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.
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.
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 ± 270 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).
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.
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 2018 Apr 28 [Epub ahead of print]
Robin Krol, Gill M McColl, Wim P M Hopman, Robert J Smeenk
Department of Gastroenterology and Hepatology, Radboud University Medical Centre, Nijmegen, The Netherlands. Electronic address: ., Department of Radiation Oncology, Radboud University Medical Centre, Nijmegen, The Netherlands., Department of Gastroenterology and Hepatology, Radboud University Medical Centre, Nijmegen, The Netherlands.