Computed Tomography Scans Are Projected to Increase Lifetime Cancer Risk

What is the risk of cancer development in patients who have undergone computed tomography scans?

Based on the risk model, computed tomography scans result in radiation exposure that can, over the course of a patient's lifetime, lead to an increased likelihood of cancer, especially leukemia and lung, colon, and bladder cancers. (Level of Evidence = 4)

The risk model used data from a registry of computed tomography scans from 143 facilities throughout the United States. The authors estimated absorbed doses for 18 organs and estimated lifetime radiation-induced cancer risk using the National Cancer Institute's Radiation Risk Assessment Tool. From these data, the authors estimate that 61,500,000 patients received one or more computed tomography scans in 2023; 4.2% were children. Over the course of those lifetimes, the authors estimate that 103,000 radiation-induced cancers will occur (90% uncertainty limit, 96,400–109,500) because of these scans. The cancers most likely to increase are leukemia and lung, colon, and bladder cancers. If computed tomography scans continue at this rate, up to 5% of all new cancers could be traced back to radiation exposure.

Study design: Other

Funding source: Government

Setting: Population-based

Reference: Smith-Bindman R, Chu PW, Azman Firdaus H, et al. Projected lifetime cancer risks from current computed tomography imaging. JAMA Intern Med. 2025;185(6):710-719.

Editor’s Note: Dr. Shaughnessy is an assistant medical editor for AFP.