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Title: The Accuracy of Inhomogeneity Corrections in Intensity Modulated Radiation Therapy Planning in Philips Pinnacle System

Abstract

The degree of accuracy of inhomogeneity corrections in a treatment planning system is dependent on the algorithm used by the system. The choice of field size, however, could have an effect on the calculation accuracy as well. There have been several evaluation studies on the accuracy of inhomogeneity corrections used by different algorithms. Most of these studies, however, focus on evaluating the dose in phantom using simplified geometry and open/static fields. This work focuses on evaluating the degree of dose accuracy in calculations involving intensity-modulated radiation therapy (IMRT) fields incident on a phantom containing both lung- and bone-equivalent heterogeneities using 6 and 10 MV beams. IMRT treatment plans were generated using the Philips Pinnacle treatment planning system and delivered to a phantom containing 55 thermoluminescent dosimeter (TLD) locations within the lung and bone and near the lung and bone interfaces with solid water. The TLD readings were compared with the dose predicted by the planning system. We find satisfactory agreement between planned and delivered doses, with an overall absolute average difference between measurement and calculation of 1.2% for the 6 MV and 3.1% for the 10 MV beam with larger variations observed near the interfaces and in areas of high-dosemore » gradient. The results presented here demonstrate that the convolution algorithm used in the Pinnacle treatment planning system produces accurate results in IMRT plans calculated and delivered to inhomogeneous media, even in regions that potentially lack electronic equilibrium.« less

Authors:
 [1];  [1]
  1. Department of Therapeutic Radiology-Radiation Oncology, University of Minnesota, Minneapolis, MN (United States)
Publication Date:
OSTI Identifier:
21590484
Resource Type:
Journal Article
Journal Name:
Medical Dosimetry
Additional Journal Information:
Journal Volume: 36; Journal Issue: 3; Other Information: DOI: 10.1016/j.meddos.2010.03.010; PII: S0958-3947(10)00037-3; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0958-3947
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; ACCURACY; ALGORITHMS; EVALUATION; LUNGS; PHANTOMS; RADIATION DOSES; RADIOTHERAPY; SKELETON; THERMOLUMINESCENT DOSEMETERS; THERMOLUMINESCENT DOSIMETRY; BODY; DOSEMETERS; DOSES; DOSIMETRY; LUMINESCENT DOSEMETERS; MATHEMATICAL LOGIC; MEASURING INSTRUMENTS; MEDICINE; MOCKUP; NUCLEAR MEDICINE; ORGANS; RADIOLOGY; RESPIRATORY SYSTEM; STRUCTURAL MODELS; THERAPY

Citation Formats

Alaei, Parham, E-mail: alaei001@umn.edu, and Higgins, Patrick D. The Accuracy of Inhomogeneity Corrections in Intensity Modulated Radiation Therapy Planning in Philips Pinnacle System. United States: N. p., 2011. Web. doi:10.1016/j.meddos.2010.03.010.
Alaei, Parham, E-mail: alaei001@umn.edu, & Higgins, Patrick D. The Accuracy of Inhomogeneity Corrections in Intensity Modulated Radiation Therapy Planning in Philips Pinnacle System. United States. doi:10.1016/j.meddos.2010.03.010.
Alaei, Parham, E-mail: alaei001@umn.edu, and Higgins, Patrick D. Sat . "The Accuracy of Inhomogeneity Corrections in Intensity Modulated Radiation Therapy Planning in Philips Pinnacle System". United States. doi:10.1016/j.meddos.2010.03.010.
@article{osti_21590484,
title = {The Accuracy of Inhomogeneity Corrections in Intensity Modulated Radiation Therapy Planning in Philips Pinnacle System},
author = {Alaei, Parham, E-mail: alaei001@umn.edu and Higgins, Patrick D.},
abstractNote = {The degree of accuracy of inhomogeneity corrections in a treatment planning system is dependent on the algorithm used by the system. The choice of field size, however, could have an effect on the calculation accuracy as well. There have been several evaluation studies on the accuracy of inhomogeneity corrections used by different algorithms. Most of these studies, however, focus on evaluating the dose in phantom using simplified geometry and open/static fields. This work focuses on evaluating the degree of dose accuracy in calculations involving intensity-modulated radiation therapy (IMRT) fields incident on a phantom containing both lung- and bone-equivalent heterogeneities using 6 and 10 MV beams. IMRT treatment plans were generated using the Philips Pinnacle treatment planning system and delivered to a phantom containing 55 thermoluminescent dosimeter (TLD) locations within the lung and bone and near the lung and bone interfaces with solid water. The TLD readings were compared with the dose predicted by the planning system. We find satisfactory agreement between planned and delivered doses, with an overall absolute average difference between measurement and calculation of 1.2% for the 6 MV and 3.1% for the 10 MV beam with larger variations observed near the interfaces and in areas of high-dose gradient. The results presented here demonstrate that the convolution algorithm used in the Pinnacle treatment planning system produces accurate results in IMRT plans calculated and delivered to inhomogeneous media, even in regions that potentially lack electronic equilibrium.},
doi = {10.1016/j.meddos.2010.03.010},
journal = {Medical Dosimetry},
issn = {0958-3947},
number = 3,
volume = 36,
place = {United States},
year = {2011},
month = {10}
}