Growing reliance on CT scans worldwide is prompting modern questions about their long-term safety, according to recent data.
A French scientific journal, Science et Vie, reports that the discussion has shifted from the benefits of screening to concerns about radiation doses, the necessity of prescriptions, and safe usage limits.
Increasing Use and Concerning Numbers
In 2023, approximately 93 million CT scans were performed in the United States, involving more than 62 million people.
While this type of imaging has become routine and essential in medical practice, it utilizes ionizing X-rays that, over time, can increase the risk of cancer.
A recent study published in JAMA Internal Medicine, as reported by Vetera, warns that current levels of CT scans could potentially cause around 103,000 additional cancer cases over the lifetimes of those exposed.
If current practices continue, this figure represents roughly 5% of all new cancer cases annually.
For comparison, 5.4% of cancers are attributed to alcohol consumption and 7.6% to obesity, positioning CT scans as a potentially significant health risk factor in modern times.
Who is Most at Risk?
The risk isn’t evenly distributed. Children are more sensitive to ionizing radiation, particularly in their first year of life, and each scan carries a relatively higher risk compared to adults.
For adults, the risk is linked to the number of exposures; the more frequent the scans, the higher the cumulative probability of developing cancer. The areas most vulnerable are the abdomen, chest, and pelvis.
The study indicates that scans of the abdomen and pelvis alone may be responsible for over 37,000 cancer cases.
Potential Cancer Types
Certain cancers appear at higher rates following prolonged radiation exposure, including lung cancer, colon cancer, bladder cancer, thyroid cancer, and leukemia.
Among women, there’s an observed increase in breast and thyroid cancers, even with radiation doses similar to those received by men.
This disparity is attributed to biological factors and statistical models partially based on data from survivors of the atomic bombings of Hiroshima and Nagasaki.
Despite the limitations of these models, researchers affirm the robustness of the findings, as the study relied on data from more than 120,000 actual clinical scans, considering multiple factors such as age, gender, scanned area, and the number of imaging phases.
Medical Community Response
The medical community is approaching these findings with caution. The American College of Radiology, a leading reference organization in the United States, emphasizes that CT scanning has reduced mortality rates in hospitals, enables rapid and accurate diagnoses, avoids many unnecessary surgeries, and helps guide treatments more effectively.
The organization also notes that no study has definitively proven a direct link between a specific scan and a cancer case in a particular patient.
At the same time, the College stresses the importance of dose-reduction techniques, certification of imaging centers to ensure quality and safety, and a move toward safer medical imaging.
The solution isn’t to eliminate scans, but to rationalize their use. Initiatives like Choosing Wisely offer practical tools to facilitate doctors make informed decisions.
Patients can also ask key questions: Is the scan truly necessary? Are there radiation-free alternatives (such as MRI or ultrasound)? And does the center adhere to established standards? This information is crucial as medical imaging plays an increasingly important role in healthcare, and understanding the associated risks is vital for both patients and providers.
