Metamodeling of late rectal bleeding in patients undergoing radiotherapy for prostate cancer.

61 Background: Predictive models for late rectal bleeding (LRB) after radiotherapy (RT) for prostate cancer were established by several studies, with good performance on development population (POP). Nonetheless, they were found to be unsatisfactory in their generalization to independent validation cohorts. Aim of the study is to build a metamodel for grade 2-3 (G23) and grade 3 (G3) LRB (LENT/SOMA) starting from literature evidence and to...