Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions

The purpose of this comparative study was to test the accuracy of anisotropic analytical algorithm (AAA) and pencil beam convolution (PBC) algorithms of Eclipse treatment planning system (TPS) for dose calculations in the low‐ and high‐dose buildup regions. AAA and PBC algorithms were used to create...

Descripción completa

Detalles Bibliográficos
Autores principales: Oinam, Arun S., Singh, Lakhwant
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2010
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5720424/
https://www.ncbi.nlm.nih.gov/pubmed/21081894
http://dx.doi.org/10.1120/jacmp.v11i4.3351
_version_ 1783284646030606336
author Oinam, Arun S.
Singh, Lakhwant
author_facet Oinam, Arun S.
Singh, Lakhwant
author_sort Oinam, Arun S.
collection PubMed
description The purpose of this comparative study was to test the accuracy of anisotropic analytical algorithm (AAA) and pencil beam convolution (PBC) algorithms of Eclipse treatment planning system (TPS) for dose calculations in the low‐ and high‐dose buildup regions. AAA and PBC algorithms were used to create two intensity‐modulated radiotherapy (IMRT) plans of the same optimal fluence generated from a clinically simulated oropharynx case in an in‐house fabricated head and neck phantom. The TPS computed buildup doses were compared with the corresponding measured doses in the phantom using thermoluminescence dosimeters (TLD 100). Analysis of dose distribution calculated using PBC and AAA shows an increase in gamma value in the dose buildup region indicating large dose deviation. For the surface areas of 1, 50 and [Formula: see text] , PBC overestimates doses as compared to AAA calculated value in the range of 1.34%–3.62% at 0.6 cm depth, 1.74%–2.96% at 0.4 cm depth, and 1.96%–4.06% at 0.2 cm depth, respectively. In high‐dose buildup region, AAA calculated doses were lower by an average of [Formula: see text] , while PBC was overestimated by [Formula: see text] as compared to TLD measured doses at 0.2 cm depth. However, at 0.4 and 0.6 cm depth, PBC overestimated TLD measured doses by [Formula: see text] and [Formula: see text] , respectively, while AAA underestimated the TLD measured doses by [Formula: see text] and [Formula: see text] at the same respective depth. In low‐dose buildup region, both AAA and PBC overestimated the TLD measured doses at all depths except [Formula: see text] by AAA at 0.2 cm depth. The differences between AAA and PBC at all depths were statistically significant [Formula: see text] in high‐dose buildup region, whereas it is not statistically significant in low‐dose buildup region. In conclusion, AAA calculated the dose more accurately than PBC in clinically important high‐dose buildup region at 0.4 cm and 0.6 cm depths. The use of an orfit cast increases the dose buildup effect, and this buildup effect decreases with depth. PACS number: 87.53.Bn
format Online
Article
Text
id pubmed-5720424
institution National Center for Biotechnology Information
language English
publishDate 2010
publisher John Wiley and Sons Inc.
record_format MEDLINE/PubMed
spelling pubmed-57204242018-04-02 Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions Oinam, Arun S. Singh, Lakhwant J Appl Clin Med Phys Radiation Oncology Physics The purpose of this comparative study was to test the accuracy of anisotropic analytical algorithm (AAA) and pencil beam convolution (PBC) algorithms of Eclipse treatment planning system (TPS) for dose calculations in the low‐ and high‐dose buildup regions. AAA and PBC algorithms were used to create two intensity‐modulated radiotherapy (IMRT) plans of the same optimal fluence generated from a clinically simulated oropharynx case in an in‐house fabricated head and neck phantom. The TPS computed buildup doses were compared with the corresponding measured doses in the phantom using thermoluminescence dosimeters (TLD 100). Analysis of dose distribution calculated using PBC and AAA shows an increase in gamma value in the dose buildup region indicating large dose deviation. For the surface areas of 1, 50 and [Formula: see text] , PBC overestimates doses as compared to AAA calculated value in the range of 1.34%–3.62% at 0.6 cm depth, 1.74%–2.96% at 0.4 cm depth, and 1.96%–4.06% at 0.2 cm depth, respectively. In high‐dose buildup region, AAA calculated doses were lower by an average of [Formula: see text] , while PBC was overestimated by [Formula: see text] as compared to TLD measured doses at 0.2 cm depth. However, at 0.4 and 0.6 cm depth, PBC overestimated TLD measured doses by [Formula: see text] and [Formula: see text] , respectively, while AAA underestimated the TLD measured doses by [Formula: see text] and [Formula: see text] at the same respective depth. In low‐dose buildup region, both AAA and PBC overestimated the TLD measured doses at all depths except [Formula: see text] by AAA at 0.2 cm depth. The differences between AAA and PBC at all depths were statistically significant [Formula: see text] in high‐dose buildup region, whereas it is not statistically significant in low‐dose buildup region. In conclusion, AAA calculated the dose more accurately than PBC in clinically important high‐dose buildup region at 0.4 cm and 0.6 cm depths. The use of an orfit cast increases the dose buildup effect, and this buildup effect decreases with depth. PACS number: 87.53.Bn John Wiley and Sons Inc. 2010-08-26 /pmc/articles/PMC5720424/ /pubmed/21081894 http://dx.doi.org/10.1120/jacmp.v11i4.3351 Text en © 2010 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
Oinam, Arun S.
Singh, Lakhwant
Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions
title Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions
title_full Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions
title_fullStr Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions
title_full_unstemmed Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions
title_short Verification of IMRT dose calculations using AAA and PBC algorithms in dose buildup regions
title_sort verification of imrt dose calculations using aaa and pbc algorithms in dose buildup regions
topic Radiation Oncology Physics
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5720424/
https://www.ncbi.nlm.nih.gov/pubmed/21081894
http://dx.doi.org/10.1120/jacmp.v11i4.3351
work_keys_str_mv AT oinamaruns verificationofimrtdosecalculationsusingaaaandpbcalgorithmsindosebuildupregions
AT singhlakhwant verificationofimrtdosecalculationsusingaaaandpbcalgorithmsindosebuildupregions