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An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer
PURPOSE: Gold-marker-based image-guided radiation therapy (IGRT) of the prostate allows to correct for inter- and intrafraction motion and therefore to safely reduce margins for the prostate planning target volume (PTV). However, pelvic PTVs, when coadministered in a single plan (registered to gold...
Autores principales: | , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Springer Berlin Heidelberg
2017
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5570790/ https://www.ncbi.nlm.nih.gov/pubmed/28726055 http://dx.doi.org/10.1007/s00066-017-1182-1 |
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author | Groher, M. Kopp, P. Drerup, M. Deutschmann, H. Sedlmayer, F. Wolf, Frank |
author_facet | Groher, M. Kopp, P. Drerup, M. Deutschmann, H. Sedlmayer, F. Wolf, Frank |
author_sort | Groher, M. |
collection | PubMed |
description | PURPOSE: Gold-marker-based image-guided radiation therapy (IGRT) of the prostate allows to correct for inter- and intrafraction motion and therefore to safely reduce margins for the prostate planning target volume (PTV). However, pelvic PTVs, when coadministered in a single plan (registered to gold markers [GM]), require reassessment of the margin concept since prostate movement is independent from the pelvic bony anatomy to which the lymphatics are usually referenced to. METHODS: We have therefore revisited prostate translational movement relative to the bony anatomy to obtain adequate margins for the pelvic PTVs compensating mismatch resulting from referencing pelvic target volumes to GMs in the prostate. Prostate movement was analyzed in a set of 28 patients (25 fractions each, totaling in 684 fractions) and the required margins calculated for the pelvic PTVs according to Van Herk’s margin formula [Formula: see text] . RESULTS: The overall mean prostate movement relative to bony anatomy was 0.9 ± 3.1, 0.6 ± 3.4, and 0.0 ± 0.7 mm in anterior/posterior (A/P), inferior/superior (I/S) and left/right (L/R) direction, respectively. Calculated margins to compensate for the resulting mismatch to bony anatomy were 9/9/2 mm in A/P, I/S, and L/R direction and 10/11/6 mm if an additional residual error of 2 mm was assumed. CONCLUSION: GM-based IGRT for pelvic PTVs is feasible if margins are adapted accordingly. Margins could be reduced further if systematic errors which are introduced during the planning CT were eliminated. |
format | Online Article Text |
id | pubmed-5570790 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2017 |
publisher | Springer Berlin Heidelberg |
record_format | MEDLINE/PubMed |
spelling | pubmed-55707902017-09-19 An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer Groher, M. Kopp, P. Drerup, M. Deutschmann, H. Sedlmayer, F. Wolf, Frank Strahlenther Onkol Short Communication PURPOSE: Gold-marker-based image-guided radiation therapy (IGRT) of the prostate allows to correct for inter- and intrafraction motion and therefore to safely reduce margins for the prostate planning target volume (PTV). However, pelvic PTVs, when coadministered in a single plan (registered to gold markers [GM]), require reassessment of the margin concept since prostate movement is independent from the pelvic bony anatomy to which the lymphatics are usually referenced to. METHODS: We have therefore revisited prostate translational movement relative to the bony anatomy to obtain adequate margins for the pelvic PTVs compensating mismatch resulting from referencing pelvic target volumes to GMs in the prostate. Prostate movement was analyzed in a set of 28 patients (25 fractions each, totaling in 684 fractions) and the required margins calculated for the pelvic PTVs according to Van Herk’s margin formula [Formula: see text] . RESULTS: The overall mean prostate movement relative to bony anatomy was 0.9 ± 3.1, 0.6 ± 3.4, and 0.0 ± 0.7 mm in anterior/posterior (A/P), inferior/superior (I/S) and left/right (L/R) direction, respectively. Calculated margins to compensate for the resulting mismatch to bony anatomy were 9/9/2 mm in A/P, I/S, and L/R direction and 10/11/6 mm if an additional residual error of 2 mm was assumed. CONCLUSION: GM-based IGRT for pelvic PTVs is feasible if margins are adapted accordingly. Margins could be reduced further if systematic errors which are introduced during the planning CT were eliminated. Springer Berlin Heidelberg 2017-07-19 2017 /pmc/articles/PMC5570790/ /pubmed/28726055 http://dx.doi.org/10.1007/s00066-017-1182-1 Text en © The Author(s) 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. |
spellingShingle | Short Communication Groher, M. Kopp, P. Drerup, M. Deutschmann, H. Sedlmayer, F. Wolf, Frank An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer |
title | An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer |
title_full | An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer |
title_fullStr | An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer |
title_full_unstemmed | An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer |
title_short | An IGRT margin concept for pelvic lymph nodes in high-risk prostate cancer |
title_sort | igrt margin concept for pelvic lymph nodes in high-risk prostate cancer |
topic | Short Communication |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5570790/ https://www.ncbi.nlm.nih.gov/pubmed/28726055 http://dx.doi.org/10.1007/s00066-017-1182-1 |
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