Background: Diagnostic imaging is frequently used in Crohn's disease (CD) for diagnosis, evaluation of complications, and determination of response to treatment. Patients with CD are at risk for high radiation exposure in their lifetime. The aim of our study was to compare the effective dose of radiation in CD patients the year prior to and the year after initiation of anti-tumor necrosis factor (anti-TNF) agents or corticosteroids.
Methods: We conducted a retrospective review of 99 CD patients initiated on anti-TNF therapy or corticosteroids between 2004 and 2009 in a tertiary care center.
Results: Sixty-five patients were initiated on anti-TNF agents and 34 were initiated on corticosteroids. The anti-TNF cohort was significantly younger at diagnosis and at the time of initiation of anti-TNF or steroid therapy. The anti-TNF group had significantly more stricturing, penetrating, and perianal disease than the corticosteroid group. The anti-TNF cohort had a significant reduction in number of radiologic exams (5.5 vs. 3.7, P < 0.01) as well as a significant reduction in the cumulative radiation dose (28.1 vs. 15.0 mSv, P < 0.01) the year after initiation of therapy. This reduction was largely attributable to decreased use of computed tomography (CT) scans. In contrast, there was no significant change in radiation exposure in the corticosteroid cohort. Logistic regression analysis showed a strong trend toward higher exposure in patients with complicated disease behavior (stricturing or penetrating phenotype) (odds ratio [OR] 2.87, 95% confidence interval [CI] 0.98–8.38).
Conclusions: Initiation of anti-TNF therapy for treatment of CD is associated with a significant reduction in diagnostic radiation exposure. Conversely, steroid treatment does not reduce diagnostic radiation exposure.