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Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators

This study evaluates the type of detector influencing the inter‐institutional variability in flattening filter‐free (FFF) beam‐specific parameters for TrueBeam™ linear accelerators (Varian Medical Systems,Palo Alto, CA, USA). Twenty‐four beam data sets, including the percent depth dose (PDD), off‐ce...

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Autores principales: Tanaka, Yoshihiro, Akino, Yuichi, Mizuno, Hirokazu, Isono, Masaru, Masai, Norihisa, Yamamoto, Toshijiro
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6964765/
https://www.ncbi.nlm.nih.gov/pubmed/31738002
http://dx.doi.org/10.1002/acm2.12766
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author Tanaka, Yoshihiro
Akino, Yuichi
Mizuno, Hirokazu
Isono, Masaru
Masai, Norihisa
Yamamoto, Toshijiro
author_facet Tanaka, Yoshihiro
Akino, Yuichi
Mizuno, Hirokazu
Isono, Masaru
Masai, Norihisa
Yamamoto, Toshijiro
author_sort Tanaka, Yoshihiro
collection PubMed
description This study evaluates the type of detector influencing the inter‐institutional variability in flattening filter‐free (FFF) beam‐specific parameters for TrueBeam™ linear accelerators (Varian Medical Systems,Palo Alto, CA, USA). Twenty‐four beam data sets, including the percent depth dose (PDD), off‐center ratio (OCR), and output factor (OPF) for modeling within the Eclipse (Varian Medical Systems) treatment planning system, were collected from 19 institutions. Although many institutions collected the data using CC13 (IBA Dosimetry, Schwarzenbruck, Germany) or PTW31010 semiflex (PTW Freiburg, Freiburg, Germany) ionization chambers, some institutions used diode detectors, diamond detectors, and ionization chambers with smaller cavities. The OCR data included penumbra width, full width at half maximum (FWHM), and FFF beam‐specific parameters, including unflatness and slope. The data measured by CC13/PTW31010 ionization chambers were compared with those measured by all other detectors. PDD data demonstrated the variations within ±1% at the dose fall‐off region deeper than peak depth. The penumbra widths of the OCR measured with the CC13/PTW31010 detectors were significantly larger than those measured with all other detectors (P < 0.05). Especially the EDGE detector (Sun Nuclear Corp., Melbourne, FL, USA) and the microDiamond detectors (model 60019; PTW Freiburg) demonstrated much smaller penumbra values compared to those of the CC13/PTW31010 detectors for the 30 × 30 mm(2) field. There was no difference in the FWHM, unflatness, and slope parameters between the values for the CC13/PTW31010 detectors and all other detectors. OPF curves demonstrated small variations, and the relative difference from the mean value of each data point was almost within 1% for all field sizes. Although the penumbra region exhibited detector‐dependent variations, all other parameters showed tiny interunit variations regardless of the detector type.
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spelling pubmed-69647652020-01-27 Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators Tanaka, Yoshihiro Akino, Yuichi Mizuno, Hirokazu Isono, Masaru Masai, Norihisa Yamamoto, Toshijiro J Appl Clin Med Phys Radiation Oncology Physics This study evaluates the type of detector influencing the inter‐institutional variability in flattening filter‐free (FFF) beam‐specific parameters for TrueBeam™ linear accelerators (Varian Medical Systems,Palo Alto, CA, USA). Twenty‐four beam data sets, including the percent depth dose (PDD), off‐center ratio (OCR), and output factor (OPF) for modeling within the Eclipse (Varian Medical Systems) treatment planning system, were collected from 19 institutions. Although many institutions collected the data using CC13 (IBA Dosimetry, Schwarzenbruck, Germany) or PTW31010 semiflex (PTW Freiburg, Freiburg, Germany) ionization chambers, some institutions used diode detectors, diamond detectors, and ionization chambers with smaller cavities. The OCR data included penumbra width, full width at half maximum (FWHM), and FFF beam‐specific parameters, including unflatness and slope. The data measured by CC13/PTW31010 ionization chambers were compared with those measured by all other detectors. PDD data demonstrated the variations within ±1% at the dose fall‐off region deeper than peak depth. The penumbra widths of the OCR measured with the CC13/PTW31010 detectors were significantly larger than those measured with all other detectors (P < 0.05). Especially the EDGE detector (Sun Nuclear Corp., Melbourne, FL, USA) and the microDiamond detectors (model 60019; PTW Freiburg) demonstrated much smaller penumbra values compared to those of the CC13/PTW31010 detectors for the 30 × 30 mm(2) field. There was no difference in the FWHM, unflatness, and slope parameters between the values for the CC13/PTW31010 detectors and all other detectors. OPF curves demonstrated small variations, and the relative difference from the mean value of each data point was almost within 1% for all field sizes. Although the penumbra region exhibited detector‐dependent variations, all other parameters showed tiny interunit variations regardless of the detector type. John Wiley and Sons Inc. 2019-11-18 /pmc/articles/PMC6964765/ /pubmed/31738002 http://dx.doi.org/10.1002/acm2.12766 Text en © 2019 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
Tanaka, Yoshihiro
Akino, Yuichi
Mizuno, Hirokazu
Isono, Masaru
Masai, Norihisa
Yamamoto, Toshijiro
Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators
title Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators
title_full Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators
title_fullStr Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators
title_full_unstemmed Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators
title_short Impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for TrueBeam™ linear accelerators
title_sort impact of detector selections on inter‐institutional variability of flattening filter‐free beam data for truebeam™ linear accelerators
topic Radiation Oncology Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6964765/
https://www.ncbi.nlm.nih.gov/pubmed/31738002
http://dx.doi.org/10.1002/acm2.12766
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