Daijiworld Media Network - San Francisco

San Francisco, Apr 15: Repeated exposure to unnecessary CT scans may be as harmful as alcohol consumption and obesity when it comes to cancer risk, warns a new study by researchers from the University of California-San Francisco (UCSF). The study reveals that radiation from CT scans could be responsible for up to 5 per cent of all cancers annually in the US.

Published in JAMA Internal Medicine, the study estimates that nearly 103,000 cancer cases in 2023 may be linked to the 93 million CT scans performed across the country. This is significantly higher than previous estimates—three to four times more, according to the researchers.

“CTs can save lives, but their potential harms are often overlooked,” said Rebecca Smith-Bindman, radiologist at UCSF and lead author of the study. “Our data suggests that CT scans are on par with alcohol use and excess body weight as risk factors for cancer.”

The study highlights that child, particularly infants under one year of age, face the highest cancer risk from CT scan radiation. Among children, the most common types of cancers linked to scans were thyroid, lung, and breast cancers. In adults, CT-related risks were highest for cancers of the lung, colon, bladder, and breast, as well as leukemia.

Adults remain the most frequent recipients of CT scans, with scan numbers increasing with age and peaking among those aged 60 to 69. However, children still accounted for 4.2 per cent of the scans reviewed in the study.

CT, or computed tomography, is widely regarded as a vital diagnostic tool in modern medicine, allowing clinicians to detect tumors and diagnose a variety of conditions. Yet it also exposes patients to ionising radiation a known carcinogen.

Smith-Bindman emphasised the importance of cautious and judicious use of CT technology. “Reducing the number of unnecessary scans and lowering the radiation dose per scan would save lives,” she said.

The study was based on an extensive review of 93 million exams from over 61.5 million patients across the United States. The authors call for stricter guidelines and increased awareness to prevent overuse of CT imaging, especially in vulnerable age groups.