Computed Tomography (CT) is a diagnostic imaging tool that continues to grow in medical usage throughout the United States, although it generates concerns about exposure to radiation. Research shows that CT scans increase the risk of cancer, particularly among children and adults. The amount of radiation exposure, along with its associated risks, depends on patient age and the scanned region, followed by selection of the technique and gender characteristics.
Researchers previously predicted that CT scans conducted in 2007 would result in 29,000 future cancer diagnoses. The current research update combines recent scan records with improved radiation dose estimation models, together with population-based information. This approach enhances cancer incidence assessment to detect at-risk groups while promoting safer medical imaging practices.
The consultants assessed cancer risks from CT imaging by analysing data from 140 U.S. medical centres participating in the UCSF International CT Dose Registry. The registry gathered comprehensive metadata about each scan, which included patient information, together with scan region data, machine parameters, and body size measurements. National survey information revealed CT utilization patterns, which allowed researchers to calculate expected patient numbers using longitudinal patient assessment data.
The research team categorized scans by clinical purpose and anatomical region. Monte Carlo simulation methods calculated radiation doses in 18 organs by utilizing hybrid computational phantoms. The RadRAT program calculated lifetime cancer risk projections by adjusting results for scan characteristics as well as patient age groups, including mortality numbers and latency periods in the analyses, and conducting sensitivity tests on the results.
The United States conducted 93 million CT scans throughout 2023, involving 61.5 million patients, while 3.1 million children participated in these exams, and 90 million adults received scans during this period. Patients received the highest number of scans between the ages of 60 and 69. The analysis of cancer risks relied on data from 84.2 million scans during a period when end-of-life imaging studies were eliminated. Radiation doses to different organs showed differences between male and female patients, and greater exposure existed among people under 18 years old. These scans are projected to cause 102,700 new cancer cases over patients’ lifetimes, with 93,000 for adults, while children face 9,700 cases.
Adults developed lung and colon cancers, with leukemia as the third most frequent diagnosis, while thyroid, lung, and breast cancers were the main cancers affecting children. Infants faced higher risks from each imaging examination, but adults accumulated more total risks because they underwent more scans throughout their lives.
The scans that save lives are considered risk-free, although they have the power to generate new cancer development. CT scan exposure poses significant health risks, comparable to those from alcohol use or obesity. The anticipated rise in the number of cancer cases is the result of a combination of factors, such as the incorporation of more detailed dosage mapping, increased CT scan frequencies, and additional multiphase scanning. Organ dosages are higher than in earlier calculation models, according to current methods that process 120,000 real patient images.
The ongoing demand for CT imaging underscores the need for healthcare professionals to ensure medical necessity, reduce the degree of radiation exposure, and evaluate the requirement for multi-phase tests. The appropriate execution of the guidelines is a critical measure in reducing the health risks associated with this imaging technique.
References: Smith-Bindman R, Chu PW, Azman Firdaus H, et al. Projected lifetime cancer risks from current computed tomography imaging. JAMA Intern Med. April 14, 2025. doi:10.1001/jamainternmed.2025.0505Â
