CT Scan Radiation and Cancer

Each year, millions of people in the U.S. undergo computed tomography (CT) scans, which are vital tools for diagnosing disease but also expose patients to ionizing radiation, a known cancer risk.

In 2023, an estimated 93 million CT scans were performed on over 61 million people, with researchers projecting that about 103,000 future cancer cases may result from that year’s CT-related radiation exposure.

Although children are more sensitive to radiation, the vast majority of projected cancer cases were among adults due to higher CT usage in this group.

The most common cancers linked to CT scans were lung, colon, leukemia, and bladder cancers, with breast cancer being notably common in women. Scans of the abdomen, pelvis, and chest accounted for the largest portion of projected radiation-induced cancers.

The findings emphasize that CT scans can significantly improve diagnosis and outcomes, but their use must be carefully justified and optimized to minimize unnecessary radiation exposure.

If current trends continue, CT-related cancer could eventually contribute to about 5% of all new cancer diagnoses annually in the U.S.

Key Takeaways:

• CT scans are critical for diagnosis, but expose patients to cancer-causing radiation.
• 93 million CTs in 2023 may result in ~103,000 future cancers.
• Most cases are linked to abdominal/pelvic and chest scans.
• Children are more sensitive, but adults account for most exposure.
• CT use has grown 35% since 2007; dose reduction and careful use are essential.

Source

Smith-Bindman, Rebecca et al. “Projected Lifetime Cancer Risks From Current Computed Tomography Imaging.” JAMA internal medicine, e250505. 14 Apr. 2025, doi:10.1001/jamainternmed.2025.0505 This is an open access article distributed under the terms of the CC-BY License.