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Optimization of motion management parameters in a synchrotron‐based spot scanning system
PURPOSE: To quantify the effects of combining layer‐based repainting and respiratory gating as a strategy to mitigate the dosimetric degradation caused by the interplay effect between a moving target and dynamic spot‐scanning proton delivery. METHODS: An analytic routine modeled three‐dimensional do...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
John Wiley and Sons Inc.
2019
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6753740/ https://www.ncbi.nlm.nih.gov/pubmed/31538720 http://dx.doi.org/10.1002/acm2.12702 |
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author | Johnson, Jedediah E. Herman, Michael G. Kruse, Jon J. |
author_facet | Johnson, Jedediah E. Herman, Michael G. Kruse, Jon J. |
author_sort | Johnson, Jedediah E. |
collection | PubMed |
description | PURPOSE: To quantify the effects of combining layer‐based repainting and respiratory gating as a strategy to mitigate the dosimetric degradation caused by the interplay effect between a moving target and dynamic spot‐scanning proton delivery. METHODS: An analytic routine modeled three‐dimensional dose distributions of pencil‐beam proton plans delivered to a moving target. Spot positions and weights were established for a single field to deliver 100 cGy to a static, 15‐cm deep, 3‐cm radius spherical clinical target volume with a 1‐cm isotropic internal target volume expansion. The interplay effect was studied by modeling proton delivery from a clinical synchrotron‐based spot scanning system and respiratory target motion, patterned from surrogate patient breathing traces. Motion both parallel and orthogonal to the beam scanning direction was investigated. Repainting was modeled using a layer‐based technique. For each of 13 patient breathing traces, the dose from 20 distinct delivery schemes (combinations of four gate window amplitudes and five repainting techniques) was computed. Delivery strategies were inter‐compared based on target coverage, dose homogeneity, high dose spillage, and delivery time. RESULTS: Notable degradation and variability in plan quality were observed for ungated delivery. Decreasing the gate window reduced this variability and improved plan quality at the expense of longer delivery times. Dose deviations were substantially greater for motion orthogonal to the scan direction when compared with parallel motion. Repainting coupled with gating was effective at partially restoring dosimetric coverage at only a fraction of the delivery time increase associated with very small gate windows alone. Trends for orthogonal motion were similar, but more complicated, due to the increased severity of the interplay. CONCLUSIONS: Layer‐based repainting helps suppress the interplay effect from intra‐gate motion, with only a modest penalty in delivery time. The magnitude of the improvement in target coverage is strongly influenced by individual patient breathing patterns and the tumor motion trajectory. |
format | Online Article Text |
id | pubmed-6753740 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2019 |
publisher | John Wiley and Sons Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-67537402019-09-23 Optimization of motion management parameters in a synchrotron‐based spot scanning system Johnson, Jedediah E. Herman, Michael G. Kruse, Jon J. J Appl Clin Med Phys Radiation Oncology Physics PURPOSE: To quantify the effects of combining layer‐based repainting and respiratory gating as a strategy to mitigate the dosimetric degradation caused by the interplay effect between a moving target and dynamic spot‐scanning proton delivery. METHODS: An analytic routine modeled three‐dimensional dose distributions of pencil‐beam proton plans delivered to a moving target. Spot positions and weights were established for a single field to deliver 100 cGy to a static, 15‐cm deep, 3‐cm radius spherical clinical target volume with a 1‐cm isotropic internal target volume expansion. The interplay effect was studied by modeling proton delivery from a clinical synchrotron‐based spot scanning system and respiratory target motion, patterned from surrogate patient breathing traces. Motion both parallel and orthogonal to the beam scanning direction was investigated. Repainting was modeled using a layer‐based technique. For each of 13 patient breathing traces, the dose from 20 distinct delivery schemes (combinations of four gate window amplitudes and five repainting techniques) was computed. Delivery strategies were inter‐compared based on target coverage, dose homogeneity, high dose spillage, and delivery time. RESULTS: Notable degradation and variability in plan quality were observed for ungated delivery. Decreasing the gate window reduced this variability and improved plan quality at the expense of longer delivery times. Dose deviations were substantially greater for motion orthogonal to the scan direction when compared with parallel motion. Repainting coupled with gating was effective at partially restoring dosimetric coverage at only a fraction of the delivery time increase associated with very small gate windows alone. Trends for orthogonal motion were similar, but more complicated, due to the increased severity of the interplay. CONCLUSIONS: Layer‐based repainting helps suppress the interplay effect from intra‐gate motion, with only a modest penalty in delivery time. The magnitude of the improvement in target coverage is strongly influenced by individual patient breathing patterns and the tumor motion trajectory. John Wiley and Sons Inc. 2019-09-20 /pmc/articles/PMC6753740/ /pubmed/31538720 http://dx.doi.org/10.1002/acm2.12702 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 Johnson, Jedediah E. Herman, Michael G. Kruse, Jon J. Optimization of motion management parameters in a synchrotron‐based spot scanning system |
title | Optimization of motion management parameters in a synchrotron‐based spot scanning system |
title_full | Optimization of motion management parameters in a synchrotron‐based spot scanning system |
title_fullStr | Optimization of motion management parameters in a synchrotron‐based spot scanning system |
title_full_unstemmed | Optimization of motion management parameters in a synchrotron‐based spot scanning system |
title_short | Optimization of motion management parameters in a synchrotron‐based spot scanning system |
title_sort | optimization of motion management parameters in a synchrotron‐based spot scanning system |
topic | Radiation Oncology Physics |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6753740/ https://www.ncbi.nlm.nih.gov/pubmed/31538720 http://dx.doi.org/10.1002/acm2.12702 |
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