Scientists Warn of Looming Spike in Cancers Caused by CT Scans

A new peer-reviewed study warns that heavy reliance on CT scans in the U.S. is triggering tens of thousands of future cancer cases.

The multicenter modeling study was led by Dr. Rebecca Smith-Bindman of the University of California, San Francisco.

The results were published in JAMA Internal Medicine.

The study projects that CT use in 2023 alone could ultimately be associated with about 102,700 future cancers.

If current trends in utilization and dosing persist for decades, the authors estimate CT-related cancers could eventually account for up to 5% of annual U.S. diagnoses.

Researchers used data from the UCSF International CT Dose Registry, which includes roughly 121,000 exams from 143 sites in 20 states.

They reconstructed organ-specific doses by age, sex, and exam type, then scaled to national totals of approximately 93 million CT scans performed on 62 million patients in 2023.

Using the National Cancer Institute’s RadRAT tool and BEIR VII risk models, the team projected lifetime radiation-attributable cancers.

Roughly 102,700 future cancers are projected from 2023 scans.

Adults account for around 91% (93,000 cases), though per-exam risk is highest in children, particularly infants.

By cancer type, lung (≈22,400 cases) leads, followed by colon (≈8,700), leukemia (≈7,900), and bladder (≈7,100).

Among women, breast cancer ranks second (≈5,700).

By exam type, abdomen/pelvis CT contributes the largest share in adults (≈37,500, or ~37%), followed by chest CT (≈21,500).

For children, head CT is linked to the highest projected number of cancers (≈5,100 total, including ≈3,500 thyroid cancers).

The study also highlighted that multiphase abdomen/pelvis protocols significantly raise radiation doses, even though many indications could be addressed with single-phase imaging.

The authors noted several limitations in their study, however.

The projections rely on linear no-threshold (LNT) risk models based on historical cohorts, such as atomic bomb survivors.

While standard in radiation epidemiology, such extrapolation is indirect.

The registry covers a broad but not fully national sample, and CT dose data from 2018–2020 may not reflect the latest advances in dose-reduction technology.

Sensitivity analyses yielded a wide range of estimates, from about 80,000 to 127,000 cancers, underscoring the uncertainty around the central projection.

The study does not argue against CT scans altogether.

Instead, it urges more judicious use: eliminating low-value imaging, reducing multiphase protocols, and standardizing dose minimization, especially in pediatric cases.

“CT often saves lives,” the authors stressed, but national volume and dose levels suggest “a non-trivial population-level burden” that should not be ignored.

READ MORE – Top Oncologist: Turbo Cancers Surging in Unborn Babies of Covid-Vaxxed Mothers