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Title: Impact of Endorectal Balloon in the Dosimetry of Prostate and Surrounding Tissues in Prostate Cancer Patients Treated with IMRT

Abstract

The dosimetric effect of endorectal balloon repositioning or failure was assessed in 10 prostate cancer patients treated with intensity modulated radiation therapy (IMRT). Three extreme clinical scenarios were simulated by placing the balloon in the most superior and inferior positions within the rectum and by removing the balloon. Treatment planning was performed by obtaining a computed tomography (CT) image with the balloon in the most superior position (plan 1). Subsequently, the isodose lines of plan 1 were superpositioned over the anatomy of 2 other CTs, one obtained with the balloon in the most inferior position and another without the balloon (plans 2 and 3, respectively). Dose-volume histograms (DVHs) of the prostate and surrounding tissues were generated and compared for all 3 plans. The prescribed radiation dose to the prostate and seminal vesicles was 70 Gy in 35 fractions. Balloon repositioning resulted in significant changes only for the seminal vesicles, where the minimum doses decreased from 70.39 to 61.58 Gy, and the percent volume below 70 Gy increased from 1.62% to 8.39%. Balloon failure resulted in significant decreases in mean and minimum doses for prostate from 74.36 to 72.84 Gy and 67.62 to 50.96 Gy, respectively. Similar decreases in the meanmore » and minimum doses were also observed for seminal vesicles from 74.21 to 64.43 Gy and 70.39 to 41.74 Gy, respectively. Balloon repositioning did not affect normal tissue doses, while balloon failure significantly decreased the upper rectum mean doses from 30.79 to 19.38 Gy. This study demonstrates that repositioning of the endorectal balloon results in increased dose inhomogeneity for seminal vesicles, while balloon failure causes significant prostate and seminal vesicle underdosing without overdosing normal tissues.« less

Authors:
 [1];  [2];  [3]
  1. Wayne State University School of Medicine, Detroit, MI (United States), E-mail: mvlachaki@med.wayne.edu
  2. Johns Hopkins School of Medicine, Baltimore, MD (United States)
  3. University of Oklahoma Health Sciences Center, Oklahoma City, OK (United States)
Publication Date:
OSTI Identifier:
21045984
Resource Type:
Journal Article
Resource Relation:
Journal Name: Medical Dosimetry; Journal Volume: 32; Journal Issue: 4; Other Information: DOI: 10.1016/j.meddos.2007.02.007; PII: S0958-3947(07)00051-9; Copyright (c) 2007 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:
62 RADIOLOGY AND NUCLEAR MEDICINE; ANATOMY; CARCINOMAS; COMPUTERIZED TOMOGRAPHY; DOSIMETRY; FAILURES; PATIENTS; PROSTATE; RADIATION DOSES; RADIOTHERAPY; RECTUM

Citation Formats

Vlachaki, Maria T., Teslow, Terrance N., and Ahmad, Salahuddin. Impact of Endorectal Balloon in the Dosimetry of Prostate and Surrounding Tissues in Prostate Cancer Patients Treated with IMRT. United States: N. p., 2007. Web. doi:10.1016/j.meddos.2007.02.007.
Vlachaki, Maria T., Teslow, Terrance N., & Ahmad, Salahuddin. Impact of Endorectal Balloon in the Dosimetry of Prostate and Surrounding Tissues in Prostate Cancer Patients Treated with IMRT. United States. doi:10.1016/j.meddos.2007.02.007.
Vlachaki, Maria T., Teslow, Terrance N., and Ahmad, Salahuddin. Mon . "Impact of Endorectal Balloon in the Dosimetry of Prostate and Surrounding Tissues in Prostate Cancer Patients Treated with IMRT". United States. doi:10.1016/j.meddos.2007.02.007.
@article{osti_21045984,
title = {Impact of Endorectal Balloon in the Dosimetry of Prostate and Surrounding Tissues in Prostate Cancer Patients Treated with IMRT},
author = {Vlachaki, Maria T. and Teslow, Terrance N. and Ahmad, Salahuddin},
abstractNote = {The dosimetric effect of endorectal balloon repositioning or failure was assessed in 10 prostate cancer patients treated with intensity modulated radiation therapy (IMRT). Three extreme clinical scenarios were simulated by placing the balloon in the most superior and inferior positions within the rectum and by removing the balloon. Treatment planning was performed by obtaining a computed tomography (CT) image with the balloon in the most superior position (plan 1). Subsequently, the isodose lines of plan 1 were superpositioned over the anatomy of 2 other CTs, one obtained with the balloon in the most inferior position and another without the balloon (plans 2 and 3, respectively). Dose-volume histograms (DVHs) of the prostate and surrounding tissues were generated and compared for all 3 plans. The prescribed radiation dose to the prostate and seminal vesicles was 70 Gy in 35 fractions. Balloon repositioning resulted in significant changes only for the seminal vesicles, where the minimum doses decreased from 70.39 to 61.58 Gy, and the percent volume below 70 Gy increased from 1.62% to 8.39%. Balloon failure resulted in significant decreases in mean and minimum doses for prostate from 74.36 to 72.84 Gy and 67.62 to 50.96 Gy, respectively. Similar decreases in the mean and minimum doses were also observed for seminal vesicles from 74.21 to 64.43 Gy and 70.39 to 41.74 Gy, respectively. Balloon repositioning did not affect normal tissue doses, while balloon failure significantly decreased the upper rectum mean doses from 30.79 to 19.38 Gy. This study demonstrates that repositioning of the endorectal balloon results in increased dose inhomogeneity for seminal vesicles, while balloon failure causes significant prostate and seminal vesicle underdosing without overdosing normal tissues.},
doi = {10.1016/j.meddos.2007.02.007},
journal = {Medical Dosimetry},
number = 4,
volume = 32,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}