Inflammatory bowel disease (IBD) [i.e., Crohn’s disease (CD) and ulcerative colitis (UC)] has been considered a relative contraindication for radiation therapy (RT) to the abdomen or pelvis, potentially preventing patients with a diagnosis of IBD from receiving definitive therapy for their malignancy.

Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) conventions, a PubMed/MEDLINE literature search was conducted using the keywords RT, brachytherapy, inflammatory bowel disease, Crohn’s disease, ulcerative colitis and toxicity.

A total of 1,206 publications were screened with an addition of 8 studies identified through hand searching. Nineteen studies met the inclusion criteria for quantitative analysis. The total population across all studies was 497 patients, 50·5% having UC, 37% having CD and an additional 12·5% having unspecified IBD. Primary gastrointestinal malignancy (55%) followed by prostate cancer (40%) composed the bulk of the population. Acute and late grade 3 or greater gastrointestinal specific toxicity ranged from 0–23% to 0–13% respectively for those patients with IBD treated with RT to the abdomen or pelvis. In the literature reviewed, RT does not appear to increase fistula or stricture formation or IBD flares; however, one study did note RT to be a statistically significant risk factor for subsequent IBD flare on multivariate analysis.

A review of reported acute and late toxicities suggests that patients with IBD should still be considered for definitive radiotherapy. Patient characteristics including IBD distribution relative to the irradiated field, inflammatory activity at the time of radiation, overall disease severity and disease phenotype in the case of CD (fistulising versus stricturing versus inflammatory only) should be considered on an individual basis when evaluating potential patients. When possible, advanced techniques with strict organ at risk dose constraints should be employed to limit toxicity in this patient population.