This large retrospective cohort study evaluated the association between radiation exposure from medical imaging and the risk of hematologic cancers in over 3.7 million children and adolescents followed up to age 21 years.

Radiation doses to active bone marrow were quantified, with cumulative exposure linked to an increased risk of hematologic malignancies, particularly lymphoid and myeloid cancers.

Key findings include:

• Relative risk increased progressively with higher cumulative doses, reaching up to 3.59-fold for doses between 50 and 100 mGy.
• Approximately 10% of hematologic cancers in the cohort could be attributed to radiation from medical imaging.
• The increased risk was primarily associated with higher-dose modalities such as CT scans.

These findings highlight a small but significant increased risk of hematologic cancer in pediatric populations exposed to medical imaging radiation.

This large retrospective cohort study followed over 3.7 million children born between 1996 and 2016 across U.S. and Canadian healthcare systems to evaluate the risk of hematologic cancers associated with radiation exposure from medical imaging.

Over a mean follow-up of 10 years, 2,961 hematologic cancers were diagnosed. Radiation doses to active bone marrow were quantified, with exposures from diagnostic imaging such as CT scans linked to an increased risk of hematologic malignancies in a dose-dependent manner.

Relative risks ranged from 1.41 for low doses (1 to <5 mGy) to 3.59 for higher doses (50 to <100 mGy). The excess relative risk per 100 mGy was 2.54, indicating a significant association.

Approximately 10% of hematologic cancers in this population may be attributable to radiation from medical imaging, with higher risks linked to higher-dose procedures like CT scans.

The findings support careful consideration of radiation risks when ordering imaging in children and adolescents.