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Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment
The Halcyon™ platform is self‐contained, combining a treatment planning (Eclipse) system TPS) with information management and radiation delivery components. The standard TPS beam model is configured and locked down by the vendor. A portal dosimetry‐based system for patient‐specific QA (PSQA) is also...
Autores principales: | , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2021
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7882119/ https://www.ncbi.nlm.nih.gov/pubmed/33452738 http://dx.doi.org/10.1002/acm2.13116 |
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author | Saini, Amarjit Tichacek, Chris Johansson, William Redler, Gage Zhang, Geoffrey Moros, Eduardo G. Qayyum, Muqeem Feygelman, Vladimir |
author_facet | Saini, Amarjit Tichacek, Chris Johansson, William Redler, Gage Zhang, Geoffrey Moros, Eduardo G. Qayyum, Muqeem Feygelman, Vladimir |
author_sort | Saini, Amarjit |
collection | PubMed |
description | The Halcyon™ platform is self‐contained, combining a treatment planning (Eclipse) system TPS) with information management and radiation delivery components. The standard TPS beam model is configured and locked down by the vendor. A portal dosimetry‐based system for patient‐specific QA (PSQA) is also included. While ensuring consistency across the user base, this closed model may not be optimal for every department. We set out to commission independent TPS (RayStation 9B, RaySearch Laboratories) and PSQA (PerFraction, Sun Nuclear Corp.) systems for use with the Halcyon linac. The output factors and PDDs for very small fields (0.5 × 0.5 cm(2)) were collected to augment the standard Varian dataset. The MLC leaf‐end parameters were estimated based on the various static and dynamic tests with simple model fields and honed by minimizing the mean and standard deviation of dose difference between the ion chamber measurements and RayStation Monte Carlo calculations for 15 VMAT and IMRT test plans. Two chamber measurements were taken per plan, in the high (isocenter) and lower dose regions. The ratio of low to high doses ranged from 0.4 to 0.8. All percent dose differences were expressed relative to the local dose. The mean error was 0.0 ± 1.1% (TG119‐style confidence limit ± 2%). Gamma analysis with the helical diode array using the standard 3%Global/2mm criteria resulted in the average passing rate of 99.3 ± 0.5% (confidence limit 98.3%–100%). The average local dose error for all detectors across all plans was 0.2% ± 5.3%. The ion chamber results compared favorably with our recalculation with Eclipse and PerFraction, as well as with several published Eclipse reports. Dose distribution gamma analysis comparisons between RayStation and PerFraction with 2%Local/2mm criteria yielded an average passing rate of 98.5% ± 0.8% (confidence limit 96.9%–100%). It is feasible to use the Halcyon accelerator with independent planning and verification systems without sacrificing dosimetric accuracy. |
format | Online Article Text |
id | pubmed-7882119 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2021 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-78821192021-02-19 Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment Saini, Amarjit Tichacek, Chris Johansson, William Redler, Gage Zhang, Geoffrey Moros, Eduardo G. Qayyum, Muqeem Feygelman, Vladimir J Appl Clin Med Phys Radiation Oncology Physics The Halcyon™ platform is self‐contained, combining a treatment planning (Eclipse) system TPS) with information management and radiation delivery components. The standard TPS beam model is configured and locked down by the vendor. A portal dosimetry‐based system for patient‐specific QA (PSQA) is also included. While ensuring consistency across the user base, this closed model may not be optimal for every department. We set out to commission independent TPS (RayStation 9B, RaySearch Laboratories) and PSQA (PerFraction, Sun Nuclear Corp.) systems for use with the Halcyon linac. The output factors and PDDs for very small fields (0.5 × 0.5 cm(2)) were collected to augment the standard Varian dataset. The MLC leaf‐end parameters were estimated based on the various static and dynamic tests with simple model fields and honed by minimizing the mean and standard deviation of dose difference between the ion chamber measurements and RayStation Monte Carlo calculations for 15 VMAT and IMRT test plans. Two chamber measurements were taken per plan, in the high (isocenter) and lower dose regions. The ratio of low to high doses ranged from 0.4 to 0.8. All percent dose differences were expressed relative to the local dose. The mean error was 0.0 ± 1.1% (TG119‐style confidence limit ± 2%). Gamma analysis with the helical diode array using the standard 3%Global/2mm criteria resulted in the average passing rate of 99.3 ± 0.5% (confidence limit 98.3%–100%). The average local dose error for all detectors across all plans was 0.2% ± 5.3%. The ion chamber results compared favorably with our recalculation with Eclipse and PerFraction, as well as with several published Eclipse reports. Dose distribution gamma analysis comparisons between RayStation and PerFraction with 2%Local/2mm criteria yielded an average passing rate of 98.5% ± 0.8% (confidence limit 96.9%–100%). It is feasible to use the Halcyon accelerator with independent planning and verification systems without sacrificing dosimetric accuracy. John Wiley and Sons Inc. 2021-01-15 /pmc/articles/PMC7882119/ /pubmed/33452738 http://dx.doi.org/10.1002/acm2.13116 Text en © 2021 The Authors. Journal of Applied Clinical Medical Physics published by Wiley Periodicals, Inc. on behalf of American Association of Physicists in Medicine This is an open access article under the terms of the http://creativecommons.org/licenses/by/4.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Radiation Oncology Physics Saini, Amarjit Tichacek, Chris Johansson, William Redler, Gage Zhang, Geoffrey Moros, Eduardo G. Qayyum, Muqeem Feygelman, Vladimir Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment |
title | Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment |
title_full | Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment |
title_fullStr | Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment |
title_full_unstemmed | Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment |
title_short | Unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment |
title_sort | unlocking a closed system: dosimetric commissioning of a ring gantry linear accelerator in a multivendor environment |
topic | Radiation Oncology Physics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7882119/ https://www.ncbi.nlm.nih.gov/pubmed/33452738 http://dx.doi.org/10.1002/acm2.13116 |
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