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RADIATION DOSES IN PATIENTS WITH INFLAMMATORY BOWEL DISEASE
K Kroeker, I Birchall, R Fedorak
University of Alberta, Edmonton, Alberta
Aims: Patients with inflammatory bowel disease (IBD) undergo frequent radiographic diagnostic and therapeutic examinations; furthermore, these examinations frequently occur in adolescents and/or young adults or childbearing age. The purpose of this study was to assess the total effective dose of ionizing radiation from diagnostic imaging in patients with inflammatory bowel disease over a serial 5-year period.
Methods: The patient care database of a university-based gastroenterology specialty practice was searched to identify patients with documented Crohn's disease seen between September 2003 and September 2008. The total number of radiographic studies for each patient was counted for the preceding 5 year period, when the radiologic reports have been available electronically. The effective doses, in milli-Sieverts (mSv), of ionizing radiation was then calculated using standardized tables from the International Commission on Radiological Protection 60 weighting factors.
Results: 392 patients with a diagnosis of Crohn's disease were identified in the patient care database. Seventeen patients were excluded due to invalid personal health numbers which are required to access the electronic health record, one patient was deceased and therefore excluded. The average age of patients in this cohort is 40 years, (range 15yr - 84yr) at the time of this retrospective review. During the 5-year interval of study this group of patients had a total of 262 abdominal-pelvic CT scans, 146 small bowel follow though (SBFT) examinations, 23 barium enemas, 547 abdominal X-rays and 255 DEXA scans. This translated into an average of 0.14 CT scans (2.06mSv), 0.08 SBFT (0.23mSv), 0.01 barium enemas (0.086mSv), 0.29 abdominal X-rays (0.29mSv), and 0.08 DEXA scans (0.001mSv) per person per year. The sum of this radiation exposure was an average of 2.67mSv per patient per year. This amount of effective radiation exposure is 1.5-fold greater than the average Canadian receives each year. Approximately 77% of this radiation is from abdominal-pelvic CT scans.
Conclusions: Patients with IBD undergo frequent exposure to radiographic testing and this leads to significant and serious, exposure to ionizing radiation. The vast majority of the exposure to ionizing radiation from diagnostic imaging is from CT scans. Efforts should be made to minimize the number of radiographic examinations with radiation exposure.