ESTRO 2024 - Abstract Book

S4751

Physics - Quality assurance and auditing

ESTRO 2024

In figure 2 an example is depicted of a 1D profile in the cranial-caudal direction for one of the gel measurements, without correcting the determined geometric deviation. It shows a good overlap with the TPS dose. Furthermore, in the low dose regions some differences between the gel measurement and the TPS calculated dose were observed.

Conclusion:

The end-to-end geometric accuracy of the online adaptive ATS workflow determined using 3D gel dosimeters was small and on average 0.2 ± 0.1 (1SD) mm for the 3D displacement vector. Also, the standard deviations of the end-to end measurements were small, showing that the reproducibility is high. Profile comparison of the unregistered gel measurements showed only minor geometric shifts, which agrees with the minor geometric deviations found.

Keywords: MR-linac, End-to-End, Gel dosimetry