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Title: A practical method of modeling a treatment couch using cone-beam computed tomography for intensity-modulated radiation therapy and RapidArc treatment delivery

Abstract

The effect of a treatment couch on dose perturbation is not always fully considered in intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). In the course of inverse planning radiotherapy techniques, beam parameter optimization may change in the absence of the couch, causing errors in the calculated dose distributions. Although modern treatment planning systems (TPS) include data for the treatment couch components, they are not manufactured identically. Thus, variations in their Hounsfield unit (HU) values may exist. Moreover, a radiotherapy facility may wish to have a third-party custom tabletop installed that is not included by the TPS vendor. This study demonstrates a practical and simple method of acquiring reliable computed tomography (CT) data for the treatment couch and shows how the absorbed dose calculated with the modeled treatment couch can differ from that with the default treatment couch found in the TPS. We also experimentally verified that neglecting to incorporate the treatment couch completely in the treatment planning process might result in dose differences of up to 9.5% and 7.3% for 4-MV and 10-MV photon beams, respectively. Furthermore, 20 RapidArc and IMRT cases were used to quantify the change in calculated dose distributions caused by using either themore » default or modeled couch. From 2-dimensional (2D) ionization chamber array measurements, we observed large dose distribution differences between the measurements and calculations when the couch was omitted that varied according to the planning technique and anatomic site. Thus, incorporating the treatment couch in the dose calculation phase of treatment planning significantly decreases dose calculation errors.« less

Authors:
 [1]; ;  [2];  [3];  [1];  [4]
  1. Medical Physics Unit, McGill University Health Centre, Montreal, Quebec (Canada)
  2. Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia)
  3. Department of Radiation Oncology, Jewish General Hospital, McGill University, Montreal, Quebec (Canada)
  4. (Saudi Arabia)
Publication Date:
OSTI Identifier:
22577841
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Dosimetry; Journal Volume: 40; Journal Issue: 4; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
61 RADIATION PROTECTION AND DOSIMETRY; 62 RADIOLOGY AND NUCLEAR MEDICINE; ABSORBED RADIATION DOSES; COMPUTERIZED TOMOGRAPHY; ERRORS; IONIZATION CHAMBERS; PHOTON BEAMS; PLANNING; RADIATION DOSE DISTRIBUTIONS; RADIOTHERAPY; SIMULATION; TWO-DIMENSIONAL SYSTEMS

Citation Formats

Aldosary, Ghada, E-mail: ghada.aldosary@mail.mcgill.ca, Nobah, Ahmad, Al-Zorkani, Faisal, Devic, Slobodan, Moftah, Belal, and Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh. A practical method of modeling a treatment couch using cone-beam computed tomography for intensity-modulated radiation therapy and RapidArc treatment delivery. United States: N. p., 2015. Web. doi:10.1016/J.MEDDOS.2015.03.008.
Aldosary, Ghada, E-mail: ghada.aldosary@mail.mcgill.ca, Nobah, Ahmad, Al-Zorkani, Faisal, Devic, Slobodan, Moftah, Belal, & Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh. A practical method of modeling a treatment couch using cone-beam computed tomography for intensity-modulated radiation therapy and RapidArc treatment delivery. United States. doi:10.1016/J.MEDDOS.2015.03.008.
Aldosary, Ghada, E-mail: ghada.aldosary@mail.mcgill.ca, Nobah, Ahmad, Al-Zorkani, Faisal, Devic, Slobodan, Moftah, Belal, and Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh. Thu . "A practical method of modeling a treatment couch using cone-beam computed tomography for intensity-modulated radiation therapy and RapidArc treatment delivery". United States. doi:10.1016/J.MEDDOS.2015.03.008.
@article{osti_22577841,
title = {A practical method of modeling a treatment couch using cone-beam computed tomography for intensity-modulated radiation therapy and RapidArc treatment delivery},
author = {Aldosary, Ghada, E-mail: ghada.aldosary@mail.mcgill.ca and Nobah, Ahmad and Al-Zorkani, Faisal and Devic, Slobodan and Moftah, Belal and Biomedical Physics Department, King Faisal Specialist Hospital and Research Center, Riyadh},
abstractNote = {The effect of a treatment couch on dose perturbation is not always fully considered in intensity-modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT). In the course of inverse planning radiotherapy techniques, beam parameter optimization may change in the absence of the couch, causing errors in the calculated dose distributions. Although modern treatment planning systems (TPS) include data for the treatment couch components, they are not manufactured identically. Thus, variations in their Hounsfield unit (HU) values may exist. Moreover, a radiotherapy facility may wish to have a third-party custom tabletop installed that is not included by the TPS vendor. This study demonstrates a practical and simple method of acquiring reliable computed tomography (CT) data for the treatment couch and shows how the absorbed dose calculated with the modeled treatment couch can differ from that with the default treatment couch found in the TPS. We also experimentally verified that neglecting to incorporate the treatment couch completely in the treatment planning process might result in dose differences of up to 9.5% and 7.3% for 4-MV and 10-MV photon beams, respectively. Furthermore, 20 RapidArc and IMRT cases were used to quantify the change in calculated dose distributions caused by using either the default or modeled couch. From 2-dimensional (2D) ionization chamber array measurements, we observed large dose distribution differences between the measurements and calculations when the couch was omitted that varied according to the planning technique and anatomic site. Thus, incorporating the treatment couch in the dose calculation phase of treatment planning significantly decreases dose calculation errors.},
doi = {10.1016/J.MEDDOS.2015.03.008},
journal = {Medical Dosimetry},
number = 4,
volume = 40,
place = {United States},
year = {Thu Jan 01 00:00:00 EST 2015},
month = {Thu Jan 01 00:00:00 EST 2015}
}