Toxicity after (125)I prostate brachytherapy in patients with inflammatory bowel disease

To determine gastrointestinal (GI) toxicity after (125)I prostate brachytherapy in patients with inflammatory bowel disease (IBD).

We retrospectively reviewed 13 patients diagnosed with IBD from a cohort of over 3200 patients with low- to intermediate-risk prostate cancer treated with (125)I brachytherapy (144Gy). Acute (i.e. <12 months) and late lower GI toxicity after brachytherapy using the Radiation Therapy Oncology Group (RTOG) grading system was assessed. Possible factors (e.g. patient, treatment, dosimetry, and characteristics of IBD) influencing GI toxicity were assessed.

Median followup was 4.2 years. Ten patients had ulcerative colitis (UC) and 3 had Crohn's disease. Seven patients with UC had known involvement of the rectum. Acute RTOG GI Grade 0, 1, 2, 3, 4 toxicity was seen in 7, 1, 2, 2, 1 patients, respectively. The corresponding late RTOG GI toxicity was seen in 7, 1, 3, 1, 1 patients, respectively. Two patients required major surgery. All patients with severe GI toxicity (i.e., Grade ≥3) had UC with disease involving the rectum and underwent endoscopic biopsies of the rectum within 3 months after the implant. There was no clear association with other factors with toxicity.

Twenty-three percent and 15% patients with IBD experienced Grade 3 or higher acute and late GI toxicity, respectively, after brachytherapy. Prostate brachytherapy should be used with great caution or avoided, particularly for men with active IBD involving the rectum. Biopsies of the rectum after brachytherapy should be avoided as it may lead to ulceration.