Ionizing radiation from medical imaging, particularly CT scans, is a major source of radiation exposure for children in the U.S. and a known carcinogen linked to hematologic malignancies (blood cancers).
The large RIC cohort study (3.7 million children in the U.S. and Canada) found a significant dose-response relationship between cumulative bone marrow radiation dose and cancer risk. A dose of 15−30 mGy (1-2 head CTs) was associated with a 1.8-fold increased risk, and doses ≥30 mGy led to a 2.5-times greater risk.
The study estimated that 10.1% of all childhood hematologic malignancies are attributable to medical imaging radiation. For children who had a head CT, 25.9% of their blood cancers were estimated to be attributable to the radiation.
These findings provide robust evidence that medical imaging radiation is associated with increased blood cancer risk in children, even at relatively low doses, emphasizing the critical need to minimize radiation exposure during pediatric imaging.