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Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance
The purpose of this study was to compare the MLC error sensitivity of various measurement devices for VMAT pre‐treatment quality assurance (QA). This study used four QA devices (Scandidos Delta4, PTW 2D‐array, iRT systems IQM, and PTW Farmer chamber). Nine retrospective VMAT plans were used and nine...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2018
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978943/ https://www.ncbi.nlm.nih.gov/pubmed/29500857 http://dx.doi.org/10.1002/acm2.12288 |
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author | Saito, Masahide Sano, Naoki Shibata, Yuki Kuriyama, Kengo Komiyama, Takafumi Marino, Kan Aoki, Shinichi Ashizawa, Kazunari Yoshizawa, Kazuya Onishi, Hiroshi |
author_facet | Saito, Masahide Sano, Naoki Shibata, Yuki Kuriyama, Kengo Komiyama, Takafumi Marino, Kan Aoki, Shinichi Ashizawa, Kazunari Yoshizawa, Kazuya Onishi, Hiroshi |
author_sort | Saito, Masahide |
collection | PubMed |
description | The purpose of this study was to compare the MLC error sensitivity of various measurement devices for VMAT pre‐treatment quality assurance (QA). This study used four QA devices (Scandidos Delta4, PTW 2D‐array, iRT systems IQM, and PTW Farmer chamber). Nine retrospective VMAT plans were used and nine MLC error plans were generated for all nine original VMAT plans. The IQM and Farmer chamber were evaluated using the cumulative signal difference between the baseline and error‐induced measurements. In addition, to investigate the sensitivity of the Delta4 device and the 2D‐array, global gamma analysis (1%/1, 2%/2, and 3%/3 mm), dose difference (1%, 2%, and 3%) were used between the baseline and error‐induced measurements. Some deviations of the MLC error sensitivity for the evaluation metrics and MLC error ranges were observed. For the two ionization devices, the sensitivity of the IQM was significantly better than that of the Farmer chamber (P < 0.01) while both devices had good linearly correlation between the cumulative signal difference and the magnitude of MLC errors. The pass rates decreased as the magnitude of the MLC error increased for both Delta4 and 2D‐array. However, the small MLC error for small aperture sizes, such as for lung SBRT, could not be detected using the loosest gamma criteria (3%/3 mm). Our results indicate that DD could be more useful than gamma analysis for daily MLC QA, and that a large‐area ionization chamber has a greater advantage for detecting systematic MLC error because of the large sensitive volume, while the other devices could not detect this error for some cases with a small range of MLC error. |
format | Online Article Text |
id | pubmed-5978943 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2018 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-59789432018-06-01 Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance Saito, Masahide Sano, Naoki Shibata, Yuki Kuriyama, Kengo Komiyama, Takafumi Marino, Kan Aoki, Shinichi Ashizawa, Kazunari Yoshizawa, Kazuya Onishi, Hiroshi J Appl Clin Med Phys Radiation Oncology Physics The purpose of this study was to compare the MLC error sensitivity of various measurement devices for VMAT pre‐treatment quality assurance (QA). This study used four QA devices (Scandidos Delta4, PTW 2D‐array, iRT systems IQM, and PTW Farmer chamber). Nine retrospective VMAT plans were used and nine MLC error plans were generated for all nine original VMAT plans. The IQM and Farmer chamber were evaluated using the cumulative signal difference between the baseline and error‐induced measurements. In addition, to investigate the sensitivity of the Delta4 device and the 2D‐array, global gamma analysis (1%/1, 2%/2, and 3%/3 mm), dose difference (1%, 2%, and 3%) were used between the baseline and error‐induced measurements. Some deviations of the MLC error sensitivity for the evaluation metrics and MLC error ranges were observed. For the two ionization devices, the sensitivity of the IQM was significantly better than that of the Farmer chamber (P < 0.01) while both devices had good linearly correlation between the cumulative signal difference and the magnitude of MLC errors. The pass rates decreased as the magnitude of the MLC error increased for both Delta4 and 2D‐array. However, the small MLC error for small aperture sizes, such as for lung SBRT, could not be detected using the loosest gamma criteria (3%/3 mm). Our results indicate that DD could be more useful than gamma analysis for daily MLC QA, and that a large‐area ionization chamber has a greater advantage for detecting systematic MLC error because of the large sensitive volume, while the other devices could not detect this error for some cases with a small range of MLC error. John Wiley and Sons Inc. 2018-03-03 /pmc/articles/PMC5978943/ /pubmed/29500857 http://dx.doi.org/10.1002/acm2.12288 Text en © 2018 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 Saito, Masahide Sano, Naoki Shibata, Yuki Kuriyama, Kengo Komiyama, Takafumi Marino, Kan Aoki, Shinichi Ashizawa, Kazunari Yoshizawa, Kazuya Onishi, Hiroshi Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance |
title | Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance |
title_full | Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance |
title_fullStr | Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance |
title_full_unstemmed | Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance |
title_short | Comparison of MLC error sensitivity of various commercial devices for VMAT pre‐treatment quality assurance |
title_sort | comparison of mlc error sensitivity of various commercial devices for vmat pre‐treatment quality assurance |
topic | Radiation Oncology Physics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5978943/ https://www.ncbi.nlm.nih.gov/pubmed/29500857 http://dx.doi.org/10.1002/acm2.12288 |
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