Diagnostic medical radiation dose in patients after laparoscopic bariatric surgery

The purpose of this study was to estimate the cumulative radiation dose from computed tomography (CT) scans and upper gastrointestinal fluoroscopic exams in the post-bariatric-surgery population and correlate these values with current concepts of potential radiation-induced cancer risk.

A retrospective study of 100 roux-en-y gastric bypass (RYGB) patients and 100 gastric band patients was performed. The cumulative estimated radiation doses from CT scans and fluoroscopic studies received by these patients over a 2.5-year postoperative interval were calculated. The rate of positive radiological studies was determined. Nonlinear regression analyses were used to identify potential independent predictors of higher radiation dose.

Mean cumulative dose was 20 +/- 20 mSv for RYGB patients and 11 +/- 11 mSv for gastric band patients. The RYGB procedure and a higher preoperative body mass index were each significant predictors of higher cumulative radiation doses. Dose in the RYGB group ranged from 4 to 156 mSv. Dose in the gastric banding group ranged from 4 to 46 mSv. In the RYGB cohort, positive findings were present in 35% and 16% of CT and fluoroscopic studies, respectively, and 24% and 22% in the gastric band group. None of the fluoroscopic exams performed after the routine 24-h postoperative studies were positive.

Allowing for uncertainties of cancer risk at doses less than 50 mSv, patients undergoing laparoscopic bariatric surgery may receive radiation doses from postoperative diagnostic imaging tests that increase their lifetime cancer risk.