ESTRO 2024 - Abstract Book

S4287

Physics - Intra-fraction motion management and real-time adaptive radiotherapy

ESTRO 2024

deformation accuracy on the contours for the three models was compared on the testing set using the DSC, the 50% Hausdorff distance (HD 50% ), the 95% Hausdorff distance (HD 95% ), and the RMSE of the target center-of-mass in both the anterior-posterior (RMSE AP ) and superior-inferior (RMSE SI ) directions.

Results:

The results obtained with the three models are summarized in Table 1. We found the TM-PS to perform substantially better than the other two models, achieving for both observers an accuracy on-par to inter-observer variability. Figure 1 shows for two challenging patients the comparison between the contours warped by the three different models. It is evident how for the lung case only TM-PS was able to accurately track the tumor, while for the liver case both TM PS and TM-Sup work well even in the case of very large deformations. The inference time of TransMorph on a GPU was measured to be about 36 ms, making it fast enough for real-time tracking. Annotating 8 frames took 3 min on average and patient-specific training took an additional 8 min, both times being acceptable in current MRIgRT online adaptive workflows.