A comparative study of quality of life in patients with localized prostate cancer treated at a single institution: stereotactic ablative radiotherapy or external beam+high dose rate brachytherapy boost.

PURPOSE To compare the quality of life (QOL) in patients treated with stereotactic ablative radiation therapy (SABR) alone or high dose rate (HDR) brachytherapy+hypofractionated external beam radiotherapy (EBRT). METHODS AND MATERIALS Patient self-reported QOL was prospectively measured among patients from two sequential phase 2 clinical trials: 1-SABR 35Gy/5fractions/5 weeks, 2-15Gy HDR 1 fraction, followed by EBRT 37.5Gy/15 fractions/3 weeks. The expanded prostate cancer index composite was assessed at baseline and q6 monthly up to 5 years. Urinary, bowel and sexual domains were analyzed. A minimally clinical important change (MCIC) was defined as 0.5*standard deviation of the baseline for each domain. Fisher exact test and general linear mixed model were used (p<0.05). RESULTS 84 and 123 patients were treated on the SABR and HDR boost studies, with a median follow up of 51 and 61 months respectively. There was a significant difference in MCIC between treatments in the urinary function and bother (p<0.0001), the bowel function (p=0.0216) and the sexual function (p=0.0419) and bother (p=0.0290) domains in favor of the SABR group. Of patients who reported no problem with their sexual function at baseline, 7% and 23% respectively considered it to be a moderate to big problem on follow up (p=0.0077). CONCLUSION Patients treated with HDR-boost reported deterioration of QOL particularly in sexual domains in comparison with SABR.