ESTRO 2025 - Abstract Book

S2979

Physics - Image acquisition and processing

ESTRO 2025

For LARC patients, voxel-to-voxel and structure-based analysis showed no relevant RED discrepancies between pCBCT and CT (Figure 2). Differences were localized at tissue interfaces and in the bowel bag and were partly due to anatomical changes and registration accuracy. Residual RED differences resulted dosimetrically negligible compared with dose distributions calculated on pseudo-CT, with gamma(3%,1mm)>95%.

pCBCT registrations minimally differed from XVI CBCT, with absolute differences always below 1mm and 1°. When considering only translations, the differences were not statistically significant. ANOVA confirmed no significant