Radiation from imaging exams tied to increased cancer risk

Exposure to diagnostic low-dose ionizing radiation is associated with an increased risk of developing cancer among pediatric patients, according to a recent study published in JAMA Network Open.

Jae-Young Hong, MD, PhD, Korea University in Seoul, and colleagues looked at data from more than 12 million pediatric patients, more than 10% of whom were exposed to low-dose radiation. Overall, more cancer were detected in those exposed to radiation than those who weren’t, even after adjusting for age and sex.

“Our study found an association of increased cancer incidence with exposure to ionizing radiation and with exposure to CT scans,” the authors wrote. “Therefore, our findings raise concerns regarding the use and subsequent risks of diagnostic low-dose ionizing radiation exposure in youths.”

While diagnostic low-dose radiation has wonderful medical benefits, the researchers wrote, its high usage has brought about concerns related to its negative side effects, especially in pediatric populations.

The patients included in this study were 52.5% male, 19 years old or younger and from South Korea. Low-dose exposure took place from 2006 to 2015 and participants had to be exposed at least two years prior to receiving a cancer diagnosis. Of the more than 12 million patients, 10.6% were exposed to radiation while 14% underwent more than one imaging exam.

By 2015, the team recorded 21,912 cancers. Individuals exposed to radiation accounted for 0.1% of cancers or 1,444 individual cancer cases.

Computed tomography scans were also associated with a greater overall cancer incidence, the authors noted.

Additionally, among lymphoid and hematopoietic cancers, incidence increased the most for myeloid leukemias ad myelodysplasia. Among solid cancers, incidence of the disease increased most for breast and thyroid cancers.

“In conclusion, the associations we found of diagnostic low-dose ionizing radiation with increased incidence of cancer in youths suggest that there is incentive to limit radiation doses to as low as reasonably achievable and to only scan when justified,” Hong and colleagues wrote. “Medical professionals should weigh the benefits of diagnostic low-dose ionizing radiation with the associated risks to justify each decision.”