1041 Efficacy of Rifaximin for IBS Without Constipation in Men and Women

Abstract

Background: Radiation proctitis (RAP) is defined as damage to the rectal mucosa resulting from radiotherapy to adjacent pelvic organs. More than 50 % of patients undergoing radiotherapy for prostate cancer (PC) will encounter symptoms such as diarrhea, blood and mucus in stool and tenesms that might alter qualitiy of life and might be dose limiting. The symptoms of radiation proctitis can be quantified by the acute EORTC/RTOG lower GI toxicity or the RAP score . Material and Methods: Patients undergoing radiotherapy (XRT) for PC were randomised to rectal budesonide (BUD) or placebo (PLB) treatment over 8 weeks. EORTC/RTOG lower GI toxicity score, RAP score and quality of life scores were taken at baseline and after 2, 4, 8 and 14 weeks as well as after 1 year. Flexible rectoscopy and assessment of the Vienna rectoscopy score (VRS) was done at baseline, after 8 weeks, 14 weeks and 1 year. 17 patients were included (n=8 budesonide, n=9 placebo) into the study. Results: 6/8 BUD patients and 6/9 PLB patients developed clinical signs of acute radiation proctitis, i.e. acute EORT/RTOG lower GI toxicity ≥ 1 for at least 2 consecutive days, during 8 weeks of treatment (p=0.8167). However, BUD ameliorated the severity of RAP by significantly reducing stool frequency at week 14 and after 1 year and numerically the number of tenesms at week 8. The endoscopic score for late radiation proctitis was diminished in the budesonide group compared to placebo. Conclusions: Rectal treatment with budesonide did not significantly prevent acute radiation proctitis in this pilot study. However, clinical symptoms of proctitis could be significantly reduced and the appearance of late radiation proctitis was diminished. Therefore BUD deserves further evaluation in the context of high dose XRT with curative intent to prevent or to ameliorate side effects that might be dose limiting.