A new study published in JAMA Internal Medicine reveals that computed tomography (CT) scans performed in the United States may lead to approximately 103,000 future cancer cases over the lifetimes of patients exposed in 2023 alone.
Researchers led by Dr. Rebecca Smith-Bindman from the University of California San Francisco analyzed data from about 93 million CT scans performed on 62 million patients nationwide in 2023. Using radiation risk models and detailed patient data, they projected the long-term cancer risks associated with CT radiation exposure.
While CT scans are vital diagnostic tools that often improve patient outcomes, they expose patients to radiation at levels that can increase cancer risk. The study found that most of these projected cancers (91%) would occur in adults, but children and adolescents had higher risks per examination.
The most commonly projected future cancers included lung cancer (22,400 cases), colon cancer (8,700 cases), leukemia (7,900 cases), and bladder cancer (7,100 cases). In women, breast cancer was the second most common radiation-induced cancer. Abdominal and pelvic CT scans were responsible for the largest proportion of projected cancers (37%), followed by chest CT scans (21%).
“If current practices persist, CT-associated cancer could eventually account for 5% of all new cancer diagnoses annually,” the researchers noted.
The authors emphasize that their findings underscore the importance of justifying each CT scan and optimizing radiation doses. They suggest that single-phase scanning could be used more often to lower doses without compromising diagnostic accuracy.
This study updates a 2009 analysis that estimated 29,000 future cancers from CT scans performed in 2007. The higher projection reflects increased CT usage, more detailed data on examination types, and improved methods for estimating radiation doses.
Sign up for the Jersey Senior Weekly Email delivered every Monday to your inbox for free!