Authors: Rebecca Smith-Bindman, M.D., Susan A. Alber, Ph.D., Marilyn L. Kwan, Ph.D., Priscila Pequeno, M.Sc., Wesley E. Bolch, Ph.D., Erin J.A. Bowles, M.P.H., Robert T. Greenlee, Ph.D., +10 , and Diana L. Miglioretti, Ph.D

Published September 17, 2025

N Engl J Med 2025;393:1269-1278 DOI: 10.1056/NEJMoa2502098 VOL. 393 NO. 13

A study in the New England Journal of Medicine by Smith-Bindman et al, is reporting convincing results tying hematologic malignancies in children to cumulative radiation exposure from medical imaging, particularly CT scans. 

 Approximately 3.7 million children and adolescents were studied in the United States and Canada over a period of 20 years, with the average length of time followed being 10 years.  In general, participants were followed until the age of 21, loss of healthcare, benign or malignant tumor development, or death.    

 2961 hematologic cancers were identified.  79.3 percent of tumors were lymphoid in origin, 15.5% myeloid or acute leukemia, and 4.4 % were found to be histiocytic or dendritic cell cancers. 

 The authors note that the average ct scan of the brain accounts for 13.5 mGy of exposure.  The hematologic cancer risk was found to be cumulative, with the risk of developing a malignancy increasing with greater cumulative radiation exposure.  The average exposure for children was 14mGY.  The average exposure for children who developed hematologic malignancies was 30 mGy, resulting in a cumulative incidence of 39.9 per 10,000 participants, compared to 14.3 per 10,000 subjects hematologic cancers in children who had no exposure.  The number of hematologic malignancies increased to 55.1 per 10,000 subjects in the subgroup exposed to 50-100 mGy, a 3.59 higher risk at this dose exposure. 

 The authors concluded that a stunning 10% of pediatric hematologic cancers may have their origins from radiologic imaging.  The US has the world’s highest per capita rate of diagnostic imaging.  As such, low-yield diagnostic scans should be re-considered to prevent undue harm to our children and adolescents.  Prudent use of medical imaging is now more important than ever.  Further study is important to confirm the results of this study but given what we know about cumulative radiation exposure and children’s higher radiosensitivity, this study may indeed be accurate.  If so, changes must occur to protect patients and to live up to the creed “First do no harm.” 

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