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Hassan A, Atkinson KD. Local environment in yeast-based impedance biodosimeters strongly influences the measurable dose. Appl Radiat Isot 2024; 209:111323. [PMID: 38631246 DOI: 10.1016/j.apradiso.2024.111323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 03/12/2024] [Accepted: 04/09/2024] [Indexed: 04/19/2024]
Abstract
This work investigates the feasibility of yeast-based impedance measurements for retrospective dosimetry applications. The local environment around yeast cells in a previously developed film-badge was modeled using Geant4. A greater dose response was observed when yeast cells were surrounded by an aluminum-polymer structure, which acted as a conversion layer. Bench-top experiments were conducted using a jar-based dosimeter design that directly combined a finely-ground aluminum conversion medium with yeast powder. It was shown when irradiated in the presence of aluminum grains, yeast cells yielded a higher impedance signal, thereby indicating greater radiation-induced damage. Finally, in separate irradiation experiments, lead and aluminum sheets were placed behind yeast samples and the dosimeters were irradiated to 1 Gy. A 2-fold increase in the impedance signal was shown when samples were positioned in close contact with the lead sheet compared to the aluminum sheet. In all experiments, it was shown that the local environment significantly influences radiative energy deposition in yeast cells.
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Affiliation(s)
- A Hassan
- Ontario Tech University, 2000 Simcoe Street, N, Oshawa, Ontario, L1G 0C5, Canada.
| | - K D Atkinson
- Ontario Tech University, 2000 Simcoe Street, N, Oshawa, Ontario, L1G 0C5, Canada
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2
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White AJ, Jollota SP, Hammer CG, Khan AU, DeWerd LA, Culberson WS. Thermoluminescent dosimeters (TLD-100) for absorbed dose measurements in alpha-emitting radionuclides. Appl Radiat Isot 2024; 208:111307. [PMID: 38564840 DOI: 10.1016/j.apradiso.2024.111307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 03/25/2024] [Accepted: 03/27/2024] [Indexed: 04/04/2024]
Abstract
Early works that used thermoluminescent dosimeters (TLDs) to measure absorbed dose from alpha particles reported relatively high variation (10%) between TLDs, which is undesirable for modern dosimetry applications. This work outlines a method to increase precision for absorbed dose measured using TLDs with alpha-emitting radionuclides by applying an alpha-specific chip factor (CF) that individually characterizes the TLD sensitivity to alpha particles. Variation between TLDs was reduced from 21.8% to 6.7% for the standard TLD chips and 7.9% to 3.3% for the thin TLD chips. It has been demonstrated by this work that TLD-100 can be calibrated to precisely measure the absorbed dose to water from alpha-emitting radionuclides.
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Affiliation(s)
- Andrew J White
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI, 53705, USA.
| | - Sean P Jollota
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Cliff G Hammer
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Ahtesham U Khan
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI, 53705, USA; Department of Radiation Oncology, Northwestern Memorial Hospital, 250 E. Huron St, Chicago, IL, 60611, USA
| | - Larry A DeWerd
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI, 53705, USA
| | - Wesley S Culberson
- Department of Medical Physics, School of Medicine and Public Health, University of Wisconsin-Madison, 1111 Highland Ave, Madison, WI, 53705, USA
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3
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Olch AJ, van Luijk P, Hua CH, Avanzo M, Howell RM, Yorke E, Aznar MC, Kry SF. Physics Considerations for Evaluation of Dose for Dose-Response Models of Pediatric Late Effects From Radiation Therapy: A PENTEC Introductory Review. Int J Radiat Oncol Biol Phys 2024; 119:360-368. [PMID: 37003845 DOI: 10.1016/j.ijrobp.2023.02.060] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 02/17/2023] [Accepted: 02/25/2023] [Indexed: 04/01/2023]
Abstract
PURPOSE We describe the methods used to estimate the accuracy of dosimetric data found in literature sources used to construct the Pediatric Normal Tissue Effects in the Clinic (PENTEC) dose-response models, summarize these findings of each organ-specific task force, describe some of the dosimetric challenges and the extent to which these efforts affected the final modeling results, and provide guidance on the interpretation of the dose-response results given the various dosimetric uncertainties. METHODS AND MATERIALS Each of the PENTEC task force medical physicists reviewed all the journal articles used for dose-response modeling to identify, categorize, and quantify dosimetric uncertainties. These uncertainties fell into 6 broad categories. A uniform nomenclature was developed for describing the "dosimetric quality" of the articles used in the PENTEC reviews. Among the multidisciplinary experts in the PENTEC effort, the medical physicists were charged with the dosimetric evaluation, as they are most expert in this subject. RESULTS The percentage dosimetric uncertainty was estimated for each late effect endpoint for all PENTEC organ reports. Twelve specific sources of dose uncertainty were identified related to the 6 broad categories. The most common reason for organ dose uncertainty was that prescribed dose rather than organ dose was reported. Percentage dose uncertainties ranged from 5% to 200%. Systematic uncertainties were used to correct the dose component of the models. Random uncertainties were also described in each report and in some cases used to modify dose axis error bars. In addition, the potential effects of dose binning were described. CONCLUSIONS PENTEC reports are designed to provide guidance to radiation oncologists and treatment planners for organ dose constraints. It is critical that these dose constraint recommendations are as accurate as possible, acknowledging the large error bars for many. Achieving this accuracy is important as it enables clinicians to better balance target dose coverage with risk of late effects. Evidence-based dose constraints for pediatric patients have been lacking and, in this regard, PENTEC fills an important unmet need. One must be aware of the limitations of our recommendations, and that for some organ systems, large uncertainties exist in the dose-response model because of clinical endpoint uncertainty, dosimetric uncertainty, or both.
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Affiliation(s)
- Arthur J Olch
- Department of Radiation Oncology, University of Southern California and Children's Hospital Los Angeles, Los Angeles, California.
| | - Peter van Luijk
- Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, The Netherlands
| | - Chia-Ho Hua
- Department of Radiation Oncology, St. Jude Children's Research Hospital, Memphis, Tennessee
| | - Michele Avanzo
- Department of Medical Physics, Centro di Riferimento Oncologico di Aviano (CRO) IRCCS, Aviano, Italy
| | - Rebecca M Howell
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas
| | - Ellen Yorke
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, New York
| | - Marianne C Aznar
- Division of Cancer Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Stephen F Kry
- Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas
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4
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Andrade EMR, Paixão L, Mendes BM, Fonseca TCF. RFPID: development and 3D-printing of a female physical phantom for whole-body counter. Biomed Phys Eng Express 2024; 10:045015. [PMID: 38697045 DOI: 10.1088/2057-1976/ad4650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Accepted: 05/02/2024] [Indexed: 05/04/2024]
Abstract
Whole-body counters (WBC) are used in internal dosimetry forin vivomonitoring in radiation protection. The calibration processes of a WBC set-up include the measurement of a physical phantom filled with a certificate radioactive source that usually is referred to a standard set of individuals determined by the International Commission on Radiological Protection (ICRP). The aim of this study was to develop an anthropomorphic and anthropometric female physical phantom for the calibration of the WBC systems. The reference female computational phantom of the ICRP, now called RFPID (Reference Female Phantom for Internal Dosimetry) was printed using PLA filament and with an empty interior. The goal is to use the RFPID to reduce the uncertainties associated within vivomonitoring system. The images which generated the phantom were manipulated using ImageJ®, Amide®, GIMP®and the 3D Slicer®software. RFPID was split into several parts and printed using a 3D printer in order to print the whole-body phantom. The newly printed physical phantom RFPID was successfully fabricated, and it is suitable to mimic human tissue, anatomically similar to a human body i.e., size, shape, material composition, and density.
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Affiliation(s)
- E M R Andrade
- Nuclear Engineering Department, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Nuclear Technology Development Center, Belo Horizonte, Minas Gerais, Brazil
| | - L Paixão
- Anatomy and Imaging Department, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - B M Mendes
- Nuclear Technology Development Center, Belo Horizonte, Minas Gerais, Brazil
| | - T C F Fonseca
- Nuclear Engineering Department, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Nuclear Technology Development Center, Belo Horizonte, Minas Gerais, Brazil
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5
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Oliveira AM, Akkerman HB, Braccini S, van Breemen AJJM, Gelinck GH, Heracleous N, Leidner J, Murtas F, Peeters B, Silari M. A high-resolution large-area detector for quality assurance in radiotherapy. Sci Rep 2024; 14:10637. [PMID: 38724569 PMCID: PMC11082155 DOI: 10.1038/s41598-024-61095-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2023] [Accepted: 04/30/2024] [Indexed: 05/12/2024] Open
Abstract
Hadron therapy is an advanced radiation modality for treating cancer, which currently uses protons and carbon ions. Hadrons allow for a highly conformal dose distribution to the tumour, minimising the detrimental side-effects due to radiation received by healthy tissues. Treatment with hadrons requires sub-millimetre spatial resolution and high dosimetric accuracy. This paper discusses the design, fabrication and performance tests of a detector based on Gas Electron Multipliers (GEM) coupled to a matrix of thin-film transistors (TFT), with an active area of 60 × 80 mm2 and 200 ppi resolution. The experimental results show that this novel detector is able to detect low-energy (40 kVp X-rays), high-energy (6 MeV) photons used in conventional radiation therapy and protons and carbon ions of clinical energies used in hadron therapy. The GEM-TFT is a compact, fully scalable, radiation-hard detector that measures secondary electrons produced by the GEMs with sub-millimetre spatial resolution and a linear response for proton currents from 18 pA to 0.7 nA. Correcting known detector defects may aid in future studies on dose uniformity, LET dependence, and different gas mixture evaluation, improving the accuracy of QA in radiotherapy.
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Affiliation(s)
- Andreia Maia Oliveira
- CERN - Occupational Health & Safety and Environmental Protection Unit, Radiation Protection Group, 1211, Geneva 23, Switzerland.
- Laboratory for High Energy Physics (LHEP), Albert Einstein Center for Fundamental Physics (AEC), University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland.
- EBG MedAustron GmbH, Marie Curie-Straße 5, 2700, Wiener Neustadt, Austria.
| | - Hylke B Akkerman
- Holst Centre/TNO, High Tech, Campus 31, 5656 AE, Eindhoven, The Netherlands
| | - Saverio Braccini
- Laboratory for High Energy Physics (LHEP), Albert Einstein Center for Fundamental Physics (AEC), University of Bern, Sidlerstrasse 5, 3012, Bern, Switzerland
| | | | - Gerwin H Gelinck
- Holst Centre/TNO, High Tech, Campus 31, 5656 AE, Eindhoven, The Netherlands
| | - Natalie Heracleous
- CERN - Occupational Health & Safety and Environmental Protection Unit, Radiation Protection Group, 1211, Geneva 23, Switzerland
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Johannes Leidner
- CERN - Occupational Health & Safety and Environmental Protection Unit, Radiation Protection Group, 1211, Geneva 23, Switzerland
- Medidee Services SA, Chemin de Rovéréaz 5, 1012, Lausanne, Switzerland
| | - Fabrizio Murtas
- CERN - Occupational Health & Safety and Environmental Protection Unit, Radiation Protection Group, 1211, Geneva 23, Switzerland
- INFN-LNF, 00044, Frascati, Italy
| | - Bart Peeters
- Holst Centre/TNO, High Tech, Campus 31, 5656 AE, Eindhoven, The Netherlands
| | - Marco Silari
- CERN - Occupational Health & Safety and Environmental Protection Unit, Radiation Protection Group, 1211, Geneva 23, Switzerland
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Vilches-Freixas G, Bosmans G, Douralis A, Martens J, Meijers A, Rinaldi I, Salvo K, Thomas R, Palmans H, Lourenço A. Experimental comparison of cylindrical and plane parallel ionization chambers for reference dosimetry in continuous and pulsed scanned proton beams. Phys Med Biol 2024; 69:105021. [PMID: 38640918 DOI: 10.1088/1361-6560/ad40f9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 04/19/2024] [Indexed: 04/21/2024]
Abstract
Objective. In this experimental work we compared the determination of absorbed dose to water using four ionization chambers (ICs), a PTW-34045 Advanced Markus, a PTW-34001 Roos, an IBA-PPC05 and a PTW-30012 Farmer, irradiated under the same conditions in one continuous- and in two pulsed-scanned proton beams.Approach. The ICs were positioned at 2 cm depth in a water phantom in four square-field single-energy scanned-proton beams with nominal energies between 80 and 220 MeV and in the middle of 10 × 10 × 10 cm3dose cubes centered at 10 cm or 12.5 cm depth in water. The water-equivalent thickness (WET) of the entrance window and the effective point of measurement was considered when positioning the plane parallel (PP) ICs and the cylindrical ICs, respectively. To reduce uncertainties, all ICs were calibrated at the same primary standards laboratory. We used the beam quality (kQ) correction factors for the ICs under investigation from IAEA TRS-398, the newly calculated Monte Carlo (MC) values and the anticipated IAEA TRS-398 updated recommendations.Main results. Dose differences among the four ICs ranged between 1.5% and 3.7% using both the TRS-398 and the newly recommendedkQvalues. The spread among the chambers is reduced with the newlykQvalues. The largest differences were observed between the rest of the ICs and the IBA-PPC05 IC, obtaining lower dose with the IBA-PPC05.Significance. We provide experimental data comparing different types of chambers in different proton beam qualities. The observed dose differences between the ICs appear to be related to inconsistencies in the determination of thekQvalues. For PP ICs, MC studies account for the physical thickness of the entrance window rather than the WET. The additional energy loss that the wall material invokes is not negligible for the IBA-PPC05 and might partially explain the lowkQvalues determined for this IC. To resolve this inconsistency and to benchmark MC values,kQvalues measured using calorimetry are needed.
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Affiliation(s)
- Gloria Vilches-Freixas
- Department of Radiation Oncology (Maastro), GROW Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Geert Bosmans
- Department of Radiation Oncology (Maastro), GROW Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | | | - Jonathan Martens
- Department of Radiation Oncology (Maastro), GROW Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Arturs Meijers
- Paul Scherrer Institut, Villigen, Switzerland (current address), University Medical Centre Groningen, Groningen, The Netherlands
| | - Ilaria Rinaldi
- Department of Radiation Oncology (Maastro), GROW Research Institute for Oncology and Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Koen Salvo
- UZ Leuven, Particle Therapy Interuniversity Center Leuven - PARTICLE, Leuven, Belgium
| | - Russell Thomas
- National Physical Laboratory, Teddington, United Kingdom
- University College London, London, United Kingdom
| | - Hugo Palmans
- National Physical Laboratory, Teddington, United Kingdom
- MedAustron Ion Therapy Center, Wiener Neustadt, Austria
| | - Ana Lourenço
- National Physical Laboratory, Teddington, United Kingdom
- University College London, London, United Kingdom
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7
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Yu S, Shi H, Zhong X. Tissue equivalent conversion of silicon-based microdosemeters in hadron therapy. Radiat Prot Dosimetry 2024; 200:670-676. [PMID: 38665036 DOI: 10.1093/rpd/ncae096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Revised: 11/10/2023] [Accepted: 03/28/2024] [Indexed: 05/09/2024]
Abstract
Silicon has been developed as a microdosemeter, as it can provide sensitive volumes at submicrometric levels, does not need a gas supply, has a fast response, and has low power consumption. However, since the energy response in silicon is not the same as that in tissue, a spectral conversion from silicon to tissue is necessary to obtain the probability distribution of energy deposition in tissue. In this work, we present a method for microdosimetric spectra conversion from silicon to tissue based on the scaled Fourier transformation and the geometric scaling factor, which shows relatively good results in the spectral conversion from diamond to tissue. The results illustrate that the method can convert the energy deposition spectra from silicon to tissue with proper accuracy. Meanwhile, the inconsistency between the converted and actual spectra due to the inherent difference was also observed. Whereas, the reasons for the disagreement are different. For the plateau part of the Bragg curve, the discrepancy between the converted and actual spectra is due to the poor tissue equivalent of silicon. For the proximal part of the Bragg curve, the spectral difference is attributed to the different shapes of the energy deposition spectra obtained in silicon and water, which is the same as that in the diamond. In summary, this method can be employed in the tissue equivalent conversion of silicon microdosemeter, but the poor tissue equivalent of silicon limited the accuracy of this method. In addition, the correction for the deviation between the converted and calculated spectra due to the difference in spectral shapes is required to improve the practicality of this mod.
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Affiliation(s)
- Songke Yu
- School of Electronic Engineering, Chengdu Technological University, Chengdu, 611730, China
| | - Hui Shi
- Technology and Innovation Application Center, CGN Environmental Technology Co. Ltd, Shenzhen, 518000, China
| | - Xiaojuan Zhong
- Library, Chengdu Technological University, Chengdu, Pidu District, 611730, China
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8
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Narita R, Sakurai Y. Estimation of internal-exposure contribution in radiation dose exposure for boron neutron capture therapy. Radiat Prot Dosimetry 2024; 200:623-628. [PMID: 38527175 DOI: 10.1093/rpd/ncae073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2023] [Revised: 02/12/2024] [Accepted: 03/03/2024] [Indexed: 03/27/2024]
Abstract
Although boron neutron capture therapy (BNCT) causes minor damage to normal cells owing to the nuclear reactions induced by neutrons with major elements of tissues such as hydrogen and nitrogen, it is useful to estimate the accurate exposure dose for radiation protection. This study aims to estimate the contribution of internal exposure in radiation exposure dose for BNCT. The study was performed by referring to clinical studies at a reactor-based BNCT facility on the basis of computational dosimetry. Five irradiation regions of head and neck were selected for the estimation. The results suggest that external exposure occurred primarily in and around the irradiation field. Furthermore, during the exposure dose estimation in BNCT, internal exposure was found to be not negligible, implying that the irradiation regions in treatment planning must be considered for avoiding damage to certain critical organs that are susceptible to internal exposure.
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Affiliation(s)
- Ryosuke Narita
- Graduate School of Engineering, Kyoto University, Kyoto daigaku-katsura, Nishikyo-ku, Kyoto 615-8530, Japan
| | - Yoshinori Sakurai
- Institute for Integrated Radiation and Nuclear Science, Kyoto University, 2, Asashiro-Nishi, Kumatori-cho, Sennan-gun, Osaka 590-0494, Japan
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9
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Draeger E, Roberts K, Decker RD, Bahar N, Wilson LD, Contessa J, Husain Z, Williams BB, Flood AB, Swartz HM, Carlson DJ. In Vivo Verification of Electron Paramagnetic Resonance Biodosimetry Using Patients Undergoing Radiation Therapy Treatment. Int J Radiat Oncol Biol Phys 2024; 119:292-301. [PMID: 38072322 DOI: 10.1016/j.ijrobp.2023.11.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/28/2023] [Accepted: 11/19/2023] [Indexed: 01/06/2024]
Abstract
PURPOSE Electron paramagnetic resonance (EPR) biodosimetry, used to triage large numbers of individuals incidentally exposed to unknown doses of ionizing radiation, is based on detecting a stable physical response in the body that is subject to quantifiable variation after exposure. In vivo measurement is essential to fully characterize the radiation response relevant to a living tooth measured in situ. The purpose of this study was to verify EPR spectroscopy in vivo by estimating the radiation dose received in participants' teeth. METHODS AND MATERIALS A continuous wave L-band spectrometer was used for EPR measurements. Participants included healthy volunteers and patients undergoing head and neck and total body irradiation treatments. Healthy volunteers completed 1 measurement each, and patients underwent measurement before starting treatment and between subsequent fractions. Optically stimulated luminescent dosimeters and diodes were used to determine the dose delivered to the teeth to validate EPR measurements. RESULTS Seventy measurements were acquired from 4 total body irradiation and 6 head and neck patients over 15 months. Patient data showed a linear increase of EPR signal with delivered dose across the dose range tested. A linear least-squares weighted fit of the data gave a statistically significant correlation between EPR signal and absorbed dose (P < .0001). The standard error of inverse prediction (SEIP), used to assess the usefulness of fits, was 1.92 Gy for the dose range most relevant for immediate triage (≤7 Gy). Correcting for natural background radiation based on patient age reduced the SEIP to 1.51 Gy. CONCLUSIONS This study demonstrated the feasibility of using spectroscopic measurements from radiation therapy patients to validate in vivo EPR biodosimetry. The data illustrated a statistically significant correlation between the magnitude of EPR signals and absorbed dose. The SEIP of 1.51 Gy, obtained under clinical conditions, indicates the potential value of this technique in response to large radiation events.
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Affiliation(s)
- Emily Draeger
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut.
| | - Kenneth Roberts
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Roy D Decker
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Nina Bahar
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Lynn D Wilson
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Joseph Contessa
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Zain Husain
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut
| | - Benjamin B Williams
- Department of Radiology & EPR Center, Geisel Medical School at Dartmouth, Hanover, New Hampshire
| | - Ann Barry Flood
- Department of Radiology & EPR Center, Geisel Medical School at Dartmouth, Hanover, New Hampshire
| | - Harold M Swartz
- Department of Radiology & EPR Center, Geisel Medical School at Dartmouth, Hanover, New Hampshire
| | - David J Carlson
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut.
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Penoncello GP, Voss MM, Gao Y, Sensoy L, Cao M, Pepin MD, Herchko SM, Benedict SH, DeWees TA, Rong Y. Multicenter Multivendor Evaluation of Dose Volume Histogram Creation Consistencies for 8 Commercial Radiation Therapy Dosimetric Systems. Pract Radiat Oncol 2024; 14:e236-e248. [PMID: 37914082 DOI: 10.1016/j.prro.2023.09.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2023] [Revised: 09/11/2023] [Accepted: 09/26/2023] [Indexed: 11/03/2023]
Abstract
PURPOSE To evaluate dose volume histogram (DVH) construction differences across 8 major commercial treatment planning systems (TPS) and dose reporting systems for clinically treated plans of various anatomic sites and target sizes. METHODS AND MATERIALS Dose files from 10 selected clinically treated plans with a hypofractionation, stereotactic radiation therapy prescription or sharp dose gradients such as head and neck plans ranging from prescription doses of 18 Gy in 1 fraction to 70 Gy in 35 fractions, each calculated at 0.25 and 0.125 cm grid size, were created and anonymized in Eclipse TPS, and exported to 7 other major TPS (Pinnacle, RayStation, and Elements) and dose reporting systems (MIM, Mobius, ProKnow, and Velocity) systems for comparison. Dose-volume constraint points of clinical importance for each plan were collected from each evaluated system (D0.03 cc [Gy], volume, and the mean dose were used for structures without specified constraints). Each reported constraint type and structure volume was normalized to the value from Eclipse for a pairwise comparison. A Wilcoxon rank-sum test was used for statistical significance and a multivariable regression model was evaluated adjusting for plan, grid size, and distance to target center. RESULTS For all DVH points relative to Eclipse, all systems reported median values within 1.0% difference of each other; however, they were all different from Eclipse. Considering mean values, Pinnacle, RayStation, and Elements averaged at 1.038, 1.046, and 1.024, respectively, while MIM, Mobius, ProKnow, and Velocity reported 1.026, 1.050, 1.033, and 1.022, respectively relative to Eclipse. Smaller dose grid size improved agreement between the systems marginally without statistical significance. For structure volumes relative to Eclipse, larger differences are seen across all systems with a range in median values up to 3.0% difference and mean up to 10.1% difference. CONCLUSIONS Large variations were observed between all systems. Eclipse generally reported, at statistically significant levels, lower values than all other evaluated systems. The nonsignificant change resulting from lowering the dose grid resolution indicates that this resolution may be less important than other aspects of calculating DVH curves, such as the 3-dimensional modeling of the structure.
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Affiliation(s)
- Gregory P Penoncello
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona; Department of Radiation Oncology, University of Colorado, Aurora, Colorado
| | - Molly M Voss
- Division of Biomedical Statistics and Informatics, Mayo Clinic, Scottsdale, Arizona
| | - Yu Gao
- Department of Radiation Oncology, Stanford University, Palo Alto, California
| | - Levent Sensoy
- Department of Radiation Oncology, University of Miami, Miami, Florida
| | - Minsong Cao
- Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California
| | - Mark D Pepin
- Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota
| | - Steven M Herchko
- Department of Radiation Oncology, Mayo Clinic, Jacksonville, Florida
| | - Stanley H Benedict
- Department of Radiation Oncology, University of California Davis, Sacramento, California
| | - Todd A DeWees
- Department of Computational and Quantitative Medicine, City of Hope, Duarte, California; Department of Radiation Oncology, City of Hope, Duarte, California.
| | - Yi Rong
- Department of Radiation Oncology, Mayo Clinic, Phoenix, Arizona.
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11
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Kosaka T, Takatsu J, Inoue T, Iijima K, Suzuki M, Murakami N, Shikama N. Dosimetric evaluation in Helical TomoTherapy for lung SBRT using Monte Carlo-based independent dose verification software. J Appl Clin Med Phys 2024; 25:e14305. [PMID: 38368607 PMCID: PMC11087163 DOI: 10.1002/acm2.14305] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Revised: 01/24/2024] [Accepted: 02/05/2024] [Indexed: 02/20/2024] Open
Abstract
PURPOSE To elucidate the dosimetric errors caused by a model-based algorithm in lung stereotactic body radiation therapy (SBRT) with Helical TomoTherapy (HT) using Monte Carlo (MC)-based dose verification software. METHODS For 38 plans of lung SBRT, the dose calculation accuracy of a treatment planning system (TPS) of HT was compared with the results of DoseCHECK, the commercial MC-based independent verification software. The following indices were extracted to evaluate the correlation of dosimetric errors: (1) target volume, (2) average computed tomography (CT) value of the planning target volume (PTV) margin, and (3) average CT value of surrounding 2-mm area of the PTV (PTV ring). Receiver operating characteristic (ROC) analyses determined the threshold for 5% of differences in PTV D95%. Then, the 38 plans were classified into two groups using the cutoff values of ROC analysis for these three indices. Dosimetric differences between groups were statistically compared using the Mann-Whitney U test. RESULTS TPS of HT overestimated by more than 5% in the PTV D95% in 16 of 38 plans. The PTV ring showed the strongest correlation with dosimetric differences. The cutoff value for the target volume, the PTV margin, and the PTV ring was 14.7 cc, -754 HU, and -708 HU, respectively. The area under the curve (AUC) for the target volume, the PTV margin, and the PTV ring were 0.835, 0.878, and 0.932, respectively. Dosimetric errors more than 5% were observed when the PTV volume was less than 15 cc or when the CT value around the target was less than -700 HU. CONCLUSION The TPS of HT might overestimate the PTV dose by more than 5% if any the three indices in this study were below threshold. Therefore, independent verification with an MC-based algorithm should be strongly recommended for lung SBRT in HT.
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Affiliation(s)
- Takahiro Kosaka
- Juntendo University Graduate School of Medicine, Bunkyo-ku, Tokyo, Japan
- Department of Radiology, Juntendo University Urayasu Hospital, Urayasu-shi, Chiba, Japan
| | - Jun Takatsu
- Department of Radiation Oncology, Faculty of Medicine, Juntendo University, Bunkyo-ku, Tokyo, Japan
| | - Tatsuya Inoue
- Department of Radiology, Juntendo University Urayasu Hospital, Urayasu-shi, Chiba, Japan
- Department of Radiation Oncology, Faculty of Medicine, Juntendo University, Bunkyo-ku, Tokyo, Japan
| | - Kotaro Iijima
- Department of Radiation Oncology, Faculty of Medicine, Juntendo University, Bunkyo-ku, Tokyo, Japan
| | - Michimasa Suzuki
- Department of Radiology, Juntendo University Urayasu Hospital, Urayasu-shi, Chiba, Japan
| | - Naoya Murakami
- Department of Radiation Oncology, Graduate School of Medicine, Juntendo University, Bunkyo-ku, Tokyo, Japan
| | - Naoto Shikama
- Department of Radiation Oncology, Graduate School of Medicine, Juntendo University, Bunkyo-ku, Tokyo, Japan
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12
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Swartz HM, Flood AB. Rethinking the Role of Biodosimetry to Assess Risks for Acute Radiation Syndrome in Very Large Radiation Events: Reconsidering Legacy Concepts. Radiat Res 2024; 201:440-448. [PMID: 38714319 DOI: 10.1667/rade-23-00141.1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2023] [Accepted: 02/16/2024] [Indexed: 05/09/2024]
Abstract
The development of effective uses of biodosimetry in large-scale events has been hampered by residual, i.e., "legacy" thinking based on strategies that scale up from biodosimetry in small accidents. Consequently, there remain vestiges of unrealistic assumptions about the likely magnitude of victims in "large" radiation events and incomplete analyses of the logistics for making biodosimetry measurements/assessments in the field for primary triage. Elements remain from an unrealistic focus on developing methods to use biodosimetry in the initial stage of triage for a million or more victims. Based on recent events and concomitant increased awareness of the potential for large-scale events as well as increased sophistication in planning and experience in the development of biodosimetry, a more realistic assessment of the most effective roles of biodosimetry in large-scale events is urgently needed. We argue this leads to a conclusion that the most effective utilization of biodosimetry in very large events would occur in a second stage of triage, after initially winnowing the population by identifying those most in need of acute medical attention, based on calculations of geographic sites where significant exposures could have occurred. Understanding the potential roles and limitations of biodosimetry in large-scale events involving significant radiation exposure should lead to development of the most effective and useful biodosimetric techniques for each stage of triage for acute radiation syndrome injuries, i.e., based on more realistic assumptions about the underlying event and the logistics for carrying out biodosimetry for large populations.
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Affiliation(s)
- Harold M Swartz
- Department of Radiology and Dartmouth Institute of Health Policy and Clinical Practice, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire
- Clin-EPR, LLC, Lyme, New Hampshire
| | - Ann Barry Flood
- Department of Radiology and Dartmouth Institute of Health Policy and Clinical Practice, Geisel School of Medicine, Dartmouth College, Hanover, New Hampshire
- Clin-EPR, LLC, Lyme, New Hampshire
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13
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Böhlen TT, Germond JF, Desorgher L, Veres I, Bratel A, Landström E, Engwall E, Herrera FG, Ozsahin EM, Bourhis J, Bochud F, Moeckli R. Very high-energy electron therapy as light-particle alternative to transmission proton FLASH therapy - An evaluation of dosimetric performances. Radiother Oncol 2024; 194:110177. [PMID: 38378075 DOI: 10.1016/j.radonc.2024.110177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/29/2024] [Accepted: 02/16/2024] [Indexed: 02/22/2024]
Abstract
PURPOSE Clinical translation of FLASH-radiotherapy (RT) to deep-seated tumours is still a technological challenge. One proposed solution consists of using ultra-high dose rate transmission proton (TP) beams of about 200-250 MeV to irradiate the tumour with the flat entrance of the proton depth-dose profile. This work evaluates the dosimetric performance of very high-energy electron (VHEE)-based RT (50-250 MeV) as a potential alternative to TP-based RT for the clinical transfer of the FLASH effect. METHODS Basic physics characteristics of VHEE and TP beams were compared utilizing Monte Carlo simulations in water. A VHEE-enabled research treatment planning system was used to evaluate the plan quality achievable with VHEE beams of different energies, compared to 250 MeV TP beams for a glioblastoma, an oesophagus, and a prostate cancer case. RESULTS Like TP, VHEE above 100 MeV can treat targets with roughly flat (within ± 20 %) depth-dose distributions. The achievable dosimetric target conformity and adjacent organs-at-risk (OAR) sparing is consequently driven for both modalities by their lateral beam penumbrae. Electron beams of 400[500] MeV match the penumbra of 200[250] MeV TP beams and penumbra is increased for lower electron energies. For the investigated patient cases, VHEE plans with energies of 150 MeV and above achieved a dosimetric plan quality comparable to that of 250 MeV TP plans. For the glioblastoma and the oesophagus case, although having a decreased conformity, even 100 MeV VHEE plans provided a similar target coverage and OAR sparing compared to TP. CONCLUSIONS VHEE-based FLASH-RT using sufficiently high beam energies may provide a lighter-particle alternative to TP-based FLASH-RT with comparable dosimetric plan quality.
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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
| | - Laurent Desorgher
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | - Izabella Veres
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland
| | | | | | | | - Fernanda G Herrera
- 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
| | - Jean Bourhis
- 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
| | - Raphaël Moeckli
- Institute of Radiation Physics, Lausanne University Hospital and Lausanne University, Lausanne, Switzerland.
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Dover L, Dulaney C. PROshot: Regional Nodal Irradiation, Prophylactic Radiation for Bone Metastases, Adaptive Therapy for Hodgkin Lymphoma, Immunoscore, and Heart Dosimetry. Pract Radiat Oncol 2024; 14:175-180. [PMID: 38702114 DOI: 10.1016/j.prro.2024.01.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Revised: 01/22/2024] [Accepted: 01/23/2024] [Indexed: 05/06/2024]
Affiliation(s)
- Laura Dover
- Department of Radiation Oncology, Ascension St. Vincent's East, Birmingham, Alabama
| | - Caleb Dulaney
- Department of Radiation Oncology, Anderson Regional Health System, Meridian, Mississippi.
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Hashemi S, Shirmardi SP, Hosntalab M, Sardari D, Saniei E. Internal absorbed dose calculation in body organs due to injection of Rhenium-188 labeled to Mu-9 antibody. Appl Radiat Isot 2024; 207:111235. [PMID: 38430824 DOI: 10.1016/j.apradiso.2024.111235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 01/30/2024] [Accepted: 02/12/2024] [Indexed: 03/05/2024]
Abstract
The use of radiopharmaceuticals has gained a special place in the diagnosis and treatment of cancers and evaluation of the function of different organs of the body. In this study, the absorbed dose distribution of organs after injection of 188Re-Mu-9 has been investigated using MIRD method and MCNP-4C simulation code. The 188Re-Mu-9 labeled was injected the mouse body and the amount of 188Re-labeled accumulation was evaluated after 1, 4 and 2 4 h. Having a map of the distribution of radiopharmaceutical activity in the animal body, it is possible to convert it into a human model to obtain the internal dose received by 188Re-Mu-9 injection using the MIRD calculation method and the MCNP simulation code. According to the results of the study, the animal/human model can be acceptable method for dose estimation of antibody-based radiopharmaceuticals.
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Affiliation(s)
- S Hashemi
- Medical Radiation Engineering Department, Science and Research Branch, Islamic Azad University (IAU), P.O. Box: 14515-775, Tehran, Iran
| | - S P Shirmardi
- Radiation Application Research School, Nuclear Science and Technology Research Institute (NSTRI), P.O.Box: 14395-836, Tehran, Iran.
| | - M Hosntalab
- Medical Radiation Engineering Department, Science and Research Branch, Islamic Azad University (IAU), P.O. Box: 14515-775, Tehran, Iran
| | - D Sardari
- Medical Radiation Engineering Department, Science and Research Branch, Islamic Azad University (IAU), P.O. Box: 14515-775, Tehran, Iran
| | - E Saniei
- Department of Medical Radiation Engineering, Central Tehran Branch, Islamic Azad University, Tehran, Iran
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Zhang X, Shi J, Wu X, Li L, Sun W, Zou Y, Chen G, Wu S, Duan S. Dosimetric Comparison of Commonly Used Volumetric Modulated Arc Therapy Field Arrangements Based on Flattening Filter-Free Beams for Synchronous Bilateral Breast Carcinoma Radiation Therapy. Pract Radiat Oncol 2024; 14:e190-e202. [PMID: 37967748 DOI: 10.1016/j.prro.2023.11.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 10/14/2023] [Accepted: 11/05/2023] [Indexed: 11/17/2023]
Abstract
PURPOSE Flattening filter-free (FFF)-based volumetric modulated arc therapy (VMAT) has been shown to be feasible and significantly improves treatment efficiency and lung protection for synchronous bilateral breast irradiation (SBBI). This research compared the commonly used VMAT field arrangements using FFF beams. METHODS Twenty-eight patients underwent SBBI were retrospectively enrolled to design irradiation plans using tangential arc VMAT (taVMAT), half arc VMAT (haVMAT), and large arc VMAT (laVMAT). Dosimetric and delivery parameters of all designed plans were recorded and compared. RESULTS Comparable target volume coverage was observed for all field arrangements. taVMAT significantly reduced the dose to spinal cord and the volume covered by 5 Gy (V5Gy) and V7Gy of the lungs while decreasing the conformity index of the target volume. It also increased the volume covered by 105% of the prescription dose (V105%) and V107% of the target volume. haVMAT considerably decreased V20 Gy and V30 Gy of the lungs, mean dose (Dmean) and V30 Gy of the heart and the liver. It also notably reduced Dmean and V40 Gy of the left anterior descending coronary artery while increasing the beam-on time. laVMAT significantly reduced the mean treatment time (range, 113-117 seconds) compared with the other field arrangements. CONCLUSIONS There were distinct differences in various dosimetric and delivery parameters for different field arrangements, highlighting the importance of selecting the appropriate field arrangement based on specific treatment goals and considerations. This study contributes valuable insights into the use of FFF-based VMAT techniques in SBBI.
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Affiliation(s)
- Xingxing Zhang
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Juntian Shi
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Xiuxiu Wu
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Liting Li
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Wei Sun
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Yongmei Zou
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Guoquan Chen
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Shaokun Wu
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China
| | - Song Duan
- Guangdong Provincial Key Laboratory of Malignant Tumor Epigenetics and Gene Regulation, Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China; Department of Radiation Oncology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, China.
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Alzahrani NM, Henry AM, Clark AK, Al‐Qaisieh BM, Murray LJ, Nix MG. Dosimetric impact of contour editing on CT and MRI deep-learning autosegmentation for brain OARs. J Appl Clin Med Phys 2024; 25:e14345. [PMID: 38664894 PMCID: PMC11087158 DOI: 10.1002/acm2.14345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/12/2024] [Accepted: 03/05/2024] [Indexed: 05/12/2024] Open
Abstract
PURPOSE To establish the clinical applicability of deep-learning organ-at-risk autocontouring models (DL-AC) for brain radiotherapy. The dosimetric impact of contour editing, prior to model training, on performance was evaluated for both CT and MRI-based models. The correlation between geometric and dosimetric measures was also investigated to establish whether dosimetric assessment is required for clinical validation. METHOD CT and MRI-based deep learning autosegmentation models were trained using edited and unedited clinical contours. Autosegmentations were dosimetrically compared to gold standard contours for a test cohort. D1%, D5%, D50%, and maximum dose were used as clinically relevant dosimetric measures. The statistical significance of dosimetric differences between the gold standard and autocontours was established using paired Student's t-tests. Clinically significant cases were identified via dosimetric headroom to the OAR tolerance. Pearson's Correlations were used to investigate the relationship between geometric measures and absolute percentage dose changes for each autosegmentation model. RESULTS Except for the right orbit, when delineated using MRI models, the dosimetric statistical analysis revealed no superior model in terms of the dosimetric accuracy between the CT DL-AC models or between the MRI DL-AC for any investigated brain OARs. The number of patients where the clinical significance threshold was exceeded was higher for the optic chiasm D1% than other OARs, for all autosegmentation models. A weak correlation was consistently observed between the outcomes of dosimetric and geometric evaluations. CONCLUSIONS Editing contours before training the DL-AC model had no significant impact on dosimetry. The geometric test metrics were inadequate to estimate the impact of contour inaccuracies on dose. Accordingly, dosimetric analysis is needed to evaluate the clinical applicability of DL-AC models in the brain.
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Affiliation(s)
- Nouf M. Alzahrani
- Department of Diagnostic RadiologyKing Abdulaziz UniversityJeddahSaudi Arabia
- School of MedicineUniversity of LeedsLeedsUK
- Department of Medical Physics and EngineeringSt James's University HospitalLeedsUK
| | - Ann M. Henry
- School of MedicineUniversity of LeedsLeedsUK
- Department of Clinical OncologySt James's University HospitalLeedsUK
| | - Anna K. Clark
- Department of Medical Physics and EngineeringSt James's University HospitalLeedsUK
| | - Bashar M. Al‐Qaisieh
- Department of Medical Physics and EngineeringSt James's University HospitalLeedsUK
| | - Louise J. Murray
- School of MedicineUniversity of LeedsLeedsUK
- Department of Clinical OncologySt James's University HospitalLeedsUK
| | - Michael G. Nix
- Department of Medical Physics and EngineeringSt James's University HospitalLeedsUK
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Dunn L, Tamborriello A, Subramanian B, Xu X, Ruruku TT. Assessing the sensitivity and suitability of a range of detectors for SIMT PSQA. J Appl Clin Med Phys 2024; 25:e14343. [PMID: 38569013 PMCID: PMC11087180 DOI: 10.1002/acm2.14343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 03/07/2024] [Accepted: 03/14/2024] [Indexed: 04/05/2024] Open
Abstract
PURPOSE Single-isocenter multi-target intracranial stereotactic radiotherapy (SIMT) is an effective treatment for brain metastases with complex treatment plans and delivery optimization necessitating rigorous quality assurance. This work aims to assess five methods for quality assurance of SIMT treatment plans in terms of their suitability and sensitivity to delivery errors. METHODS Sun Nuclear ArcCHECK and SRS MapCHECK, GafChromic EBT Radiochromic Film, machine log files, and Varian Portal Dosimetry were all used to measure 15 variations of a single SIMT plan. Variations of the original plan were created with Python. They comprised various degrees of systematic MLC offsets per leaf up to 2 mm, random per-leaf variations with differing minimum and maximum magnitudes, simulated collimator, and dose miscalibrations (MU scaling). The erroneous plans were re-imported into Eclipse and plan-quality degradation was assessed by comparing each plan variation to the original clinical plan in terms of the percentage of clinical goals passing relative to the original plan. Each erroneous plan could be then ranked by the plan-quality degradation percentage following recalculation in the TPS so that the effects of each variation could be correlated with γ pass rates and detector suitability. RESULTS & CONCLUSIONS It was found that 2%/1 mm is a good starting point for the ArcCHECK, Portal Dosimetry, and the SRS MapCHECK methods, respectively, and provides clinically relevant error detection sensitivity. Looser dose criteria of 5%/1 mm or 5%/1.5 mm are suitable for film dosimetry and log-file-based methods. The statistical methods explored can be expanded to other areas of patient-specific QA and detector assessment.
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Affiliation(s)
- Leon Dunn
- GenesisCare BerwickSt John of God Berwick Specialist CentreBerwickVictoriaAustralia
| | | | | | - Xiaolei Xu
- GenesisCare RingwoodRingwood Private HospitalRingwood EastVictoriaAustralia
| | - Tyrone Te Ruruku
- GenesisCare BerwickSt John of God Berwick Specialist CentreBerwickVictoriaAustralia
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Mansouri Z, Salimi Y, Akhavanallaf A, Shiri I, Teixeira EPA, Hou X, Beauregard JM, Rahmim A, Zaidi H. Deep transformer-based personalized dosimetry from SPECT/CT images: a hybrid approach for [ 177Lu]Lu-DOTATATE radiopharmaceutical therapy. Eur J Nucl Med Mol Imaging 2024; 51:1516-1529. [PMID: 38267686 PMCID: PMC11043201 DOI: 10.1007/s00259-024-06618-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Accepted: 01/15/2024] [Indexed: 01/26/2024]
Abstract
PURPOSE Accurate dosimetry is critical for ensuring the safety and efficacy of radiopharmaceutical therapies. In current clinical dosimetry practice, MIRD formalisms are widely employed. However, with the rapid advancement of deep learning (DL) algorithms, there has been an increasing interest in leveraging the calculation speed and automation capabilities for different tasks. We aimed to develop a hybrid transformer-based deep learning (DL) model that incorporates a multiple voxel S-value (MSV) approach for voxel-level dosimetry in [177Lu]Lu-DOTATATE therapy. The goal was to enhance the performance of the model to achieve accuracy levels closely aligned with Monte Carlo (MC) simulations, considered as the standard of reference. We extended our analysis to include MIRD formalisms (SSV and MSV), thereby conducting a comprehensive dosimetry study. METHODS We used a dataset consisting of 22 patients undergoing up to 4 cycles of [177Lu]Lu-DOTATATE therapy. MC simulations were used to generate reference absorbed dose maps. In addition, MIRD formalism approaches, namely, single S-value (SSV) and MSV techniques, were performed. A UNEt TRansformer (UNETR) DL architecture was trained using five-fold cross-validation to generate MC-based dose maps. Co-registered CT images were fed into the network as input, whereas the difference between MC and MSV (MC-MSV) was set as output. DL results are then integrated to MSV to revive the MC dose maps. Finally, the dose maps generated by MSV, SSV, and DL were quantitatively compared to the MC reference at both voxel level and organ level (organs at risk and lesions). RESULTS The DL approach showed slightly better performance (voxel relative absolute error (RAE) = 5.28 ± 1.32) compared to MSV (voxel RAE = 5.54 ± 1.4) and outperformed SSV (voxel RAE = 7.8 ± 3.02). Gamma analysis pass rates were 99.0 ± 1.2%, 98.8 ± 1.3%, and 98.7 ± 1.52% for DL, MSV, and SSV approaches, respectively. The computational time for MC was the highest (~2 days for a single-bed SPECT study) compared to MSV, SSV, and DL, whereas the DL-based approach outperformed the other approaches in terms of time efficiency (3 s for a single-bed SPECT). Organ-wise analysis showed absolute percent errors of 1.44 ± 3.05%, 1.18 ± 2.65%, and 1.15 ± 2.5% for SSV, MSV, and DL approaches, respectively, in lesion-absorbed doses. CONCLUSION A hybrid transformer-based deep learning model was developed for fast and accurate dose map generation, outperforming the MIRD approaches, specifically in heterogenous regions. The model achieved accuracy close to MC gold standard and has potential for clinical implementation for use on large-scale datasets.
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Affiliation(s)
- Zahra Mansouri
- Division of Nuclear Medicine and Molecular Imaging, Department of Medical Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Yazdan Salimi
- Division of Nuclear Medicine and Molecular Imaging, Department of Medical Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Azadeh Akhavanallaf
- Division of Nuclear Medicine and Molecular Imaging, Department of Medical Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Isaac Shiri
- Division of Nuclear Medicine and Molecular Imaging, Department of Medical Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Eliluane Pirazzo Andrade Teixeira
- Division of Nuclear Medicine and Molecular Imaging, Department of Medical Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland
| | - Xinchi Hou
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Jean-Mathieu Beauregard
- Cancer Research Centre and Department of Radiology and Nuclear Medicine, Université Laval, Quebec City, QC, Canada
| | - Arman Rahmim
- Department of Radiology, University of British Columbia, Vancouver, BC, Canada
| | - Habib Zaidi
- Division of Nuclear Medicine and Molecular Imaging, Department of Medical Imaging, Geneva University Hospital, CH-1211, Geneva, Switzerland.
- Department of Nuclear Medicine, University Medical Center Groningen, University of Groningen, 9700 RB, Groningen, Netherlands.
- Department of Nuclear Medicine, University of Southern Denmark, DK-500, Odense, Denmark.
- University Research and Innovation Center, Óbuda University, Budapest, Hungary.
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Sohrabi M, Malekitakbolagh M, Nedaei HA. Breakthrough electroneutron multi-response miniature dosimetry/spectrometry in medical accelerator. Sci Rep 2024; 14:9557. [PMID: 38664481 PMCID: PMC11045717 DOI: 10.1038/s41598-024-59871-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 04/16/2024] [Indexed: 04/28/2024] Open
Abstract
Breakthrough multi-response miniature dosimetry/spectrometry of electroneutrons (EN) was made on surface and in-depths of whole-body polyethylene phantom under 10 cm × 10 cm electron beam of 20 MV Varian Clinac 2100C electron medical accelerator commonly applied for prostate treatment. While dosimetry/spectrometry of photoneutrons (PN) has been well characterized for decades, those of ENs lagged behind due to very low EN reaction cross section and lack of sensitive neutron dosimeters/spectrometers meeting neutron dosimetry requirements. Recently, Sohrabi "miniature neutron dosimeter/spectrometer" and "Stripe polycarbonate dosimeter" have broken this barrier and determined seven EN ambient dose equivalent (ENDE) (µSv.Gy-1) responses from electron beam and from albedo ENs including beam thermal (21 ± 2.63), albedo thermal (43 ± 3.70), total thermal (64 ± 6.33), total epithermal (32 ± 3.90), total fast (112.00), total thermal + epithermal (l96 ± 10), and total thermal + epithermal + fast (208 ± 10.23) ENs. Having seven ENDE responses of this study and seven PNDE responses of previous study with the same accelerator obtained at identical conditions by the same principle author provided the opportunity to compare the two sets of responses. The PNDE (µSv.Gy-1) responses have comparatively higher values and 22.60 times at isocenter which provide for the first time breakthrough ENDE responses not yet reported in any studies before worldwide.
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Affiliation(s)
- Mehdi Sohrabi
- Health Physics and Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran.
| | - Maryam Malekitakbolagh
- Health Physics and Dosimetry Research Laboratory, Department of Energy Engineering and Physics, Amirkabir University of Technology, Tehran, Iran
| | - Hasan Ali Nedaei
- Department of Radiotherapy Oncology, Cancer Institute, University of Medical Sciences, Tehran, Iran
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Kuhlmann ML, Pojtinger S. Implementation of a new EGSnrc particle source class for computed tomography: validation and uncertainty quantification. Phys Med Biol 2024; 69:095021. [PMID: 38537305 DOI: 10.1088/1361-6560/ad3886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 03/26/2024] [Indexed: 04/25/2024]
Abstract
Objective. Personalized dose monitoring and risk management are of increasing significance with the growing number of computer tomography (CT) examinations. These require high-quality Monte Carlo (MC) simulations that are of the utmost importance for the new developments in personalized CT dosimetry. This work aims to extend the MC framework EGSnrc source code with a new particle source. This, in turn, allows CT-scanner-specific dose and image calculations for any CT scanner. The novel method can be used with all modern EGSnrc user codes, particularly for the simulation of the effective dose based on DICOM images and the calculation of CT images.Approach. The new particle source can be used with input data derived by the user. The input data can be generated by the user based on a previously developed method for the experimental characterization of any CT scanner (doi.org/10.1016/j.ejmp.2015.09.006). Furthermore, the new particle source was benchmarked by air kerma measurements in an ionization chamber at a clinical CT scanner. For this, the simulated angular distribution and attenuation characteristics were compared to measurements to verify the source output free in air. In a second validation step, simulations of air kerma in a homogenous cylindrical and an anthropomorphic thorax phantom were performed and validated against experimentally determined results. A detailed uncertainty evaluation of the simulated air kerma values was developed.Main results. We successfully implemented a new particle source class for the simulation of realistic CT scans. This method can be adapted to any CT scanner. For the attenuation characteristics, there was a maximal deviation of 6.86% between the measurement and the simulation. The mean deviation for all tube voltages was 2.36% (σ= 1.6%). For the phantom measurements and simulations, all the values agreed within 5.0%. The uncertainty evaluation resulted in an uncertainty of 5.5% (k=1).
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Affiliation(s)
- Marie-Luise Kuhlmann
- Dosimetry for Radiation Therapy and Diagnostic Radiology, Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, D-38116, Germany
- Technische Universität Dortmund, Dortmund, D-44227, Germany
| | - Stefan Pojtinger
- Dosimetry for Radiation Therapy and Diagnostic Radiology, Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, D-38116, Germany
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22
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da Silva DB, da Silva AX, Alves CFE, Magalhaes LAG. Calibration system correction factor for measuring the reference air kerma rate (RAKR) applied to high dose rate 192Ir sources (HDR). Biomed Phys Eng Express 2024; 10:035034. [PMID: 38507785 DOI: 10.1088/2057-1976/ad35cd] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Accepted: 03/20/2024] [Indexed: 03/22/2024]
Abstract
The aim of this study was to use computer simulation to analyze the impact of the aluminum fixing support on the Reference Air Kerma (RAK), a physical quantity obtained in a calibration system that was experimentally developed in the Laboratory of Radiological Sciences of the University of the State of Rio de Janeiro (LCR-UERJ). Correction factors due to scattered radiation and the geometry of the192Ir sources were also sought to be determined. The computational simulation was validated by comparing some parameters of the experimental results with the computational results. These parameters were: verification of the inverse square law of distance, determination of (RAKR), analysis of the source spectrum with and without encapsulation, and the sensitivity curve of the Sourcecheck 4PI ionization chamber response, as a function of the distance from the source along the axial axis, using the microSelectron-v2 (mSv2) and GammaMedplus (GMp) sources. Kerma was determined by activity in the Reference air, with calculated values of 1.725 × 10-3U. Bq-1and 1.710 × 10-3U. Bq-1for the ionization chamber NE 2571 and TN 30001, respectively. The expanded uncertainty for these values was 0.932% and 0.919%, respectively, for a coverage factor (k = 2). The correction factor due to the influence of the aluminum fixing support for measurements at 1 cm and 10 cm from the source was 0.978 and 0.969, respectively. The geometric correction factor of the sources was ksg= 1.005 with an expanded uncertainty of 0.7% for a coverage factor (k = 2). This value has a difference of approximately 0.2% compared to the experimental values.
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Affiliation(s)
- Douglas Batista da Silva
- Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
- Department of Radiological Sciences, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil
| | - Ademir Xavier da Silva
- Nuclear Engineering Program, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
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23
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Ranjith CP, Krishnan M, Raveendran V, Chaudhari L, Laskar S. An artificial neural network based approach for predicting the proton beam spot dosimetric characteristics of a pencil beam scanning technique. Biomed Phys Eng Express 2024; 10:035033. [PMID: 38652667 DOI: 10.1088/2057-1976/ad3ce0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 04/10/2024] [Indexed: 04/25/2024]
Abstract
Utilising Machine Learning (ML) models to predict dosimetric parameters in pencil beam scanning proton therapy presents a promising and practical approach. The study developed Artificial Neural Network (ANN) models to predict proton beam spot size and relative positional errors using 9000 proton spot data. The irradiation log files as input variables and corresponding scintillation detector measurements as the label values. The ANN models were developed to predict six variables: spot size in thex-axis,y-axis, major axis, minor axis, and relative positional errors in thex-axis andy-axis. All ANN models used a Multi-layer perception (MLP) network using one input layer, three hidden layers, and one output layer. Model performance was validated using various statistical tools. The log file recorded spot size and relative positional errors, which were compared with scintillator-measured data. The Root Mean Squared Error (RMSE) values for the x-spot and y-spot sizes were 0.356 mm and 0.362 mm, respectively. Additionally, the maximum variation for the x-spot relative positional error was 0.910 mm, while for the y-spot, it was 1.610 mm. The ANN models exhibit lower prediction errors. Specifically, the RMSE values for spot size prediction in the x, y, major, and minor axes are 0.053 mm, 0.049 mm, 0.053 mm, and 0.052 mm, respectively. Additionally, the relative spot positional error prediction model for the x and y axes yielded maximum errors of 0.160 mm and 0.170 mm, respectively. The normality of models was validated using the residual histogram and Q-Q plot. The data over fit, and bias were tested using K (k = 5) fold cross-validation, and the maximum RMSE value of the K fold cross-validation among all the six ML models was less than 0.150 mm (R-Square 0.960). All the models showed excellent prediction accuracy. Accurately predicting beam spot size and positional errors enhances efficiency in routine dosimetric checks.
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Affiliation(s)
- C P Ranjith
- Department of Medical Physics, Centre for Interdisciplinary Research, D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India
- Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Mayakannan Krishnan
- Department of Medical Physics, Centre for Interdisciplinary Research, D. Y. Patil Education Society (Deemed to be University), Kolhapur, Maharashtra, India
| | - Vysakh Raveendran
- Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Lalit Chaudhari
- Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Homi Bhabha National Institute, Mumbai, Maharashtra, India
| | - Siddhartha Laskar
- Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Homi Bhabha National Institute, Mumbai, Maharashtra, India
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Patodi V, Soni TP, Singh DK, Patni N, Jakhotia N, Chittappurath V, Kuyyanangadan R, Jenny A, Kanniyappan E, Gupta AK, Gupta TC, Singhal H, Natrajan T, Kather FS. Dosimetric comparison of O-ring versus conventional C-arm linear accelerator for volumetric modulated arc therapy (VMAT) of head and neck cancer and carcinoma cervix patients. Radiat Prot Dosimetry 2024; 200:538-543. [PMID: 38441907 DOI: 10.1093/rpd/ncae043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 01/22/2024] [Accepted: 02/12/2024] [Indexed: 04/23/2024]
Abstract
The objective of this study is dosimetric comparison between the O-ring Halcyon and C-arm Clinac iX linac for volumetric modulated arc therapy (VMAT) plans for head & neck (H&N) cancer and carcinoma cervix patients. Total 60 patients of H&N cancer and carcinoma cervix were enrolled prospectively from March 2021 to March 2023. VMAT plans with 6 MV photons for Halcyon and Clinac iX were generated and compared for each patient by dose volume histogram for planning target volume coverage and organ at risk (OAR) sparing. There were no differences in between both the linacs for PTV D2% and D98%, homogeneity index, conformity index, Dmax (maximum dose) and Dmean (mean dose) of OAR. Halcyon had significantly shorter treatment time compared to Clinac iX. Halcyon delivered higher integral dose and monitor units. O-ring Halcyon produces VMAT plans comparable to other C-arm linacs for H&N and carcinoma cervix patients.
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Affiliation(s)
- Vibhor Patodi
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Tej P Soni
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Dinesh K Singh
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Nidhi Patni
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Naresh Jakhotia
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Vineeth Chittappurath
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Rajkamal Kuyyanangadan
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Ashna Jenny
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Elumalai Kanniyappan
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Anil K Gupta
- Department of Surgical Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Tara C Gupta
- Department of Medical Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Harish Singhal
- Department of Clinical Trials, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
| | - Thirumoorthy Natrajan
- Department of Radiation Oncology, Narayana Multispeciality Hospital, Jaipur, Rajasthan, India
| | - Farzana S Kather
- Department of Radiation Oncology, Bhagwan Mahaveer Cancer Hospital and Research Centre, Jaipur, Rajasthan, India
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Yanheng P, Zhen W, Yisheng H, Shenshen G, Rui Q, Hui Z, Junli L. CPU-GPU-coupled acceleration method for point flux calculation in Monte Carlo particle transport. Radiat Prot Dosimetry 2024; 200:525-537. [PMID: 38411255 DOI: 10.1093/rpd/ncae032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 11/22/2023] [Accepted: 02/10/2024] [Indexed: 02/28/2024]
Abstract
In Monte Carlo particle transport simulations, point flux tallying is a variance reduction technique that performs well with small detectors and finds broad application in source-detector problems and local point dose calculations. However, its use in large-scale point flux tallying computation adds substantial computational time. To address this issue, we propose a CPU-GPU-coupled acceleration method, which separates the complex logic and computationally intensive parts of particle transport calculation and assigns them to the CPU and GPU, respectively. This proposed method greatly enhances the efficiency of large-scale point flux tallies, providing significant convenience for subsequent dose calculations and other related steps. We validated our method by comparing the performance of a pure CPU program with our CPU-GPU accelerated program using the NUREG/CR-6115 PWR benchmark problem. The results indicate identical outcomes for photon point flux estimation, with the accelerated program being ~50 times faster.
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Affiliation(s)
- Pu Yanheng
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Wu Zhen
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Tsinghua University, Beijing 100084, China
- Nuctech Company Limited, Beijing 100084, China
| | - Hao Yisheng
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Gao Shenshen
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Qiu Rui
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Zhang Hui
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Tsinghua University, Beijing 100084, China
| | - Li Junli
- Department of Engineering Physics, Tsinghua University, Beijing 100084, China
- Key Laboratory of Particle & Radiation Imaging, Ministry of Education, Tsinghua University, Beijing 100084, China
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26
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Ling B, Chen L, Zhang J, Cao X, Ye W, Ouyang Y, Chi F, Ding Z. [Dosimetric analysis of different optimization algorithms for three-dimensional brachytherapy for gynecologic tumors]. Nan Fang Yi Ke Da Xue Xue Bao 2024; 44:773-779. [PMID: 38708512 DOI: 10.12122/j.issn.1673-4254.2024.04.20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/07/2024]
Abstract
OBJECTIVE To investigate the dosimetric difference between manual and inverse optimization in 3-dimensional (3D) brachytherapy for gynecologic tumors. METHODS This retrospective study was conducted among a total of 110 patients with gynecologic tumors undergoing intracavitary combined with interstitial brachytherapy or interstitial brachytherapy. Based on the original images, the brachytherapy plans were optimized for each patient using Gro, IPSA1, IPSA2 (with increased volumetric dose limits on the basis of IPSA1) and HIPO algorithms. The dose-volume histogram (DVH) parameters of the clinical target volume (CTV) including V200, V150, V100, D90, D98 and CI, and the dosimetric parameters D2cc, D1cc, and D0.1cc for the bladder, rectum, and sigmoid colon were compared among the 4 plans. RESULTS Among the 4 plans, Gro optimization took the longest time, followed by HIPO, IPSA2 and IPSA1 optimization. The mean D90, D98, and V100 of HIPO plans were significantly higher than those of Gro and IPSA plans, and D90 and V100 of IPSA1, IPSA2 and HIPO plans were higher than those of Gro plans (P < 0.05), but the CI of the 4 plans were similar (P > 0.05). For the organs at risk (OARs), the HIPO plan had the lowest D2cc of the bladder and rectum; the bladder absorbed dose of Gro plans were significantly greater than those of IPSA1 and HIPO (P < 0.05). The D2cc and D1cc of the rectum in IPSA1, IPSA2 and HIPO plans were better than Gro (P < 0.05). The D2cc and D1cc of the sigmoid colon did not differ significantly among the 4 plans. CONCLUSION Among the 4 algorithms, the HIPO algorithm can better improve dose coverage of the target and lower the radiation dose of the OARs, and is thus recommended for the initial plan optimization. Clinically, the combination of manual optimization can achieve more individualized dose distribution of the plan.
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Affiliation(s)
- B Ling
- Department of Radiation Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - L Chen
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - J Zhang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - X Cao
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - W Ye
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - Y Ouyang
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - F Chi
- Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou 510060, China
| | - Z Ding
- Department of Radiation Medicine, School of Public Health, Southern Medical University, Guangzhou 510515, China
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Fleta C, Pellegrini G, Godignon P, Rodríguez FG, Paz-Martín J, Kranzer R, Schüller A. State-of-the-art silicon carbide diode dosimeters for ultra-high dose-per-pulse radiation at FLASH radiotherapy. Phys Med Biol 2024; 69:095013. [PMID: 38530300 DOI: 10.1088/1361-6560/ad37eb] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 03/26/2024] [Indexed: 03/27/2024]
Abstract
Objective.The successful implementation of FLASH radiotherapy in clinical settings, with typical dose rates >40 Gy s-1, requires accurate real-time dosimetry.Approach.Silicon carbide (SiC) p-n diode dosimeters designed for the stringent requirements of FLASH radiotherapy have been fabricated and characterized in an ultra-high pulse dose rate electron beam. The circular SiC PiN diodes were fabricated at IMB-CNM (CSIC) in 3μm epitaxial 4H-SiC. Their characterization was performed in PTB's ultra-high pulse dose rate reference electron beam. The SiC diode was operated without external bias voltage. The linearity of the diode response was investigated up to doses per pulse (DPP) of 11 Gy and pulse durations ranging from 3 to 0.5μs. Percentage depth dose measurements were performed in ultra-high dose per pulse conditions. The effect of the total accumulated dose of 20 MeV electrons in the SiC diode sensitivity was evaluated. The temperature dependence of the response of the SiC diode was measured in the range 19 °C-38 °C. The temporal response of the diode was compared to the time-resolved beam current during each electron beam pulse. A diamond prototype detector (flashDiamond) and Alanine measurements were used for reference dosimetry.Main results.The SiC diode response was independent both of DPP and of pulse dose rate up to at least 11 Gy per pulse and 4 MGy s-1, respectively, with tolerable deviation for relative dosimetry (<3%). When measuring the percentage depth dose under ultra-high dose rate conditions, the SiC diode performed comparably well to the reference flashDiamond. The sensitivity reduction after 100 kGy accumulated dose was <2%. The SiC diode was able to follow the temporal structure of the 20 MeV electron beam even for irregular pulse estructures. The measured temperature coefficient was (-0.079 ± 0.005)%/°C.Significance.The results of this study demonstrate for the first time the suitability of silicon carbide diodes for relative dosimetry in ultra-high dose rate pulsed electron beams up to a DPP of 11 Gy per pulse.
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Affiliation(s)
- Celeste Fleta
- Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Bellaterra, Barcelona, Spain
| | - Giulio Pellegrini
- Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Bellaterra, Barcelona, Spain
| | - Philippe Godignon
- Instituto de Microelectrónica de Barcelona, IMB-CNM (CSIC), Bellaterra, Barcelona, Spain
| | - Faustino Gómez Rodríguez
- Departamento de Física de Partículas, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
- Laboratorio de Radiofísica, RIAIDT, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - José Paz-Martín
- Departamento de Física de Partículas, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - Rafael Kranzer
- PTW-Freiburg (R&D), Freiburg 79115, Germany
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University Oldenburg, 26121, Germany
| | - Andreas Schüller
- Physikalisch-Technische Bundesanstalt (PTB), Braunschweig, Germany
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Hill MA, Staut N, Thompson JM, Verhaegen F. Dosimetric validation of SmART-RAD Monte Carlo modelling for x-ray cabinet radiobiology irradiators. Phys Med Biol 2024; 69:095014. [PMID: 38518380 PMCID: PMC11031639 DOI: 10.1088/1361-6560/ad3720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2023] [Revised: 02/23/2024] [Accepted: 03/22/2024] [Indexed: 03/24/2024]
Abstract
Objective. Accuracy and reproducibility in the measurement of radiation dose and associated reporting are critically important for the validity of basic and preclinical radiobiological studies performed with kilovolt x-ray radiation cabinets. This is essential to enable results of radiobiological studies to be repeated, as well as enable valid comparisons between laboratories. In addition, the commonly used single point dose value hides the 3D dose heterogeneity across the irradiated sample. This is particularly true for preclinical rodent models, and is generally difficult to measure directly. Radiation transport simulations integrated in an easy to use application could help researchers improve quality of dosimetry and reporting.Approach. This paper describes the use and dosimetric validation of a newly-developed Monte Carlo (MC) tool, SmART-RAD, to simulate the x-ray field in a range of standard commercial x-ray cabinet irradiators used for preclinical irradiations. Comparisons are made between simulated and experimentally determined dose distributions for a range of configurations to assess the potential use of this tool in determining dose distributions through samples, based on more readily available air-kerma calibration point measurements.Main results. Simulations gave very good dosimetric agreement with measured depth dose distributions in phantoms containing both water and bone equivalent materials. Good spatial and dosimetric agreement between simulated and measured dose distributions was obtained when using beam-shaping shielding.Significance. The MC simulations provided by SmART-RAD provide a useful tool to go from a limited number of dosimetry measurements to detailed 3D dose distributions through a non-homogeneous irradiated sample. This is particularly important when trying to determine the dose distribution in more complex geometries. The use of such a tool can improve reproducibility and dosimetry reporting in preclinical radiobiological research.
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Affiliation(s)
- Mark A Hill
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Nick Staut
- SmART Scientific Solutions BV, Maastricht, The Netherlands
| | - James M Thompson
- MRC Oxford Institute for Radiation Oncology, Department of Oncology, University of Oxford, ORCRB Roosevelt Drive, Oxford OX3 7DQ, United Kingdom
| | - Frank Verhaegen
- SmART Scientific Solutions BV, Maastricht, The Netherlands
- Department of Radiation Oncology (Maastro), Research Institute for Oncology & Reproduction, Maastricht University Medical Centre+, Maastricht, The Netherlands
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Collins S, Ogilvy A, Hare W, Hilts M, Jirasek A. Iterative image reconstruction algorithm analysis for optical CT radiochromic gel dosimetry. Biomed Phys Eng Express 2024; 10:035031. [PMID: 38579691 DOI: 10.1088/2057-1976/ad3afe] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 04/05/2024] [Indexed: 04/07/2024]
Abstract
Background.Modern radiation therapy technologies aim to enhance radiation dose precision to the tumor and utilize hypofractionated treatment regimens. Verifying the dose distributions associated with these advanced radiation therapy treatments remains an active research area due to the complexity of delivery systems and the lack of suitable three-dimensional dosimetry tools. Gel dosimeters are a potential tool for measuring these complex dose distributions. A prototype tabletop solid-tank fan-beam optical CT scanner for readout of gel dosimeters was recently developed. This scanner does not have a straight raypath from source to detector, thus images cannot be reconstructed using filtered backprojection (FBP) and iterative techniques are required.Purpose.To compare a subset of the top performing algorithms in terms of image quality and quantitatively determine the optimal algorithm while accounting for refraction within the optical CT system. The following algorithms were compared: Landweber, superiorized Landweber with the fast gradient projection perturbation routine (S-LAND-FGP), the fast iterative shrinkage/thresholding algorithm with total variation penalty term (FISTA-TV), a monotone version of FISTA-TV (MFISTA-TV), superiorized conjugate gradient with the nonascending perturbation routine (S-CG-NA), superiorized conjugate gradient with the fast gradient projection perturbation routine (S-CG-FGP), superiorized conjugate gradient with with two iterations of CG performed on the current iterate and the nonascending perturbation routine (S-CG-2-NA).Methods.A ray tracing simulator was developed to track the path of light rays as they traverse the different mediums of the optical CT scanner. Two clinical phantoms and several synthetic phantoms were produced and used to evaluate the reconstruction techniques under known conditions. Reconstructed images were analyzed in terms of spatial resolution, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), signal non-uniformity (SNU), mean relative difference (MRD) and reconstruction time. We developed an image quality based method to find the optimal stopping iteration window for each algorithm. Imaging data from the prototype optical CT scanner was reconstructed and analysed to determine the optimal algorithm for this application.Results.The optimal algorithms found through the quantitative scoring metric were FISTA-TV and S-CG-2-NA. MFISTA-TV was found to behave almost identically to FISTA-TV however MFISTA-TV was unable to resolve some of the synthetic phantoms. S-CG-NA showed extreme fluctuations in the SNR and CNR values. S-CG-FGP had large fluctuations in the SNR and CNR values and the algorithm has less noise reduction than FISTA-TV and worse spatial resolution than S-CG-2-NA. S-LAND-FGP had many of the same characteristics as FISTA-TV; high noise reduction and stability from over iterating. However, S-LAND-FGP has worse SNR, CNR and SNU values as well as longer reconstruction time. S-CG-2-NA has superior spatial resolution to all algorithms while still maintaining good noise reduction and is uniquely stable from over iterating.Conclusions.Both optimal algorithms (FISTA-TV and S-CG-2-NA) are stable from over iterating and have excellent edge detection with ESF MTF 50% values of 1.266 mm-1and 0.992 mm-1. FISTA-TV had the greatest noise reduction with SNR, CNR and SNU values of 424, 434 and 0.91 × 10-4, respectively. However, low spatial resolution makes FISTA-TV only viable for large field dosimetry. S-CG-2-NA has better spatial resolution than FISTA-TV with PSF and LSF MTF 50% values of 1.581 mm-1and 0.738 mm-1, but less noise reduction. S-CG-2-NA still maintains good SNR, CNR, and SNU values of 168, 158 and 1.13 × 10-4, respectively. Thus, S-CG-2-NA is a well rounded reconstruction algorithm that would be the preferable choice for small field dosimetry.
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Affiliation(s)
- Steve Collins
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Andy Ogilvy
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Warren Hare
- Dept. Mathematics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
| | - Michelle Hilts
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
- Medical Physics, BC Cancer-Kelowna, Kelowna BC V1Y 5L3, Canada
| | - Andrew Jirasek
- Dept. Physics, University of British Columbia-Okanagan, Kelowna, BC, V1V 1V7, Canada
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Duetschler A, Safai S, Weber DC, Lomax AJ, Zhang Y. The impact of motion on onboard MRI-guided pencil beam scanned proton therapy treatments. Phys Med Biol 2024; 69:095003. [PMID: 38537287 DOI: 10.1088/1361-6560/ad3885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2023] [Accepted: 03/26/2024] [Indexed: 04/16/2024]
Abstract
Objective.Online magnetic resonance imaging (MRI) guidance could be especially beneficial for pencil beam scanned (PBS) proton therapy of tumours affected by respiratory motion. For the first time to our knowledge, we investigate the dosimetric impact of respiratory motion on MRI-guided proton therapy compared to the scenario without magnetic field.Approach.A previously developed analytical proton dose calculation algorithm accounting for perpendicular magnetic fields was extended to enable 4D dose calculations. For two geometrical phantoms and three liver and two lung patient cases, static treatment plans were optimised with and without magnetic field (0, 0.5 and 1.5 T). Furthermore, plans were optimised using gantry angle corrections (0.5 T +5° and 1.5 T +15°) to reproduce similar beam trajectories compared to the 0 T reference plans. The effect of motion was then considered using 4D dose calculations without any motion mitigation and simulating 8-times volumetric rescanning, with motion for the patient cases provided by 4DCT(MRI) data sets. Each 4D dose calculation was performed for different starting phases and the CTV dose coverageV95%and homogeneityD5%-D95%were analysed.Main results.For the geometrical phantoms with rigid motion perpendicular to the beam and parallel to the magnetic field, a comparable dosimetric effect was observed independent of the magnetic field. Also for the five 4DCT(MRI) cases, the influence of motion was comparable for all magnetic field strengths with and without gantry angle correction. On average, the motion-induced decrease in CTVV95%from the static plan was 17.0% and 18.9% for 1.5 T and 0.5 T, respectively, and 19.9% without magnetic field.Significance.For the first time, this study investigates the combined impact of magnetic fields and respiratory motion on MR-guided proton therapy. The comparable dosimetric effects irrespective of magnetic field strength indicate that the effects of motion for future MR-guided proton therapy may not be worse than for conventional PBS proton therapy.
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Affiliation(s)
- Alisha Duetschler
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
- Department of Physics, ETH Zürich, 8092 Zürich, CH, Switzerland
| | - Sairos Safai
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
| | - Damien C Weber
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
- Department of Radiation Oncology, University Hospital of Zürich, 8091 Zürich, CH, Switzerland
- Department of Radiation Oncology, Inselspital, Bern University Hospital, University of Bern, 3010 Bern, CH, Switzerland
| | - Antony J Lomax
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
- Department of Physics, ETH Zürich, 8092 Zürich, CH, Switzerland
| | - Ye Zhang
- Center for Proton Therapy, Paul Scherrer Institute, 5232 Villigen PSI, CH, Switzerland
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Lu F, Li W, Jin J, Li K, Zhou J. Comparison of the performance of two thermoluminescent dosimetry systems for the personal dose-equivalent Hp(10) measurement. Radiat Prot Dosimetry 2024; 200:481-486. [PMID: 38324740 DOI: 10.1093/rpd/ncae009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 12/05/2023] [Accepted: 01/09/2024] [Indexed: 02/09/2024]
Abstract
The performance of two thermoluminescent dosimetry systems (RGD-3D and RE2000) manufactured in China and Finland was compared. Both of these dosimetry systems demonstrated satisfactory results as their performance met the requirements of the standard. The two dosimetry systems showed similar performance in the energy response. The RGD-3D dosimetry system performed better in nonlinear response, minimum detectable level and blind sample tests, whereas the RE2000 dosimetry system showed better stability.
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Affiliation(s)
- Fengfan Lu
- Chongqing Industry Polytechnic College, Chongqing 401120, China
| | - Wei Li
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400707, China
| | - Jing Jin
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400707, China
| | - Kui Li
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400707, China
| | - Jinghua Zhou
- Chongqing Municipal Center for Disease Control and Prevention, Chongqing 400707, China
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Vidal M, Gérard A, Floquet V, Forthomme J, Christensen JB, Almhagen E, Grusell E, Heymans V, Rossomme S, Dumas S, Trimaud R, Hérault J. Beam monitor chamber calibration of a synchro-cyclotron high dose rate per pulse pulsed scanned proton beam. Phys Med Biol 2024; 69:085016. [PMID: 38252970 DOI: 10.1088/1361-6560/ad2123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 01/22/2024] [Indexed: 01/24/2024]
Abstract
Objective. Ionization chambers, mostly used for beam calibration and for reference dosimetry, can show high recombination effects in pulsed high dose rate proton beams. The aims of this paper are: first, to characterize the linearity response of newly designed asymmetrical beam monitor chambers (ABMC) in a 100-226 MeV pulsed high dose rate per pulse scanned proton beam; and secondly, to calibrate the ABMC with a PPC05 (IBA Dosimetry) plane parallel ionization chamber and compare to calibration with a home-made Faraday cup (FC).Approach. The ABMC response linearity was evaluated with both the FC and a PTW 60019 microDiamond detector. Regarding ionometry-based ABMC calibration, recombination factors were evaluated theoretically, then numerically, and finally experimentally measured in water for a plane parallel ionization chamber PPC05 (IBA Dosimetry) throughkssaturation curves. Finally, ABMC calibration was also achieved with FC and compared to the ionometry method for 7 energies.Main results. Linearity measurements showed that recombination losses in the new ABMC design were well taken into account for the whole range of the machine dose rates. The two-voltage-method was not suitable for recombination correction, but Jaffé's plots analysis was needed, emphasizing the current IAEA TRS-398 reference protocol limitations. Concerning ABMC calibration, FC based absorbed dose estimation and PPC05-based absorbed dose estimation differ by less than 6.3% for the investigated energies.Significance.So far, no update on reference dosimetry protocols is available to estimate the absorbed dose in ionization chambers for clinical high dose rate per pulse pulsed scanned proton beams. This work proposes a validation of the new ABMC design, a method to take into account the recombination effect for ionometry-based ABMC calibration and a comparison with FC dose estimation in this type of proton beams.
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Affiliation(s)
- Marie Vidal
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Anaïs Gérard
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Vincent Floquet
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | | | - Jeppe Brage Christensen
- DTU Health Tech, Technical University of Denmark, Roskilde, Denmark
- Department of Radiation Safety and Security, Paul Scherrer Institute, PSI Villigen, Switzerland
| | - Erik Almhagen
- Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science-Skandion Clinics Uppsala, Sweden
| | - Erik Grusell
- Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Immunology, Genetics and Pathology, Medical Radiation Science-Skandion Clinics Uppsala, Sweden
| | | | | | - Serge Dumas
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Richard Trimaud
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
| | - Joël Hérault
- Institut Méditerranéen de Protonthérapie-Centre Antoine Lacassagne, Fédération Claude Lalanne, Nice, France
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Bateman JJ, Buchanan E, Corsini R, Farabolini W, Korysko P, Garbrecht Larsen R, Malyzhenkov A, Ortega Ruiz I, Rieker V, Gerbershagen A, Dosanjh M. Development of a novel fibre optic beam profile and dose monitor for very high energy electron radiotherapy at ultrahigh dose rates. Phys Med Biol 2024; 69:085006. [PMID: 38478998 DOI: 10.1088/1361-6560/ad33a0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 03/13/2024] [Indexed: 04/04/2024]
Abstract
Objective. Very high energy electrons (VHEE) in the range of 50-250 MeV are of interest for treating deep-seated tumours with FLASH radiotherapy (RT). This approach offers favourable dose distributions and the ability to deliver ultra-high dose rates (UHDR) efficiently. To make VHEE-based FLASH treatment clinically viable, a novel beam monitoring technology is explored as an alternative to transmission ionisation monitor chambers, which have non-linear responses at UHDR. This study introduces the fibre optic flash monitor (FOFM), which consists of an array of silica optical fibre-based Cherenkov sensors with a photodetector for signal readout.Approach. Experiments were conducted at the CLEAR facility at CERN using 200 MeV and 160 MeV electrons to assess the FOFM's response linearity to UHDR (characterised with radiochromic films) required for FLASH radiotherapy. Beam profile measurements made on the FOFM were compared to those using radiochromic film and scintillating yttrium aluminium garnet (YAG) screens.Main results. A range of photodetectors were evaluated, with a complementary-metal-oxide-semiconductor (CMOS) camera being the most suitable choice for this monitor. The FOFM demonstrated excellent response linearity from 0.9 Gy/pulse to 57.4 Gy/pulse (R2= 0.999). Furthermore, it did not exhibit any significant dependence on the energy between 160 MeV and 200 MeV nor the instantaneous dose rate. Gaussian fits applied to vertical beam profile measurements indicated that the FOFM could accurately provide pulse-by-pulse beam size measurements, agreeing within the error range of radiochromic film and YAG screen measurements, respectively.Significance. The FOFM proves to be a promising solution for real-time beam profile and dose monitoring for UHDR VHEE beams, with a linear response in the UHDR regime. Additionally it can perform pulse-by-pulse beam size measurements, a feature currently lacking in transmission ionisation monitor chambers, which may become crucial for implementing FLASH radiotherapy and its associated quality assurance requirements.
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Affiliation(s)
- Joseph J Bateman
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
| | - Emma Buchanan
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Roberto Corsini
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Wilfrid Farabolini
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Pierre Korysko
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Robert Garbrecht Larsen
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
- Particle Therapy Research Centre (PARTREC), Department of Radiation Oncology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Alexander Malyzhenkov
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Iñaki Ortega Ruiz
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
| | - Vilde Rieker
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
- Department of Physics, University of Oslo, NO-0316 Blindern, Oslo, Norway
| | - Alexander Gerbershagen
- Particle Therapy Research Centre (PARTREC), Department of Radiation Oncology, University Medical Centre Groningen, University of Groningen, Groningen, The Netherlands
| | - Manjit Dosanjh
- John Adams Institute for Accelerator Science, Department of Physics, University of Oxford, Oxford, OX1 3RH, United Kingdom
- European Organization for Nuclear Research (CERN), Meyrin, 1211, Geneva, Switzerland
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Blum I, Wong JS, Godino Padre K, Stolzenberg J, Fuchs H, Baumann KS, Poppe B, Looe HK. Fano cavity test and investigation of the response of the Roos chamber irradiated by proton beams in perpendicular magnetic fields up to 1 T. Phys Med Biol 2024; 69:085021. [PMID: 38452383 DOI: 10.1088/1361-6560/ad311a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 03/07/2024] [Indexed: 03/09/2024]
Abstract
Objective. The aim of this work is to investigate the response of the Roos chamber (type 34001) irradiated by clinical proton beams in magnetic fields.Approach. At first, a Fano test was implemented in Monte Carlo software package GATE version 9.2 (based on Geant4 version 11.0.2) using a cylindrical slab geometry in a magnetic field up to 1 T. In accordance to an experimental setup (Fuchset al2021), the magnetic field correction factorskQB⃗of the Roos chamber were determined at different energies up to 252 MeV and magnetic field strengths up to 1 T, by separately simulating the ratios of chamber signalsMQ/MQB⃗,without and with magnetic field, and the dose-conversion factorsDw,QB⃗/Dw,Qin a small cylinder of water, with and without magnetic field. Additionally, detailed simulations were carried out to understand the observed magnetic field dependence.Main results. The Fano test was passed with deviations smaller than 0.25% between 0 and 1 T. The ratios of the chamber signals show both energy and magnetic field dependence. The maximum deviation of the dose-conversion factors from unity of 0.22% was observed at the lowest investigated proton energy of 97.4 MeV andB⃗= 1 T. The resultingkQB⃗factors increase initially with the applied magnetic field and decrease again after reaching a maximum at around 0.5 T; except for the lowest 97.4 MeV beam that show no observable magnetic field dependence. The deviation from unity of the factors is also larger for higher proton energies, where the maximum lies at 1.0035(5), 1.0054(7) and 1.0069(7) for initial energies ofE0= 152, 223.4 and 252 MeV, respectively.Significance. Detailed Monte Carlo studies showed that the observed effect can be mainly attributed to the differences in the transport of electrons produced both outside and inside of the air cavity in the presence of a magnetic field.
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Affiliation(s)
- Isabel Blum
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University, Oldenburg, Germany
| | - Jing Syuen Wong
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University, Oldenburg, Germany
| | - Krishna Godino Padre
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University, Oldenburg, Germany
| | - Jessica Stolzenberg
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University, Oldenburg, Germany
| | - Hermann Fuchs
- Division of Medical Physics, Department of Radiation Oncology, Medical University of Vienna, Vienna, Austria
| | - Kilian-Simon Baumann
- University Hospital Giessen-Marburg, Department of Radiotherapy and Radiooncology, Marburg, Germany
- University of Applied Sciences, Institute of Medical Physics and Radiation Protection, Giessen, Germany
- Marburg Ion-Beam Therapy Center, Marburg, Germany
| | - Björn Poppe
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University, Oldenburg, Germany
| | - Hui Khee Looe
- University Clinic for Medical Radiation Physics, Medical Campus Pius Hospital, Carl von Ossietzky University, Oldenburg, Germany
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Stokke C, Gnesin S, Tran-Gia J, Cicone F, Holm S, Cremonesi M, Blakkisrud J, Wendler T, Gillings N, Herrmann K, Mottaghy FM, Gear J. EANM guidance document: dosimetry for first-in-human studies and early phase clinical trials. Eur J Nucl Med Mol Imaging 2024; 51:1268-1286. [PMID: 38366197 PMCID: PMC10957710 DOI: 10.1007/s00259-024-06640-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 02/04/2024] [Indexed: 02/18/2024]
Abstract
The numbers of diagnostic and therapeutic nuclear medicine agents under investigation are rapidly increasing. Both novel emitters and novel carrier molecules require careful selection of measurement procedures. This document provides guidance relevant to dosimetry for first-in human and early phase clinical trials of such novel agents. The guideline includes a short introduction to different emitters and carrier molecules, followed by recommendations on the methods for activity measurement, pharmacokinetic analyses, as well as absorbed dose calculations and uncertainty analyses. The optimal use of preclinical information and studies involving diagnostic analogues is discussed. Good practice reporting is emphasised, and relevant dosimetry parameters and method descriptions to be included are listed. Three examples of first-in-human dosimetry studies, both for diagnostic tracers and radionuclide therapies, are given.
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Affiliation(s)
- Caroline Stokke
- Department of Diagnostic Physics and Computational Radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway.
- Department of Physics, University of Oslo, Oslo, Norway.
| | - Silvano Gnesin
- Institute of Radiation Physics, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Johannes Tran-Gia
- Department of Nuclear Medicine, University Hospital Würzburg, Würzburg, Germany
| | - Francesco Cicone
- Nuclear Medicine Unit, Department of Experimental and Clinical Medicine, "Magna Graecia" University of Catanzaro, Catanzaro, Italy
| | - Søren Holm
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Marta Cremonesi
- Department of Medical Imaging and Radiation Sciences, European Institute of Oncology, IRCCS, Milan, Italy
| | - Johan Blakkisrud
- Department of Diagnostic Physics and Computational Radiology, Division of Radiology and Nuclear Medicine, Oslo University Hospital, Oslo, Norway
| | - Thomas Wendler
- Computer-Aided Medical Procedures and Augmented Reality, Technische Universität München, Munich, Germany
- Clinical Computational Medical Imaging Research, Department of Diagnostic and Interventional Radiology and Neuroradiology, University Hospital Augsburg, Augsburg, Germany
| | - Nic Gillings
- Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Copenhagen, Denmark
| | - Ken Herrmann
- Department of Nuclear Medicine, University of Duisburg-Essen, and German Cancer Consortium (DKTK)-University Hospital Essen, Essen, Germany
- National Center for Tumor Diseases (NCT), NCT West, Heidelberg, Germany
| | - Felix M Mottaghy
- Department of Radiology and Nuclear Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University Medical Centre, Maastricht, The Netherlands
- Department of Nuclear Medicine, University Hospital RWTH Aachen, Aachen, Germany
| | - Jonathan Gear
- Joint Department of Physics, Royal Marsden NHSFT & Institute of Cancer Research, Sutton, UK
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Uijtewaal P, Borman P, Cote B, LeChasseur Y, Therriault-Proulx F, Flores R, Smith S, Koenig G, Raaymakers B, Fast M. Performance characterization of a novel hybrid dosimetry insert for simultaneous spatial, temporal, and motion-included dosimetry for MR-linac. Med Phys 2024; 51:2983-2997. [PMID: 38088939 DOI: 10.1002/mp.16870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 11/13/2023] [Accepted: 11/17/2023] [Indexed: 04/05/2024] Open
Abstract
BACKGROUND Several (online) adaptive radiotherapy procedures are available to maximize healthy tissue sparing in the presence of inter/intrafractional motion during stereotactic body radiotherapy (SBRT) on an MR-linac. The increased treatment complexity and the motion-delivery interplay during these treatments require MR-compatible motion phantoms with time-resolved dosimeters to validate end-to-end workflows. This is not possible with currently available phantoms. PURPOSE Here, we demonstrate a new commercial hybrid film-scintillator cassette, combining high spatial resolution radiochromic film with four time-resolved plastic scintillator dosimeters (PSDs) in an MRI-compatible motion phantom. METHODS First, the PSD's performance for consistency, dose linearity, and pulse repetition frequency (PRF) dependence was evaluated using an RW3 solid water slab phantom. We then demonstrated the MRI4D scintillator cassette's suitability for time-resolved and motion-included quality assurance for adapt-to-shape (ATS), trailing, gating, and multileaf collimator (MLC) tracking adaptations on a 1.5 T MR-linac. To do this, the cassette was inserted into the Quasar MRI4D phantom, which we used statically or programmed with artificial and patient-derived motion. Simultaneously with dose measurements, the beam-gating latency was estimated from the time difference between the target entering/leaving the gating window and the beam-on/off times derived from the time-resolved dose measurements. RESULTS Experiments revealed excellent detector consistency (standard deviation ≤ $\le$ 0.6%), dose linearity (R2 = 1), and only very low PRF dependence ( ≤ $\le$ 0.4%). The dosimetry cassette demonstrated a near-perfect agreement during an ATS workflow between the time-resolved PSD and treatment planning system (TPS) dose (0%-2%). The high spatial resolution film measurements confirmed this with a 1%/1-mm local gamma pass-rate of 90%. When trailing patient-derived prostate motion for a prostate SBRT delivery, the time-resolved cassette measurements demonstrated how trailing mitigated the motion-induced dose reductions from 1%-17% to 1%-2% compared to TPS dose. The cassette's simultaneously measured spatial dose distribution highlighted the dosimetric gain of trailing by improving the 3%/3-mm local gamma pass-rates from 80% to 97% compared to the static dose. Similarly, the cassette demonstrated the benefit of real-time adaptations when compensating patient-derived respiratory motion by showing how the TPS dose was restored from 2%-56% to 0%-12% (gating) and 1%-26% to 1%-7% (MLC tracking) differences. Larger differences are explainable by TPS-PSD coregistration uncertainty combined with a steep dose gradient outside the PTV. The cassette also demonstrated how the spatial dose distributions were drastically improved by the real-time adaptations with 1%/1-mm local gamma pass-rates that were increased from 8 to 79% (gating) and from 35 to 89% (MLC tracking). The cassette-determined beam-gating latency agreed within ≤ $\le$ 12 ms with the ground truth latency measurement. Film and PSD dose agreed well for most cases (differences relative to TPS dose < $<$ 4%), while film-PSD coregistration uncertainty caused relative differences of 5%-8%. CONCLUSIONS This study demonstrates the excellent suitability of a new commercial hybrid film-scintillator cassette for simultaneous spatial, temporal, and motion-included dosimetry.
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Affiliation(s)
- Prescilla Uijtewaal
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Pim Borman
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
| | | | | | | | | | | | | | | | - Martin Fast
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands
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Gibbons T, Perkins A, Barnett J. Safety, biodistribution and radiation dosimetry of the Arg-Gly-Asp peptide 99m Tc-maraciclatide in healthy volunteers. Nucl Med Commun 2024; 45:295-303. [PMID: 38312052 PMCID: PMC10916747 DOI: 10.1097/mnm.0000000000001814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Accepted: 12/19/2023] [Indexed: 02/06/2024]
Abstract
BACKGROUND 99m Tc-Maraciclatide is a radiolabelled RGD (Arg-Gly-Asp) peptide that binds with high affinity to α v β 3 and α v β 5 integrins, common receptors upregulated in disease states involving angiogenesis and inflammation. As such, it holds promise as a novel diagnostic imaging agent for a range of pathological conditions. The present study provides the safety, biodistribution and radiation dosimetry of 99m Tc-maraciclatide in healthy volunteers. METHODS A phase 1, randomised, placebo-controlled study assessed the safety, biodistribution and radiation dosimetry of 99m Tc-maraciclatide in healthy volunteers. Participants were randomised into three groups receiving 99m Tc-maraciclatide and three chemical amounts of maraciclatide in an escalating dose protocol. Eight participants in each group received the required amount of maraciclatide via intravenous injection, with the remaining two receiving a placebo. Biodistribution was assessed by acquiring scintigraphic images at time points up to 24 h after a bolus injection of 99m Tc-maraciclatide. 99m Tc-maraciclatide activity in plasma and urine was measured up to 7 days post-administration. RESULTS 99m Tc-maraciclatide was safe and well tolerated, with no serious adverse events reported. Initial uptakes of 99m Tc were highest in the gastrointestinal tract (20%), liver (15%), and lungs (9%). Similarly, the regions with the highest normalised cumulated activities were the contents of the urinary bladder and voided urine (3.4 ± 0.4 MBq*h/MBq), the combined walls of the small intestine and upper and lower large intestine (0.9 ± 0.2 MBq*h/MBq), liver (0.8 ± 0.2 MBq*h/MBq), lung (0.4 ± 0.1 MBq*h/MBq). The main route of 99m Tc excretion was renal (55%), with a systemic urinary clearance of approximately 6.7 ml/min/kg. The pharmacokinetic analysis gave a mean apparent terminal elimination half-life of the unlabelled molecular maraciclatide of approximately 1 h, independent of dose. The mean ED per unit injected activity was 7.8 ± 0.8 µSv/MBq. CONCLUSION 99m Tc-maraciclatide is a safe radiopharmaceutical formulation with a dosimetry profile similar to other 99m Tc-based imaging agents.
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Affiliation(s)
- Tatjana Gibbons
- Nuffield Department of Women's and Reproductive Health, University of Oxford, John Radcliffe Hospital, Oxford
| | - Alan Perkins
- Radiological Sciences, School of Medicine, University of Nottingham, Nottingham and
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Liu M, Cygler JE, Tiberi D, Doody J, Malone S, Vandervoort E. Dosimetric impact of rotational errors in trigeminal neuralgia radiosurgery using CyberKnife. J Appl Clin Med Phys 2024; 25:e14238. [PMID: 38131465 PMCID: PMC11005971 DOI: 10.1002/acm2.14238] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2023] [Revised: 11/23/2023] [Accepted: 11/27/2023] [Indexed: 12/23/2023] Open
Abstract
PURPOSE Trigeminal neuralgia (TN) can be treated on the CyberKnife system using two different treatment delivery paths: the general-purpose full path corrects small rotations, while the dedicated trigeminal path improves dose fall-off but does not allow rotational corrections. The study evaluates the impact of uncorrected rotations on brainstem dose and the length of CN5 (denoted as Leff) covered by the prescription dose. METHODS AND MATERIALS A proposed model estimates the delivered dose considering translational and rotational delivery errors for TN treatments on the CyberKnife system. The model is validated using radiochromic film measurements with and without rotational setup error for both paths. Leff and the brainstem dose is retrospectively assessed for 24 cases planned using the trigeminal path. For 15 cases, plans generated using both paths are compared for the target coverage and toxicity to the brainstem. RESULTS In experimental validations, measured and estimated doses agree at 1%/1 mm level. For 24 cases, the treated Leff is 5.3 ± 1.7 mm, reduced from 5.9 ± 1.8 mm in the planned dose. Constraints for the brainstem are met in 23 cases for the treated dose but require frequent treatment interruption to maintain rotational corrections <0.5° using the trigeminal path. The treated length of CN5, and plan quality metrics are similar for the two paths, favoring the full path where rotations are corrected. CONCLUSIONS We validated an analytical model that can provide patient-specific tolerances on rotations to meet plan objectives. Treatment using the full path can reduce treatment time and allow for rotational corrections.
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Affiliation(s)
- Ming Liu
- Department of Medical PhysicsThe Ottawa Hospital Cancer CenterOttawaOntarioCanada
- Department of PhysicsCarleton UniversityOttawaOntarioCanada
| | - Joanna E Cygler
- Department of Medical PhysicsThe Ottawa Hospital Cancer CenterOttawaOntarioCanada
- Department of PhysicsCarleton UniversityOttawaOntarioCanada
- Department of RadiologyUniversity of OttawaOttawaOntarioCanada
| | - David Tiberi
- Department of Radiation OncologyThe Ottawa Hospital Cancer CentreOttawaOntarioCanada
- Department of Radiation OncologyUniversity of OttawaOttawaOntarioCanada
| | - Janice Doody
- Radiation Medicine ProgramThe Ottawa Hospital Cancer CentreOttawaOntarioCanada
| | - Shawn Malone
- Department of Radiation OncologyThe Ottawa Hospital Cancer CentreOttawaOntarioCanada
- Department of Radiation OncologyUniversity of OttawaOttawaOntarioCanada
| | - Eric Vandervoort
- Department of Medical PhysicsThe Ottawa Hospital Cancer CenterOttawaOntarioCanada
- Department of PhysicsCarleton UniversityOttawaOntarioCanada
- Department of RadiologyUniversity of OttawaOttawaOntarioCanada
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Liang X, Li P, Wu Q. A novel AP/PA total body irradiation technique using abutting IMRT fields at extended SSD. J Appl Clin Med Phys 2024; 25:e14213. [PMID: 38425126 PMCID: PMC11005982 DOI: 10.1002/acm2.14213] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 11/06/2023] [Accepted: 11/07/2023] [Indexed: 03/02/2024] Open
Abstract
PURPOSE To develop a Total Body Irradiation (TBI) technique using IMRT at extended SSD that can be performed in any size Linac room. METHODS Patients studied were placed on a platform close to the floor, directly under the gantry with cranial-caudal axis parallel to the gantry rotation plane and at SSD ∼200 cm. Two abutting fields with the same external isocenter at gantry angles of ±21˚, collimator angle of 90˚, and field size of 25 × 40 cm2 are employed for both supine and prone positions. An iterative optimization algorithm was developed to generate a uniform dose at the patient mid-plane with adequate shielding to critical organs such as lungs and kidneys. The technique was validated in both phantom and patient CT images for treatment planning, and dose measurement and QA were performed in phantom. RESULTS A uniform dose distribution in the mid-plane within ±5% of the prescription dose was reached after a few iterations. This was confirmed with ion-chamber measurements in phantom. The mean dose to lungs and kidneys can be adjusted according to clinical requirements and can be as low as ∼25% of the prescription dose. For a typical prescription dose of 200 cGy/fraction, the total MU was ∼2400/1200 for the superior/inferior field. The overall treatment time for both supine/prone positions was ∼54 min to meet the maximum absorbed dose rate criteria of 15 cGy/min. IMRT QA with portal dosimetry shows excellent agreement. CONCLUSIONS We have developed a promising TBI technique using abutting IMRT fields at extended SSD. The patient is in a comfortable recumbent position with good reproducibility and less motion during treatment. An additional benefit of this technique is that full 3D dose distribution is available from the TPS with a DVH summary for organs of interest. The technique allows precise sparing of lungs and kidneys and can be executed in any linac room.
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Affiliation(s)
- Xiaomin Liang
- Medical Physics Graduate ProgramDuke Kunshan UniversityKunshanJiangsuChina
| | - Peixiong Li
- Medical Physics Graduate ProgramDuke Kunshan UniversityKunshanJiangsuChina
| | - Qiuwen Wu
- Department of Radiation OncologyDuke University Medical CenterDurhamNorth CarolinaUSA
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Ren C, Pan Q, Fu C, Wang P, Zheng Z, Hsu B, Huo L. Phase I, first-in-human study of XTR004, a novel 18F-labeled tracer for myocardial perfusion PET: Biodistribution, radiation dosimetry, pharmacokinetics, and safety after a single injection at rest. J Nucl Cardiol 2024; 34:101823. [PMID: 38360262 DOI: 10.1016/j.nuclcard.2024.101823] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 02/03/2024] [Accepted: 02/06/2024] [Indexed: 02/17/2024]
Abstract
OBJECTIVES This study assessed the imaging characteristics, pharmacokinetics and safety of XTR004, a novel 18F-labeled Positron Emission Tomography (PET) myocardial perfusion imaging tracer, after a single injection at rest in humans. METHODS Eleven healthy subjects (eight men and three women) received intravenous XTR004 (239-290 megabecquerel [MBq]). Safety profiles were monitored on the dosing day and three follow-up visits. Multiple whole-body PET scans were conducted over 4.7 h to evaluate biodistribution and radiation dosimetry. Blood and urine samples collected for 7.25 h were metabolically corrected to characterize pharmacokinetics. RESULTS In the first 0-12 min PET images of ten subjects, liver (26.81 ± 4.01), kidney (11.43 ± 2.49), lung (6.75 ± 1.76), myocardium (4.72 ± 0.67) and spleen (3.1 ± 0.84) exhibited the highest percentage of the injected dose (%ID). Myocardial uptake of XTR004 in the myocardium initially reached 4.72 %ID and 7.06 g/mL, and negligibly changed within an hour (Δ: 7.20%, 5.95%). The metabolically corrected plasma peaked at 2.5 min (0.0013896 %ID/g) and halved at 45.2 min. Whole-body effective dose was 0.0165 millisievert (mSv)/MBq. Cumulative urine excretion was 8.18%. Treatment-related adverse events occurred in seven out of eleven subjects (63.6%), but no severe adverse event was reported. CONCLUSIONS XTR004 demonstrated a favorable safety profile, rapid, high, and stable myocardial uptake and excellent potential for PET myocardial perfusion imaging (MPI). Further exploration of XTR004 PET MPI for detecting myocardial ischemia is warranted.
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Affiliation(s)
- Chao Ren
- Nuclear Medicine Department, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Center for Rare Diseases Research, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Qingqing Pan
- Nuclear Medicine Department, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Center for Rare Diseases Research, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Chao Fu
- Nuclear Medicine Department, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Center for Rare Diseases Research, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Peipei Wang
- Nuclear Medicine Department, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Center for Rare Diseases Research, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China
| | - Zhiquan Zheng
- Medical Department, Sinotau Pharmaceutical Group, Beijing, China
| | - Bailing Hsu
- Nuclear Science and Engineering Institute, University of Missouri-Columbia, Columbia, MO, USA.
| | - Li Huo
- Nuclear Medicine Department, Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine, State Key Laboratory of Complex Severe and Rare Diseases, Center for Rare Diseases Research, Peking Union Medical College Hospital, Chinese Academy of Medical Science and Peking Union Medical College, Beijing, China.
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Chu PW, Kofler C, Haas B, Lee C, Wang Y, Chu CA, Stewart C, Mahendra M, Delman BN, Bolch WE, Smith-Bindman R. Dose length product to effective dose coefficients in adults. Eur Radiol 2024; 34:2416-2425. [PMID: 37798408 DOI: 10.1007/s00330-023-10262-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 08/04/2023] [Accepted: 08/09/2023] [Indexed: 10/07/2023]
Abstract
OBJECTIVES The most accurate method for estimating patient effective dose (a principal metric for tracking patient radiation exposure) from computed tomography (CT) requires time-intensive Monte Carlo simulation. A simpler method multiplies a scalar coefficient by the widely available scanner-reported dose length product (DLP) to estimate effective dose. We developed new adult effective dose coefficients using actual patient scans and assessed their agreement with Monte Carlo simulation. METHODS A multicenter sample of 216,906 adult CT scans was prospectively assembled in 2015-2020 from the University of California San Francisco International CT Dose Registry and the University of Florida library of computational phantoms. We generated effective dose coefficients for eight body regions, stratified by patient sex, diameter, and scanner manufacturer. We applied the new coefficients to DLPs to calculate effective doses and assess their correlations with Monte Carlo radiation transport-generated effective dose. RESULTS Effective dose coefficients varied by body region and decreased in magnitude with increasing patient diameter. Coefficients were approximately twofold higher for torso scans in smallest compared with largest diameter categories. For example, abdomen and pelvis coefficients decreased from 0.027 to 0.013 mSv/mGy-cm between the 16-20 cm and 41+ cm categories. There were modest but consistent differences by sex and manufacturer. Diameter-based coefficients used to estimate effective dose produced strong correlations with the reference standard (Pearson correlations 0.77-0.86). The reported conversion coefficients differ from previous studies, particularly in neck CT. CONCLUSIONS New effective dose coefficients derived from empirical clinical scans can be used to easily estimate effective dose using scanner-reported DLP. CLINICAL RELEVANCE STATEMENT Scalar coefficients multiplied by DLP offer a simple approximation to effective dose, a key radiation dose metric. New effective dose coefficients from this study strongly correlate with gold standard, Monte Carlo-generated effective dose, and differ somewhat from previous studies. KEY POINTS • Previous effective dose coefficients were derived from theoretical models rather than real patient data. • The new coefficients (from a large registry/phantom library) differ from previous studies. • The new coefficients offer reasonably reliable values for estimating effective dose.
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Affiliation(s)
- Philip W Chu
- Department of Epidemiology and Biostatistics, University of California San Francisco, 550 16th Street, Box 0560, San Francisco, CA, 94143, USA
| | - Cameron Kofler
- Department of Radiology, The University of Chicago, Chicago, IL, USA
| | - Brian Haas
- Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Choonsik Lee
- Radiation Epidemiology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD, USA
| | - Yifei Wang
- Department of Epidemiology and Biostatistics, University of California San Francisco, 550 16th Street, Box 0560, San Francisco, CA, 94143, USA
| | - Cameron A Chu
- Department of Epidemiology and Biostatistics, University of California San Francisco, 550 16th Street, Box 0560, San Francisco, CA, 94143, USA
| | - Carly Stewart
- Department of Epidemiology and Biostatistics, University of California San Francisco, 550 16th Street, Box 0560, San Francisco, CA, 94143, USA
| | - Malini Mahendra
- Department of Pediatrics, Division of Pediatric Critical Care, UCSF Benioff Children's Hospital, University of California at San Francisco, San Francisco, USA
- Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, CA, USA
| | - Bradley N Delman
- Department of Diagnostic, Molecular and Interventional Radiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Wesley E Bolch
- Department of Biomedical Engineering, University of Florida, Gainesville, FL, USA
| | - Rebecca Smith-Bindman
- Department of Epidemiology and Biostatistics, University of California San Francisco, 550 16th Street, Box 0560, San Francisco, CA, 94143, USA.
- Philip R. Lee Institute for Health Policy Studies, University of California, San Francisco, CA, USA.
- Department of Obstetrics, Gynecology and Reproductive Sciences, University of California, San Francisco, CA, USA.
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Muthu S, Mudhana G. Dosimetric Systems in Pre-Treatment QA for Stereotactic Treatments: Correlation Agreements and Target Volume Dependency. Asian Pac J Cancer Prev 2024; 25:1425-1432. [PMID: 38680004 DOI: 10.31557/apjcp.2024.25.4.1425] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2023] [Indexed: 05/01/2024] Open
Abstract
AIM This study comprehensively investigated pre-treatment quality assurance (QA) for 100 cancer patients undergoing stereotactic treatments (SRS/SRT) using various detectors. METHODS The study conducted QA for SRS/SRT treatments planned with a 6MV SRS beam at a dose rate of 1,000 MU/min, utilizing Eclipse v13.6 Treatment Planning System (TPS). Point dose measurements employed 0.01cm3 and 0.13cm3 cylindrical ionization chambers, while planar dose verification utilized Gafchromic EBT-XD Film and Portal Imager (aS1000). Plans were categorized by target volume, and a thorough analysis compared point dose agreements, planar dose gamma pass rates, and their correlations with chamber volume mean dose, detector type, and point dose agreement. Additionally, the consistency between different ionization chambers was assessed. RESULTS Point dose agreement generally improved with increasing target volume, except for volumes over 10cm3 with 0.01cm3 chambers, showing a contrary trend. Significant differences (p<0.05) were observed between TPS and measured doses for both chambers. Gamma pass rate improved with increasing target volume in EBT XD and aS1000 analyses, except for the >10cm3 group in EBT XD. EBT XD demonstrated better agreement with TPS for target volumes up to 10cm3 compared to aS1000, with a statistically significant difference (p<0.05) between the detectors. Strong correlations were found between chamber point dose and chamber volume mean dose agreement, as well as between the two gamma criteria analyses of the same detector type in the planar dose correlation analysis. However, weak correlations were discovered for other analyses. CONCLUSION This study found weak correlation between different detector types in pre-treatment QA for point dose and planar dose evaluation. However, within a specific detector type, strong correlation was observed for different point dose evaluation methods and gamma criteria. This highlights the importance of cautious interpretation of QA results, particularly for SRS QA, due to the lack of correlation between detector types.
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Affiliation(s)
- Sivakumar Muthu
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Chennai - 600 127, India
- Department of Radiotherapy, Sri Shankara Cancer Hospital & Research Centre, Bangalore - 560 004, India
| | - Gopinath Mudhana
- Department of Physics, School of Advanced Sciences, Vellore Institute of Technology, Chennai - 600 127, India
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Sui J, Sun J, Xie K, Gao L, Lin T, Ni X. [Research on Position Verification of Multi-Leaf Collimator (MLC) and Dose Verification Based on Electronic Portal Imaging Device]. Zhongguo Yi Liao Qi Xie Za Zhi 2024; 48:150-155. [PMID: 38605613 DOI: 10.12455/j.issn.1671-7104.230545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/13/2024]
Abstract
Objective A quality control (QC) system based on the electronic portal imaging device (EPID) system was used to realize the Multi-Leaf Collimator (MLC) position verification and dose verification functions on Primus and VenusX accelerators. Methods The MLC positions were calculated by the maximum gradient method of gray values to evaluate the deviation. The dose of images acquired by EPID were reconstructed using the algorithm combining dose calibration and dose calculation. The dose data obtained by EPID and two-dimensional matrix (MapCheck/PTW) were compared with the dose calculated by Pinnacle/TiGRT TPS for γ passing rate analysis. Results The position error of VenusX MLC was less than 1 mm. The position error of Primus MLC was significantly reduced after being recalibrated under the instructions of EPID. For the dose reconstructed by EPID, the average γ passing rates of Primus were 98.86% and 91.39% under the criteria of 3%/3 mm, 10% threshold and 2%/2 mm, 10% threshold, respectively. The average γ passing rates of VenusX were 98.49% and 91.11%, respectively. Conclusion The EPID-based accelerator quality control system can improve the efficiency of accelerator quality control and reduce the workload of physicists.
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Affiliation(s)
- Jianfeng Sui
- Radiotherapy Department, Changzhou No.2 People's Hospital, Affiliated Hospital of Nanjing Medical University, Changzhou, 213161
- Center of Medical Physics, Nanjing Medical University, Changzhou, 213161
- Jiangsu Province Engineering Research Center of Medical Physics, Changzhou, 213161
| | - Jiawei Sun
- Radiotherapy Department, Changzhou No.2 People's Hospital, Affiliated Hospital of Nanjing Medical University, Changzhou, 213161
- Center of Medical Physics, Nanjing Medical University, Changzhou, 213161
- Jiangsu Province Engineering Research Center of Medical Physics, Changzhou, 213161
| | - Kai Xie
- Radiotherapy Department, Changzhou No.2 People's Hospital, Affiliated Hospital of Nanjing Medical University, Changzhou, 213161
- Center of Medical Physics, Nanjing Medical University, Changzhou, 213161
- Jiangsu Province Engineering Research Center of Medical Physics, Changzhou, 213161
| | - Liugang Gao
- Radiotherapy Department, Changzhou No.2 People's Hospital, Affiliated Hospital of Nanjing Medical University, Changzhou, 213161
- Center of Medical Physics, Nanjing Medical University, Changzhou, 213161
- Jiangsu Province Engineering Research Center of Medical Physics, Changzhou, 213161
| | - Tao Lin
- Radiotherapy Department, Changzhou No.2 People's Hospital, Affiliated Hospital of Nanjing Medical University, Changzhou, 213161
- Center of Medical Physics, Nanjing Medical University, Changzhou, 213161
- Jiangsu Province Engineering Research Center of Medical Physics, Changzhou, 213161
| | - Xinye Ni
- Radiotherapy Department, Changzhou No.2 People's Hospital, Affiliated Hospital of Nanjing Medical University, Changzhou, 213161
- Center of Medical Physics, Nanjing Medical University, Changzhou, 213161
- Jiangsu Province Engineering Research Center of Medical Physics, Changzhou, 213161
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Chea M, Croisé M, Huet C, Bassinet C, Benadjaoud MA, Jenny C. MR compatible detectors assessment for a 0.35 T MR-linac commissioning. Radiat Oncol 2024; 19:40. [PMID: 38509543 PMCID: PMC10956263 DOI: 10.1186/s13014-024-02431-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 03/11/2024] [Indexed: 03/22/2024] Open
Abstract
PURPOSE To assess a large panel of MR compatible detectors on the full range of measurements required for a 0.35 T MR-linac commissioning by using a specific statistical method represented as a continuum of comparison with the Monte Carlo (MC) TPS calculations. This study also describes the commissioning tests and the secondary MC dose calculation validation. MATERIAL AND METHODS Plans were created on the Viewray TPS to generate MC reference data. Absolute dose points, PDD, profiles and output factors were extracted and compared to measurements performed with ten different detectors: PTW 31010, 31021, 31022, Markus 34045 and Exradin A28 MR ionization chambers, SN Edge shielded diode, PTW 60019 microdiamond, PTW 60023 unshielded diode, EBT3 radiochromic films and LiF µcubes. Three commissioning steps consisted in comparison between calculated and measured dose: the beam model validation, the output calibration verification in four different phantoms and the commissioning tests recommended by the IAEA-TECDOC-1583. MAIN RESULTS The symmetry for the high resolution detectors was higher than the TPS data of about 1%. The angular responses of the PTW 60023 and the SN Edge were - 6.6 and - 11.9% compared to the PTW 31010 at 60°. The X/Y-left and the Y-right penumbras measured by the high resolution detectors were in good agreement with the TPS values except for the PTW 60023 for large field sizes. For the 0.84 × 0.83 cm2 field size, the mean deviation to the TPS of the uncorrected OF was - 1.7 ± 1.6% against - 4.0 ± 0.6% for the corrected OF whereas we found - 4.8 ± 0.8% for passive dosimeters. The mean absolute dose deviations to the TPS in different phantoms were 0 ± 0.4%, - 1.2 ± 0.6% and 0.5 ± 1.1% for the PTW 31010, PTW 31021 and Exradin A28 MR respectively. CONCLUSIONS The magnetic field effects on the measurements are considerably reduced at low magnetic field. The PTW 31010 ionization chamber can be used with confidence in different phantoms for commissioning and QA tests requiring absolute dose verifications. For relative measurements, the PTW 60019 presented the best agreement for the full range of field size. For the profile assessment, shielded diodes had a behaviour similar to the PTW 60019 and 60023 while the ionization chambers were the most suitable detectors for the symmetry. The output correction factors published by the IAEA TRS 483 seem to be applicable at low magnetic field pending the publication of new MR specific values.
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Affiliation(s)
- Michel Chea
- Medical Physics Department, Pitié-Salpêtrière Hospital, AP-HP Sorbonne University, 47-83 Boulevard de l'Hôpital, 75651, Paris Cedex 13, France.
| | - Mathilde Croisé
- Medical Physics Department, Pitié-Salpêtrière Hospital, AP-HP Sorbonne University, 47-83 Boulevard de l'Hôpital, 75651, Paris Cedex 13, France
| | - Christelle Huet
- Institut de Radioprotection et Sûreté Nucléaire (IRSN), PSE-SANTE/SDOS/LDRI, 92260, Fontenay-aux-Roses, France
| | - Céline Bassinet
- Institut de Radioprotection et Sûreté Nucléaire (IRSN), PSE-SANTE/SDOS/LDRI, 92260, Fontenay-aux-Roses, France
| | - Mohamed-Amine Benadjaoud
- Institut de Radioprotection et Sûreté Nucléaire (IRSN), PSE-SANTE/SERAMED, 92260, Fontenay-aux-Roses, France
| | - Catherine Jenny
- Medical Physics Department, Pitié-Salpêtrière Hospital, AP-HP Sorbonne University, 47-83 Boulevard de l'Hôpital, 75651, Paris Cedex 13, France
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Karger CP, Elter A, Dorsch S, Mann P, Pappas E, Oldham M. Validation of complex radiotherapy techniques using polymer gel dosimetry. Phys Med Biol 2024; 69:06TR01. [PMID: 38330494 DOI: 10.1088/1361-6560/ad278f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 02/08/2024] [Indexed: 02/10/2024]
Abstract
Modern radiotherapy delivers highly conformal dose distributions to irregularly shaped target volumes while sparing the surrounding normal tissue. Due to the complex planning and delivery techniques, dose verification and validation of the whole treatment workflow by end-to-end tests became much more important and polymer gel dosimeters are one of the few possibilities to capture the delivered dose distribution in 3D. The basic principles and formulations of gel dosimetry and its evaluation methods are described and the available studies validating device-specific geometrical parameters as well as the dose delivery by advanced radiotherapy techniques, such as 3D-CRT/IMRT and stereotactic radiosurgery treatments, the treatment of moving targets, online-adaptive magnetic resonance-guided radiotherapy as well as proton and ion beam treatments, are reviewed. The present status and limitations as well as future challenges of polymer gel dosimetry for the validation of complex radiotherapy techniques are discussed.
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Affiliation(s)
- Christian P Karger
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Alina Elter
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
- Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, D-69120 Heidelberg, Germany
| | - Stefan Dorsch
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Philipp Mann
- Department of Medical Physics in Radiation Oncology, German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Evangelos Pappas
- Radiology & Radiotherapy Sector, Department of Biomedical Sciences, University of West Attica, Athens, Greece
| | - Mark Oldham
- Department of Radiation Oncology, Duke University Medical Center, Durham, NC, United States of America
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Lee C, Moroz B, Thome C, Gaudreau K, Emami P, Little MP. Reconstruction of organ doses for patients undergoing computed tomography examinations in Canada 1992-2019. Radiat Prot Dosimetry 2024; 200:379-386. [PMID: 38186237 PMCID: PMC10954068 DOI: 10.1093/rpd/ncad315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 10/31/2023] [Accepted: 11/30/2023] [Indexed: 01/09/2024]
Abstract
We derived the first comprehensive organ dose library for Canadian pediatric and adult patients who underwent computed tomography (CT) scans between 1992 and 2019 to support epidemiological analysis of radiation risk. We calculated organ absorbed doses for Canadian CT patients in two steps. First, we modeled Computed Tomography Dose Index (CTDI) values by patient age, scan body part, and scan year for the scan period between 1992 and 2019 using national survey data conducted in Canada and partially the United Kingdom survey data as surrogates. Second, we converted CTDI values to organ absorbed doses using a library of organ dose conversion coefficients built in an organ dose calculation program, the National Cancer Institute dosimetry system for CT. In result, we created a library of doses delivered to 33 organs and tissues by different patient ages and genders, scan body parts and scan years. In the scan period before 2000, the organs receiving the greatest dose in the head, chest and abdomen-pelvis scans were the active marrow (3.7-15.2 mGy), lungs (54.7-62.8 mGy) and colon (54.9-68.5 mGy), respectively. We observed organ doses reduced by 24% (pediatric head and torso scans, and adult head scans) and 55% (adult torso scans) after 2000. The organ dose library will be used to analyse the risk of radiation exposure from CT scans in the Canadian CT patient cohort.
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Affiliation(s)
- Choonsik Lee
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, 20850, United States
| | - Brian Moroz
- Computing and Software Solutions for Science, LLC, Bethany Beach, DE, 19930, United States
| | - Christopher Thome
- Medical Sciences Division, NOSM University, Sudbury, ON, P3E 2C6, Canada
- School of Natural Sciences, Laurentian University, Sudbury, ON, P3E 2C6, Canada
| | - Katherine Gaudreau
- Medical Sciences Division, NOSM University, Sudbury, ON, P3E 2C6, Canada
| | - Pirouz Emami
- Department of Physics & Astronomy, McMaster University, Hamilton, ON, ON L8S 4L8, Canada
| | - Mark P Little
- Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, MD, 20850, United States
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Taubaldiev A, Živanović M. Gamma irradiation system's performance tests. Radiat Prot Dosimetry 2024; 200:368-378. [PMID: 38186202 DOI: 10.1093/rpd/ncad311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Revised: 11/29/2023] [Accepted: 12/06/2023] [Indexed: 01/09/2024]
Abstract
This study reviews the performance analysis of a 137Cs irradiation system that has recently been installed in the laboratory of Uzbek National Institute of Metrology. The laboratory is responsible for calibrating calibration facilities and for calibrating most protection level radiation monitoring instruments used in medical, nuclear, industrial and academic settings in Uzbekistan. This system employs the most advanced radiation safety standards, along with 21st century source automation methods. In this work, we review the system's performance according to ISO 4037 and present measurement uncertainty budget. Our analysis shows excellent results in terms of scattered radiation, beam uniformity and field size, change in source position, test for source impurities, chamber stability and source calibration, and all these parameters fully comply with the requirements of ISO 4037.
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Affiliation(s)
- Azamat Taubaldiev
- Uzbek National Institute of Metrology, 333 A, 333 B, Farobiy street, Almazar district, 100174 Tashkent, Uzbekistan
- Tashkent State Technical University Named after Islam Karimov, University street 2, 100095 Tashkent, Uzbekistan
| | - Miloš Živanović
- Vinča Institute of Nuclear Sciences - National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovića Alasa 12-14, 11351 Vinča, Belgrade, Serbia
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48
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Rindhatayathon P, Pungkun V. Investigating the impact of new dosimetric quantities recommended by ICRU 95 on the OSLD individual monitoring system at OAP, Thailand. J Radiol Prot 2024; 44:013503. [PMID: 38306678 DOI: 10.1088/1361-6498/ad255c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 02/01/2024] [Indexed: 02/04/2024]
Abstract
This research investigates the effects of new definitions of operational dosimetric quantities, especiallyHp(10) to Hp recommended by ICRU Report 95, on the dosimetry system. This paper focuses on the responses of two dosimeter types, nanoDot® and InLight®, using conversional coefficients from ICRU report 57 and ICRU report 95 conversion coefficients. The dosimeters were irradiated with various beam qualities, and their responses were compared to the acceptant limits provided by the IEC 62387. The results demonstrate higher responses at new definitions recommended by ICRU report 95, indicating the need for algorithm modifications in the dose calculation.
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Affiliation(s)
- P Rindhatayathon
- Ionizing Radiation Metrology Section, Regulatory Technical Support Division, Office of Atoms for Peace 16 Vibhavadi Rungsit Rd., Ladyao, Chatuchak, Bangkok 10900, Thailand
| | - V Pungkun
- Ionizing Radiation Metrology Section, Regulatory Technical Support Division, Office of Atoms for Peace 16 Vibhavadi Rungsit Rd., Ladyao, Chatuchak, Bangkok 10900, Thailand
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Kierkels RGJ, Hernandez V, Saez J, Angerud A, Hilgers GC, Surmann K, Schuring D, Minken AWH. Multileaf collimator characterization and modeling for a 1.5 T MR-linac using static synchronous and asynchronous sweeping gaps. Phys Med Biol 2024; 69:075004. [PMID: 38412538 DOI: 10.1088/1361-6560/ad2d7d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Accepted: 02/27/2024] [Indexed: 02/29/2024]
Abstract
Objective.The Elekta unity MR-linac delivers step-and-shoot intensity modulated radiotherapy plans using a multileaf collimator (MLC) based on the Agility MLC used on conventional Elekta linacs. Currently, details of the physical Unity MLC and the computational model within its treatment planning system (TPS)Monacoare lacking in published literature. Recently, a novel approach to characterize the physical properties of MLCs was introduced using dynamic synchronous and asynchronous sweeping gap (aSG) tests. Our objective was to develop a step-and-shoot version of the dynamic aSG test to characterize the Unity MLC and the computational MLC models in theMonacoandRayStationTPSs.Approach.Dynamic aSG were discretized into a step-and-shoot aSG by investigating the number of segments/sweep and the minimal number of monitor units (MU) per segment. The step-and-shoot aSG tests were compared to the dynamic aSG tests on a conventional linac at a source-to-detector distance of 143.5 cm, mimicking the Unity configuration. the step-and-shoot aSG tests were used to characterize the Unity MLC through measurements and dose calculations in both TPSs.Main results.The step-and-shoot aSGs tests with 100 segments and 5 MU/segment gave results very similar to the dynamic aSG experiments. The effective tongue-and-groove width of the Unity gradually increased up to 1.4 cm from the leaf tip end. The MLC models inRayStationandMonacoagreed with experimental data within 2.0% and 10%, respectively. The largest discrepancies inMonacowere found for aSG tests with >10 mm leaf interdigitation, which are non-typical for clinical plans.Significance.The step-and-shoot aSG tests accurately characterize the MLC in step-and-shoot delivery mode. The MLC model inRayStation2023B accurately describes the tongue-and-groove and leaf tip effects whereasMonacooverestimates the tongue-and-groove shadowing further away from the leaf tip end.
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Affiliation(s)
| | - Victor Hernandez
- Hospital Sant Joan de Reus, Department of Medical Physics, Reus, Spain
| | - Jordi Saez
- Hospital Clínic de Barcelona, Department of Radiation Oncology, Barcelona, Spain
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50
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Inman JL, Wu Y, Chen L, Brydon E, Ghosh D, Wan KH, De Chant J, Obst-Huebl L, Nakamura K, Ralston CY, Celniker SE, Mao JH, Zwart PH, Holman HYN, Chang H, Brown JB, Snijders AM. Long-term, non-invasive FTIR detection of low-dose ionizing radiation exposure. Sci Rep 2024; 14:6119. [PMID: 38480827 PMCID: PMC10937999 DOI: 10.1038/s41598-024-56491-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Accepted: 03/07/2024] [Indexed: 03/17/2024] Open
Abstract
Non-invasive methods of detecting radiation exposure show promise to improve upon current approaches to biological dosimetry in ease, speed, and accuracy. Here we developed a pipeline that employs Fourier transform infrared (FTIR) spectroscopy in the mid-infrared spectrum to identify a signature of low dose ionizing radiation exposure in mouse ear pinnae over time. Mice exposed to 0.1 to 2 Gy total body irradiation were repeatedly measured by FTIR at the stratum corneum of the ear pinnae. We found significant discriminative power for all doses and time-points out to 90 days after exposure. Classification accuracy was maximized when testing 14 days after exposure (specificity > 0.9 with a sensitivity threshold of 0.9) and dropped by roughly 30% sensitivity at 90 days. Infrared frequencies point towards biological changes in DNA conformation, lipid oxidation and accumulation and shifts in protein secondary structure. Since only hundreds of samples were used to learn the highly discriminative signature, developing human-relevant diagnostic capabilities is likely feasible and this non-invasive procedure points toward rapid, non-invasive, and reagent-free biodosimetry applications at population scales.
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Affiliation(s)
- Jamie L Inman
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Yulun Wu
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
- Department of Statistics, University of California, Berkeley, CA, 94720, USA
| | - Liang Chen
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Ella Brydon
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Dhruba Ghosh
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
- Paul G. Allen School of Computer Science and Engineering, University of Washington, Seattle, USA
| | - Kenneth H Wan
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Jared De Chant
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Lieselotte Obst-Huebl
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Kei Nakamura
- Accelerator Technology and Applied Physics Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Corie Y Ralston
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Susan E Celniker
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Jian-Hua Mao
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Peter H Zwart
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA
| | - Hoi-Ying N Holman
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA.
| | - Hang Chang
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA.
| | - James B Brown
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA.
- Department of Statistics, University of California, Berkeley, CA, 94720, USA.
| | - Antoine M Snijders
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd, Berkeley, CA, 94720, USA.
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