For Patients with Digestive Disorders, X-Ray Radiation Exposure May Pose Greater Hazards

Patients with inflammatory bowel disease (IBD) and other gastrointestinal (GI) disorders may be exposed to significant doses of diagnostic radiation, according to recent research.

“Our results show that significant increases in radiation exposure in the last decade have paralleled the increased use of computed tomography imaging,” said Alan N. Desmond, MB, BMedSc, MRCPI, from the Cork University Hospital (Ireland), and lead author of the study. “While cumulative exposure is highest in patients with Crohn’s disease, high exposure may also occur in patients with other gastrointestinal disorders.”

The study’s findings were published April 1, 2012, in the journal Clinical Gastroenterology and Hepatology, the official journal of the American Gastroenterological Association. Researchers studied data from 2,590 patients who were diagnosed with GI disorders at a tertiary gastroenterology center from January 1999 to January 2009. Diagnostic imaging was conducted on 57% of the patients. Findings revealed that higher levels of annual and total diagnostic radiation exposure were associated with IBD and other GI disorders, including benign conditions of the small bowel (such as celiac disease and bacterial overgrowth) and liver (such as benign liver cysts and fatty liver disease). Higher total exposures were also observed in a small number of young patients with functional GI disorders (such as irritable bowel syndrome and unexplained abdominal pain syndrome).

The clinical benefits of widely available diagnostic imaging of the GI tract are not disputed. This is especially true for patients with disorders such as Crohn’s disease, who often require abdominal imaging to determine the extent of their disease and detect complications. Access to high-quality imaging facilities and the introduction of rapid-acquisition computed tomography (CT) imaging have made CT imaging of the GI tract valuable and widely used. However, because CT uses higher levels of radiation than other imaging options, more widespread use has led to increases in the amount of radiation to which patients are exposed. This is a cause for concern, because radiation exposure might be linked with increased lifetime risk of cancer. These risks may be very relevant to younger patients.

“Most patients with gastrointestinal disorders had diagnostic X-rays performed at some point during their work-up, with older age and longer duration of follow-up both increasing the chances of having multiple X-rays performed,” added Dr. Desmond. “In this study, we were particularly interested in patients whose cumulative radiation exposures were in the top 10% for the entire population. The majority of these patients were being investigated for inflammatory bowel disease. The most concerning finding might be that more than half of the patients in this higher exposure group were younger than 35 years of age.”

Radiation-free imaging alternatives, including ultrasound, capsule endoscopy, and magnetic resonance imaging (MRI), are available. However, evidence-based guidelines on the use of diagnostic imaging in patients with GI disorders, particularly those that reduce radiation exposure, are still needed, according to the investigators.
The authors emphasize that diagnostic X-ray examinations, including CT, are valuable diagnostic tests that allow speedy and accurate diagnosis of many conditions and pose little or no risk to the majority of patients. The researchers’ findings have led them to perform additional research showing that new, low-radiation techniques for performing CT scans are particularly beneficial in patients with Crohn’s disease. They plan to publish this new research in the near future.

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Cork University Hospital