ESTRO 2025 - Abstract Book

S3213

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

ESTRO 2025

In the phantom study, the measured displacements were similar with and without weight, with no deviation exceeding the tolerance. Slightly smaller deviations were obtained when the couch was under weight, except for the lateral direction (3 measurements reached 0.5mm (9%)). Conclusion: Patients benefited from the possibility to correct their position throughout the treatment, as the combined effect of couch rotation and patient motion resulted in the need for repositioning in 43% of all couch rotations, when action limits of deviations of ≥0.5mm/0.5° were applied. As expected, all measured displacements for the phantom study were smaller than the ones observed for patients, as they only include the effects resulting from the couch rotation. Moreover, little variance was observed when using different weights, showing that the couch provides similar accuracy in various situations.

Keywords: Intrafraction, Intracranial, SRS