ESTRO 2025 - Abstract Book

S2545

Physics - Autosegmentation

ESTRO 2025

structure lacked clear anatomical boundaries. Here the clinician more often accepted the AI segmentation unaltered even if it deviated significantly from a manual delineation, even one done by the same clinician. However, such deviations typically involved small volumes (a few cm 3 ) and were within clinically acceptable inter-observer variation upon review. Figure 2 (top) shows a well-defined omission by the AI model, which was consistently corrected by clinicians. The bottom panel shows a case, where clinicians all accepted the AI prediction, despite its significant deviation from the manual delineation.