ESTRO 2022 - Abstract Book

S830

Abstract book

ESTRO 2022

matching method. Deformed contours were used to create a principal component analysis-based colorectal statistical shape model to extract the dominant deformations of the population. Geometric accuracy was validated using the Dice similarity coefficient (DSC), distance-to-agreement (DTA), and Hausdorff distance (HD) between the patient-specific and model contours for 10 test patients. Dosimetric accuracy was validated using standard Wilms’ tumor 3D conformal RT plans on the test patients. We computed colorectal RT dose data (mean, max, V 5 , V 10 , V 15 , V 20 , D 1 , D 50 , and D 95 ) and compared the patient-specific data with that of the colorectal model (Table 1). Workflow illustrated in Fig. 1.

Results Using the colorectal model on the unseen 10 test patients, the mean (min-max) DSC, DTA and HD between the patient- specific and reconstructed model contours was 0.89 (0.85-0.91), 2.1mm (1.7-3.0), and 8.6mm (5.7-14.3), respectively. For