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Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking

Implanted radiofrequency transponders were used for real‐time monitoring of the intrafraction prostate displacement between patients in the prone position and the same patients in the supine position. Thirteen patients had three transponders implanted transperineally and were treated prone with a cu...

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Autores principales: Butler, Wayne M., Merrick, Gregory S., Reed, Joshua L., Murray, Brian C., Kurko, Brian S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2013
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5714377/
https://www.ncbi.nlm.nih.gov/pubmed/23470943
http://dx.doi.org/10.1120/jacmp.v14i2.4141
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author Butler, Wayne M.
Merrick, Gregory S.
Reed, Joshua L.
Murray, Brian C.
Kurko, Brian S.
author_facet Butler, Wayne M.
Merrick, Gregory S.
Reed, Joshua L.
Murray, Brian C.
Kurko, Brian S.
author_sort Butler, Wayne M.
collection PubMed
description Implanted radiofrequency transponders were used for real‐time monitoring of the intrafraction prostate displacement between patients in the prone position and the same patients in the supine position. Thirteen patients had three transponders implanted transperineally and were treated prone with a custom‐fitted thermoplastic immobilization device. After collecting data from the last fraction, patients were realigned in the supine position and the displacements of the transponders were monitored for 5–7 minutes. Fourier transforms were applied to the data from each patient to determine periodicity and its amplitude. To remove auto correlation from the stream of displacement data, the distribution of short‐term and long‐term velocity components were calculated from Poincaré plots of paired sequential vector displacements. The mean absolute displacement was significantly greater prone than supine in the superior–inferior (SI) plane ([Formula: see text] vs. [Formula: see text] , [Formula: see text]), but not for the lateral or anterior–posterior (AP) planes. Displacements were least in the lateral direction. Fourier analyses showed the amplitude of respiratory oscillations was much greater for the SI and AP planes in the prone versus the supine position. Analysis of Poincaré plots confirmed greater short‐term variance in the prone position, but no difference in the long‐term variance. The centroid of the implanted transponders was offset from the treatment isocenter by [Formula: see text] for 1.9% of the time versus 0.8% of the time for supine. These results confirmed significantly greater net intrafraction prostate displacement of patients in the prone position than in the supine position, but most of the difference was due to respiration‐induced motion that was most pronounced in the SI and AP directions. Because the respiratory motion remained within the action threshold and also within our 5 mm treatment planning margins, there is no compelling reason to choose one treatment position over the other. PACS number: 87.50.st
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spelling pubmed-57143772018-04-02 Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking Butler, Wayne M. Merrick, Gregory S. Reed, Joshua L. Murray, Brian C. Kurko, Brian S. J Appl Clin Med Phys Radiation Oncology Physics Implanted radiofrequency transponders were used for real‐time monitoring of the intrafraction prostate displacement between patients in the prone position and the same patients in the supine position. Thirteen patients had three transponders implanted transperineally and were treated prone with a custom‐fitted thermoplastic immobilization device. After collecting data from the last fraction, patients were realigned in the supine position and the displacements of the transponders were monitored for 5–7 minutes. Fourier transforms were applied to the data from each patient to determine periodicity and its amplitude. To remove auto correlation from the stream of displacement data, the distribution of short‐term and long‐term velocity components were calculated from Poincaré plots of paired sequential vector displacements. The mean absolute displacement was significantly greater prone than supine in the superior–inferior (SI) plane ([Formula: see text] vs. [Formula: see text] , [Formula: see text]), but not for the lateral or anterior–posterior (AP) planes. Displacements were least in the lateral direction. Fourier analyses showed the amplitude of respiratory oscillations was much greater for the SI and AP planes in the prone versus the supine position. Analysis of Poincaré plots confirmed greater short‐term variance in the prone position, but no difference in the long‐term variance. The centroid of the implanted transponders was offset from the treatment isocenter by [Formula: see text] for 1.9% of the time versus 0.8% of the time for supine. These results confirmed significantly greater net intrafraction prostate displacement of patients in the prone position than in the supine position, but most of the difference was due to respiration‐induced motion that was most pronounced in the SI and AP directions. Because the respiratory motion remained within the action threshold and also within our 5 mm treatment planning margins, there is no compelling reason to choose one treatment position over the other. PACS number: 87.50.st John Wiley and Sons Inc. 2013-03-04 /pmc/articles/PMC5714377/ /pubmed/23470943 http://dx.doi.org/10.1120/jacmp.v14i2.4141 Text en © 2013 The Authors. This is an open access article under the terms of the Creative Commons Attribution (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
Butler, Wayne M.
Merrick, Gregory S.
Reed, Joshua L.
Murray, Brian C.
Kurko, Brian S.
Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking
title Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking
title_full Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking
title_fullStr Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking
title_full_unstemmed Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking
title_short Intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking
title_sort intrafraction displacement of prone versus supine prostate positioning monitored by real‐time electromagnetic tracking
topic Radiation Oncology Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5714377/
https://www.ncbi.nlm.nih.gov/pubmed/23470943
http://dx.doi.org/10.1120/jacmp.v14i2.4141
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