ESTRO 2024 - Abstract Book

S3089

Physics - Autosegmentation

ESTRO 2024

The predicted segmentation well matches the clinicians’ contours on the skin and chest side, while it is more uncertain, as expected, on the lateral (see Figure 2) and craniocaudal side. The cranio-caudal direction is also uncertain given the different strategies used in that regard by clinicians. In particular, the median absolute difference between predicted and observed segmentation is respectively 4.5 mm (IQR: 1.5-9.0) and 10.5 mm (IQR: 4.5-21.0) in caudal and cranial. They have thus a larger prediction along the cranio-caudal axis in both directions. This variability is also confirmed by running the same model with different random seeds for the dropout layer. Moreover, the predicted segmentation is found globally larger than the clinicians contouring (17 ml). Finally, we performed prediction on the internal test dataset, with many outliers, obtaining on average values similar to cross validation: DSC:0.875 and HD_95: 14.01 mm.