%0 Journal Article
%T Dosimetric Effects Due to Inter-Observer Variability of Organ Contouring When Utilizing a Knowledge-Based Planning System for Prostate Cancer
%A Han Liu
%A Christopher Amaloo
%A Benjamin Sintay
%A David Wiant
%J International Journal of Medical Physics,Clinical Engineering and Radiation Oncology
%P 47-58
%@ 2168-5444
%D 2021
%I Scientific Research Publishing
%R 10.4236/ijmpcero.2021.102005
%X <strong>Purpose:</strong><span style=\"font-family:;\" \"=\"\"><span style=\"font-family:Verdana;\"> Radiotherapy is a widely accepted standard of care for early-stage prostate
cancer, and it is believed that the plan quality and treatment outcome are
associated with contour accuracy of both the target and organs-at-risk (OAR).
The purposes of this study are to 1) assess geometric and dosimetric
uncertainties due to inter-observer contour variabilities and 2) evaluate the
effectiveness of geometric indicators to predict target dosimetry in prostate
radiotherapy. </span><b><span style=\"font-family:Verdana;\">Methods:</span></b><span style=\"font-family:Verdana;\"> Twenty prostate patients were selected for this
retrospective study. Five experienced clinicians created unique structure sets
containing prostate, seminal vesicles, bladder, and rectum for each patient. A
fully automated script and knowledge-based planning routine were utilized to
create standardized and unbiased plans that could be used to evaluate changes
in isodose distributions due to inter-observer variability in structure
segmentation. Plans were created on a ˇ°gold-standardˇ± structure set, as well as
on each of the user-defined structure sets. </span><b><span style=\"font-family:Verdana;\">Results:</span></b><span style=\"font-family:Verdana;\"> Inter-observer
variability of contours during structure segmentation was very low for clearly
defined organs such as the bladder but increased for organs without
well-defined borders (prostate, seminal vesicles, and rectum). For plans
generated with the user-defined structure sets, strong/moderate correlations
were observed between the geometric indicators for target structure agreement
and target coverage for both low-risk and intermediate-risk patient groups,
while OAR indicators showed no correlation to final dosimetry. </span><b><span style=\"font-family:Verdana;\">Conclusions:</span></b><span style=\"font-family:Verdana;\"> Target delineation is crucial in order to maintain adequate dosimetric coverage
regardless of the associated inter-observer uncertainties in OAR contours that
had a limited impact upon final dosimetry.</span></span>
%K Inter-Observer Variability of Organ Contouring
%K Knowledge-Based Treat-ment Planning
%K Prostate Radiotherapy
%U http://www.scirp.org/journal/PaperInformation.aspx?PaperID=109120