Anal and rectal function after intensity-modulated prostate radiotherapy with endorectal balloon

Background and purpose: Late anorectal toxicity influences quality of life after external beam radiotherapy (EBRT) for prostate cancer. A daily inserted endorectal balloon (ERB) during EBRT aims to reduce anorectal toxicity. Our goal is to objectify anorectal function over time after prostate intensity-modulated radiotherapy (IMRT) with ERB. Material and methods: Sixty men, irradiated with IMRT and an ERB, underwent barostat measurements and anorectal manometry prior to EBRT and 6 months, one year and 2 years after radiotherapy. Primary outcome measures were rectal distensibility and rectal sensibility in response to stepwise isobaric distensions and anal pressures. Results: Forty-eight men completed all measurements. EBRT reduced maximal rectal capacity 2 years after EBRT (250 +/- 10 mL vs. 211 +/- 10 mL; p < 0.001), area under the pressure-volume curve (2878 +/- 27 0 mL mmHg vs. 2521 +/- 305 mL mmHg; p = 0.043) and rectal compliance (NS). Sensory pressure thresholds for first sense and first urge (both p < 0.01) increased. Anal maximum pressure diminished after IMRT (p = 0.006). Conclusions: Rectal capacity and sensory function are increasingly affected over time after radiotherapy. There is an indication that these reductions are affected less with IMRT + ERB compared to conventional radiation techniques. (C) 2018 Elsevier B.V. All rights reserved.