Intrafractional Vaginal Dilation in Anal Cancer Patients Undergoing Pelvic Radiotherapy

The study is designed as a prospective, randomized, two-armed, single-center phase-II-trial. 60 patients will be included in the study. Patients fulfilling the inclusion criteria will be randomized into one of the two arms, which differ only in the diameter of a tampon used for vaginal dilatation during treatment. All patients will receive standard (chemo)radiotherapy with a total dose of 45-50,4 Gy (single dose 1,8-2 Gy) to the pelvic and inguinal (if required) lymphatic drainage with a boost to the anal canal up to 54-60 Gy (single doses 1.8-2.2 Gy). The primary objective is the assessment of the incidence and grade of vaginal fibrosis 12 months after (chemo)radiotherapy for anal cancer depending on the extent of intrafractional vaginal dilatation. Secondary endpoints are clinical symptoms and toxicity according to the Common Toxicity Criteria (CTC) version 5.0, assessment of clinical feasibility of daily use of a tampon for vaginal dilatation, assessment of the compliance for the use of a vaginal dilatator and quality of life assessed with the EORTC-QLQ30/-ANL27 questionnaires.