ESTRO 2024 - Abstract Book

S4409

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

ESTRO 2024

Results:

The kVCT alignment and pre-scan PET acquisition was performed when the phantom was in its planning configuration. The activity concentration and normalized target signal were 16.26 kBq/ml and 7.89 respectively at the start of the treatment. When the OAR was moved into the BTZ volume during the 2nd beam station, the motion was detected in the 11th beam station. Using an ion chamber, the total additional dose delivered to the target was measured to be in the 3% to 5% range when the OAR accidentally moved into the target.

Conclusion:

This study demonstrates that the BgRT system can detect the gross motion of a PET-avid OAR into the BTZ and stop treatment. The time lapse to detect the motion of the OAR into the BTZ depends on the amount of PET activity in the OAR, shape, size, and direction of motion of the OAR with respect to the direction of the bed for that treatment.

Keywords: Biology-guided Radiotherapy, BgRT