skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Three-Dimensional Dose Addition of External Beam Radiotherapy and Brachytherapy for Oropharyngeal Patients Using Nonrigid Registration

Abstract

Purpose: To develop and evaluate a method for adding dose distributions of combined external beam radiotherapy (EBRT) and brachytherapy (BT) for oropharyngeal patients. Methods and Materials: Two computed tomography (CT) scans were used for 5 patients: the EBRT CT, used for EBRT planning, and the BT CT, acquired after catheter implantation. For each scan, the salivary glands and the chewing and swallowing muscles were contoured, and a dose distribution was calculated. A nonrigid transformation was obtained by registering the organs' surfaces. Then the BT dose distribution was mapped onto the EBRT dose distribution by applying the transformation obtained. To account for differences in fractionation, the physical doses were converted to equivalent dose in 2 Gy (EQD{sub 2}), and the total dose was found by adding dose voxel by voxel. The robustness of the dose addition was investigated by varying delineations and input parameters of the registration method and by varying the {alpha}/{beta} parameter for EQD{sub 2}. The effect of the perturbations was quantified using dose-volume histograms (DVH) and gamma analyses (distance-to-agreement/dose-difference = 1 mm/1 Gy). Results: The variations in input parameters and delineations caused only small perturbations in the DVH of the added dose distributions. For most organs the gammamore » index was low, and it was moderately elevated for organs lying in areas with a steep gradient (median gamma index {<=}2.3 for constrictor muscles, {<=}0.7 for all other organs). Conclusions: The presented method allows adding dose distributions of combined EBRT and BT for oropharyngeal patients. In general, the method is reliable and robust with respect to uncertainties in organ delineation, perturbations in input parameters of the method, and {alpha}/{beta} values.« less

Authors:
 [1]; ; ; ; ; ; ;  [1]
  1. Department of Radiation Oncology, Daniel den Hoed Cancer Center, Erasmus Medical Center, Rotterdam (Netherlands)
Publication Date:
OSTI Identifier:
21587607
Resource Type:
Journal Article
Journal Name:
International Journal of Radiation Oncology, Biology and Physics
Additional Journal Information:
Journal Volume: 80; Journal Issue: 4; Other Information: DOI: 10.1016/j.ijrobp.2010.10.006; PII: S0360-3016(10)03423-1; Copyright (c) 2011 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0360-3016
Country of Publication:
United States
Language:
English
Subject:
62 RADIOLOGY AND NUCLEAR MEDICINE; BRACHYTHERAPY; CAT SCANNING; DOSE EQUIVALENTS; FRACTIONATION; HEAD; MUSCLES; NECK; RADIATION DOSE DISTRIBUTIONS; RADIATION DOSES; SALIVARY GLANDS; BODY; COMPUTERIZED TOMOGRAPHY; DIAGNOSTIC TECHNIQUES; DOSES; GLANDS; MEDICINE; NUCLEAR MEDICINE; ORGANS; RADIOLOGY; RADIOTHERAPY; SEPARATION PROCESSES; THERAPY; TOMOGRAPHY

Citation Formats

Vasquez Osorio, Eliana M., E-mail: e.vasquezosorio@erasmusmc.nl, Hoogeman, Mischa S., Teguh, David N., Al-Mamgani, Abrahim, Kolkman-Deurloo, Inger-Karine K., Bondar, Luiza, Levendag, Peter C., and Heijmen, Ben J.M. Three-Dimensional Dose Addition of External Beam Radiotherapy and Brachytherapy for Oropharyngeal Patients Using Nonrigid Registration. United States: N. p., 2011. Web. doi:10.1016/j.ijrobp.2010.10.006.
Vasquez Osorio, Eliana M., E-mail: e.vasquezosorio@erasmusmc.nl, Hoogeman, Mischa S., Teguh, David N., Al-Mamgani, Abrahim, Kolkman-Deurloo, Inger-Karine K., Bondar, Luiza, Levendag, Peter C., & Heijmen, Ben J.M. Three-Dimensional Dose Addition of External Beam Radiotherapy and Brachytherapy for Oropharyngeal Patients Using Nonrigid Registration. United States. doi:10.1016/j.ijrobp.2010.10.006.
Vasquez Osorio, Eliana M., E-mail: e.vasquezosorio@erasmusmc.nl, Hoogeman, Mischa S., Teguh, David N., Al-Mamgani, Abrahim, Kolkman-Deurloo, Inger-Karine K., Bondar, Luiza, Levendag, Peter C., and Heijmen, Ben J.M. Fri . "Three-Dimensional Dose Addition of External Beam Radiotherapy and Brachytherapy for Oropharyngeal Patients Using Nonrigid Registration". United States. doi:10.1016/j.ijrobp.2010.10.006.
@article{osti_21587607,
title = {Three-Dimensional Dose Addition of External Beam Radiotherapy and Brachytherapy for Oropharyngeal Patients Using Nonrigid Registration},
author = {Vasquez Osorio, Eliana M., E-mail: e.vasquezosorio@erasmusmc.nl and Hoogeman, Mischa S. and Teguh, David N. and Al-Mamgani, Abrahim and Kolkman-Deurloo, Inger-Karine K. and Bondar, Luiza and Levendag, Peter C. and Heijmen, Ben J.M.},
abstractNote = {Purpose: To develop and evaluate a method for adding dose distributions of combined external beam radiotherapy (EBRT) and brachytherapy (BT) for oropharyngeal patients. Methods and Materials: Two computed tomography (CT) scans were used for 5 patients: the EBRT CT, used for EBRT planning, and the BT CT, acquired after catheter implantation. For each scan, the salivary glands and the chewing and swallowing muscles were contoured, and a dose distribution was calculated. A nonrigid transformation was obtained by registering the organs' surfaces. Then the BT dose distribution was mapped onto the EBRT dose distribution by applying the transformation obtained. To account for differences in fractionation, the physical doses were converted to equivalent dose in 2 Gy (EQD{sub 2}), and the total dose was found by adding dose voxel by voxel. The robustness of the dose addition was investigated by varying delineations and input parameters of the registration method and by varying the {alpha}/{beta} parameter for EQD{sub 2}. The effect of the perturbations was quantified using dose-volume histograms (DVH) and gamma analyses (distance-to-agreement/dose-difference = 1 mm/1 Gy). Results: The variations in input parameters and delineations caused only small perturbations in the DVH of the added dose distributions. For most organs the gamma index was low, and it was moderately elevated for organs lying in areas with a steep gradient (median gamma index {<=}2.3 for constrictor muscles, {<=}0.7 for all other organs). Conclusions: The presented method allows adding dose distributions of combined EBRT and BT for oropharyngeal patients. In general, the method is reliable and robust with respect to uncertainties in organ delineation, perturbations in input parameters of the method, and {alpha}/{beta} values.},
doi = {10.1016/j.ijrobp.2010.10.006},
journal = {International Journal of Radiation Oncology, Biology and Physics},
issn = {0360-3016},
number = 4,
volume = 80,
place = {United States},
year = {2011},
month = {7}
}