Rethinking CT Scan Utilization: Balancing Diagnostic Power with Long-Term Risk
A sobering projection on CT scan–related cancer risk urges surgical and medical communities to weigh imaging benefits with caution
In modern medical practice, computed tomography (CT) scans are indispensable tools—used to evaluate acute abdominal pain, identify surgical complications, or guide trauma triage with speed and precision. Yet the same diagnostic powerhouse that enables lifesaving interventions may also carry risks we are only beginning to quantify.
A landmark study published in JAMA Internal Medicine (Smith-Bindman et al., 2025)1 has brought renewed urgency to the question of how frequently, and in what contexts, CT imaging should be deployed. Drawing on data from 93 million scans performed on 62 million Americans in 2023, researchers estimate that this volume of CT use could result in approximately 103,000 future cancers—nearly 5% of all newly diagnosed cancers in the United States annually.
"CT is frequently lifesaving, yet its potential harms are often overlooked," the authors wrote. "Even very small cancer risks will lead to a significant number of future cancers given the tremendous volume of CT use in the United States."
The Data Behind the Concern
The research team, led by epidemiologists at the University of California, San Francisco, modeled radiation exposure across a wide range of scan types, factoring in organ-specific radiation doses and corresponding cancer risks. Abdomen and pelvis scans—common in emergency and surgical settings—emerged as the largest contributors to projected cancers. Lung and colorectal cancers, already rising among younger populations, were among the most commonly linked malignancies.
The volume of CT usage in the U.S. has grown by 35% since 2007, outpacing population growth. This expansion has been driven by diagnostic expediency, broader access, and increasingly complex patient presentations. However, the unintended consequences are significant. The projected increase in lifetime cancer risk for an individual patient is relatively small—about 0.1% per CT exam—but at a population level, the numbers accumulate rapidly.
Acknowledging the Uncertainty
External experts emphasize that while the modeling is based on best-available data, there is inherent uncertainty. Much of the evidence linking ionizing radiation to cancer risk comes from large observational studies of atomic bomb survivors and occupational exposure cohorts—populations very different from the average surgical or emergency department patient.
"The estimates, while based on the best models available, are indirect, so there is considerable uncertainty about the estimates," said Stephen Duffy, emeritus professor of cancer screening at Queen Mary University of London. "I would say to patients that if you are recommended to have a CT scan, it would be wise to do so."
Importantly, the study does not argue against the use of CT imaging when clinically indicated. Rather, it encourages reflection on when and how CTs are used—especially in cases where diagnostic algorithms or alternative imaging modalities like MRI or ultrasound might suffice.
"The benefit of detecting or ruling out serious illness far outweighs the very small risk of harm," said Doreen Lau, a cancer biology researcher at Brunel University of London.
A Call to Reassess Clinical Practice
In an accompanying editorial, Ilana Richman, MD, and Mitchell Katz, MD, emphasized the need for cultural and systemic shifts in imaging behavior. They urged clinicians to avoid low-value testing, involve patients in shared decision-making, and use alternative modalities when feasible.
"As with all complex problems, there will be no simple solution," they wrote. "Educating clinicians about avoiding low-value testing and, in circumstances where alternatives are readily available, involving patients in the decision to do a CT scan may help shift culture and practice."
For acute care surgeons, this growing body of evidence provides an opportunity to re-evaluate institutional imaging protocols and reinforce decision-making grounded in benefit-risk analysis. CT will remain central to surgical evaluation, but its power must be matched with restraint.
Related Research
Berrington de González, A., Mahesh, M., Kim, K. P., et al. (2009). Projected cancer risks from computed tomographic scans performed in the United States in 2007. Arch Intern Med, 169(22), 2071–2077. https://doi.org/10.1001/archinternmed.2009.440
– One of the earliest and most influential modeling studies estimating CT-related cancer burden.Mathews, J. D., Forsythe, A. V., Brady, Z., et al. (2013). Cancer risk in 680,000 people exposed to computed tomography scans in childhood or adolescence: data linkage study of 11 million Australians. BMJ, 346, f2360. https://doi.org/10.1136/bmj.f2360
– Demonstrates increased cancer incidence in children and adolescents exposed to CT scans.Sodickson, A., Baeyens, P. F., Andriole, K. P., et al. (2009). Recurrent CT, cumulative radiation exposure, and associated radiation-induced cancer risks from CT of adults. Radiology, 251(1), 175–184. https://doi.org/10.1148/radiol.2511081296
– Evaluates cancer risks in adult populations from repeat CT imaging.Kanal, K. M., Butler, P. F., Sengupta, D., et al. (2017). U.S. diagnostic reference levels and achievable doses for 10 adult CT examinations. Radiology, 284(1), 120–133. https://doi.org/10.1148/radiol.2017161099
– Useful for benchmarking radiation dose levels in CT practice across U.S. institutions.
Smith-Bindman R, Chu PW, Azman Firdaus H, et al. Projected Lifetime Cancer Risks From Current Computed Tomography Imaging. JAMA Intern Med. Published online April 14, 2025. doi:10.1001/jamainternmed.2025.0505