Recent research published in JAMA Internal Medicine has raised concerns about the potential cancer risk associated with computed tomography (CT) scans. The study, which analyzed data from the University of California, San Francisco International CT Dose Registry, estimated that the 93 million CT scans performed in the U.S. in 2023 could lead to approximately 103,000 new cancer diagnoses, representing about 5% of all new cancer cases. The study highlights that CT scans use ionizing radiation, a known risk factor for various cancers.
However, the findings are based on statistical models rather than direct clinical outcomes. Currently, there are no peer-reviewed studies that establish a direct causal relationship between CT scans and cancer development. The theoretical risk exists due to the potential for radiation-induced DNA damage, but the radiation dose from a single CT scan is relatively low. For instance, a standard abdominal and pelvic CT scan delivers a dose of about 10 mSv, equivalent to the environmental radiation exposure over three years. Low-dose techniques, particularly for lung cancer screening, can further reduce this exposure to around 1.5 mSv, comparable to six months of natural background radiation.
CT scans play a vital role in medical diagnostics, offering significant benefits such as early cancer detection, reduced need for invasive procedures, and shorter hospital stays. Despite the risks associated with ionizing radiation, modern CT technology has improved to minimize exposure. As a result, it is essential for patients and healthcare providers to engage in informed discussions about the necessity and risks of imaging studies, balancing the potential benefits against the concerns related to radiation exposure. The American College of Radiology emphasizes the importance of not avoiding necessary medical imaging while continuing to evaluate the risks and benefits with healthcare providers.