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Czarnecki D, Zink K, Pimpinella M, Borbinha J, Teles P, Pinto M. Monte Carlo calculation of quality correction factors based on air kerma and absorbed dose to water in medium energy x-ray beams. Phys Med Biol 2020; 65:245042. [PMID: 33120372 DOI: 10.1088/1361-6560/abc5c9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Clinical dosimetry is typically performed using ion chambers calibrated in terms of absorbed dose to water. As primary measurement standards for this quantity for low and medium energy x-rays are available only since a few years, most dosimetry protocols for this photon energy range are still based on air kerma calibration. For that reason, data for beam quality correction factors [Formula: see text], necessary for the application of dose to water based protocols, are scarce in literature. Currently the international IAEA TRS-398 Code of Practice is under revision and new [Formula: see text] factors for a large number of ion chambers will be introduced in the update of this protocol. Several international groups provided the IAEA with experimental and Monte Carlo based data for this revision. Within the European Community the EURAMET 16NRM03 RTNORM project was initiated for that purpose. In the present study, Monte Carlo based results for the beam quality correction factors in medium energy x-ray beams for six ion chambers applying different Monte Carlo codes are presented. Additionally, the perturbation factor p Q , necessary for the calculation of dose to water from an air kerma calibration coefficient, was determined. The beam quality correction factor [Formula: see text] for the chambers varied in the investigated energy range by about 4%-5%, and for five out of six chambers the data could be fitted by a simple logarithmic function, if the half-value-layer was used as the beam quality specifier. Corresponding data using different Monte Carlo codes for the same ion chamber agreed within 0.5%. For the perturbation factor p Q , the data did not obey a comparable simple relationship with the beam quality specifier. The variation of p Q for all ion chambers was in the range of 3%-4%. Compared to recently published data, our p Q data is around 1% larger, although the same Monte Carlo code has been used. Compared to the latest experimental data, there are even deviations in the range of 2%.
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Affiliation(s)
- Damian Czarnecki
- Institute of Medical Physics and Radiation Protection, University of Applied Sciences Giessen (THM), Giessen, Germany
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2
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Rosado PH, Salata C, David MG, Mantuano A, Pickler A, Mota CL, de Almeida CE. Determination of the absorbed dose to water for medium-energy x-ray beams using Fricke dosimetry. Med Phys 2020; 47:5802-5809. [PMID: 32964481 DOI: 10.1002/mp.14473] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/22/2020] [Accepted: 08/30/2020] [Indexed: 12/25/2022] Open
Abstract
PURPOSE For x-ray beams in the low and medium energy range, reference dosimetry is established in terms of air kerma. Fricke dosimetry has shown great potential in the absolute measurements of the absorbed dose to water for high-energy ranges. Therefore, the main purpose of this work was to compare the absorbed dose to water for medium-energy x-ray beams obtained through Fricke dosimetry with that obtained from the air kerma rate. METHODS To determine the absorbed dose to water using Fricke dosimetry, the polyethylene bags methodology was chosen. Fricke solution was irradiated at four different beam qualities. The absorbed dose to water values obtained using Fricke dosimetry were compared to those obtained using the standard protocol, using the Z-score. RESULTS Values of the Z-score were <2 for all measurements of absorbed dose to water, which means that the values obtained using Fricke dosimetry are equivalent to those obtained using the reference protocol. The combined standard uncertainty for the absorbed dose to water obtained by Fricke dosimetry was lower than that obtained with the ionization chamber. CONCLUSIONS Chemical dosimetry using a standard FeSO4 solution has been demonstrated to be a potential option as a standard for the quantity absorbed dose to water for medium kV x-ray qualities.
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Affiliation(s)
- Paulo Henrique Rosado
- Brazilian National Ionizing Radiation Metrology Laboratory, Radioprotection and Dosimetry Institute (IRD), Rio de Janeiro, Brazil.,Department of Medical and Research Facilities, National Nuclear Energy Authority (CNEN), Rio de Janeiro, Brazil
| | - Camila Salata
- Department of Medical and Research Facilities, National Nuclear Energy Authority (CNEN), Rio de Janeiro, Brazil.,Radiological Sciences Department, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil
| | - Mariano Gazineu David
- Polytechnic Institute of the Rio de Janeiro State University (IPRJ/UERJ), Rio de Janeiro, Brazil
| | - Andrea Mantuano
- Radiological Sciences Department, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil
| | - Arissa Pickler
- Radiological Sciences Department, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil
| | - Carla Lemos Mota
- Radiological Sciences Department, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil.,Physics Department, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil
| | - Carlos E de Almeida
- Radiological Sciences Department, Rio de Janeiro State University (UERJ), Rio de Janeiro, Brazil
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Bancheri J, Ketelhut S, Büermann L, Seuntjens J. Monte Carlo and water calorimetric determination of kilovoltage beam radiotherapy ionization chamber correction factors. ACTA ACUST UNITED AC 2020; 65:105001. [DOI: 10.1088/1361-6560/ab82e7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Renaud J, Palmans H, Sarfehnia A, Seuntjens J. Absorbed dose calorimetry. ACTA ACUST UNITED AC 2020; 65:05TR02. [DOI: 10.1088/1361-6560/ab4f29] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Lawless MJ, Dimaso L, Palmer B, Micka J, Culberson WS, DeWerd LA. Monte Carlo and60Co‐based kilovoltage x‐ray dosimetry methods. Med Phys 2018; 45:5564-5576. [DOI: 10.1002/mp.13213] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Revised: 09/07/2018] [Accepted: 09/07/2018] [Indexed: 11/08/2022] Open
Affiliation(s)
- Michael J. Lawless
- Department of Human Oncology University of Wisconsin‐Madison Madison WI 53705USA
| | - Lianna Dimaso
- Department of Medical Physics University of Wisconsin‐Madison Madison WI 53705USA
| | - Benjamin Palmer
- Department of Medical Physics University of Wisconsin‐Madison Madison WI 53705USA
| | - John Micka
- Department of Medical Physics University of Wisconsin‐Madison Madison WI 53705USA
| | - Wesley S. Culberson
- Department of Medical Physics University of Wisconsin‐Madison Madison WI 53705USA
| | - Larry A. DeWerd
- Department of Medical Physics University of Wisconsin‐Madison Madison WI 53705USA
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Noblet C, Delpon G, Supiot S, Potiron V, Paris F, Chiavassa S. A new tissue segmentation method to calculate 3D dose in small animal radiation therapy. Radiat Oncol 2018; 13:32. [PMID: 29482652 PMCID: PMC5828405 DOI: 10.1186/s13014-018-0971-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 02/11/2018] [Indexed: 11/22/2022] Open
Abstract
Background In pre-clinical animal experiments, radiation delivery is usually delivered with kV photon beams, in contrast to the MV beams used in clinical irradiation, because of the small size of the animals. At this medium energy range, however, the contribution of the photoelectric effect to absorbed dose is significant. Accurate dose calculation therefore requires a more detailed tissue definition because both density (ρ) and elemental composition (Zeff) affect the dose distribution. Moreover, when applied to cone beam CT (CBCT) acquisitions, the stoichiometric calibration of HU becomes inefficient as it is designed for highly collimated fan beam CT acquisitions. In this study, we propose an automatic tissue segmentation method of CBCT imaging that assigns both density (ρ) and elemental composition (Zeff) in small animal dose calculation. Methods The method is based on the relationship found between CBCT number and ρ*Zeff product computed from known materials. Monte Carlo calculations were performed to evaluate the impact of ρZeff variation on the absorbed dose in tissues. These results led to the creation of a tissue database composed of artificial tissues interpolated from tissue values published by the ICRU. The ρZeff method was validated by measuring transmitted doses through tissue substitute cylinders and a mouse with EBT3 film. Measurements were compared to the results of the Monte Carlo calculations. Results The study of the impact of ρZeff variation over the range of materials, from ρZeff = 2 g.cm− 3 (lung) to 27 g.cm− 3 (cortical bone) led to the creation of 125 artificial tissues. For tissue substitute cylinders, the use of ρZeff method led to maximal and average relative differences between the Monte Carlo results and the EBT3 measurements of 3.6% and 1.6%. Equivalent comparison for the mouse gave maximal and average relative differences of 4.4% and 1.2%, inside the 80% isodose area. Gamma analysis led to a 94.9% success rate in the 10% isodose area with 4% and 0.3 mm criteria in dose and distance. Conclusions Our new tissue segmentation method was developed for 40kVp CBCT images. Both density and elemental composition are assigned to each voxel by using a relationship between HU and the product ρZeff. The method, validated by comparing measurements and calculations, enables more accurate small animal dose distribution calculated on low energy CBCT images.
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Affiliation(s)
- C Noblet
- Medical Physics Department, Institut de Cancérologie de l'Ouest Centre René Gauducheau, 44805, Saint-Herblain, France. .,CRCINA, Inserm U1232, Université de Nantes, Nantes, France.
| | - G Delpon
- Medical Physics Department, Institut de Cancérologie de l'Ouest Centre René Gauducheau, 44805, Saint-Herblain, France.,CRCINA, Inserm U1232, Université de Nantes, Nantes, France
| | - S Supiot
- CRCINA, Inserm U1232, Université de Nantes, Nantes, France.,Radiotherapy Department, Institut de Cancérologie de l'Ouest Centre René Gauducheau, 44805, Saint-Herblain, France
| | - V Potiron
- CRCINA, Inserm U1232, Université de Nantes, Nantes, France.,LABCT, Institut de Cancérologie de l'Ouest Centre René Gauducheau, 44805, Saint-Herblain, France
| | - F Paris
- CRCINA, Inserm U1232, Université de Nantes, Nantes, France.,LABCT, Institut de Cancérologie de l'Ouest Centre René Gauducheau, 44805, Saint-Herblain, France
| | - S Chiavassa
- Medical Physics Department, Institut de Cancérologie de l'Ouest Centre René Gauducheau, 44805, Saint-Herblain, France.,CRCINA, Inserm U1232, Université de Nantes, Nantes, France
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Renaud J, Rossomme S, Sarfehnia A, Vynckier S, Palmans H, Kacperek A, Seuntjens J. Development and application of a water calorimeter for the absolute dosimetry of short-range particle beams. Phys Med Biol 2016; 61:6602-6619. [DOI: 10.1088/0031-9155/61/18/6602] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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8
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de Prez L, de Pooter J, Jansen B, Aalbers T. A water calorimeter for on-site absorbed dose to water calibrations in60Co and MV-photon beams including MRI incorporated treatment equipment. Phys Med Biol 2016; 61:5051-76. [DOI: 10.1088/0031-9155/61/13/5051] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Dufreneix S, Ostrowsky A, Rapp B, Daures J, Bordy JM. Accuracy of a dose-area product compared to an absorbed dose to water at a point in a 2 cm diameter field. Med Phys 2016; 43:4085. [DOI: 10.1118/1.4953207] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Noblet C, Chiavassa S, Smekens F, Sarrut D, Passal V, Suhard J, Lisbona A, Paris F, Delpon G. Validation of fast Monte Carlo dose calculation in small animal radiotherapy with EBT3 radiochromic films. Phys Med Biol 2016; 61:3521-35. [DOI: 10.1088/0031-9155/61/9/3521] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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[Small animal image-guided radiotherapy: A new era for preclinical studies]. Cancer Radiother 2016; 20:43-53. [PMID: 26856635 DOI: 10.1016/j.canrad.2015.08.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 08/03/2015] [Accepted: 08/05/2015] [Indexed: 12/11/2022]
Abstract
Preclinical external beam radiotherapy irradiations used to be delivered with a static broad beam. To promote the transfer from animal to man, the preclinical treatment techniques dedicated to the animal have been optimized to be similar to those delivered to patients in clinical practice. In this context, preclinical irradiators have been developed. Due to the small sizes of the animals, and the irradiation beams, the scaling to the small animal dimensions involves specific problems. Reducing the size and energy of the irradiation beams require very high technical performance, especially for the mechanical stability of the irradiator and the spatial resolution of the imaging system. In addition, the determination of the reference absorbed dose rate must be conducted with a specific methodology and suitable detectors. To date, three systems are used for preclinical studies in France. The aim of this article is to present these new irradiators dedicated to small animals from a physicist point of view, including the commissioning and the quality control.
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Pinto M, Pimpinella M, Quini M, D’Arienzo M, Astefanoaei I, Loreti S, Guerra AS. A graphite calorimeter for absolute measurements of absorbed dose to water: application in medium-energy x-ray filtered beams. Phys Med Biol 2016; 61:1738-64. [DOI: 10.1088/0031-9155/61/4/1738] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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13
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Hill R, Healy B, Holloway L, Kuncic Z, Thwaites D, Baldock C. Advances in kilovoltage x-ray beam dosimetry. Phys Med Biol 2014; 59:R183-231. [DOI: 10.1088/0031-9155/59/6/r183] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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14
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Perichon N, Rapp B, Denoziere M, Daures J, Ostrowsky A, Bordy JM. Comparison between absorbed dose to water standards established by water calorimetry at the LNE-LNHB and by application of international air-kerma based protocols for kilovoltage medium energy x-rays. Phys Med Biol 2013; 58:2787-806. [DOI: 10.1088/0031-9155/58/9/2787] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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