ESTRO 2024 - Abstract Book

S4325

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

ESTRO 2024

Figure 2: Couch movement between initial and verification CBCT represented by the prostate match in vertical and longitudinal directions for each scored fraction (color-coded), displayed for the 4 mm margin with scoring by RTT1 (a) and RTT2 (b), and for 3 mm margin with scoring by RTT1 (c) and RTT2 (d)

Conclusion:

It is safe to reduce the PTV margins from 5 to 4 mm for the elective pelvic lymph nodes for prostate patients treated with oART. This can reduce dose received by the bowel. Further margin reductions can be motivated for patients presenting little intrafraction motion. Necessary PTV margins for cervix patients treated with oART is yet to be decided.

Keywords: adaption, margin, Ethos

2339

Poster Discussion

Automated online adaptive PT for oesophageal cancer in a commercial TPS: a path to margin reduction