Abstract

PURPOSE: A number of studies have previously assessed the role of teaching interventions to improve organ-at-risk (OAR) delineation. We present a preliminary study demonstrating the benefit of a combined atlas and real time software based-feedback intervention to aid in contouring of OARs in the head and neck.
METHODS AND MATERIALS: The study consisted of a baseline evaluation, a real-time feedback intervention, atlas presentation, and a follow-up evaluation. At baseline evaluation, 8 resident observers contoured 26 organs-at-risk on a computed tomography scan without intervention or aid. They then received feedback comparing their contours both statistically and graphically to a set of atlas-based expert contours. Additionally, they received access to an atlas to contour these structures. The resident observers were then asked to contour the same 26 organs-at-risk on a separate computed tomography scan with atlas access. In addition, 6 experts (5 radiation oncologists specializing in the head and neck, and 1 neuroradiologist) contoured the 26 organs-at-risk on both scans. A STAPLE composite of the expert contours was used as a gold-standard set for analysis of organs-at-risk contouring.
RESULTS: Of the 8 resident observers who initially participated in the study, 7 completed both phases of the study. Dice Similarity Coefficients (DSCs) were calculated for each user-drawn structure relative to the expert STAPLE composite for each structure. Mean DSC across all structures increased between Phase 1 and Phase 2 for each resident observer demonstrating a statistically significant improvement in overall OAR-contouring ability (p CONCLUSIONS: Our data suggest that a combined atlas and real-time feedback-based educational intervention detectably improves contouring of OARs in the head and neck.