Radiation from CT scans could lead to thousands of future cancer diagnoses, study finds
Approximately 93 million computed tomography examinations, or CT scans, are performed on 62 million patients annually in the United States — but the radiation from that process can raise the risk of future cancers. Now a new study is projecting just how many cases of cancer could be linked to CT scans.
In the study, published in JAMA Internal Medicine on Monday, researchers estimate that over the lifetime of those millions of patients, about 103,000 radiation-induced cancers are projected to result from CT exams done in 2023.
"If current practices persist, CT-associated cancer could eventually account for 5% of all new cancer diagnoses annually," the authors wrote.
The risk is estimated to be higher for children or adolescents, although adults are more likely to get CT scans and account for a higher number of projected cancer cases in the study, the researchers said.
The largest number of cancers was projected to result from abdomen and pelvis CT in adults, followed by chest CT scans. The most common cancers overall were lung cancer, colon cancer, leukemia and bladder cancer. In female patients specifically, breast cancer was the second most common.
The use of CT is "inextricably woven into the fabric of modern medicine," according to an accompanying editor's note, which highlighted the need to balance the the benefits and risks of the widely used imaging tool.
"CT scanning is accurate, quick, well-tolerated, and relatively inexpensive. Its success as an imaging modality is also what makes it so challenging to constrain. CT has become essential to the diagnostic process for many serious conditions, from trauma to cancer," the editors wrote.
But they say the estimates found in the study should serve as a wake-up call — putting CT scanning on par with other well-known risk factors for cancer, including alcohol and obesity.
The editor's note also offers potential guidance, including the use of alternative, radiation-free imaging options; reducing radiation dose for CT scans; and educating clinicians about avoiding low-value testing.
This isn't the first time the issue of CT scans and cancer has been raised.
A 2015 investigation from Consumer Reports found up to one-third of CT scans performed could be unnecessary, exposing patients to unneeded radiation.
