Radiation exposure during imaging may be causing some pediatric cancer cases
New data suggest there may be a link between medical imaging during childhood and the development of hematologic cancer.
Published in the New England Journal of Medicine, the findings indicate that although the risk of developing cancer due to radiation exposure during medical imaging is small, there are clear associations between the two. Researchers analyzed data from nearly 4 million children gathered over a 10-year period and determined that of those who were eventually diagnosed with blood cancer, up to 10% may be attributable to imaging.
"While medical imaging can be lifesaving, our findings underscore the critical need to carefully evaluate and minimize radiation exposure during pediatric imaging to safeguard children's long-term health," Rebecca Smith-Bindman, MD, with the department of epidemiology and biostatistics at the University of California, San Francisco, and colleagues noted. "This involves ensuring that imaging is performed only when it provides essential information for the child's care and, in cases such as CT scans, using the lowest possible radiation doses."
Researchers reviewed the medical records of just over 3.7 million children born between 1996 and 2016. The team included data up to the time of the children’s tumor diagnosis, death, loss of insurance coverage or until they turned 21, giving them ample health histories to review. For the kids who underwent medical imaging, the team quantified their cumulative radiation exposure, comparing those figures to the specific type and number of exams completed and any eventual diagnoses of blood cancer.
Through this, the group made several observations. First, of the nearly 3,000 blood cancers diagnosed, the majority were lymphoid cancers, which accounted for 79.3%; myeloid cancers or acute leukemia were the next most common, at 15.5%, while histiocytic- or dendritic-cell cancers accounted for 4.4%.
The mean exposure among children subjected to at least 1 mGy was around 14 mGy overall compared to 24.5 mGy for the children who were eventually diagnosed with cancer. For context, a single CT scan of the head and neck carries a mean exposure of 13.7 mGy.
The team noted a direct relationship between increased radiation exposure and the likelihood that a child would be diagnosed with cancer. For example, compared to kids who did not undergo medical imaging, those who were exposed to less than 15 mGy were 1.41 times more likely to be diagnosed with blood cancer, while 50 to 100 mGy increased the odds to 3.59.
Of the cancers diagnosed, the group estimated that a little over 10% were likely owed to radiation from medical imaging and CT in particular.
This latest research echoes similar findings published in JAMA earlier this year and also authored by Smith-Bindman. That study suggested that the nearly 100 million CT scans conducted in the U.S. during 2023 will result in approximately 103,000 future cancer diagnoses annually due to radiation exposure alone. That figure equates to approximately 5% of all cancers diagnosed in the U.S. every year. It should be noted that particular study was based on statistical modeling, not actual patient outcomes.
That study also focused on adults, rather than children. Although providers must ensure that all medical imaging is used judiciously, it is especially important in the pediatric population, as children are more vulnerable to the adverse effects of radiation, the authors noted.
Read more about these latest findings here.
In addition to her background in journalism, Hannah also has patient-facing experience in clinical settings, having spent more than 12 years working as a registered rad tech. She began covering the medical imaging industry for Innovate Healthcare in 2021.