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Clinical consequences of changing the sliding window IMRT dose rate

Changing pulse repetition frequency or dose rate used for IMRT treatments can alter the number of monitor units (MUs) and the time required to deliver a plan. This work was done to develop a practical picture of the magnitude of these changes. We used Varian's Eclipse Treatment Planning System...

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Autores principales: Ghasroddashti, E., Smith, W.L., Quirk, S., Kirkby, C.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2012
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5716514/
https://www.ncbi.nlm.nih.gov/pubmed/22766951
http://dx.doi.org/10.1120/jacmp.v13i4.3810
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author Ghasroddashti, E.
Smith, W.L.
Quirk, S.
Kirkby, C.
author_facet Ghasroddashti, E.
Smith, W.L.
Quirk, S.
Kirkby, C.
author_sort Ghasroddashti, E.
collection PubMed
description Changing pulse repetition frequency or dose rate used for IMRT treatments can alter the number of monitor units (MUs) and the time required to deliver a plan. This work was done to develop a practical picture of the magnitude of these changes. We used Varian's Eclipse Treatment Planning System to calculate the number of MUs and beam‐on times for a total of 40 different treatment plans across an array of common IMRT sites including prostate/pelvis, prostate bed, head and neck, and central nervous system cancers using dose rates of 300, 400 and [Formula: see text]. In general, we observed a 4%–7% increase in the number of MUs delivered and a 10–40 second decrease in the beam‐on time for each [Formula: see text] of dose rate increase. The increase in the number of MUs resulted in a reduction of the “beam‐on time saved”. The exact magnitude of the changes depended on treatment site and planning target volume. These changes can lead to minor, but not negligible, concerns with respect to radiation protection and treatment planning. Although the number of MUs increased more rapidly for more complex treatment plans, the absolute beam‐on time savings was greater for these plans because of the higher total number of MUs required to deliver them. We estimate that increasing the IMRT dose rate from 300 to [Formula: see text] has the potential to add up to two treatment slots per day for each IMRT linear accelerator. These results will be of value to anyone considering general changes to IMRT dose rates within their clinic. PACS number: 87.55.N
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spelling pubmed-57165142018-04-02 Clinical consequences of changing the sliding window IMRT dose rate Ghasroddashti, E. Smith, W.L. Quirk, S. Kirkby, C. J Appl Clin Med Phys Radiation Oncology Physics Changing pulse repetition frequency or dose rate used for IMRT treatments can alter the number of monitor units (MUs) and the time required to deliver a plan. This work was done to develop a practical picture of the magnitude of these changes. We used Varian's Eclipse Treatment Planning System to calculate the number of MUs and beam‐on times for a total of 40 different treatment plans across an array of common IMRT sites including prostate/pelvis, prostate bed, head and neck, and central nervous system cancers using dose rates of 300, 400 and [Formula: see text]. In general, we observed a 4%–7% increase in the number of MUs delivered and a 10–40 second decrease in the beam‐on time for each [Formula: see text] of dose rate increase. The increase in the number of MUs resulted in a reduction of the “beam‐on time saved”. The exact magnitude of the changes depended on treatment site and planning target volume. These changes can lead to minor, but not negligible, concerns with respect to radiation protection and treatment planning. Although the number of MUs increased more rapidly for more complex treatment plans, the absolute beam‐on time savings was greater for these plans because of the higher total number of MUs required to deliver them. We estimate that increasing the IMRT dose rate from 300 to [Formula: see text] has the potential to add up to two treatment slots per day for each IMRT linear accelerator. These results will be of value to anyone considering general changes to IMRT dose rates within their clinic. PACS number: 87.55.N John Wiley and Sons Inc. 2012-07-05 /pmc/articles/PMC5716514/ /pubmed/22766951 http://dx.doi.org/10.1120/jacmp.v13i4.3810 Text en © 2012 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
Ghasroddashti, E.
Smith, W.L.
Quirk, S.
Kirkby, C.
Clinical consequences of changing the sliding window IMRT dose rate
title Clinical consequences of changing the sliding window IMRT dose rate
title_full Clinical consequences of changing the sliding window IMRT dose rate
title_fullStr Clinical consequences of changing the sliding window IMRT dose rate
title_full_unstemmed Clinical consequences of changing the sliding window IMRT dose rate
title_short Clinical consequences of changing the sliding window IMRT dose rate
title_sort clinical consequences of changing the sliding window imrt dose rate
topic Radiation Oncology Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5716514/
https://www.ncbi.nlm.nih.gov/pubmed/22766951
http://dx.doi.org/10.1120/jacmp.v13i4.3810
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