ESTRO 2025 - Abstract Book

S364

Brachytherapy - Physics

ESTRO 2025

stable, with deviations from the DPM being due to measurement disturbances and patient motion. Also, we assumed that the differences between image-based and AIEMT-based reconstruction were caused by the AIEMT based reconstruction uncertainty and the image-based reconstruction uncertainty, allowing image-based reconstruction residual uncertainty calculation. Uncertainties were calculated according to Figure 1.

Results: The DPM showed a mean(std) reproducibility of 0.0±0.1, 0.2±0.4, 0.2±0.3 mm for ovoids, tandem, whole applicator. The mean(std) AIEMT-based applicator reconstruction uncertainty in patients was 0.6±0.4, 0.3±0.3, 0.4±0.3 mm for ovoids, tandem, whole applicator. The mean(std) image-based applicator reconstruction residual uncertainty in patients was 1.2±1.3, 0.8±0.7, and 1.0±1.1 mm for ovoids, tandem, whole applicator, without significant difference between imaging modalities. Histograms are visible in Figure 2.