ESTRO 2025 - Abstract Book

S3032

Physics - Image acquisition and processing

ESTRO 2025

Results: During radiotherapy, patients experienced significant anatomical changes, particularly notable volume shrinkage in the parotid gland. Both Seq2Morph and B-Spline algorithms captured this shrinkage; however, Seq2Morph outperformed B-Spline with an SSIM of 0.86±0.05, v.s. 0.83±0.05, (p-value < 0.01). Regarding structure-based evaluation, compared to B-Spline, Seq2Morph achieved a 5% higher Dice score for the parotid glands, and exhibited a 23% and 11% reduction in HD_avg and HD_95, respectively. Seq2Morph completed calculations in under 10 seconds, substantially shorter than B-Spline’s 200 seconds for DIR between all weekly CBCTs and the planning CT.