The Concerning New Research
A groundbreaking study published in JAMA Internal Medicine on April 14, 2025, has sent ripples through the medical community with its sobering projection: radiation from CT scans performed in just one year could potentially lead to over 100,000 future cancer diagnoses.
The research, led by Dr. Rebecca Smith-Bindman from the University of California San Francisco, analyzed data from approximately 93 million CT examinations performed on 62 million patients in 2023. Using sophisticated risk modeling, the team projected that these scans could result in approximately 103,000 future cancers over the lifetime of the exposed patients.
“If current practices persist, CT-associated cancer could eventually account for 5% of all new cancer diagnoses annually,” the study authors wrote, highlighting the potential magnitude of this public health concern.
This isn’t just a statistical abstraction. For many of us who have undergone CT scans or have loved ones who have, this research raises important questions about the balance between necessary medical care and potential long-term risks.
Understanding the Risk: Not All CT Scans Are Equal
The study found that while children face higher per-examination cancer risks, adults account for the majority (91%) of projected radiation-induced cancers due to higher CT utilization rates. The most common projected cancers include:
- Lung cancer (22,400 cases)
- Colon cancer (8,700 cases)
- Leukemia (7,900 cases)
- Bladder cancer (7,100 cases)
- Breast cancer in women (5,700 cases)
Abdominal and pelvic CT scans in adults were associated with the highest number of projected cancers (37%), followed by chest CT scans (21%).
It’s important to note that these are projections based on risk models, not observed cases. The American College of Radiology (ACR) has responded to the study, stating that “the theoretical radiation risk proposed by Smith-Bindman, et al, is consistent with prior statistical modeling studies that are not based on actual patient outcomes” and that “there are no published studies directly linking CT scans (even multiple CT scans) to cancer.”
The Life-Saving Benefits of CT Scans
While the potential risks are concerning, we must also acknowledge the tremendous benefits CT scans provide. Computed tomography ranks as one of the top five medical developments in the last 50 years, according to most medical surveys. The technology is so valuable that its inventors were awarded the 1979 Nobel Prize in Medicine.
CT scans allow doctors to see inside the body with remarkable clarity, helping them to:
- Diagnose conditions quickly and accurately
- Reduce the need for exploratory surgeries
- Guide treatment for trauma, cardiac disease, and stroke
- Improve cancer diagnosis and treatment
- Reduce hospital stays
- Place patients in appropriate care settings
In emergency situations, CT scans can be truly life
-saving. They allow doctors to quickly assess internal injuries that might not be visible externally. For instance, a patient with seemingly minor external injuries from a car accident might have internal bleeding that only a CT scan can detect in time for life-saving surgery.
Finding the Balance: When Are CT Scans Worth the Risk?
The key question for patients and healthcare providers is: When does the benefit of a CT scan outweigh the potential risk?
Dr. Cynthia McCollough, CT imaging expert and past president of the American Association of Physicists in Medicine, puts it in perspective: “Any risk from a CT scan of a sick patient is likely much less than the risk of the underlying disease.”
The American College of Radiology emphasizes that “Americans should not forgo necessary, life-saving medical imaging and continue to discuss the benefits and risks of these exams with their healthcare providers.”
Here are some important considerations:
-
Medical necessity: CT scans should only be performed when medically necessary and when the information they provide will impact treatment decisions.
-
Alternative imaging: Sometimes, other imaging methods like ultrasound or MRI, which don’t use ionizing radiation, can provide the needed information.
-
Risk vs. benefit: For patients with acute or potentially serious conditions, the immediate benefit of accurate diagnosis far outweighs the small long-term risk.
-
Age considerations: Children are more sensitive to radiation and have more years ahead for potential cancer development, so extra caution is warranted.
What’s Being Done to Reduce Risks?
The medical community has been working to address radiation concerns through several initiatives:
Image Gently and Image Wisely Campaigns
These campaigns, launched by alliances of medical professionals, aim to raise awareness about radiation protection. Their core principles include:
- Using the lowest possible radiation dose to achieve diagnostic-quality images
- Scanning only when necessary
- Scanning only the indicated area
- Using child-sized protocols for pediatric patients
Technological Improvements
Modern CT scanners include dose-reduction features that maintain image quality while lowering radiation exposure. Iterative reconstruction methods now allow for high-quality images with lower radiation doses.
Regulatory Oversight
The FDA and other agencies provide guidelines for CT use, though actual protocols are determined at the facility level. Organizations like the American College of Radiology have established “reference levels” for radiation doses for specific examinations.
What Can You Do as a Patient?
As patients, we aren’t powerless in this situation. Here are steps you can take to protect yourself and your loved ones:
-
Ask questions: Before undergoing a CT scan, ask your doctor:
- How will this exam improve my healthcare?
- Are there alternatives that don’t use radiation?
- Is this facility accredited by the American College of Radiology?
-
Keep records: Maintain a record of your imaging procedures, including dates and types of scans.
-
Seek accredited facilities: Choose imaging centers that are accredited, which ensures they meet quality and safety standards.
-
Avoid duplicate scans: If you’ve had a recent CT scan, make sure your new doctor has access to those images to avoid unnecessary repetition.
-
Consider second opinions: For non-emergency situations, consider getting a second opinion if you’re unsure about the necessity of a recommended CT scan.
A Personal Perspective
As someone who has benefited from CT technology, I understand the complex emotions this research might trigger. My own father’s life was saved when a CT scan detected internal bleeding after a seemingly minor fall. Without that scan, doctors wouldn’t have known surgery was needed.
Yet I also recognize the importance of being an informed patient. The goal isn’t to avoid all CT scans but to ensure they’re used appropriately and with the lowest possible radiation dose.
Moving Forward: Balancing Innovation and Safety
The medical community continues to work toward optimizing CT use—maintaining its life-saving benefits while minimizing potential risks. This includes:
- Developing better protocols for determining when CT scans are necessary
- Continuing to improve technology to reduce radiation doses
- Enhancing education for healthcare providers about radiation risks
- Implementing quality improvement programs to monitor and reduce radiation exposure
Informed Decisions Save Lives
The projection of 103,000 future cancers from a single year of CT scans is concerning, but it shouldn’t cause panic. Instead, it should prompt thoughtful conversations between patients and healthcare providers about when imaging is truly necessary.
CT scans remain an invaluable tool in modern medicine. Their ability to provide detailed images of internal structures has revolutionized diagnosis and treatment, saving countless lives. The key is ensuring they’re used judiciously and with appropriate safety measures.
As patients, we should be informed but not fearful. By understanding both the benefits and risks of CT scans, we can make better healthcare decisions for ourselves and our loved ones.
What has been your experience with CT scans? Have you discussed radiation risks with your doctor? Share your thoughts in the comments below.
