ESTRO 2024 - Abstract Book

S4215

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

ESTRO 2024

Of the 180 additional fractions measured, 13 (7%) had CTV motion which would result in the CTV being outside of the derived population margins in a single direction.

Conclusion:

Population based oART PTV margins were derived for Bladder Cancer using the Ethos and are reduced compared with standard IGRT. The smaller PTV margins achievable using oART result in improvements in OAR dosimetry whilst maintaining target coverage. Measurement of motion on an additional 10 patients showed the margins resulted in CTV coverage by 95% of prescription dose, and these margins have been implemented clinically. Clinical trials should be conducted to establish any difference in toxicity and clinical outcomes with oART.

Keywords: Margin, adaptive, dosimetry

References:

[1] Astrom. L. M. et al. (2022) Online adaptive radiotherapy of urinary bladder cancer with full re-optimization to the anatomy of the day: Initial experience and dosimetric benefits. Radiotherapy and Oncology Vol. 171, pp 37-42.