Children with Crohn's disease and other types of inflammatory bowel disease (IBD) accumulate a heavy burden of ionizing radiation from repeated CT scans and x-ray exams to monitor their conditions, according to a study from Cohen Children's Medical Center in New Hyde Park, NY.
Jeremiah Levine, MD, chair of pediatric gastroenterology, and colleagues reviewed medical records during the first five months of 2008 for 257 of 472 consecutive pediatric patients treated at the hospital for IBD. Cumulative effective doses of ionizing radiation from medical imaging were calculated for each patient. Patients with incomplete records or an exposure to radiation from procedures not related to IBD were excluded. Children with Crohn's disease accounted for 171 cases, and ulcerative colitis was attributed to the remaining 86.
The overall mean cumulative dose was 17.56 mSv (± 15.91). The average cumulative effective dose for patients with Crohn's was 20.5 mSv. Their exposure was substantially higher than the average cumulative effective dose of 11.7 mSv for patients with ulcerative colitis.
Based on reports from David Brenner, PhD, director of radiological research at Columbia University, a cumulative effective dose of 50 mSv or more was selected as the threshold for high accumulation in these young patients.
Overall, 15 children (5.8%) had a cumulative effective dose of more than 50 mSv. This included 14 of the 171 patients with Crohn's disease and one of 86 with ulcerative colitis.
Children with Crohn's disease who received IBD-related surgery tended to accumulate the most radiation. Other factors significantly associated with high accumulations included the presence of strictures and/or penetrating disease, long disease duration, elevated platelet count at the time of diagnosis, and female gender.
Patients with high cumulative effective dose received 61% of their radiation exposure (mean, 43 mSv) from CT scans. Children receiving lower levels received 75% of their radiation from upper gastrointestinal series (mean, 5.9 mSv) and small bowel series (mean, 5.2 mSv) involving x-ray imaging.
The findings were published in the March issue of the Journal of Pediatric Gastroenterology and Nutrition (2011, Vol. 52:3, pp. 280-285).
High radiation doses were recorded at the children's medical center despite efforts to persuade its pediatric gastroenterologists and radiologists to hold the line on ordering CT and other imaging procedures involving high levels of ionizing radiation, Levine told AuntMinnie.com in a phone interview.
Attending physicians can cut the radiation exposure from an upper gastrointestinal (GI) and small intestine pass-through procedure by eliminating the upper GI portion of the exam, Levine noted. The large-bowel portion of the exam is often unnecessary because the large intestine has already been examined during standard endoscopy.
Radiation from the small intestine pass-through can also be eliminated by substituting MRI or capsule endoscopy, he said. Payor resistance to the two approaches can be overcome by ordering a pass-through for the initial exam and then using either MRI or capsule endoscopy for subsequent evaluations, Levine said.
Adding radiation dose tracking to patient records would lead to better control over emergency room physicians who overprescribe CT for abdominal pain, and freestanding radiology services that lack quality control to reduce doses for their pediatric patients, he said.
A cumulative radiation record could work like a vaccination record to warn the patient's family and physicians when the accumulated dose has exceeded recommended limits.
"It would give you a better handle on the patient's overall exposure," Levine said.
