BACKGROUND: Radiation-induced late fecal incontinence (LFI) is one of the most quality-of-life impairing symptoms in prostate cancer. We aimed to assess the impact of radiotherapy (RT) technique and dose-volume effects on LFI using a robust score. METHODS: We identified 409 patients who underwent curative intent using standard fractionated radiation therapy, 190 of them were finally included and analyzed. The severity of LFI was assessed using the Jorge & Wexner score. RESULTS: With a median follow-up of 55 months (range 15-96) months, LFI crude rate was 11.5%. In the multivariate analyses, image-guided radiotherapy (IGRT), rectal maximum dose (Dmax) and anal canal minimum dose (Dmin) were significantly associated with LFI risk. The use of IGRT was associated with lower risk of LFI (p = 0.02)
higher rectum Dmax (≥ 68.4 Gy
p = 0.02) and anal canal Dmin (≥ 6.4 Gy
p = 0.04) were associated with increased risk. CONCLUSION: Our results suggest a significant impact of the total dose delivered to the anorectal volumes and the use of IGRT to spare organs at risk during radiation delivery.