ESTRO 2021 Abstract Book

S109

ESTRO 2021

Whitney U test. PROs were analyzed per protocol (n=51 in boost group and n=64 in control group). 2-year DFS was estimated using Kaplan-Meier method and compared using log-rank test in intention-to treat analysis (n=64 in both groups). Results The boost group experienced a significantly stronger decline in global health at 3 and 6 months (ES -0,4 and ES -0,4), physical functioning at 6 months (ES -1,1), role functioning at 3 and 6 months (ES -0,8 and ES -0,6) and social functioning at 6 months (ES -0,6) compared to the control group. The boost group reported significantly more often fatigue at 3 and 6 months (83% vs. 66% resp. 89% vs. 76%), pain at 3 and 6 months (67% vs. 36% resp. 80% vs. 44%) and diarrhea at 3 months (45% resp.29%) compared to the control group. From 12 months onwards, QoL and symptoms were similar between groups, apart from more blood and mucus in stool in the boost group. DFS at 2 years was 75% [95% confidence interval (CI): 65-86] in the boost group and 80% [95%CI: 70-90] in the control group (p=0,9).

Conclusion In patients with LARC, dose-escalated CRT resulted in a transient deterioration in global health and physical, role, and social functioning and more pain, fatigue and diarrhea up to 6 months following start of treatment compared to standard CRT. From 12 months onwards, the impact of dose-escalated CRT on QoL largely resolved. Dose-escalated CRT did not affect 2-year DFS. OC-0178 Impact of gender on quality of life and toxicity following (chemo)radiotherapy for bladder cancer L. Philipps 1 , N. Porta 2 , N. James 3 , R. Huddart 3 , S. Hafeez 3 , E. Hall 4 1 Institute of Cancer research, Clinical Trials and Statistics Unit, London, United Kingdom; 2 Institute of Cancer Research , Clinical Trials and Statistics Unit, London, United Kingdom; 3 Institute of Cancer Research, Institute