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Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy

The purpose of this study was to quantify the variability of the breast surface position when aligning whole‐breast patients to bony landmarks based on MV portal films or skin marks alone. Surface imaging was used to assess the breast surface position of 11 whole‐breast radiotherapy patients, but wa...

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Autores principales: Padilla, Laura, Kang, Hyejoo, Washington, Maxine, Hasan, Yasmin, Chmura, Steve J., Al‐Hallaq, Hania
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4273911/
https://www.ncbi.nlm.nih.gov/pubmed/25207578
http://dx.doi.org/10.1120/jacmp.v15i5.4921
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author Padilla, Laura
Kang, Hyejoo
Washington, Maxine
Hasan, Yasmin
Chmura, Steve J.
Al‐Hallaq, Hania
author_facet Padilla, Laura
Kang, Hyejoo
Washington, Maxine
Hasan, Yasmin
Chmura, Steve J.
Al‐Hallaq, Hania
author_sort Padilla, Laura
collection PubMed
description The purpose of this study was to quantify the variability of the breast surface position when aligning whole‐breast patients to bony landmarks based on MV portal films or skin marks alone. Surface imaging was used to assess the breast surface position of 11 whole‐breast radiotherapy patients, but was not used for patient positioning. On filmed fractions, AlignRT v5.0 was used to capture the patient's surface after initial positioning based on skin marks (28 “preshifts” surfaces), and after treatment couch shifts based on MV films (41 “postshifts” surfaces). Translations and rotations based on surface captures were recorded, as well as couch shifts based on MV films. For nonfilmed treatments, “daily” surface images were captured following positioning to skin marks alone. Group mean and systematic and random errors were calculated for all datasets. Pearson correlation coefficients, setup margins, and 95% limits of agreement (LOA) were calculated for preshifts translations and MV film shifts. LOA between postshifts surfaces and the filmed treatment positions were also computed. All the surface captures collected were retrospectively compared to both a DICOM reference surface created from the planning CT and to an AlignRT reference surface. All statistical analyses were performed using the DICOM reference surface dataset. AlignRT reference surface data was only used to calculate the LOA with the DICOM reference data. This helped assess any outcome differences between both reference surfaces. Setup margins for preshifts surfaces and MV films range between 8.3–12.0 mm and 5.4–13.4 mm, respectively. The largest margin is along the left–right (LR) direction for preshift surfaces, and along craniocaudal (CC) for films. LOA ranges between the preshifts surfaces and MV film shifts are large (12.6–21.9 mm); these decrease for postshifts surfaces (9.8–18.4 mm), but still show significant disagreements between the two modalities due to their focus on different anatomical landmarks (patient's topography versus bony anatomy). Pearson's correlation coefficients further support this by showing low to moderate correlations in the anterior–posterior (AP) and LR directions (0.47–0.69) and no correlation along [Formula: see text]. The use of an AlignRT reference surface compared to the DICOM reference surface does not significantly affect the LOA. Alignment of breast patients based solely on bony alignment may lead to interfractional inconsistencies in the breast surface position. The use of surface imaging tools highlights these discrepancies, and allows the radiation oncology team to better assess the possible effects on treatment quality. PACS number: 87
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spelling pubmed-42739112018-04-02 Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy Padilla, Laura Kang, Hyejoo Washington, Maxine Hasan, Yasmin Chmura, Steve J. Al‐Hallaq, Hania J Appl Clin Med Phys Radiation Oncology Physics The purpose of this study was to quantify the variability of the breast surface position when aligning whole‐breast patients to bony landmarks based on MV portal films or skin marks alone. Surface imaging was used to assess the breast surface position of 11 whole‐breast radiotherapy patients, but was not used for patient positioning. On filmed fractions, AlignRT v5.0 was used to capture the patient's surface after initial positioning based on skin marks (28 “preshifts” surfaces), and after treatment couch shifts based on MV films (41 “postshifts” surfaces). Translations and rotations based on surface captures were recorded, as well as couch shifts based on MV films. For nonfilmed treatments, “daily” surface images were captured following positioning to skin marks alone. Group mean and systematic and random errors were calculated for all datasets. Pearson correlation coefficients, setup margins, and 95% limits of agreement (LOA) were calculated for preshifts translations and MV film shifts. LOA between postshifts surfaces and the filmed treatment positions were also computed. All the surface captures collected were retrospectively compared to both a DICOM reference surface created from the planning CT and to an AlignRT reference surface. All statistical analyses were performed using the DICOM reference surface dataset. AlignRT reference surface data was only used to calculate the LOA with the DICOM reference data. This helped assess any outcome differences between both reference surfaces. Setup margins for preshifts surfaces and MV films range between 8.3–12.0 mm and 5.4–13.4 mm, respectively. The largest margin is along the left–right (LR) direction for preshift surfaces, and along craniocaudal (CC) for films. LOA ranges between the preshifts surfaces and MV film shifts are large (12.6–21.9 mm); these decrease for postshifts surfaces (9.8–18.4 mm), but still show significant disagreements between the two modalities due to their focus on different anatomical landmarks (patient's topography versus bony anatomy). Pearson's correlation coefficients further support this by showing low to moderate correlations in the anterior–posterior (AP) and LR directions (0.47–0.69) and no correlation along [Formula: see text]. The use of an AlignRT reference surface compared to the DICOM reference surface does not significantly affect the LOA. Alignment of breast patients based solely on bony alignment may lead to interfractional inconsistencies in the breast surface position. The use of surface imaging tools highlights these discrepancies, and allows the radiation oncology team to better assess the possible effects on treatment quality. PACS number: 87 John Wiley and Sons Inc. 2014-09-08 /pmc/articles/PMC4273911/ /pubmed/25207578 http://dx.doi.org/10.1120/jacmp.v15i5.4921 Text en © 2014 The Authors. This is an open access article under the terms of the http://creativecommons.org/licenses/by/3.0/ License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
spellingShingle Radiation Oncology Physics
Padilla, Laura
Kang, Hyejoo
Washington, Maxine
Hasan, Yasmin
Chmura, Steve J.
Al‐Hallaq, Hania
Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy
title Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy
title_full Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy
title_fullStr Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy
title_full_unstemmed Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy
title_short Assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy
title_sort assessment of interfractional variation of the breast surface following conventional patient positioning for whole‐breast radiotherapy
topic Radiation Oncology Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4273911/
https://www.ncbi.nlm.nih.gov/pubmed/25207578
http://dx.doi.org/10.1120/jacmp.v15i5.4921
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