ESTRO 2025 - Abstract Book

S3726

Physics - Radiomics, functional and biological imaging and outcome prediction

ESTRO 2025

Results: The cohort had a median follow-up time of 34.4 months. Our workflow selected the top 17 important features for each model. When evaluated on the same independent test set, the four models—CT features-only, BED features only, a combination of CT and BED features, and a composite model including features from CT and BED that includes their interaction matrices—achieved log-rank test statistics of 6.1, 19.62, 14.43, and 21.83, with corresponding p-values of 1.35 x 10 -2 , 9.44 x 10 -6 , 1.45 x 10 -4 , and 2.98 x 10 -6 , respectively. The four models achieved Concordance Index (CI) of 0.679, 0.734, 0.710, and 0.740, respectively. The composite model demonstrated the highest log-rank test statistic and CI, indicating that incorporating interactions between CT and BED enhances predictive accuracy for treatment in a time-to-event analysis for patients with primary NSCLC undergoing SBRT treatment.