The purpose of this study is to evaluate whether computer-assisted segmentation is clinically feasible in target volume delineation for prostate cancer patients treated with whole pelvic IMRT.
An atlas was created, comprised of 44 clinically node-negative prostate cancer patients. Three regions of interest (ROIs) were chosen for analysis: prostate, pelvic lymph nodes, and rectum. For a separate tester set of 15 patients with previously contoured ROIs by three experienced physicians, atlas-assisted contours were compared to manual contours by calculating a volumetric overlap index. In the tester set patients, the average overlap between the manually drawn and atlas-based contours for the prostate, pelvic lymph nodes, and rectum was 60%, 51%, and 64%, respectively. The volume differences were significant in the rectum and pelvic lymph nodes (p = 0.049 and p = 0.016, respectively); this was not true for the prostate. A subset analysis based on physician-specific atlases showed that the average overlap index for the pelvic lymph nodal volume increased from 51% to 60%, while the other ROIs had no significant changes. Despite significant inter-physician differences, atlas-based segmentation for pelvic lymph node delineation serves as an initial guideline for physicians, potentially improving both consistency and efficiency in contouring.
Written by:
Pejavar S, Yom SS, Hwang A, Speight J, Gottschalk A, Hsu IC, Roach M, Xia P. Are you the author?
Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA, USA.
Reference: Technol Cancer Res Treat. 2012 Dec 26. Epub ahead of print.
doi: 10.7785/tcrt.2012.500313
PubMed Abstract
PMID: 23289478
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