Diana L. Miglioretti, PhD, from the University of Washington in Seattle, and colleagues conducted a retrospective observational study to quantify trends in the use of CT in pediatrics from 1996 to 2010, and the associated radiation exposure and cancer risk. The radiation doses for 744 CT scans performed from 2001 to 2011 were calculated.
Between 1996 and 2005, the researchers found that for children younger than 5, the use of CT doubled, and for children aged 5 to 14 years, CT use tripled. Rates remained stable from 2006 to 2007 and declined thereafter. Per-scan, the effective doses varied from 0.03 to 69.2 mSv. For younger patients and girls, the projected lifetime attributable risks of solid cancer were higher than for older patients and boys, with higher risks also seen for abdomen/pelvis or spine CT versus other types of CT scans. For children younger than 5, the risk of leukemia was highest from head scans (1.9 cases per 10,000 scans). About 4,870 cancers are projected as a result of the four million pediatric CT scans of the head, abdomen/pelvis, chest, or spine performed each year. Forty-three percent of these might be prevented by reducing the highest 25 percent of doses to the median.
"The increased use of CT in pediatrics, combined with the wide variability in radiation doses, has resulted in many children receiving a high-dose examination," the authors write. "Dose-reduction strategies targeted to the highest quartile of doses could dramatically reduce the number of radiation-induced cancers."
Several authors disclosed financial ties to the pharmaceutical industry.