1
|
Overgaard CB, Reaz F, Sitarz M, Poulsen P, Overgaard J, Bassler N, Grau C, Sørensen BS. An experimental setup for proton irradiation of a murine leg model for radiobiological studies. Acta Oncol 2023; 62:1566-1573. [PMID: 37603112 DOI: 10.1080/0284186x.2023.2246641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/03/2023] [Indexed: 08/22/2023]
Abstract
BACKGROUND The purpose of this study was to introduce an experimental radiobiological setup used for in vivo irradiation of a mouse leg target in multiple positions along a proton beam path to investigate normal tissue- and tumor models with varying linear energy transfer (LET). We describe the dosimetric characterizations and an acute- and late-effect assay for normal tissue damage. METHODS The experimental setup consists of a water phantom that allows the right hind leg of three to five mice to be irradiated at the same time. Absolute dosimetry using a thimble (Semiflex) and a plane parallel (Advanced Markus) ionization chamber and Monte Carlo simulations using Geant4 and SHIELD-HIT12A were applied for dosimetric validation of positioning along the spread-out Bragg peak (SOBP) and at the distal edge and dose fall-off. The mice were irradiated in the center of the SOBP delivered by a pencil beam scanning system. The SOBP was 2.8 cm wide, centered at 6.9 cm depth, with planned physical single doses from 22 to 46 Gy. The biological endpoint was acute skin damage and radiation-induced late damage (RILD) assessed in the mouse leg. RESULTS The dose-response curves illustrate the percentage of mice exhibiting acute skin damage, and at a later point, RILD as a function of physical doses (Gy). Each dose-response curve represents a specific severity score of each assay, demonstrating a higher ED50 (50% responders) as the score increases. Moreover, the results reveal the reversible nature of acute skin damage as a function of time and the irreversible nature of RILD as time progresses. CONCLUSIONS We want to encourage researchers to report all experimental details of their radiobiological setups, including experimental protocols and model descriptions, to facilitate transparency and reproducibility. Based on this study, more experiments are being performed to explore all possibilities this radiobiological experimental setup permits.
Collapse
Affiliation(s)
- Cathrine Bang Overgaard
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Fardous Reaz
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark
| | - Mateusz Sitarz
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark
| | - Per Poulsen
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark
| | - Jens Overgaard
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Niels Bassler
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark
| | - Cai Grau
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark
| | - Brita Singers Sørensen
- Department of Experimental Clinical Oncology, Aarhus University Hospital, Denmark
- Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Danish Centre for Particle Therapy, Aarhus University Hospital, Denmark
| |
Collapse
|
2
|
Henthorn NT, Gardner LL, Aitkenhead AH, Rowland BC, Shin J, Smith EAK, Merchant MJ, Mackay RI, Kirkby KJ, Chaudhary P, Prise KM, McMahon SJ, Underwood TSA. Proposing a Clinical Model for RBE Based on Proton Track-End Counts. Int J Radiat Oncol Biol Phys 2023; 116:916-926. [PMID: 36642109 DOI: 10.1016/j.ijrobp.2022.12.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 12/21/2022] [Accepted: 12/29/2022] [Indexed: 01/15/2023]
Abstract
PURPOSE In proton therapy, the clinical application of linear energy transfer (LET) optimization remains contentious, in part because of challenges associated with the definition and calculation of LET and its exact relationship with relative biological effectiveness (RBE) because of large variation in experimental in vitro data. This has raised interest in other metrics with favorable properties for biological optimization, such as the number of proton track ends in a voxel. In this work, we propose a novel model for clinical calculations of RBE, based on proton track end counts. METHODS AND MATERIALS We developed an effective dose concept to translate between the total proton track-end count per unit mass in a voxel and a proton RBE value. Dose, track end, and dose-averaged LET (LETd) distributions were simulated using Monte Carlo models for a series of water phantoms, in vitro radiobiological studies, and patient treatment plans. We evaluated the correlation between track ends and regions of elevated biological effectiveness in comparison to LETd-based models of RBE. RESULTS Track ends were found to correlate with biological effects in in vitro experiments with an accuracy comparable to LETd. In patient simulations, our track end model identified the same biological hotspots as predicted by LETd-based radiobiological models of proton RBE. CONCLUSIONS These results suggest that, for clinical optimization and evaluation, an RBE model based on proton track end counts may match LETd-based models in terms of information provided while also offering superior statistical properties.
Collapse
Affiliation(s)
- Nicholas T Henthorn
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom.
| | - Lydia L Gardner
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Adam H Aitkenhead
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Benjamin C Rowland
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Jungwook Shin
- Department of Radiation Oncology, Harvard Medical School and Massachusetts General Hospital, Boston, Massachusetts
| | - Edward A K Smith
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Michael J Merchant
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Ranald I Mackay
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Karen J Kirkby
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom
| | - Pankaj Chaudhary
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Kevin M Prise
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Stephen J McMahon
- Patrick G. Johnston Centre for Cancer Research, Queen's University Belfast, Belfast, United Kingdom
| | - Tracy S A Underwood
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom; Manchester Academic Health Science Centre, The Christie NHS Foundation Trust, Manchester, United Kingdom; Leo Cancer Care Ltd, Unit 1 Woodbridge House, Chapel Rd, Smallfield, Horley RH6 9NW, United Kingdom
| |
Collapse
|
3
|
Schneider M, Bodenstein E, Bock J, Dietrich A, Gantz S, Heuchel L, Krause M, Lühr A, von Neubeck C, Nexhipi S, Schürer M, Tillner F, Beyreuther E, Suckert T, Müller JR. Combined proton radiography and irradiation for high-precision preclinical studies in small animals. Front Oncol 2022; 12:982417. [PMID: 36419890 PMCID: PMC9677333 DOI: 10.3389/fonc.2022.982417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/02/2022] [Indexed: 08/22/2023] Open
Abstract
BACKGROUND AND PURPOSE Proton therapy has become a popular treatment modality in the field of radiooncology due to higher spatial dose conformity compared to conventional radiotherapy, which holds the potential to spare normal tissue. Nevertheless, unresolved research questions, such as the much debated relative biological effectiveness (RBE) of protons, call for preclinical research, especially regarding in vivo studies. To mimic clinical workflows, high-precision small animal irradiation setups with image-guidance are needed. MATERIAL AND METHODS A preclinical experimental setup for small animal brain irradiation using proton radiographies was established to perform planning, repositioning, and irradiation of mice. The image quality of proton radiographies was optimized regarding the resolution, contrast-to-noise ratio (CNR), and minimal dose deposition in the animal. Subsequently, proof-of-concept histological analysis was conducted by staining for DNA double-strand breaks that were then correlated to the delivered dose. RESULTS The developed setup and workflow allow precise brain irradiation with a lateral target positioning accuracy of<0.26mm for in vivo experiments at minimal imaging dose of<23mGy per mouse. The custom-made software for image registration enables the fast and precise animal positioning at the beam with low observer-variability. DNA damage staining validated the successful positioning and irradiation of the mouse hippocampus. CONCLUSION Proton radiography enables fast and effective high-precision lateral alignment of proton beam and target volume in mouse irradiation experiments with limited dose exposure. In the future, this will enable irradiation of larger animal cohorts as well as fractionated proton irradiation.
Collapse
Affiliation(s)
- Moritz Schneider
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Elisabeth Bodenstein
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Johanna Bock
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Antje Dietrich
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- German Cancer Consortium Deutsches Konsortium für Translationale Krebsforschung (DKTK), partner site Dresden- German Cancer Research Center DKFZ, Heidelberg, Germany
| | - Sebastian Gantz
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Lena Heuchel
- Technical University (TU) Dortmund- Faculty of Physics, Medical Physics and Radiotherapy, Dortmund, Germany
| | - Mechthild Krause
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
- German Cancer Consortium Deutsches Konsortium für Translationale Krebsforschung (DKTK), partner site Dresden- German Cancer Research Center DKFZ, Heidelberg, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universitat Dresden, Dresden, Germany
| | - Armin Lühr
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
- Technical University (TU) Dortmund- Faculty of Physics, Medical Physics and Radiotherapy, Dortmund, Germany
| | - Cläre von Neubeck
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- German Cancer Consortium Deutsches Konsortium für Translationale Krebsforschung (DKTK), partner site Dresden- German Cancer Research Center DKFZ, Heidelberg, Germany
- Department of Particle Therapy, University Hospital Essen, University of Duisburg-Essen, Essen, Germany
| | - Sindi Nexhipi
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
| | - Michael Schürer
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- National Center for Tumor Diseases (NCT), Partner Site Dresden, Dresden, Germany
| | - Falk Tillner
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology - OncoRay, Dresden, Germany
- Department of Radiotherapy and Radiation Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universitat Dresden, Dresden, Germany
| | - Elke Beyreuther
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiation Physics, Dresden, Germany
| | - Theresa Suckert
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- German Cancer Consortium Deutsches Konsortium für Translationale Krebsforschung (DKTK), partner site Dresden- German Cancer Research Center DKFZ, Heidelberg, Germany
| | - Johannes Richard Müller
- OncoRay, National Center for Radiation Research in Oncology- Faculty of Medicine and University Hospital Carl Gustav Carus- Technische Universitat Dresden-Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
- Deutsche Forschungsgemeinschaft Cluster of Excellence 'Physics of Life', Technische Universität Dresden, Dresden, Germany
| |
Collapse
|
4
|
Suckert T, Nexhipi S, Dietrich A, Koch R, Kunz-Schughart LA, Bahn E, Beyreuther E. Models for Translational Proton Radiobiology-From Bench to Bedside and Back. Cancers (Basel) 2021; 13:4216. [PMID: 34439370 PMCID: PMC8395028 DOI: 10.3390/cancers13164216] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 12/25/2022] Open
Abstract
The number of proton therapy centers worldwide are increasing steadily, with more than two million cancer patients treated so far. Despite this development, pending questions on proton radiobiology still call for basic and translational preclinical research. Open issues are the on-going discussion on an energy-dependent varying proton RBE (relative biological effectiveness), a better characterization of normal tissue side effects and combination treatments with drugs originally developed for photon therapy. At the same time, novel possibilities arise, such as radioimmunotherapy, and new proton therapy schemata, such as FLASH irradiation and proton mini-beams. The study of those aspects demands for radiobiological models at different stages along the translational chain, allowing the investigation of mechanisms from the molecular level to whole organisms. Focusing on the challenges and specifics of proton research, this review summarizes the different available models, ranging from in vitro systems to animal studies of increasing complexity as well as complementing in silico approaches.
Collapse
Affiliation(s)
- Theresa Suckert
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Sindi Nexhipi
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, 01309 Dresden, Germany
| | - Antje Dietrich
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Robin Koch
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany; (R.K.); (E.B.)
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
| | - Leoni A. Kunz-Schughart
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- National Center for Tumor Diseases (NCT), Partner Site Dresden, 01307 Dresden, Germany
| | - Emanuel Bahn
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany; (R.K.); (E.B.)
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
- German Cancer Research Center (DKFZ), Clinical Cooperation Unit Radiation Oncology, 69120 Heidelberg, 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, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- Helmholtz-Zentrum Dresden—Rossendorf, Institute of Radiation Physics, 01328 Dresden, Germany
| |
Collapse
|
5
|
Otterlei OM, Indelicato DJ, Toussaint L, Ytre-Hauge KS, Pilskog S, Fjaera LF, Rørvik E, Pettersen HES, Muren LP, Lassen-Ramshad Y, Di Pinto M, Stokkevåg CH. Variation in relative biological effectiveness for cognitive structures in proton therapy of pediatric brain tumors. Acta Oncol 2021; 60:267-274. [PMID: 33131367 DOI: 10.1080/0284186x.2020.1840626] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
BACKGROUND Clinically, a constant value of 1.1 is used for the relative biological effectiveness (RBE) of protons, whereas in vitro the RBE has been shown to vary depending on physical dose, tissue type, and linear energy transfer (LET). As the LET increases at the distal end of the proton beam, concerns exist for an elevated RBE in normal tissues. The aim of this study was therefore to investigate the heterogeneity of RBE to brain structures associated with cognition (BSCs) in pediatric suprasellar tumors. MATERIAL AND METHODS Intensity-modulated proton therapy (IMPT) plans for 10 pediatric craniopharyngioma patients were re-calculated using 11 phenomenological and two plan-based variable RBE models. Based on LET, tissue dependence and number of data points used to fit the models, the three RBE models considered the most relevant for the studied endpoint were selected. Thirty BSCs were investigated in terms of RBE and dose/volume parameters. RESULTS For a representative patient, the median (range) dose-weighted mean RBE (RBEd) across all BSCs from the plan-based models was among the lowest (1.09 (1.02-1.52) vs. the phenomenological models at 1.21 (0.78-2.24)). Omitting tissue dependency resulted in RBEd at 1.21 (1.04-2.24). Across all patients, the narrower RBE model selection gave median RBEd values from 1.22 to 1.30. CONCLUSION For all BSCs, there was a systematic model-dependent variation in RBEd, mirroring the uncertainty in biological effects of protons. According to a refined selection of in vitro models, the RBE variation across BSCs was in effect underestimated when using a fixed RBE of 1.1.
Collapse
Affiliation(s)
| | | | - Laura Toussaint
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Sara Pilskog
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| | | | - Eivind Rørvik
- Department of Physics and Technology, University of Bergen, Bergen, Norway
| | | | - Ludvig P. Muren
- Department of Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | | | - Marcos Di Pinto
- Department of Radiation Oncology, University of Florida, Jacksonville, FL, USA
| | - Camilla H. Stokkevåg
- Department of Physics and Technology, University of Bergen, Bergen, Norway
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway
| |
Collapse
|