Outpatient application of formalin for chronic rectal bleeding after prostate irradiation: a quasi-experimental study.

PURPOSE: The aim of this quasi-experimental study is to evaluate a novel technique for an outpatient application of formalin for chronic rectal bleeding after prostate irradiation.

METHODS: This is a quasi- experimental clinical trial developed between January 2010 and July 2015, including 35 patients with chronic radiation rectitis (CRP) due to a previous prostate radiation course. The study's eligibility was (1) completed external beam radiation therapy for prostate carcinoma >6 months previously, (2) rectal bleeding, defined as a frequency of >1× per week and/or needing of blood transfusions, and (3) diagnosis of chronic proctitis at colonoscopy. The 5% formalin application was performed by a custom applicator, which requires neither anesthesia nor sigmoidoscopy. The endpoint of the study was bleeding cessation and hemoglobin level.

RESULTS: The onset of bleeding due to chronic rectitis was 12 months (6-36). During a median follow-up of 24 months, the rate of overall efficacy was 94%. The sustained complete response in 1 and 2 years was 80% and 73%, respectively. The Hb mean pre- and post-treatment differed significantly (12.2 vs 14.4, p = 0.0001). The rates of blood transfusion differed significantly, pre- and post-treatment (17% vs 5.7%, p = 0.031).

CONCLUSION: The technique is very effective and safe, resulting to a significant improvement of hemoglobin levels and quality of life scores. Further studies are warranted to compare this technique with other treatment options for chronic radiation-induced rectal bleeding.