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Ashraf MR, Melemenidis S, Liu K, Grilj V, Jansen J, Velasquez B, Connell L, Schulz JB, Bailat C, Libed A, Manjappa R, Dutt S, Soto L, Lau B, Garza A, Larsen W, Skinner L, Yu AS, Surucu M, Graves EE, Maxim PG, Kry SF, Vozenin MC, Schüler E, Loo BW. Multi-Institutional Audit of FLASH and Conventional Dosimetry With a 3D Printed Anatomically Realistic Mouse Phantom. Int J Radiat Oncol Biol Phys 2024; 120:287-300. [PMID: 38493902 DOI: 10.1016/j.ijrobp.2024.03.017] [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: 10/19/2023] [Revised: 03/03/2024] [Accepted: 03/10/2024] [Indexed: 03/19/2024]
Abstract
PURPOSE We conducted a multi-institutional dosimetric audit between FLASH and conventional dose rate (CONV) electron irradiations by using an anatomically realistic 3-dimensional (3D) printed mouse phantom. METHODS AND MATERIALS A computed tomography (CT) scan of a live mouse was used to create a 3D model of bony anatomy, lungs, and soft tissue. A dual-nozzle 3D printer was used to print the mouse phantom using acrylonitrile butadiene styrene (∼1.02 g/cm3) and polylactic acid (∼1.24 g/cm3) simultaneously to simulate soft tissue and bone densities, respectively. The lungs were printed separately using lightweight polylactic acid (∼0.64 g/cm3). Hounsfield units (HU), densities, and print-to-print stability of the phantoms were assessed. Three institutions were each provided a phantom and each institution performed 2 replicates of irradiations at selected anatomic regions. The average dose difference between FLASH and CONV dose distributions and deviation from the prescribed dose were measured with radiochromic film. RESULTS Compared with the reference CT scan, CT scans of the phantom demonstrated mass density differences of 0.10 g/cm3 for bone, 0.12 g/cm3 for lung, and 0.03 g/cm3 for soft tissue regions. Differences in HU between phantoms were <10 HU for soft tissue and bone, with lung showing the most variation (54 HU), but with minimal effect on dose distribution (<0.5%). Mean differences between FLASH and CONV decreased from the first to the second replicate (4.3%-1.2%), and differences from the prescribed dose decreased for both CONV (3.6%-2.5%) and FLASH (6.4%-2.7%). Total dose accuracy suggests consistent pulse dose and pulse number, although these were not specifically assessed. Positioning variability was observed, likely due to the absence of robust positioning aids or image guidance. CONCLUSIONS This study marks the first dosimetric audit for FLASH using a nonhomogeneous phantom, challenging conventional calibration practices reliant on homogeneous phantoms. The comparison protocol offers a framework for credentialing multi-institutional studies in FLASH preclinical research to enhance reproducibility of biologic findings.
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Affiliation(s)
- M Ramish Ashraf
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Stavros Melemenidis
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Kevin Liu
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Veljko Grilj
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Jeannette Jansen
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland
| | - Brett Velasquez
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Luke Connell
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Joseph B Schulz
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Claude Bailat
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Switzerland
| | - Aaron Libed
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Rakesh Manjappa
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Suparna Dutt
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Luis Soto
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Brianna Lau
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Aaron Garza
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - William Larsen
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Lawrie Skinner
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Amy S Yu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Murat Surucu
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California
| | - Edward E Graves
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California
| | - Peter G Maxim
- Department of Radiation Oncology, University of California, Irvine, California
| | - Stephen F Kry
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas; Imaging and Radiation Oncology Core, MD Anderson Cancer Center, Houston, USA
| | - Marie-Catherine Vozenin
- Radiation Oncology Laboratory, Department of Radiation Oncology, Lausanne, University Hospital and University of Lausanne, Switzerland; Radiotherapy and Radiobiology Sector, Radiation Therapy Service, University Hospital of Geneva, Geneva, Switzerland.
| | - Emil Schüler
- Department of Radiation Physics, Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas.
| | - Billy W Loo
- Department of Radiation Oncology, Stanford University School of Medicine, Stanford, California; Stanford Cancer Institute, Stanford University School of Medicine, Stanford, California.
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Whitmore L, Mackay RI, van Herk M, Korysko P, Farabolini W, Malyzhenkov A, Corsini R, Jones RM. CERN-based experiments and Monte-Carlo studies on focused dose delivery with very high energy electron (VHEE) beams for radiotherapy applications. Sci Rep 2024; 14:11120. [PMID: 38750131 PMCID: PMC11096185 DOI: 10.1038/s41598-024-60997-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 04/30/2024] [Indexed: 05/18/2024] Open
Abstract
Very High Energy Electron (VHEE) beams are a promising alternative to conventional radiotherapy due to their highly penetrating nature and their applicability as a modality for FLASH (ultra-high dose-rate) radiotherapy. The dose distributions due to VHEE need to be optimised; one option is through the use of quadrupole magnets to focus the beam, reducing the dose to healthy tissue and allowing for targeted dose delivery at conventional or FLASH dose-rates. This paper presents an in depth exploration of the focusing achievable at the current CLEAR (CERN Linear Electron Accelerator for Research) facility, for beam energies >200 MeV. A shorter, more optimal quadrupole setup was also investigated using the TOPAS code in Monte Carlo simulations, with dimensions and beam parameters more appropriate to a clinical situation. This work provides insight into how a focused VHEE radiotherapy beam delivery system might be achieved.
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Affiliation(s)
- L Whitmore
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK
- The Cockcroft Institute of Science and Technology, Daresbury, UK
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, USA
| | - R I Mackay
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | - M van Herk
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, UK
- Christie Medical Physics and Engineering, The Christie NHS Foundation Trust, Manchester, UK
| | - P Korysko
- Department of Physics, University of Oxford, Oxford, UK
- CERN, 1211, Geneva 23, Switzerland
| | | | | | | | - R M Jones
- Department of Physics and Astronomy, University of Manchester, Manchester, M13 9PL, UK.
- The Cockcroft Institute of Science and Technology, Daresbury, UK.
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Frederiksen AT, Jensen MB, Poulsen PR, Bassler N, Sørensen BS, Sitarz M. Evaluation of in vitro irradiation setup: Designed for the horizontal beamline at the Danish Centre for Particle Therapy. Acta Oncol 2024; 63:23-27. [PMID: 38349282 DOI: 10.2340/1651-226x.2024.19657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 11/02/2023] [Indexed: 02/15/2024]
Abstract
BACKGROUND Radiobiological experimental setups are challenged by precise sample positioning along depth dose profile, scattering conditions, and practical difficulties that must be addressed in individual designs. The aim of this study was to produce cell survival curves with several irradiation modalities, by using a setup designed at the Danish Centre for Particle Therapy (DCPT) for in vitro proton irradiations using a horizontal beam line and thereby evaluating the setups use for in vitro irradiations experiments. MATERIALS AND METHODS The setup is a water phantom suitable for in vitro research with multiple irradiation modalities, in particular the pencil scanning proton beam available from a horizontal experimental beamline. The phantom included a water tank of 39.0 × 17.0 × 20.5 cm. Cell survival-curves were produced using the cell line V79 Chinese hamster lung fibroblast cells (V79s) in biological triplicates of clonogenic assays. Cell survival curves were produced with both a 18 MeV electron beam, 6 MV photon beam, and a Spread-Out Bragg Peak (SOBP) proton beam formed by pristine energies of 85-111 MeV where three positions were examined. RESULTS Survival curves with uncertainty areas were made for all modalities. Dosimetric uncertainty amounted to, respectively, 4%, 3% and 3% for proton, electron, and high energy photon irradiations. Cell survival fraction uncertainty was depicted as the standard deviation between replications of the experiment. CONCLUSION Cell survival curves could be produced with acceptable uncertainties using this novel water phantom and cellular laboratory workflow. The setup is useful for future in vitro irradiation experiments.
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Affiliation(s)
- Anders Tobias Frederiksen
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark; Institute for Biomedicine, Aarhus University, Aarhus, Denmark; Department of Public Health, Department of Biostatistics, Aarhus University, Aarhus, Denmark.
| | - Morten Bjørn Jensen
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus Denmark; Department for Medical Physics, Aarhus University Hospital, Aarhus, Denmark
| | - Per Rugaard Poulsen
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus Denmark
| | - Niels Bassler
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus Denmark
| | - Brita Singers Sørensen
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus Denmark; Department of Experimental Clinical Oncology, Aarhus University Hospital, Aarhus, Denmark
| | - Mateusz Sitarz
- Danish Centre for Particle Therapy (DCPT), Aarhus University Hospital, Aarhus Denmark
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Biltekin F, Bäumer C, Esser J, Ghanem O, Ozyigit G, Timmermann B. Preclinical Dosimetry for Small Animal Radiation Research in Proton Therapy: A Feasibility Study. Int J Part Ther 2023; 10:13-22. [PMID: 37823014 PMCID: PMC10563666 DOI: 10.14338/ijpt-22-00035.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 02/10/2023] [Indexed: 10/13/2023] Open
Abstract
Purpose To evaluate the feasibility of the three-dimensional (3D) printed small animal phantoms in dosimetric verification of proton therapy for small animal radiation research. Materials and Methods Two different phantoms were modeled using the computed-tomography dataset of real rat and tumor-bearing mouse, retrospectively. Rat phantoms were designed to accommodate both EBT3 film and ionization chamber. A subcutaneous tumor-bearing mouse phantom was only modified to accommodate film dosimetry. All phantoms were printed using polylactic-acid (PLA) filament. Optimal printing parameters were set to create tissue-equivalent material. Then, proton therapy plans for different anatomical targets, including whole brain and total lung irradiation in the rat phantom and the subcutaneous tumor model in the mouse phantom, were created using the pencil-beam scanning technique. Point dose and film dosimetry measurements were performed using 3D-printed phantoms. In addition, all phantoms were analyzed in terms of printing accuracy and uniformity. Results Three-dimensionally printed phantoms had excellent uniformity over the external body, and printing accuracy was within 0.5 mm. According to our findings, two-dimensional dosimetry with EBT3 showed acceptable levels of γ passing rate for all measurements except for whole brain irradiation (γ passing rate, 89.8%). In terms of point dose analysis, a good agreement (<0.1%) was found between the measured and calculated point doses for all anatomical targets. Conclusion Three-dimensionally printed small animal phantoms show great potential for dosimetric verifications of clinical proton therapy for small animal radiation research.
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Affiliation(s)
- Fatih Biltekin
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
| | - Christian Bäumer
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- TU Dortmund University, Department of Physics, Dortmund, Germany
| | - Johannes Esser
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Osamah Ghanem
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
| | - Gokhan Ozyigit
- Department of Radiation Oncology, Faculty of Medicine, Hacettepe University, Ankara, Turkey
| | - Beate Timmermann
- West German Proton Therapy Centre Essen (WPE), Essen, Germany
- West German Cancer Centre (WTZ), Essen, Germany
- German Cancer Consortium (DKTK), Heidelberg, Germany
- TU Dortmund University, Department of Physics, Dortmund, Germany
- Department of Particle Therapy, University Hospital Essen, Essen, Germany
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Silvestre Patallo I, Subiel A, Carter R, Flynn S, Schettino G, Nisbet A. Characterization of Inorganic Scintillator Detectors for Dosimetry in Image-Guided Small Animal Radiotherapy Platforms. Cancers (Basel) 2023; 15:987. [PMID: 36765943 PMCID: PMC9913621 DOI: 10.3390/cancers15030987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/24/2023] [Accepted: 02/01/2023] [Indexed: 02/09/2023] Open
Abstract
The purpose of the study was to characterize a detection system based on inorganic scintillators and determine its suitability for dosimetry in preclinical radiation research. Dose rate, linearity, and repeatability of the response (among others) were assessed for medium-energy X-ray beam qualities. The response's variation with temperature and beam angle incidence was also evaluated. Absorbed dose quality-dependent calibration coefficients, based on a cross-calibration against air kerma secondary standard ionization chambers, were determined. Relative output factors (ROF) for small, collimated fields (≤10 mm × 10 mm) were measured and compared with Gafchromic film and to a CMOS imaging sensor. Independently of the beam quality, the scintillator signal repeatability was adequate and linear with dose. Compared with EBT3 films and CMOS, ROF was within 5% (except for smaller circular fields). We demonstrated that when the detector is cross-calibrated in the user's beam, it is a useful tool for dosimetry in medium-energy X-rays with small fields delivered by Image-Guided Small Animal Radiotherapy Platforms. It supports the development of procedures for independent "live" dose verification of complex preclinical radiotherapy plans with the possibility to insert the detectors in phantoms.
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Affiliation(s)
- Ileana Silvestre Patallo
- Medical Radiation Physics and Science Groups, National Physical Laboratory (NPL), Guilford TW11 0LW, UK
| | - Anna Subiel
- Medical Radiation Physics and Science Groups, National Physical Laboratory (NPL), Guilford TW11 0LW, UK
| | - Rebecca Carter
- Cancer Institute, University College London, London WC1E 6DD, UK
| | - Samuel Flynn
- Medical Radiation Physics and Science Groups, National Physical Laboratory (NPL), Guilford TW11 0LW, UK
- School of Physics and Astronomy, University of Birmingham, Edgbaston Campus, Birmingham B15 2TT, UK
| | - Giuseppe Schettino
- Medical Radiation Physics and Science Groups, National Physical Laboratory (NPL), Guilford TW11 0LW, UK
- Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Andrew Nisbet
- Department of Medical Physics & Biomedical Engineering, University College London, Mallet Place Engineering Building, London WC1E 6BT, UK
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