1032-1044. [PMID: 35810988 DOI: 10.1016/j.ijrobp.2022.05.038] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/26/2022] [Accepted: 05/24/2022] [Indexed: 11/28/2022]
Abstract
PURPOSE The FLASH effect designates normal tissue sparing by ultra-high dose rate (UHDR) compared to conventional dose rate (CONV) irradiation without compromising tumor control. Understanding the magnitude of this effect and its dependency on dose are essential requirements for an optimized clinical translation of FLASH radiation therapy. In this context, we evaluated available experimental data on the magnitudes of normal tissue sparing provided by the FLASH effect as a function of dose, and followed a phenomenological data-driven approach for its parameterization. METHODS We gathered available in vivo data of the normal tissue sparing of CONV compared to UHDR single fraction doses and converted it to a common scale using isoeffect dose ratios, hereafter referred to as FLASH modifying factors (FMF). We then evaluated the suitability of a piecewise linear function with two pieces to parametrize FMF × D as a function of dose D. RESULTS We found that the magnitude of FMF generally decreases (i.e., sparing increases) as function of single fraction dose and that individual data series can be described by the piecewise linear function. The sparing magnitude appears organ specific. Pooled skin reaction data followed a consistent trend as a function of dose. Average FMF values and their standard deviations were 0.95±0.11 for all data below 10 Gy, 0.92±0.06 for mouse gut data between 10-25 Gy, and 0.96±0.07 and 0.71±0.06 for mammalian skin reaction data between 10-25 Gy and >25 Gy, respectively. CONCLUSIONS The magnitude of normal tissue sparing by FLASH is increasing with dose and is dependent on the irradiated tissue. A piecewise linear function can parameterize currently available individual data series.
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Affiliation(s)
- Till Tobias Böhlen
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean-François Germond
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Jean Bourhis
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Esat Mahmut Ozsahin
- Department of Radiation Oncology, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - François Bochud
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland..
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271
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Lee E, Lourenço AM, Speth J, Lee N, Subiel A, Romano F, Thomas R, Amos RA, Zhang Y, Xiao Z, Mascia A. Ultra-high dose rate pencil beam scanning proton dosimetry using ion chambers and a calorimeter in support of first in-human flash clinical trial. Med Phys 2022; 49:6171-6182. [PMID: 35780318 PMCID: PMC9546035 DOI: 10.1002/mp.15844] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 06/20/2022] [Accepted: 06/27/2022] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To provide ultra-high dose rate pencil beam scanning proton dosimetry comparison of clinically used plane-parallel ion chambers, PTW Advanced Markus and IBA PPC05, with a proton graphite calorimeter in support of first in-human proton FLASH clinical trial. METHODS Absolute dose measurement intercomparison of the plane-parallel plate ion chambers and the proton graphite calorimeter was performed at 5 cm water equivalent depth using rectangular 250 MeV single layer treatment plans designed for the first in-human FLASH clinical trial. The dose rate for each field was designed to remain above 60 Gy/s. The ion recombination effects of the plane-parallel plate ion chambers at various bias voltages were also investigated in the range of dose rates between 5 - 60 Gy/s. Two independent model-based extrapolation methods were used to calculate the ion recombination correction factors ks to compare with the two-voltage technique from most widely used clinical protocols. RESULTS The mean measured dose to water with the proton graphite calorimeter across all the pre-defined fields is 7.702 ± 0.037 Gy. The average ratio over the pre-defined fields of the PTW Advanced Markus chamber dose to the calorimeter reference dose is 1.002 ± 0.007 while the IBA PPC05 chamber shows ∼3% higher reading of 1.033 ± 0.007. The relative difference in the ks values determined from between the linear and quadratic extrapolation methods and the two-voltage technique for the PTW Advanced Markus chamber are not statistically significant and the trends of dose rate dependence are similar. The IBA PPC05 shows a flat response in terms of ion recombination effects based on the ks values calculated using the two-voltage technique. Differences in ks values for the PPC05 between the two-voltage technique and other model-based extrapolation methods are not statistically significant at FLASH dose rates. Some of the ks values for the PPC05 that were extrapolated from the three-voltage linear method and the semi-empirical model were reported less than unity possibly due to the charge multiplication effect, which was negligible compared to the volume recombination effect in FLASH dose rates. CONCLUSIONS The absolute dose measurements of both PTW Advanced Markus and IBA PPC05 chambers are in a good agreement with the NPL graphite calorimeter reference dose considering overall uncertainties. Both ion chambers also demonstrate good reproducibility as well as stability as refence dosimeters in ultra-high dose rate pencil beam scanning proton radiotherapy. The dose rate dependency of the ion recombination effects of both ion chambers in cyclotron generated PBS proton beams is acceptable and therefore, both chambers are suitable to use in clinical practice for the range of dose rates between 5 - 60 Gy/s. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Eunsin Lee
- Department of Radiation OncologyUniversity of CincinnatiCincinnatiOhioUSA
- Cincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Ana Mónica Lourenço
- National Physical LaboratoryMedical Science GroupTeddingtonUK
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonUK
| | - Joseph Speth
- University of Cincinnati Medical CenterCincinnatiOhioUSA
| | - Nigel Lee
- National Physical LaboratoryMedical Science GroupTeddingtonUK
| | - Anna Subiel
- National Physical LaboratoryMedical Science GroupTeddingtonUK
| | - Francesco Romano
- Istituto Nazionale di Fisica NucleareSezione di CataniaCataniaItaly
| | - Russell Thomas
- National Physical LaboratoryMedical Science GroupTeddingtonUK
- Faculty of Engineering and Physical ScienceUniversity of SurreyGuildfordSurreyUK
| | - Richard A. Amos
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonUK
| | - Yongbin Zhang
- Department of Radiation OncologyUniversity of CincinnatiCincinnatiOhioUSA
- Cincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Zhiyan Xiao
- Department of Radiation OncologyUniversity of CincinnatiCincinnatiOhioUSA
- Cincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
| | - Anthony Mascia
- Department of Radiation OncologyUniversity of CincinnatiCincinnatiOhioUSA
- Cincinnati Children's Hospital Medical CenterCincinnatiOhioUSA
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272
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Léost F, Delpon G, Garcion E, Gestin JF, Hatt M, Potiron V, Rbah-Vidal L, Supiot S. « Adaptation of the tumour and its ecosystem to radiotherapies: Mechanisms, imaging and therapeutic approaches » XIVe édition du workshop organisé par le réseau « Vectorisation, Imagerie, Radiothérapies » du Cancéropôle Grand-Ouest, 22–25 septembre 2021, Le Bono, France. Bull Cancer 2022; 109:1088-1093. [DOI: 10.1016/j.bulcan.2022.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 06/03/2022] [Accepted: 06/07/2022] [Indexed: 10/16/2022]
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273
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Schültke E, Lerch M, Kirschstein T, Lange F, Porath K, Fiedler S, Davis J, Paino J, Engels E, Barnes M, Klein M, Hall C, Häusermann D, Hildebrandt G. Modification of the Langendorff system of the isolated beating heart for experimental radiotherapy at a synchrotron: 4000 Gy in a heart beat. JOURNAL OF SYNCHROTRON RADIATION 2022; 29:1027-1032. [PMID: 35787570 PMCID: PMC9255585 DOI: 10.1107/s1600577522004489] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/12/2021] [Accepted: 04/28/2022] [Indexed: 05/27/2023]
Abstract
Microbeam radiotherapy could help to cure malignant tumours which are currently still considered therapy-resistant. With an irradiation target in the thoracic cavity, the heart would be one of the most important organs at risk. To assess the acute adverse effects of microbeam irradiation in the heart, a powerful ex vivo tool was created by combining the Langendorff model of the isolated beating mammalian heart with X-Tream dosimetry. In a first pilot experiment conducted at the Biomedical and Imaging Beamline of the Australian Synchrotron, the system was tested at a microbeam peak dose approximately ten times higher than the anticipated future microbeam irradiation treatment doses. The entire heart was irradiated with a dose of 4000 Gy at a dose rate of >6000 Gy s-1, using an array of 50 µm-wide microbeams spaced at a centre-to-centre distance of 400 µm. Although temporary arrhythmias were seen, they reverted spontaneously to a stable rhythm and no cardiac arrest occurred. This amazing preservation of cardiac function is promising for future therapeutic approaches.
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Affiliation(s)
- Elisabeth Schültke
- Department of Radiooncology, Rostock University Medical Center, Südring 75, 18059 Rostock, Germany
| | - Michael Lerch
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Timo Kirschstein
- Oscar Langendorff Institute of Physiology, University of Rostock Medical Center, Rostock, Germany
- Center for Transdisciplinary Neurosciences Rostock, Rostock, Germany
| | - Falko Lange
- Oscar Langendorff Institute of Physiology, University of Rostock Medical Center, Rostock, Germany
- Center for Transdisciplinary Neurosciences Rostock, Rostock, Germany
| | - Katrin Porath
- Oscar Langendorff Institute of Physiology, University of Rostock Medical Center, Rostock, Germany
| | - Stefan Fiedler
- European Molecular Biology Laboratory, Notkestrasse 85, 22607 Hamburg, Germany
| | - Jeremy Davis
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Jason Paino
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Elette Engels
- Centre for Medical Radiation Physics, University of Wollongong, Wollongong, Australia
| | - Micah Barnes
- Australian Synchrotron/ANSTO, Clayton, Australia
| | - Mitzi Klein
- Australian Synchrotron/ANSTO, Clayton, Australia
| | | | | | - Guido Hildebrandt
- Department of Radiooncology, Rostock University Medical Center, Südring 75, 18059 Rostock, Germany
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274
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Kang TM, Hardcastle N, Singh AK, Slotman BJ, Videtic GMM, Stephans KL, Couñago F, Louie AV, Guckenberger M, Harden SV, Plumridge NM, Siva S. Practical considerations of single-fraction stereotactic ablative radiotherapy to the lung. Lung Cancer 2022; 170:185-193. [PMID: 35843149 DOI: 10.1016/j.lungcan.2022.06.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 06/21/2022] [Accepted: 06/24/2022] [Indexed: 10/17/2022]
Abstract
Stereotactic ablative radiotherapy (SABR) is a well-established treatment for patients with medically inoperable early-stage non-small cell lung cancer (NSCLC) and pulmonary oligometastases. The use of single-fraction SABR in this setting is supported by excellent local control and safety profiles which appear equivalent to multi-fraction SABR based on the available data. The resource efficiency and reduction in hospital outpatient visits associated with single-fraction SABR have been particularly advantageous during the COVID-19 pandemic. Despite the increased interest, single-fraction SABR in subgroups of patients remains controversial, including those with centrally located tumours, synchronous targets, proximity to dose-limiting organs at risk, and concomitant severe respiratory illness. This review provides an overview of the published randomised evidence evaluating single-fraction SABR in primary lung cancer and pulmonary oligometastases, the common clinical challenges faced, immunogenic effect of SABR, as well as technical and cost-utility considerations.
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Affiliation(s)
- Therese Mj Kang
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Nicholas Hardcastle
- Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum, Department of Oncology, University of Melbourne, Australia; Centre for Medical Radiation Physics, University of Wollongong, New South Wales, Australia
| | - Anurag K Singh
- Department of Radiation Medicine, Roswell Park Comprehensive Cancer Center, Buffalo, New York, USA
| | - Ben J Slotman
- Department of Radiation Oncology, Amsterdam University Medical Center, Amsterdam, the Netherlands
| | - Gregory M M Videtic
- Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, Ohio, USA
| | - Kevin L Stephans
- Department of Radiation Oncology, Cleveland Clinic Taussig Cancer Institute, Cleveland, Ohio, USA
| | - Felipe Couñago
- Department of Radiation Oncology, Hospital Universitario Quirónsalud, Madrid, Spain
| | - Alexander V Louie
- Department of Radiation Oncology, Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada
| | - Matthias Guckenberger
- Department of Radiation Oncology, University Hospital Zurich, University of Zurich, Zurich, Switzerland
| | - Susan V Harden
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Nikki M Plumridge
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
| | - Shankar Siva
- Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia; Sir Peter MacCallum, Department of Oncology, University of Melbourne, Australia.
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275
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Kusumoto T, Inaniwa T, Mizushima K, Sato S, Hojo S, Kitamura H, Konishi T, Kodaira S. Radiation Chemical Yields of 7-Hydroxy-Coumarin-3-Carboxylic Acid for Proton- and Carbon-Ion Beams at Ultra-High Dose Rates: Potential Roles in FLASH Effects. Radiat Res 2022; 198:255-262. [PMID: 35738014 DOI: 10.1667/rade-21-00.230.1] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Accepted: 06/06/2022] [Indexed: 11/03/2022]
Abstract
It has been observed that healthy tissues are spared at ultra-high dose rate (UHDR: >40 Gy/s), so called FLASH effect. To elucidate the mechanism of FLASH effect, we evaluate changes in radiation chemical yield (G value) of 7-hydroxy-coumarin-3-carboxylic acid (7OH-C3CA), which is formed by the reaction of hydroxyl radicals with coumarin-3-carboxylic acid (C3CA), under carbon ions (140 MeV/u) and protons (27.5 and 55 MeV) in a wide-dose-rate range up to 100 Gy/s. The relative G value, which is the G value at each dose rate normalized by that at the conventional dose (CONV: 0.1 Gy/s >), 140 MeV/u carbon-ion beam is almost equivalent to 27.5 and 55 MeV proton beams. This finding implies that UHDR irradiations using carbon-ion beams have a potential to spare healthy tissues. Furthermore, we evaluate the G value of 7OH-C3CA under the de-oxygenated condition to investigate roles of oxygen to the generation of 7OH-C3CA effect. The G value of 7OH-C3CA under the de-oxygenated condition is lower than that under the oxygenated condition. The G value of 7OH-C3CA under the de-oxygenated condition is higher than those under UHDR irradiations. By direct measurements of the oxygen concentration during 55 MeV proton irradiations, the oxygen concentration drops by 0.1%/Gy, which is independent of the dose rate. When the oxygen concentration directly affects to yields of 7OH-C3CA, the rate of decrease in the oxygen concentration may be correlated with that of decrease in the G value of 7OH-C3CA. However, the reduction rate of G value under UHDR is significantly higher than the oxygen consumption. This finding implied that the influence of the reaction between water radiolysis species formed by neighborhood tracks could be strongly related to the mechanisms of UHDR effect.
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Affiliation(s)
- Tamon Kusumoto
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
| | - Taku Inaniwa
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
| | - Kota Mizushima
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
| | - Shinji Sato
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
| | - Satoru Hojo
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
| | - Hisashi Kitamura
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
| | - Teruaki Konishi
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
| | - Satoshi Kodaira
- National Institutes for Quantum and Radiological Science and Technology, 4-9-1 Anagawa, Inage-ku, 263-8555 Chiba, Japan
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276
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Technical aspects of proton minibeam radiation therapy: Minibeam generation and delivery. Phys Med 2022; 100:64-71. [PMID: 35750002 DOI: 10.1016/j.ejmp.2022.06.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 06/02/2022] [Accepted: 06/13/2022] [Indexed: 11/23/2022] Open
Abstract
Proton minibeam radiation therapy (pMBRT) is a novel therapeutic strategy that combines the normal tissue sparing of sub-millimetric, spatially fractionated beams with the improved ballistics of protons. This may allow a safe dose escalation in the tumour and has already proven to provide a remarkable increase of the therapeutic index for high-grade gliomas in animal experiments. One of the main challenges in pMBRT concerns the generation of minibeams and the implementation in a clinical environment. This article reviews the different approaches for generating minibeams, using mechanical collimators and focussing magnets, and discusses the technical aspects of the implementation and delivery of pMBRT.
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277
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Matuszak N, Kruszyna-Mochalska M, Skrobala A, Ryczkowski A, Romanski P, Piotrowski I, Kulcenty K, Suchorska WM, Malicki J. Nontarget and Out-of-Field Doses from Electron Beam Radiotherapy. Life (Basel) 2022; 12:858. [PMID: 35743890 PMCID: PMC9225003 DOI: 10.3390/life12060858] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 06/03/2022] [Accepted: 06/06/2022] [Indexed: 06/15/2023] Open
Abstract
In clinical radiotherapy, the most important aspects are the dose distribution in the target volume and healthy organs, including out-of-field doses in the body. Compared to photon beam radiation, dose distribution in electron beam radiotherapy has received much less attention, mainly due to the limited range of electrons in tissues. However, given the growing use of electron intraoperative radiotherapy and FLASH, further study is needed. Therefore, in this study, we determined out-of-field doses from an electron beam in a phantom model using two dosimetric detectors (diode E and cylindrical Farmer-type ionizing chamber) for electron energies of 6 MeV, 9 MeV and 12 MeV. We found a clear decrease in out-of-field doses as the distance from the field edge and depth increased. The out-of-field doses measured with the diode E were lower than those measured with the Farmer-type ionization chamber at each depth and for each electron energy level. The out-of-field doses increased when higher energy megavoltage electron beams were used (except for 9 MeV). The out-of-field doses at shallow depths (1 or 2 cm) declined rapidly up to a distance of 3 cm from the field edge. This study provides valuable data on the deposition of radiation energy from electron beams outside the irradiation field.
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Affiliation(s)
- Natalia Matuszak
- Department of Electroradiology, Poznan University of Medical Sciences, 61-866 Poznan, Poland; (M.K.-M.); (A.S.); (I.P.); (W.M.S.); (J.M.)
- Radiobiology Laboratory, Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland;
| | - Marta Kruszyna-Mochalska
- Department of Electroradiology, Poznan University of Medical Sciences, 61-866 Poznan, Poland; (M.K.-M.); (A.S.); (I.P.); (W.M.S.); (J.M.)
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland; (A.R.); (P.R.)
| | - Agnieszka Skrobala
- Department of Electroradiology, Poznan University of Medical Sciences, 61-866 Poznan, Poland; (M.K.-M.); (A.S.); (I.P.); (W.M.S.); (J.M.)
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland; (A.R.); (P.R.)
| | - Adam Ryczkowski
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland; (A.R.); (P.R.)
| | - Piotr Romanski
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland; (A.R.); (P.R.)
| | - Igor Piotrowski
- Department of Electroradiology, Poznan University of Medical Sciences, 61-866 Poznan, Poland; (M.K.-M.); (A.S.); (I.P.); (W.M.S.); (J.M.)
- Radiobiology Laboratory, Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland;
| | - Katarzyna Kulcenty
- Radiobiology Laboratory, Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland;
| | - Wiktoria Maria Suchorska
- Department of Electroradiology, Poznan University of Medical Sciences, 61-866 Poznan, Poland; (M.K.-M.); (A.S.); (I.P.); (W.M.S.); (J.M.)
- Radiobiology Laboratory, Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland;
| | - Julian Malicki
- Department of Electroradiology, Poznan University of Medical Sciences, 61-866 Poznan, Poland; (M.K.-M.); (A.S.); (I.P.); (W.M.S.); (J.M.)
- Department of Medical Physics, Greater Poland Cancer Centre, 61-866 Poznan, Poland; (A.R.); (P.R.)
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278
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Blain G, Vandenborre J, Villoing D, Fiegel V, Fois GR, Haddad F, Koumeir C, Maigne L, Métivier V, Poirier F, Potiron V, Supiot S, Servagent N, Delpon G, Chiavassa S. Proton Irradiations at Ultra-High Dose Rate vs. Conventional Dose Rate: Strong Impact on Hydrogen Peroxide Yield. Radiat Res 2022; 198:318-324. [PMID: 35675499 DOI: 10.1667/rade-22-00021.1] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 05/25/2022] [Indexed: 11/03/2022]
Abstract
During ultra-high dose rate (UHDR) external radiation therapy, healthy tissues appear to be spared while tumor control remains the same compared to conventional dose rate. However, the understanding of radiochemical and biological mechanisms involved are still to be discussed. This study shows how the hydrogen peroxide (H2O2) production, one of the reactive oxygen species (ROS), could be controlled by early heterogenous radiolysis processes in water during UHDR proton-beam irradiations. Pure water was irradiated in the plateau region (track-segment) with 68 MeV protons under conventional (0.2 Gy/s) and several UHDR conditions (40 Gy/s to 60 kGy/s) at the ARRONAX cyclotron. Production of H2O2 was then monitored using the Ghormley triiodide method. New values of GTS(H2O2) were added in conventional dose rate. A substantial decrease in H2O2 production was observed from 0.2 to 1.5 kGy/s with a more dramatic decrease below 100 Gy/s. At higher dose rate, up to 60 kGy/s, the H2O2 production stayed stable with a mean decrease of 38% ± 4%. This finding, associated to the decrease in the production of hydroxyl radical (•OH) already observed in other studies in similar conditions can be explained by the well-known spur theory in radiation chemistry. Thus, a two-step FLASH-RT mechanism can be envisioned: an early step at the microsecond scale mainly controlled by heterogenous radiolysis, and a second, slower, dominated by O2 depletion and biochemical processes. To validate this hypothesis, more measurements of radiolytic species will soon be performed, including radicals and associated lifetimes.
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Affiliation(s)
- Guillaume Blain
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | - Johan Vandenborre
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | | | - Vincent Fiegel
- Institut de Cancérologie de l'Ouest, Saint-Herblain, France
| | - Giovanna Rosa Fois
- Université Clermont Auvergne, CNRS/IN2P3, LPC, 63000 Clermont-Ferrand, France
| | - Ferid Haddad
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France.,GIP ARRONAX, Saint-Herblain, France
| | | | - Lydia Maigne
- Université Clermont Auvergne, CNRS/IN2P3, LPC, 63000 Clermont-Ferrand, France
| | - Vincent Métivier
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | | | | | | | - Noël Servagent
- Laboratoire SUBATECH, UMR 6457, CNRS IN2P3, IMT Atlantique, Université de Nantes, France
| | - Grégory Delpon
- Institut de Cancérologie de l'Ouest, Saint-Herblain, France
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279
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Taylor E, Hill RP, Létourneau D. Modeling the impact of spatial oxygen heterogeneity on radiolytic oxygen depletion during FLASH radiotherapy. Phys Med Biol 2022; 67. [PMID: 35576920 DOI: 10.1088/1361-6560/ac702c] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 05/16/2022] [Indexed: 12/12/2022]
Abstract
Purpose.It has been postulated that the delivery of radiotherapy at ultra-high dose rates ('FLASH') reduces normal tissue toxicities by depleting them of oxygen. The fraction of normal tissue and cancer cells surviving radiotherapy depends on dose and oxygen levels in an exponential manner and even a very small fraction of tissue at low oxygen levels can determine radiotherapy response. To quantify the differential impact of FLASH radiotherapy on normal and tumour tissues, the spatial heterogeneity of oxygenation in tissue should thus be accounted for.Methods.The effect of FLASH on radiation-induced normal and tumour tissue cell killing was studied by simulating oxygen diffusion, metabolism, and radiolytic oxygen depletion (ROD) over domains with simulated capillary architectures. To study the impact of heterogeneity, two architectural models were used: (1) randomly distributed capillaries and (2) capillaries forming a regular square lattice array. The resulting oxygen partial pressure distribution histograms were used to simulate normal and tumour tissue cell survival using the linear quadratic model of cell survival, modified to incorporate oxygen-enhancement ratio effects. The ratio ('dose modifying factors') of conventional low-dose-rate dose and FLASH dose at iso-cell survival was computed and compared with empirical iso-toxicity dose ratios.Results.Tumour cell survival was found to be increased by FLASH as compared to conventional radiotherapy, with a 0-1 order of magnitude increase for expected levels of tumour hypoxia, depending on the relative magnitudes of ROD and tissue oxygen metabolism. Interestingly, for the random capillary model, the impact of FLASH on well-oxygenated (normal) tissues was found to be much greater, with an estimated increase in cell survival by up to 10 orders of magnitude, even though reductions in mean tissue partial pressure were modest, less than ∼7 mmHg for the parameter values studied. The dose modifying factor for normal tissues was found to lie in the range 1.2-1.7 for a representative value of normal tissue oxygen metabolic rate, consistent with preclinical iso-toxicity results.Conclusions.The presence of very small nearly hypoxic regions in otherwise well-perfused normal tissues with high mean oxygen levels resulted in a greater proportional sparing of normal tissue than tumour cells during FLASH irradiation, possibly explaining empirical normal tissue sparing and iso-tumour control results.
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Affiliation(s)
- Edward Taylor
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
| | - Richard P Hill
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada.,Department of Medical Biophysics, University of Toronto, Toronto, Ontario, Canada
| | - Daniel Létourneau
- Radiation Medicine Program, Princess Margaret Cancer Centre, Toronto, Ontario, Canada.,Department of Radiation Oncology, University of Toronto, Toronto, Ontario, Canada
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280
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Rinati GV, Felici G, Galante F, Gasparini A, Kranzer R, Mariani G, Pacitti M, Prestopino G, Schüller A, Vanreusel V, Verellen D, Verona C, Marinelli M. Application of a novel diamond detector for commissioning of FLASH radiotherapy electron beams. Med Phys 2022; 49:5513-5522. [PMID: 35652248 PMCID: PMC9543846 DOI: 10.1002/mp.15782] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 04/18/2022] [Accepted: 05/23/2022] [Indexed: 11/06/2022] Open
Abstract
Purpose A diamond detector prototype was recently proposed by Marinelli et al. (Medical Physics 2022, https://doi.org/10.1002/mp.15473) for applications in ultrahigh‐dose‐per‐pulse (UH‐DPP) and ultrahigh‐dose‐rate (UH‐DR) beams, as used in FLASH radiotherapy (FLASH‐RT). In the present study, such so‐called flashDiamond (fD) was investigated from the dosimetric point of view, under pulsed electron beam irradiation. It was then used for the commissioning of an ElectronFlash linac (SIT S.p.A., Italy) both in conventional and UH‐DPP modalities. Methods Detector calibration was performed in reference conditions, under 60Co and electron beam irradiation. Its response linearity was investigated in UH‐DPP conditions. For this purpose, the DPP was varied in the 1.2–11.9 Gy range, by changing either the beam applicator or the pulse duration from 1 to 4 μs. Dosimetric validation of the fD detector prototype was then performed in conventional modality, by measuring percentage depth dose (PDD) curves, beam profiles, and output factors (OFs). All such measurements were carried out in a motorized water phantom. The obtained results were compared with the ones from commercially available dosimeters, namely, a microDiamond, an Advanced Markus ionization chamber, a silicon diode detector, and EBT‐XD GAFchromic films. Finally, the fD detector was used to fully characterize the 7 and 9 MeV UH‐DPP electron beams delivered by the ElectronFlash linac. In particular, PDDs, beam profiles, and OFs were measured, for both energies and all the applicators, and compared with the ones from EBT‐XD films irradiated in the same experimental conditions. Results The fD calibration coefficient resulted to be independent from the investigated beam qualities. The detector response was found to be linear in the whole investigated DPP range. A very good agreement was observed among PDDs, beam profiles, and OFs measured by the fD prototype and reference detectors, both in conventional and UH‐DPP irradiation modalities. Conclusions The fD detector prototype was validated from the dosimetric point of view against several commercial dosimeters in conventional beams. It was proved to be suitable in UH‐DPP and UH‐DR conditions, for which no other commercial real‐time active detector is available to date. It was shown to be a very useful tool to perform fast and reproducible beam characterizations in standard clinical motorized water phantom setups. All of the previously mentioned demonstrate the suitability of the proposed detector for the commissioning of UH‐DR linac beams for preclinical FLASH‐RT applications.
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Affiliation(s)
- Gianluca Verona Rinati
- Dipartimento di Ingegneria Industriale, Università di Roma "Tor Vergata,", Roma, 00133, Italy
| | | | | | - Alessia Gasparini
- Iridium Kankernetwerk, Antwerp, 2610, Belgium.,Antwerp University, Faculty of Medicine and Health Sciences, Antwerp, 2610, Belgium
| | - Rafael Kranzer
- PTW-Freiburg, Freiburg, 79115, Germany.,University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University, Oldenburg, 26121, Germany
| | | | | | - Giuseppe Prestopino
- Dipartimento di Ingegneria Industriale, Università di Roma "Tor Vergata,", Roma, 00133, Italy
| | - Andreas Schüller
- Physikalisch-Technische Bundesanstalt, Braunschweig, 38116, Germany
| | - Verdi Vanreusel
- Iridium Kankernetwerk, Antwerp, 2610, Belgium.,Antwerp University, Faculty of Medicine and Health Sciences, Antwerp, 2610, Belgium
| | - Dirk Verellen
- Iridium Kankernetwerk, Antwerp, 2610, Belgium.,Antwerp University, Faculty of Medicine and Health Sciences, Antwerp, 2610, Belgium
| | - Claudio Verona
- Dipartimento di Ingegneria Industriale, Università di Roma "Tor Vergata,", Roma, 00133, Italy
| | - Marco Marinelli
- Dipartimento di Ingegneria Industriale, Università di Roma "Tor Vergata,", Roma, 00133, Italy
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281
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Jin JY. Prospect of radiotherapy technology development in the era of immunotherapy. JOURNAL OF THE NATIONAL CANCER CENTER 2022; 2:106-112. [PMID: 39034954 PMCID: PMC11256706 DOI: 10.1016/j.jncc.2022.04.001] [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: 12/17/2021] [Revised: 04/06/2022] [Accepted: 04/08/2022] [Indexed: 10/18/2022] Open
Abstract
Radiotherapy (RT) is one of the important modalities for cancer treatments. Mounting evidence suggests that the host immune system is involved in the tumor cell killing during RT, and future RT technology development should aim to minimize radiation dose to the immune system while maintaining a sufficient dose to the tumor. A brief history of RT technology development is first summarized. Three RT technologies, namely FLASH RT, proton therapy, and spatially fractionated RT (SFRT), are singled out for the era of immunotherapy. Besides the technical aspects, the mechanism of FLASH effect is discussed, which is likely the combined results of the recombination effect, oxygen depletion effect and immune sparing effect. The proton therapy should have the advantage of causing much less immune damage in comparison to X-ray based RT due to the Bragg peak. However, the relative biological effectiveness (RBE) uncertainty and range uncertainty may hinder the translation of this advantage into clinical benefit. Research approaches to overcome these two technical hurdles are discussed. Various SFRT approaches and their application are reviewed. These approaches are categorized as single-field 1D/2D SFRT, multi-field 3D SFRT and quasi-3D SFRT techniques. A 3D SFRT approach, which is achieved by placing the Bragg peak of a proton 2D SFRT field in discrete depths, may have special potential because all 3 technologies (FLASH RT, proton therapy and SFRT) may be used in this approach.
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Affiliation(s)
- Jian-Yue Jin
- Radiation Oncology, Seidman Cancer Center, University Hospitals, Case Western Reserve University, Cleveland, United States
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282
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Compact and very high dose-rate plasma focus radiation sources for medical applications. Radiat Phys Chem Oxf Engl 1993 2022. [DOI: 10.1016/j.radphyschem.2022.110296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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283
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El Naqa I, Pogue BW, Zhang R, Oraiqat I, Parodi K. Image guidance for FLASH radiotherapy. Med Phys 2022; 49:4109-4122. [PMID: 35396707 PMCID: PMC9844128 DOI: 10.1002/mp.15662] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 03/10/2022] [Accepted: 03/30/2022] [Indexed: 01/19/2023] Open
Abstract
FLASH radiotherapy (FLASH-RT) is an emerging ultra-high dose (>40 Gy/s) delivery that promises to improve the therapeutic potential by limiting toxicities compared to conventional RT while maintaining similar tumor eradication efficacy. Image guidance is an essential component of modern RT that should be harnessed to meet the special emerging needs of FLASH-RT and its associated high risks in planning and delivering of such ultra-high doses in short period of times. Hence, this contribution will elaborate on the imaging requirements and possible solutions in the entire chain of FLASH-RT treatment, from the planning, through the setup and delivery with online in vivo imaging and dosimetry, up to the assessment of biological mechanisms and treatment response. In patient setup and delivery, higher temporal sampling than in conventional RT should ensure that the short treatment is delivered precisely to the targeted region. Additionally, conventional imaging tools such as cone-beam computed tomography will continue to play an important role in improving patient setup prior to delivery, while techniques based on magnetic resonance imaging or positron emission tomography may be extremely valuable for either linear accelerator (Linac) or particle FLASH therapy, to monitor and track anatomical changes during delivery. In either planning or assessing outcomes, quantitative functional imaging could supplement conventional imaging for more accurate utilization of the biological window of the FLASH effect, selecting for or verifying things such as tissue oxygen and existing or transient hypoxia on the relevant timescales of FLASH-RT delivery. Perhaps most importantly at this time, these tools might help improve the understanding of the biological mechanisms of FLASH-RT response in tumor and normal tissues. The high dose deposition of FLASH provides an opportunity to utilize pulse-to-pulse imaging tools such as Cherenkov or radiation acoustic emission imaging. These could provide individual pulse mapping or assessing the 3D dose delivery superficially or at tissue depth, respectively. In summary, the most promising components of modern RT should be used for safer application of FLASH-RT, and new promising developments could be advanced to cope with its novel demands but also exploit new opportunities in connection with the unique nature of pulsed delivery at unprecedented dose rates, opening a new era of biological image guidance and ultrafast, pulse-based in vivo dosimetry.
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Affiliation(s)
- Issam El Naqa
- Department of Machine Learning, Moffitt Cancer Center, Tampa, FL 33612, USA,Corresponding Author:
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, Hanover, NH 03755, USA,Department of Medical Physics, University of Wisconsin-Madison, WI 53705, USA
| | - Rongxiao Zhang
- Giesel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Ibrahim Oraiqat
- Department of Machine Learning, Moffitt Cancer Center, Tampa, FL 33612, USA
| | - Katia Parodi
- Department of Medical Physics, Ludwig-Maximilians-Universität München, Am Coulombwall 1, Garching 85748, Germany
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284
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Van Slyke AL, El Khatib M, Velalopoulou A, Diffenderfer E, Shoniyozov K, Kim MM, Karagounis IV, Busch TM, Vinogradov SA, Koch CJ, Wiersma RD. Oxygen Monitoring in Model Solutions and In Vivo in Mice During Proton Irradiation at conventional and FLASH Dose Rates. Radiat Res 2022; 198:181-189. [PMID: 35640166 PMCID: PMC10176203 DOI: 10.1667/rade-21-00232.1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Accepted: 05/06/2022] [Indexed: 11/03/2022]
Abstract
FLASH is a high-dose-rate form of radiation therapy that has the reported ability, compared with conventional dose rates, to spare normal tissues while being equipotent in tumor control, thereby increasing the therapeutic ratio. The mechanism underlying this normal tissue sparing effect is currently unknown, however one possibility is radiochemical oxygen depletion (ROD) during dose delivery in tissue at FLASH dose rates. In order to investigate this possibility, we used the phosphorescence quenching method to measure oxygen partial pressure before, during and after proton radiation delivery in model solutions and in normal muscle and sarcoma tumors in mice, at both conventional (Conv) (∼0.5 Gy/s) and FLASH (∼100 Gy/s) dose rates. Radiation dosimetry was determined by Advanced Markus Chamber and EBT-XL film. For solutions contained in sealed glass vials, phosphorescent probe Oxyphor PtG4 (1 μM) was dissolved in a buffer (10 mM HEPES) containing glycerol (1 M), glucose (5 mM) and glutathione (5 mM), designed to mimic the reducing and free radical-scavenging nature of the intracellular environment. In vivo oxygen measurements were performed 24 h after injection of PtG4 into the interstitial space of either normal thigh muscle or intra-muscular sarcoma tumors in mice. The "g-value" for ROD is reported in mmHg/Gy, which represents a slight modification of the more standard chemical definition (μM/Gy). In solutions, proton irradiation at conventional dose rates resulted in a g-value for ROD of up to 0.55 mmHg/Gy, consistent with earlier studies using X or gamma rays. At FLASH dose rates, the g-value for ROD was ∼25% lower, 0.37 mmHg/Gy. pO2 levels were stable after each dose delivery. For normal muscle in vivo, oxygen depletion during irradiation was counterbalanced by resupply from the vasculature. This process was fast enough to maintain tissue pO2 virtually unchanged at Conv dose rates. However, during FLASH irradiation there was a stepwise decrease in pO2 (g-value ∼0.28 mmHg/Gy), followed by a rebound to the initial level after ∼8 s. The g-values were smaller and recovery times longer in tumor tissue when compared to muscle and may be related to the lower initial endogenous pO2 levels in the former. Considering that the FLASH effect is seen in vivo even at doses as low as 10 Gy, it is difficult to reconcile the amount of protection seen by oxygen depletion alone. However, the phosphorescence probe in our experiments was confined to the extracellular space, and it remains possible that intracellular oxygen depletion was greater than observed herein. In cell-mimicking solutions the oxygen depletion g-vales were indeed significantly higher than observed in vivo.
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Affiliation(s)
| | - Mirna El Khatib
- Department of Biochemistry and Biophysics, Perelman School of Medicine, and Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | | | - Eric Diffenderfer
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia
| | | | - Michele M Kim
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia
| | - Ilias V Karagounis
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia
| | - Theresa M Busch
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia
| | - Sergei A Vinogradov
- Department of Biochemistry and Biophysics, Perelman School of Medicine, and Department of Chemistry, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Cameron J Koch
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia
| | - Rodney D Wiersma
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia
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285
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Karsch L, Pawelke J, Brand M, Hans S, Hideghéty K, Jansen J, Lessmann E, Löck S, Schürer M, Schurig R, Seco J, Szabó ER, Beyreuther E. Beam pulse structure and dose rate as determinants for the flash effect observed in zebrafish embryo. Radiother Oncol 2022; 173:49-54. [PMID: 35661675 DOI: 10.1016/j.radonc.2022.05.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 05/20/2022] [Accepted: 05/26/2022] [Indexed: 01/21/2023]
Abstract
BACKGROUND AND PURPOSE Continuing recent experiments at the research electron accelerator ELBE at the Helmholtz-Zentrum Dresden-Rossendorf the influence of beam pulse structure on the Flash effect was investigated. MATERIALS AND METHODS The proton beam pulse structure of an isochronous cyclotron (UHDRiso) and a synchrocyclotron (UHDRsynchro) was mimicked at ELBE by quasi-continuous electron bunches at 13 MHz delivering mean dose rates of 287 Gy/s and 177 Gy/s and bunch dose rates of 106Gy/s and 109 Gy/s, respectively. For UHDRsynchro, 40 ms macro pulses at a frequency of 25 Hz superimposed the bunch delivery. For comparison, a maximum beam intensity (2.5 x 105 Gy/s mean and ∼109 Gy/s bunch dose rate) and a reference irradiation (of ∼8 Gy/min mean dose rate) were applied. Radiation induced changes were assessed in zebrafish embryos over four days post irradiation. RESULTS Relative to the reference a significant protecting Flash effect was observed for all electron beam pulse regimes with less severe damage the higher the mean dose rate of the electron beam. Accordingly, the macro pulsing induced prolongation of treatment time at UHDRsynchro regime reduces the protecting effect compared to the maximum regime delivered at same bunch but higher mean dose rate. The Flash effect of the UHDRiso regime was confirmed at a clinical isochronous cyclotron comparing the damage induced by proton beams delivered at 300 Gy/s and ∼9 Gy/min. CONCLUSION The recent findings indicate that the mean dose rate or treatment time are decisive for the normal tissue protecting Flash effect in zebrafish embryo.
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Affiliation(s)
- Leonhard Karsch
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Jörg Pawelke
- Helmholtz-Zentrum Dresden - Rossendorf (HZDR), Institute of Radiooncology - OncoRay, Dresden, Germany; OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Michael Brand
- Center for Regenerative Therapies TU Dresden (CRTD), and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Stefan Hans
- Center for Regenerative Therapies TU Dresden (CRTD), and Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| | - Katalin Hideghéty
- ELI-ALPS, ELI-HU Non-Profit Ltd., Szeged, Hungary; Oncotherapy Department, University of Szeged, Szeged, Hungary
| | - Jeannette Jansen
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Elisabeth Lessmann
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Steffen Löck
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany; German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Michael Schürer
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; National Center for Tumor Diseases Dresden (NCT/UCC), Germany: German Cancer Research Center (DKFZ), Heidelberg, Germany, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Dresden, Germany, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany
| | - Rico Schurig
- Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Joao Seco
- Division of Biomedical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Heidelberg, Germany; Faculty of Physics and Astronomy, Heidelberg University, Germany
| | | | - Elke Beyreuther
- OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden - Rossendorf, Dresden, Germany; Helmholtz-Zentrum Dresden - Rossendorf, Institute of Radiation Physics, Dresden, Germany.
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Chermat R, Ziaee M, Mak DY, Refet-Mollof E, Rodier F, Wong P, Carrier JF, Kamio Y, Gervais T. Radiotherapy on-chip: microfluidics for translational radiation oncology. LAB ON A CHIP 2022; 22:2065-2079. [PMID: 35477748 DOI: 10.1039/d2lc00177b] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The clinical importance of radiotherapy in the treatment of cancer patients justifies the development and use of research tools at the fundamental, pre-clinical, and ultimately clinical levels, to investigate their toxicities and synergies with systemic agents on relevant biological samples. Although microfluidics has prompted a paradigm shift in drug discovery in the past two decades, it appears to have yet to translate to radiotherapy research. However, the materials, dimensions, design versatility and multiplexing capabilities of microfluidic devices make them well-suited to a variety of studies involving radiation physics, radiobiology and radiotherapy. This review will present the state-of-the-art applications of microfluidics in these fields and specifically highlight the perspectives offered by radiotherapy on-a-chip in the field of translational radiobiology and precision medicine. This body of knowledge can serve both the microfluidics and radiotherapy communities by identifying potential collaboration avenues to improve patient care.
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Affiliation(s)
- Rodin Chermat
- μFO Lab, Polytechnique Montréal, Montréal, QC, Canada.
- Institut du Cancer de Montréal, (ICM), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - Maryam Ziaee
- μFO Lab, Polytechnique Montréal, Montréal, QC, Canada.
- Institut du Cancer de Montréal, (ICM), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - David Y Mak
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
| | - Elena Refet-Mollof
- μFO Lab, Polytechnique Montréal, Montréal, QC, Canada.
- Institut du Cancer de Montréal, (ICM), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
| | - Francis Rodier
- Institut du Cancer de Montréal, (ICM), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
- Département de radiologie, radio-oncologie et médecine nucléaire, Université de Montréal, Montreal, QC, Canada
| | - Philip Wong
- Radiation Medicine Program, Princess Margaret Cancer Centre, University Health Network, Toronto, ON, Canada
- Institut du Cancer de Montréal, (ICM), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
- Department of Radiation Oncology, University of Toronto, Toronto, ON, Canada
| | - Jean-François Carrier
- Département de radiologie, radio-oncologie et médecine nucléaire, Université de Montréal, Montreal, QC, Canada
- Département de Physique, Université de Montréal, Montréal, QC, Canada
- Département de Radio-oncologie, Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, QC, Canada
| | - Yuji Kamio
- Département de Radio-oncologie, Centre Hospitalier de l'Université de Montréal (CHUM), Montréal, QC, Canada
- Département de Pharmacologie et Physiologie, Université de Montréal, Montreal, QC, Canada
| | - Thomas Gervais
- μFO Lab, Polytechnique Montréal, Montréal, QC, Canada.
- Institut du Cancer de Montréal, (ICM), Centre de Recherche du Centre Hospitalier de l'Université de Montréal (CRCHUM), Montreal, QC, Canada
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287
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Hart A, Cecchi D, Giguère C, Larose F, Therriault-Proulx F, Esplen N, Beaulieu L, Bazalova-Carter M. Lead-doped scintillator dosimeters for detection of ultrahigh dose-rate x-rays. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac69a5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 04/22/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Objective. Lead-doped scintillator dosimeters may be well suited for the dosimetry of FLASH-capable x-ray radiotherapy beams. Our study explores the dose rate dependence and temporal resolution of scintillators that makes them promising in the accurate detection of ultrahigh dose-rate (UHDR) x-rays. Approach. We investigated the response of scintillators with four material compositions to UHDR x-rays produced by a conventional x-ray tube. Scintillator output was measured using the HYPERSCINT-RP100 dosimetry research platform. Measurements were acquired at high frame rates (400 fps) which allowed for accurate dose measurements of sub-second radiation exposures from 1 to 100 ms. Dose-rate dependence was assessed by scaling tube current of the x-ray tube. Scintillator measurements were validated against Monte Carlo simulations of the probe geometries and UHDR x-ray system. Calibration factors converting dose-to-medium to dose-to-water were obtained from simulation data of plastic and lead-doped scintillator materials. Main Results. The results of this work suggest that lead-doped scintillators were dose-rate independent for UHDR x-rays from 1.1 to 40.1 Gy s−1 and capable of measuring conventional radiotherapy dose-rates (0.1 Gy s−1) at extended distance from the x-ray focal spot. Dose-to-water measured with a 5% lead-doped scintillator detector agreed with simulations within 0.6%. Significance. Lead-doped scintillators may be a valuable tool for the accurate real-time dosimetry of FLASH-capable UHDR x-ray beams.
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288
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Esplen N, Egoriti L, Paley B, Planche T, Hoehr C, Gottberg A, Bazalova-Carter M. Design optimization of an electron-to-photon conversion target for ultra-high dose rate x-ray (FLASH) experiments at TRIUMF. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac5ed6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/17/2022] [Indexed: 12/29/2022]
Abstract
Abstract
Objective. To develop a bremsstrahlung target and megavoltage (MV) x-ray irradiation platform for ultrahigh dose-rate (UHDR) irradiation of small-animals on the Advanced Rare Isotope Laboratory (ARIEL) electron linac (e-linac) at TRIUMF. Approach. An electron-to-photon converter design for UHDR radiotherapy (RT) was centered around optimization of a tantalum–aluminum (Ta–Al) explosion-bonded target. Energy deposition within a homogeneous water-phantom and the target itself were evaluated using EGSnrc and FLUKA MC codes, respectively, for various target thicknesses (0.5–1.5 mm), beam energies (E
e− = 8, 10 MeV) and electron (Gaussian) beam sizes (
2
σ
= 2–10 mm). Depth dose-rates in a 3D-printed mouse phantom were also calculated to infer the compatibility of the 10 MV dose distributions for FLASH-RT in small-animal models. Coupled thermo-mechanical FEA simulations in ANSYS were subsequently used to inform the stress–strain conditions and fatigue life of the target assembly. Main results. Dose-rates of up to 128 Gy s−1 at the phantom surface, or 85 Gy s−1 at 1 cm depth, were obtained for a 1 × 1 cm2 field size, 1 mm thick Ta target and 7.5 cm source-to-surface distance using the FLASH-mode beam (E
e− = 10 MeV, 2
σ
= 5 mm, P = 1 kW); furthermore, removal of the collimation assembly and using a shorter (3.5 cm) SSD afforded dose-rates >600 Gy s−1, albeit at the expense of field conformality. Target temperatures were maintained below the tantalum, aluminum and cooling-water thresholds of 2000 °C, 300 °C and 100 °C, respectively, while the aluminum strain behavior remained everywhere elastic and helped ensure the converter survives its prescribed 5 yr operational lifetime. Significance. Effective design iteration, target cooling and failure mitigation have culminated in a robust target compatible with intensive transient (FLASH) and steady-state (diagnostic) applications. The ARIEL UHDR photon source will facilitate FLASH-RT experiments concerned with sub-second, pulsed or continuous beam irradiations at dose rates in excess of 40 Gy s−1.
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289
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Yang Y, Shi C, Chen CC, Tsai P, Kang M, Huang S, Lin CH, Chang FX, Chhabra AM, Choi JI, Tome WA, Ii CBS, Lin H. A high spatiotemporal resolution 2D strip ionization chamber array for proton pencil beam scanning FLASH radiotherapy. Med Phys 2022; 49:5464-5475. [PMID: 35593052 DOI: 10.1002/mp.15706] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2022] [Revised: 04/18/2022] [Accepted: 05/02/2022] [Indexed: 11/10/2022] Open
Abstract
PURPOSE Experimental measurements of 2D dose rate distributions in proton pencil beam scanning (PBS) FLASH radiation therapy (RT) are currently lacking. In this study, we characterize a newly designed 2D strip-segmented ionization chamber array (SICA) with high spatial and temporal resolution and demonstrate its applications in a modern proton PBS delivery system at both conventional and ultra-high dose rates. METHODS A dedicated research beamline of the Varian ProBeam system was employed to deliver a 250 MeV proton PBS beam with nozzle currents up to 215 nA. In the research and clinical beamlines, the spatial, temporal, and dosimetric performance of the SICA was characterized and compared with measurements using parallel-plate ion chambers (IBA PPC05 and PTW Advanced Markus chamber), a 2D scintillator camera (IBA Lynx), Gafchromic films (EBT-XD), and a Faraday Cup. A novel reconstruction approach was proposed to enable the measurement of 2D dose and dose rate distributions using such a strip-type detector. RESULTS The SICA demonstrated a position accuracy of 0.12 ± 0.02 mm at a 20 kHz sampling rate (50 μs per event) and a linearity of R2 > 0.99 for both dose and dose rate with nozzle beam currents ranging from 1 nA to 215 nA. The 2D dose comparison to the film measurement resulted in a gamma passing rate of 99.8% (2 mm/2%). A measurement-based proton PBS 2D FLASH dose rate distribution was compared to simulation results and showed a gamma passing rate of 97.3% (2 mm/2%). CONCLUSIONS The newly designed SICA demonstrated excellent spatial, temporal, and dosimetric performance and is well suited for commissioning, quality assurance (QA), and a wide range of clinical applications in proton PBS clinical and FLASH radiotherapy. This article is protected by copyright. All rights reserved.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | - J Isabelle Choi
- New York Proton Center, New York, NY, USA.,Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Wolfgang A Tome
- Department of Radiation Oncology, Montefiore Medical Center and Albert Einstein College of Medicine, Bronx, New York, USA
| | - Charles B Simone Ii
- New York Proton Center, New York, NY, USA.,Department of Radiation Oncology, Memorial Sloan Kettering Cancer Center, New York, NY, USA
| | - Haibo Lin
- New York Proton Center, New York, NY, USA.,Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY, USA
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290
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Zhang G, Gao W, Peng H. Design of static and dynamic ridge filters for FLASH-IMPT: a simulation study. Med Phys 2022; 49:5387-5399. [PMID: 35595708 DOI: 10.1002/mp.15717] [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: 02/11/2022] [Revised: 05/10/2022] [Accepted: 05/10/2022] [Indexed: 11/08/2022] Open
Abstract
PURPOSE This paper focused on the design and optimization of ridge filter-based intensity-modulated proton therapy (IMPT), and its potential applications for FLASH. Differing from the standard pencil beam scanning (PBS) mode, no energy/layer switching is required and total treatment time can be shortened. METHODS Unique dose influence matrices were generated as a proton beam traverse through slabs of different thicknesses (i.e. modulation by different layers). To establish the references for comparison, conventional IMPT plans (single field) were created using a large-scale non-linear solver. The spot weights from the reference IMPT plans were used as inputs for optimizing the design of ridge filters. Two designs were evaluated: model A (static) and model B (dynamic). The ridge filters designs were first verified (by GEANT4 simulation) in a water phantom and then in a H&N case. Direct comparison was made between the GEANT4 simulation results of two models and their respective references, with regard to plan quality, dose-averaged dose rate (DADR), and total treatment time. RESULTS In both the water phantom and the H&N case, two models are able to modulate dose distributions with high conformity, showing no significant difference relative to the reference plans. Dose rate volume histograms (DRVHs) suggest that in order to achieve a dose rate of 40 Gy/s over 90% PTV, the beam intensity needs to be 2.5×1011 protons/s for both models. For a fraction dose of 10 Gy, the total treatment time (including both irradiation time and dead time) can be shortened by a factor of 4.9 (model A) and 6.5 (model B), relative to the reference plans. CONCLUSION Two proposed designs (both static and dynamic) can be used for PBS-IMPT requiring no layer switching. They are promising candidates for FLASH-IMPT capable of reducing treatment time and achieving high dose rates, while maintaining dose conformity simultaneously. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Guoliang Zhang
- Department of Medical Physics, School of Physics and Technology, Wuhan University
| | - Wenchao Gao
- Cancer Radiation Therapy Center, Fifth Medical Center of Chinese PLA General Hospital
| | - Hao Peng
- Department of Medical Physics, School of Physics and Technology, Wuhan University.,ProtonSmart Inc
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291
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Sørensen BS, Sitarz MK, Ankjærgaard C, Johansen JG, Andersen CE, Kanouta E, Grau C, Poulsen P. Pencil beam scanning proton FLASH maintains tumor control while normal tissue damage is reduced in a mouse model. Radiother Oncol 2022; 175:178-184. [PMID: 35595175 DOI: 10.1016/j.radonc.2022.05.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/12/2022] [Accepted: 05/12/2022] [Indexed: 01/16/2023]
Abstract
PURPOSE Preclinical studies indicate a normal tissue sparing effect when ultra-high dose rate (FLASH) radiation is used, while tumor response is maintained. This differential response has promising perspectives for improved clinical outcome. This study investigates tumor control and normal tissue toxicity of pencil beam scanning (PBS) proton FLASH in a mouse model. METHODS AND MATERIALS Tumor bearing hind limbs of non-anaesthetized CDF1 mice were irradiated in a single fraction with a PBS proton beam using either conventional (CONV) dose rate (0.33-0.63 Gy/s field dose rate, 244 MeV) or FLASH (71-89 Gy/s field dose rate, 250 MeV). 162 mice with a C3H mouse mammary carcinoma subcutaneously implanted in the foot were irradiated with physical doses of 40-60 Gy (8-14 mice per dose point). The endpoints were tumor control (TC) assessed as no recurrent tumor at 90 days after treatment, the level of acute moist desquamation (MD) to the skin of the foot within 25 days post irradiation, and radiation induced fibrosis (RIF) within 24 weeks post irradiation. RESULTS TCD50 (dose for 50% tumor control) was similar for CONV and FLASH with values (and 95% confidence intervals) of 49.1 (47.0-51.4) Gy for CONV and 51.3 (48.6-54.2) Gy for FLASH. RIF analysis was restricted to mice with tumor control. Both endpoints showed distinct normal tissue sparing effect of proton FLASH with MDD50 (dose for 50% of mice displaying moist desquamation) of <40.1 Gy for CONV and 52.3 (50.0-54.6) Gy for FLASH, (dose modifying factor at least 1.3) and FD50 (dose for 50% of mice displaying fibrosis) of 48.6 (43.2-50.8) Gy for CONV and 55.6 (52.5-60.1) Gy for FLASH (dose modifying factor of 1.14). CONCLUSIONS FLASH had the same tumor control as CONV, but reduced normal tissue damage assessed as acute skin damage and radiation induced fibrosis.
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Affiliation(s)
- Brita Singers Sørensen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark.
| | | | | | - Jacob G Johansen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | | | - Eleni Kanouta
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Cai Grau
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark
| | - Per Poulsen
- Danish Centre for Particle Therapy, Aarhus University Hospital, Aarhus, Denmark; Department of Oncology, Aarhus University Hospital, Aarhus, Denmark
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292
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Abolfath R, Baikalov A, Bartzsch S, Afshordi N, Mohan R. The effect of non-ionizing excitations on the diffusion of ion species and inter-track correlations in FLASH ultra-high dose rate radiotherapy. Phys Med Biol 2022; 67. [PMID: 35453139 DOI: 10.1088/1361-6560/ac69a6] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Accepted: 04/22/2022] [Indexed: 12/17/2022]
Abstract
Purpose. We present a microscopic mechanism that accounts for the outward burst of 'cold' ion species (IS) in a high-energy particle track due to coupling with 'hot' non-ion species (NIS). IS refers to radiolysis products of ionized molecules, whereas NIS refers to non-ionized excitations of molecules in a medium. The interaction is mediated by a quantized field of acoustic phonons, a channel that allows conversion of thermal energy of NIS to kinetic energy of IS, a flow of heat from the outer to the inner core of the track structure.Methods. We perform step-by-step Monte Carlo (MC) simulations of ionizing radiation track structures in water to score the spatial coordinates and energy depositions that form IS and NIS at atto-second time scales. We subsequently calculate the resulting temperature profiles of the tracks with MC track structure simulations and verify the results analytically using the Rutherford scattering formulation. These temperature profiles are then used as boundary conditions in a series of multi-scale atomistic molecular dynamic (MD) simulations that describe the sudden expansion and enhanced diffusive broadening of tracks initiated by the non-equilibrium spectrum of high-energy IS. We derive a stochastic coarse-grained Langevin equation of motion for IS from first-principle MD to describe the irreversible femto-second flow of thermal energy pumping from NIS to IS, mediated by quantized fields of acoustic phonons. A pair-wise Lennard-Jones potential implemented in a classical MD is then employed to validate the results calculated from the Langevin equation.Results. We demonstrate the coexistence of 'hot' NIS with 'cold' IS in the radiation track structures right after their generation. NIS, concentrated within nano-scale volumes wrapping around IS, are the main source of intensive heat-waves and the outward burst of IS due to femto-second time scale IS-NIS coupling. By comparing the transport of IS coupled to NIS with identical configurations of non-interacting IS in thermal equilibrium at room temperature, we demonstrate that the energy gain of IS due to the surrounding hot nanoscopic volumes of NIS significantly increases their effective diffusion constants. Comparing the average track separation and the time scale calculated for a deposited dose of 10 Gy and a dose rate of 40 Gy s-1, typical values used in FLASH ultra high dose rate (UHDR) experiments, we find that the sudden expansion of tracks and ballistic transport proposed in this work strengthens the hypothesis of inter-track correlations recently introduced to interpret mitigation of the biological responses at the FLASH-UHDR (Abolfathet al2020Med. Phys.47, 6551-6561).Conclusions. The much higher diffusion constants predicted in the present model suggest higher inter-track chemical reaction rates at FLASH-UHDR, as well as lower intra-track reaction rates. This study explains why research groups relying on the current Monte Carlo frameworks have reported negligible inter-track overlaps, simply because of underestimation of the diffusion constants. We recommend incorporation of the IS-NIS coupling and heat exchange in all MC codes to enable these tool-kits to appropriately model reaction-diffusion rates at FLASH-UHDR.Novelty. To introduce a hypothetical pathway of outward burst of radiolysis products driven by highly localized thermal spikes wrapping around them and to investigate the interplay of the non-equilibrium spatio-temporal distribution of the chemical activities of diffusive high-energy particle tracks on inter-track correlations at FLASH-UHDR.
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Affiliation(s)
- Ramin Abolfath
- Department of Radiation Physics and Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 75031, United States of America
| | - Alexander Baikalov
- Technical University of Munich, Department of Physics, Garching, Germany.,Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, Neuherberg, Germany
| | - Stefan Bartzsch
- Helmholtz Zentrum München GmbH, German Research Center for Environmental Health, Institute of Radiation Medicine, Neuherberg, Germany.,Technical University of Munich, School of Medicine and Klinikum Rechts der Isar, Department of Radiation Oncology, Munich, Germany
| | | | - Radhe Mohan
- Department of Radiation Physics and Oncology, University of Texas MD Anderson Cancer Center, Houston, TX 75031, United States of America
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293
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Al Dahhan NZ, Cox E, Nieman BJ, Mabbott DJ. Cross-translational models of late-onset cognitive sequelae and their treatment in pediatric brain tumor survivors. Neuron 2022; 110:2215-2241. [PMID: 35523175 DOI: 10.1016/j.neuron.2022.04.009] [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: 11/09/2021] [Revised: 03/21/2022] [Accepted: 04/08/2022] [Indexed: 10/18/2022]
Abstract
Pediatric brain tumor treatments have a high success rate, but survivors are at risk of cognitive sequelae that impact long-term quality of life. We summarize recent clinical and animal model research addressing pathogenesis or evaluating candidate interventions for treatment-induced cognitive sequelae. Assayed interventions encompass a broad range of approaches, including modifications to radiotherapy, modulation of immune response, prevention of treatment-induced cell loss or promotion of cell renewal, manipulation of neuronal signaling, and lifestyle/environmental adjustments. We further emphasize the potential of neuroimaging as a key component of cross-translation to contextualize laboratory research within broader clinical findings. This cross-translational approach has the potential to accelerate discovery to improve pediatric cancer survivors' long-term quality of life.
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Affiliation(s)
- Noor Z Al Dahhan
- Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON, Canada
| | - Elizabeth Cox
- Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON, Canada; Department of Psychology, University of Toronto, Toronto, ON, Canada
| | - Brian J Nieman
- Translational Medicine, Hospital for Sick Children, Toronto, ON, Canada; Mouse Imaging Centre, Hospital for Sick Children, Toronto, ON, Canada; Department of Medical Biophysics, University of Toronto, Toronto, ON, Canada; Ontario Institute for Cancer Research, Toronto, ON, Canada
| | - Donald J Mabbott
- Neurosciences and Mental Health, Hospital for Sick Children, Toronto, ON, Canada; Department of Psychology, University of Toronto, Toronto, ON, Canada; Department of Psychology, Hospital for Sick Children, Toronto, ON, Canada.
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294
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Cooper CR, Jones D, Jones GDD, Petersson K. FLASH irradiation induces lower levels of DNA damage ex vivo, an effect modulated by oxygen tension, dose, and dose rate. Br J Radiol 2022; 95:20211150. [PMID: 35171701 PMCID: PMC10993968 DOI: 10.1259/bjr.20211150] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2021] [Revised: 01/07/2022] [Accepted: 01/31/2022] [Indexed: 12/17/2022] Open
Abstract
OBJECTIVE FLASH irradiation reportedly produces less normal tissue toxicity, while maintaining tumour response. To investigate oxygen's role in the 'FLASH effect', we assessed DNA damage levels following irradiation at different oxygen tensions, doses and dose rates. METHODS Samples of whole blood were irradiated (20 Gy) at various oxygen tensions (0.25-21%) with 6 MeV electrons at dose rates of either 2 kGy/s (FLASH) or 0.1 Gy/s (CONV), and subsequently with various doses (0-40 Gy) and intermediate dose rates (0.3-1000 Gy/s). DNA damage of peripheral blood lymphocytes (PBL) were assessed by the alkaline comet assay. RESULTS Following 20 Gy irradiation, lower levels of DNA damage were induced for FLASH, the difference being significant at 0.25% (p < 0.05) and 0.5% O2 (p < 0.01). The differential in DNA damage at 0.5% O2 was found to increase with total dose and dose rate, becoming significant for doses ≥20 Gy and dose rates ≥30 Gy/s. CONCLUSION This study shows, using the alkaline comet assay, that lower levels of DNA damage are induced following FLASH irradiation, an effect that is modulated by the oxygen tension, and increases with the total dose and dose rate of irradiation, indicating that an oxygen related mechanism, e.g. transient radiation-induced oxygen depletion, may contribute to the tissue sparing effect of FLASH irradiation. ADVANCES IN KNOWLEDGE This paper is first to directly show that FLASH-induced DNA damage is modulated by oxygen tension, total dose and dose rate, with FLASH inducing significantly lower levels of DNA damage for doses ≥20 Gy and dose rates ≥30 Gy/s, at 0.5% O2.
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Affiliation(s)
- Christian R Cooper
- Leicester Cancer Research Centre, University of Leicester,
Robert Kilpatrick Clinical Sciences Building, Leicester Royal
Infirmary, Leicester,
UK
| | - Donald Jones
- Leicester Cancer Research Centre, University of Leicester,
Robert Kilpatrick Clinical Sciences Building, Leicester Royal
Infirmary, Leicester,
UK
| | - George DD Jones
- Leicester Cancer Research Centre, University of Leicester,
Robert Kilpatrick Clinical Sciences Building, Leicester Royal
Infirmary, Leicester,
UK
| | - Kristoffer Petersson
- MRC Oxford Institute for Radiation Oncology, University of
Oxford, Old Road Campus Research Building,
Oxford, UK
- Department of Haematology, Oncology and Radiation Physics,
Skåne University Hospital Lund University,
Lund, Sweden
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295
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Tinganelli W, Weber U, Puspitasari A, Simoniello P, Abdollahi A, Oppermann J, Schuy C, Horst F, Helm A, Fournier C, Durante M. FLASH with carbon ions: tumor control, normal tissue sparing, and distal metastasis in a mouse osteosarcoma model. Radiother Oncol 2022; 175:185-190. [DOI: 10.1016/j.radonc.2022.05.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 04/30/2022] [Accepted: 05/02/2022] [Indexed: 12/30/2022]
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296
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Poirier Y, Xu J, Mossahebi S, Therriault‐Proulx F, Sawant A. Technical note: Characterization and practical applications of a novel plastic scintillator for on‐line dosimetry for ultra‐high dose rate (FLASH). Med Phys 2022; 49:4682-4692. [DOI: 10.1002/mp.15671] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2021] [Revised: 03/23/2022] [Accepted: 03/30/2022] [Indexed: 11/06/2022] Open
Affiliation(s)
- Yannick Poirier
- University of Maryland School of Medicine Baltimore MD 21201
- McGill University Montreal QC H3A 2T5 Canada
| | - Junliang Xu
- University of Maryland School of Medicine Baltimore MD 21201
| | - Sina Mossahebi
- University of Maryland School of Medicine Baltimore MD 21201
| | | | - Amit Sawant
- University of Maryland School of Medicine Baltimore MD 21201
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297
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Zhu H, Xie D, Yang Y, Huang S, Gao X, Peng Y, Wang B, Wang J, Xiao D, Wu D, Li C, Li C, Qian CN, Deng X. Radioprotective effect of X-ray abdominal FLASH irradiation: Adaptation to oxidative damage and inflammatory response may be benefiting factors. Med Phys 2022; 49:4812-4822. [PMID: 35451077 DOI: 10.1002/mp.15680] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 04/08/2022] [Accepted: 04/12/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND Ultrahigh dose-rate irradiation (FLASH-IR) was reported to be efficient in tumor control while reducing normal tissue radiotoxicity. However, the mechanism of such phenomenon is still unclear. Besides, the FLASH experiments using high energy X-ray, the most common modality in clinical radiotherapy, is rarely reported. This study aims to investigate the radiobiological response using 6 MV X-ray FLASH-IR or conventional dose-rate IR (CONV-IR). METHODS The superconducting linac of Chengdu THz Free Electron Laser (CTFEL) facility was used for FLASH-IR, a diamond radiation detector and a CeBr3 scintillation detector were used to monitor the time structure and dose rate of FLASH pulses. BALB/c nude mice received whole abdominal 6 MV X-ray FLASH-IR or CONV-IR, the prescribed dose was 15 Gy or 10 Gy and the delivered absolute dose was monitored with EBT3 films. The mice were either euthanized 24 h post-IR to evaluate acute tissue responses or followed up for 6 weeks to observe late-stage responses and survival probability. Complete blood count, histological analyses, and measurement of cytokine expression and redox status were performed. RESULTS The mean dose rate of >150 Gy/s and instantaneous dose rate of >5.5×105 Gy/s was reached in FLASH-IR at the center of mice body. After 6 weeks' follow-up of mice that received 15 Gy IR, the FLASH group showed faster body weight recovery and higher survival probability than the CONV group. Histological analysis showed that FLASH-IR induced less acute intestinal damage than CONV-IR. Complete blood count and cytokine concentration measurement found that the inflammatory blood cell counts and pro-inflammatory cytokine concentrations were elevated at the acute stage after both FLASH-IR and CONV-IR. However, FLASH irradiated mice had significantly fewer inflammatory blood cells and diminished pro-inflammatory cytokine at the late stage. Moreover, higher reactive oxygen species (ROS) signal intensities but significantly reduced lipid peroxidation were found in the FLASH group than in the CONV group in the acute stage. CONCLUSIONS The radioprotective effect of 6 MV X-ray FLASH-IR was observed. The differences in inflammatory responses and redox status between the two groups may be the factors responsible for reduced radiotoxicities following FLASH-IR. Further studies are required to thoroughly evaluate the impact of ROS on FLASH effect. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Hongyu Zhu
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Dehuan Xie
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Yiwei Yang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Shaomin Huang
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Xingwang Gao
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Yinglin Peng
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Bin Wang
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Jianxin Wang
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Dexin Xiao
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Dai Wu
- Institute of Applied Electronics, China Academy of Engineering Physics, Mianyang, 621900, China
| | - Changzhi Li
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
| | - Chenghua Li
- Center of Growth, Metabolism and Aging, Key Laboratory of Biological Resources and Ecological Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu, 610065, China
| | - Chao-Nan Qian
- Department of Nasopharyngeal Carcinoma, Sun Yat-Sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China.,Department of Radiation Oncology, Guangzhou Concord Cancer Center, Guangzhou, 510799, China
| | - Xiaowu Deng
- Department of Radiation Oncology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, 510060, China
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Bourgouin A, Knyziak A, Marinelli M, Kranzer R, Schüller A, Kapsch RP. Characterization of the PTB ultra-high pulse dose rate reference electron beam. Phys Med Biol 2022; 67. [DOI: 10.1088/1361-6560/ac5de8] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 03/15/2022] [Indexed: 11/12/2022]
Abstract
Abstract
Purpose. This investigation aims to present the characterisation and optimisation of an ultra-high pulse dose rate (UHPDR) electron beam at the PTB facility in Germany. A Monte Carlo beam model has been developed for dosimetry study for future investigation in FLASH radiotherapy and will be presented. Material and methods. The 20 MeV electron beams generated by the research linear accelerator has been characterised both in-beamline with profile monitors and magnet spectrometer, and in-water with a diamond detector prototype. The Monte Carlo model has been used to investigate six different setups to enable different dose per pulse (DPP) ranges and beam sizes in water. The properties of the electron radiation field in water have also been characterised in terms of beam size, quality specifier R
50 and flatness. The beam stability has also been studied. Results. The difference between the Monte-Carlo simulated and measured R
50 was smaller than 0.5 mm. The simulated beam sizes agreed with the measured ones within 2 mm. Two suitable setups have been identified for delivering reference UHPDR electron beams. The first one is characterised by a SSD of 70 cm, while in the second one an SSD of 90 cm is used in combination with a 2 mm aluminium scattering plates. The two set-ups are quick and simple to install and enable an expected overall DPP range from 0.13 Gy up to 6.7 Gy per pulse. Conclusion. The electron beams generated by the PTB research accelerator have shown to be stable throughout the four-months length of this investigation. The Monte Carlo models have shown to be in good agreement for beam size and depth dose and within 1% for the beam flatness. The diamond detector prototype has shown to be a promising tool to be used for relative measurements in UHPDR electron beams.
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Cavallone M, Jorge PG, Moeckli R, Bailat C, Flacco A, Prezado Y, Delorme R. Determination of the ion collection efficiency of the Razor Nano Chamber for ultra-high dose-rate electron beams. Med Phys 2022; 49:4731-4742. [PMID: 35441716 PMCID: PMC9539950 DOI: 10.1002/mp.15675] [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: 10/11/2021] [Revised: 04/07/2022] [Accepted: 04/12/2022] [Indexed: 11/10/2022] Open
Abstract
Background Ultra‐high dose‐rate (UHDR) irradiations (>40 Gy/s) have recently garnered interest in radiotherapy (RT) as they can trigger the so‐called “FLASH” effect, namely a higher tolerance of normal tissues in comparison with conventional dose rates when a sufficiently high dose is delivered to the tissue. To transfer this to clinical RT treatments, adapted methods and practical tools for online dosimetry need to be developed. Ionization chambers remain the gold standards in RT but the charge recombination effects may be very significant at such high dose rates, limiting the use of some of these dosimeters. The reduction of the sensitive volume size can be an interesting characteristic to reduce such effects. Purpose In that context, we have investigated the charge collection behavior of the recent IBA Razor™ Nano Chamber (RNC) in UHDR pulses to evaluate its potential interest for FLASH RT. Methods In order to quantify the RNC ion collection efficiency (ICE), simultaneous dose measurements were performed under UHDR electron beams with dose‐rate‐independent Gafchromic™ EBT3 films that were used as the dose reference. A dose‐per‐pulse range from 0.01 to 30 Gy was investigated, varying the source‐to‐surface distance, the pulse duration (1 and 3 μs investigated) and the LINAC gun grid tension as irradiation parameters. In addition, the RNC measurements were corrected from the inherent beam shot‐to‐shot variations using an independent current transformer. An empirical logistic model was used to fit the RNC collection efficiency measurements and the results were compared with the Advanced Markus plane parallel ion chamber. Results The RNC ICE was found to decrease as the dose‐per‐pulse increases, starting from doses above 0.2 Gy/pulse and down to 40% of efficiency at 30 Gy/pulse. The RNC resulted in a higher ICE for a given dose‐per‐pulse in comparison with the Markus chamber, with a measured efficiency found higher than 85 and 55% for 1 and 10 Gy/pulse, respectively, whereas the Markus ICE was of 60 and 25% for the same doses. However, the RNC shows a higher sensitivity to the pulse duration than the Advanced Markus chamber, with a lower efficiency found at 1 μs than at 3 μs, suggesting that this chamber could be more sensitive to the dose rate within the pulse. Conclusions The results confirmed that the small sensitive volume of the RNC ensures higher ICE compared with larger chambers. The RNC was thus found to be a promising online dosimetry tool for FLASH RT and we proposed an ion recombination model to correct its response up to extreme dose‐per‐pulses of 30 Gy.
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Affiliation(s)
- Marco Cavallone
- Institut Curie, PSL Research University, Radiation Oncology Department, Proton Therapy Centre, Centre Universitaire, Orsay, 91898, France.,Laboratoire d'Optique Appliquée, ENSTA Paris, École Polytechnique, CNRS-UMR7639, Institut Polytechnique de Paris, Palaiseau Cedex, 91762, France
| | | | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital, Lausanne, Switzerland
| | - Alessandro Flacco
- Laboratoire d'Optique Appliquée, ENSTA Paris, École Polytechnique, CNRS-UMR7639, Institut Polytechnique de Paris, Palaiseau Cedex, 91762, France
| | - Yolanda Prezado
- Institut Curie, Université PSL, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, 91400, France.,Université Paris-Saclay, CNRS UMR3347, Inserm U1021, Signalisation Radiobiologie et Cancer, Orsay, 91400, France
| | - Rachel Delorme
- University of Grenoble Alpes, CNRS, Grenoble INP, LPSC-IN2P3, Grenoble, 38000, France.,Imagerie et Modélisation en Neurobiologie et Cancérologie (IMNC), CNRS Univ Paris-Sud, Université Paris-Saclay, Orsay, F-91400, France
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300
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Ashraf MR, Rahman M, Cao X, Duval K, Williams BB, Hoopes PJ, Gladstone DJ, Pogue BW, Zhang R, Bruza P. Individual pulse monitoring and dose control system for pre-clinical implementation of FLASH-RT. Phys Med Biol 2022; 67:10.1088/1361-6560/ac5f6f. [PMID: 35313290 PMCID: PMC10305796 DOI: 10.1088/1361-6560/ac5f6f] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2021] [Accepted: 03/21/2022] [Indexed: 11/11/2022]
Abstract
Objective.Existing ultra-high dose rate (UHDR) electron sources lack dose rate independent dosimeters and a calibrated dose control system for accurate delivery. In this study, we aim to develop a custom single-pulse dose monitoring and a real-time dose-based control system for a FLASH enabled clinical linear accelerator (Linac).Approach.A commercially available point scintillator detector was coupled to a gated integrating amplifier and a real-time controller for dose monitoring and feedback control loop. The controller was programmed to integrate dose for each radiation pulse and stop the radiation beam when the prescribed dose was delivered. Additionally, the scintillator was mounted in a solid water phantom and placed underneath mice skin forin vivodose monitoring. The scintillator was characterized in terms of its radiation stability, mean dose-rate (Ḋm), and dose per pulse (Dp) dependence.Main results.TheDpexhibited a consistent ramp-up period across ∼4-5 pulse. The plastic scintillator was shown to be linear withḊm(40-380 Gy s-1) andDp(0.3-1.3 Gy Pulse-1) to within +/- 3%. However, the plastic scintillator was subject to significant radiation damage (16%/kGy) for the initial 1 kGy and would need to be calibrated frequently. Pulse-counting control was accurately implemented with one-to-one correspondence between the intended and the actual delivered pulses. The dose-based control was sufficient to gate on any pulse of the Linac.In vivodosimetry monitoring with a 1 cm circular cut-out revealed that during the ramp-up period, the averageDpwas ∼0.045 ± 0.004 Gy Pulse-1, whereas after the ramp-up it stabilized at 0.65 ± 0.01 Gy Pulse-1.Significance.The tools presented in this study can be used to determine the beam parameter space pertinent to the FLASH effect. Additionally, this study is the first instance of real-time dose-based control for a modified Linac at ultra-high dose rates, which provides insight into the tool required for future clinical translation of FLASH-RT.
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Affiliation(s)
- M. Ramish Ashraf
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
| | - Mahbubur Rahman
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
| | - Xu Cao
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
| | - Kayla Duval
- Department of Medicine, Geisel School of Medicine, Dartmouth College Hanover NH 03755 USA
| | - Benjamin B. Williams
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
- Department of Medicine, Geisel School of Medicine, Dartmouth College Hanover NH 03755 USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756 USA
| | - P. Jack Hoopes
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756 USA
- Department of Surgery, Geisel School of Medicine, Dartmouth College, Hanover NH 03755 USA
| | - David J. Gladstone
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
- Department of Medicine, Geisel School of Medicine, Dartmouth College Hanover NH 03755 USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756 USA
| | - Brian W. Pogue
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756 USA
- Department of Surgery, Geisel School of Medicine, Dartmouth College, Hanover NH 03755 USA
| | - Rongxiao Zhang
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
- Department of Medicine, Geisel School of Medicine, Dartmouth College Hanover NH 03755 USA
- Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03756 USA
| | - Petr Bruza
- Thayer School of Engineering, Dartmouth College, Hanover NH 03755, US
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