Physical considerations on discrepancies in target volume delineation.

Details

Serval ID
serval:BIB_768C4DD3E807
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Physical considerations on discrepancies in target volume delineation.
Journal
Zeitschrift für Medizinische Physik
Author(s)
Moeckli Raphael, Jeanneret Sozzi Wendy, Mirimanoff Rene-Olivier, Ozsahin Mahmut, Zouhair Abderrahim, Valley Jean-Francois, Bochud Francois
ISSN
0939-3889
Publication state
Published
Issued date
2009
Peer-reviewed
Oui
Volume
19
Number
4
Pages
224-235
Language
english
Abstract
BACKGROUND AND PURPOSE: To compare the delineations and interpretations of target volumes by physicians in different radio-oncology centers. MATERIALS AND METHODS: Eleven Swiss radio-oncology centers delineated volumes according to ICRU 50 recommendations for one prostate and one head and neck case. In order to evaluate the consistency of the volume delineations, the following parameters were determined: 1) the target volumes (GTV, CTV and manually expanded PTV) and their extensions in the three main axes and 2) the correlation of the volume delineated by each pair of centers using the ratio of the intersection to the union (called proximity index). RESULTS: The delineated prostate volume was 105+/-55cm(3) for the CTV and 218+/-44cm(3) for the PTV. The delineated head and neck volume was 46+/-15cm(3) for the GTV, 327+/-154cm(3) for the CTV and 528+/-106cm(3) for the PTV. The mean proximity index for the prostate case was 0.50+/-0.13 for the CTV and 0.57+/-0.11 for the PTV. The proximity index for the head and neck case was 0.45+/-0.09 for the GTV, 0.42+/-0.13 for the CTV and 0.59+/-0.06 for the PTV. CONCLUSIONS: Large discrepancies between all the delineated target volumes were observed. There was an inverse relationship between the CTV volume and the margin between CTV and PTV, leading to less discrepancies in the PTV than is the CTV delineations. There was more spread in the sagittal and frontal planes due to CT pixel anisotropy, which suggests that radiation oncologists should delineate the target volumes not only in the transverse plane, but also in the sagittal and frontal planes to improve the delineation by allowing a consistency check.
Pubmed
Web of science
Create date
04/02/2010 15:46
Last modification date
20/08/2019 14:33
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