Multi-institutional Randomized Trial Testing the Utility of an Interactive Three-dimensional Contouring Atlas Among Radiation Oncology Residents

Purpose The delivery of safe and effective radiation therapy relies on accurate target delineation, particularly in the era of highly conformal treatment techniques. Current contouring resources are fragmented and can be cumbersome to use. The present study reports on the efficacy and usability of a web-based contouring atlas compared with those of existing contouring resources in a randomized trial. Methods and Materials We enrolled radiation oncology residents into a 2-phase contouring study. All residents contoured a T1N1 nasopharyngeal cancer case using the currently available resources. The participants were then randomized to recontour the case with access to existing resources or an interactive web-based contouring atlas ( eContour.org ). Contour analysis was performed using conformation number and simultaneous truth and performance level estimation. At completion of the second contouring session, the residents completed a multiple choice question knowledge test and a 10-item System Usability Scale. Results Twenty-four residents from 5 institutions completed the study. Compared with the residents using currently available resources, the residents using eContour had improved contour agreement with both the consensus (0.63 vs 0.52; P =.02) and the expert (0.58 vs 0.50; P =.01) contours for the high-risk clinical target volume and greater agreement with the expert contour for the contralateral parotid gland (0.44 ± 0.12 vs 0.56 ± 0.08; P =.003). The residents using eContour demonstrated greater knowledge of contour delineation and radiographic anatomy on a multiple-choice knowledge-based test (89% vs 77%; P =.03). Usability (89 vs 66; P