Radiation exposure in patients with inflammatory bowel disease

Background and aims: Radiological imaging is crucial for diagnosing and monitoring patients with inflammatory bowel diseases (IBD). With increasing awareness of radiation risks, imaging doses should be 'as low as reasonably achievable', with a risk level that one should try to stay underneath 75 mSv. However, real-world data on cumulative exposure are limited. We retrospectively analyzed radiation exposure of patients with IBD in a Belgian tertiary referral center.

Methods: Radiation-exposure examinations were reviewed using the electronic health records. Annual (AED) and cumulative effective dose (CED) were calculated. A sub-analysis of patients diagnosed after January 1st, 2007, was performed, as detailed radiation doses were maintained prospectively from that date onwards.

Results: In total, 4333 IBD patients (2753 Crohn's disease [CD], 1512 ulcerative colitis [UC]) were included. The median (Interquartile range [IQR]) AED was 0.47 (0.02-1.67) mSv/year, and higher in CD than in UC (0.59 [0.05-1.79] vs. 0.28 [0.01- 1.44] mSv/year, p=0.855). CED ≥75 mSv was reached in 5.5% of patients after a median [IQR] of 24 [13-34] years of follow-up. Sub-analysis of 1754 patients diagnosed from 2007 showed a median (IQR) AED of 0.74 (0.02- 2.76) mSv/yr, again higher for CD than UC (1.16 [0.02-3.42] vs. 0.29 [0.01-2.28] mSv/yr, p=0.189). Here, 3.3% reached a CED ≥75 mSv after a median (IQR) of 9 [6-12] years of follow-up. Most common reasons for radiation exposure were comorbidities like malignancy.

Conclusion: Up to 5.5% of IBD patients reached a CED ≥75mSv. While most imaging decisions were deemed appropriate, caution against excessive radiation remains crucial.