Quantifying exposure to diagnostic medical radiation in patients with inflammatory bowel disease: are we contributing to malignancy?


Dr P. Gibson, Department of Medicine, Box Hill Hospital, Box Hill, Victoria 3128, Australia.
E-mail: peter.gibson@med.monash.edu.au


Background  While potential risks of diagnostic medical radiation are acknowledged, actual exposure of patients in routine clinical practice is poorly documented.

Aim  To quantify such exposure to vulnerable abdominal organs in patients with inflammatory bowel disease who are already at risk of intestinal cancer.

Methods  All incidences of exposure to diagnostic medical radiation were documented in a consecutive series of 100 patients with inflammatory bowel disease (62 Crohn’s disease, 37 ulcerative colitis, 1 indeterminate colitis) attending a hospital-based clinic. Total effective dose (mSv) was calculated using published tables. Predictors of high or no irradiation were evaluated by multivariate logistic regression analysis.

Results  Thirteen patients had no documented diagnostic irradiation. Twenty-three patients received an effective dose greater than 25 mSv. An at-risk effective dose >50 mSv was received by 11 patients. Dosage was higher in patients with Crohn’s disease than ulcerative colitis (P = 0.02) and in patients undergoing surgery (P = 0.004). However, no predictive factors for high radiation dosage or for no exposure were identified.

Conclusions  At-risk irradiation from diagnostic medical radiation is common in patients with inflammatory bowel disease, and might potentially contribute to the elevated risk of intra-abdominal and other cancers. The level of irradiation should be considered in clinical decisions regarding abdominal imaging.