ESTRO 2025 - Abstract Book

S2891

Physics - Dose prediction, optimisation and applications of photon and electron planning

ESTRO 2025

RayStation®, guided by the delineated structures. DIRs were used to deform fraction-specific doses to CT full to calculate total estimated delivered dose (figure1). DIR quality was assessed by calculating the Dice Similarity Coefficient (DSC).

Results: Figure2 shows dose-volume-histograms for bladder and rectum. Both PotD approaches resulted in clinical relevant lower dose to bladder compared to a non-adaptive approach. For rectum a non-adaptive approach was inferior only for Patient B. A benefit of the complex PotD approach was solely observed in Patient B for the bladder, with a reduction of 17% and 10% compared to the simple approach for V30 and V40, respectively. The difference between planned and estimated delivered dose distribution to bladder was minimal for both patients, while considerably deviations were found for rectum. The mean(±SD) DSC for all evaluated structures was 0.96±0.03.