🌅 The Share of Cancers Linked to CT Scans

SOURCE

Smith-Bindman et al. (2025)

WHAT TO KNOW

• A new study by an international team of researchers found the radiation emitted by CT scans could be responsible for roughly 5% of all U.S. cancer diagnoses in a single year. The team’s analysis found nearly 103,000 cancers could have resulted from the 93 million CT scans performed in 2023, up to four times more than previous estimates.

WHY IT MATTERS

• Experts responding to the study say the results shouldn’t be interpreted as a warning against undergoing a CT scan since the findings were based on statistical modeling, not actual patient outcomes, and, in any case, the benefit of detecting or ruling out a serious illness still far outweighs the risk of harm. That said, the experts also believe it’s important to be aware the risk is higher than previously believed, particularly for young children.

CONNECT THE DOTS

• It’s long been known that CT scans, while indispensable, indeed carry a risk of cancer, as patients are exposed to ionizing radiation, which is a known carcinogen. Since 2007, the number of annual CT exams performed by doctors in the U.S. has increased by more than 30%, partly due to what the researchers describe as “low-value, potentially unnecessary imaging.”