Some CT Scans May Have Too Much Radiation, Researchers Say
Uncertainty Surrounds CT Scan Safety
Rebecca Smith-Bindman, a professor at the University of California-San Francisco medical school, has spent well over a decade researching the disquieting risk that one of modern medicine’s most valuable tools, computerized tomography scans, can sometimes cause cancer.
High Doses of Radiation
About 93 million CT scans are performed every year in the United States, according to IMV, a medical market research company that tracks imaging. More than half of those scans are for people 60 and older. Yet, there is scant regulation of radiation levels as the machines scan organs and structures inside bodies. Dosages are erratic, varying widely from one clinic to another, and are too often unnecessarily high, Smith-Bindman and other critics say.
Large Variation in Doses
“It’s unfathomable,” Smith-Bindman said. “We keep doing more and more CTs, and the doses keep going up.”
One CT scan can expose a patient to 10 or 15 times as much radiation as another, Smith-Bindman said. “There is very large variation,” she said, “and the doses vary by an order of magnitude — tenfold, not 10% different — for patients seen for the same clinical problem.” In outlier institutions, the variation is even higher, according to research she and a team of international collaborators have published.
Estimated Cancer Risk
She and other researchers estimated in 2009 that high doses could be responsible for 2% of cancers. Ongoing research shows it’s probably higher, since far more scans are performed today.
New Regulations Aim to Improve Safety
The cancer risk from CT scans for any individual patient is very low, although it rises for patients who have numerous scans throughout their lives. Radiologists don’t want to scare off patients who can benefit from imaging, which plays a crucial role in identifying life-threatening conditions like cancers and aneurysms and guides doctors through complicated procedures.
But the new data collection rules from the Centers for Medicare & Medicaid Services issued in the closing months of the Biden administration are aimed at making imaging safer. They also require a more careful assessment of the dosing, quality, and necessity of CT scans.
New Rules for Hospitals and Providers
The requirements, rolled out in January, are being phased in over about three years for hospitals, outpatient settings, and physicians. Under the complicated reporting system, not every radiologist or health care setting is required to comply immediately. Providers could face financial penalties under Medicare if they don’t comply, though those will be phased in, too, starting in 2027.
Industry Reaction
The Leapfrog Group, an organization that tracks hospital safety, welcomed the new rules. “Radiation exposure is a very serious patient safety issue, so we commend CMS for focusing on CT scans,” said Leah Binder, the group’s president and CEO. Leapfrog has set standards for pediatric exposure to imaging radiation, “and we find significant variation among hospitals,” Binder added.
Concerns from Industry
The American College of Radiology and three other associations involved in medical imaging, however, objected to the draft CMS rules when they were under review, arguing in written comments in 2023 that they were excessively cumbersome, would burden providers, and could add to the cost of scans. The group was also concerned, at that time, that health providers would have to use a single, proprietary tech tool for gathering the dosing and any related scan data.
Private Company Involvement
The single company in question, Alara Imaging, supplies free software that radiologists and radiology programs need to comply with the new regulations. The promise to keep it free is included in the company’s copyright. Smith-Bindman is a co-founder of Alara Imaging, and UCSF also has a stake in the company, which is developing other health tech products unrelated to the CMS imaging rule that it does plan to commercialize.
New Developments
But the landscape has recently changed. ACR said in a statement from Judy Burleson, ACR vice president for quality management programs, that CMS is allowing in other vendors — and that ACR itself is “in discussion with Alara” on the data collection and submission. In addition, a company called Medisolv, which works on health care quality, said at least one client is working with another vendor, Imalogix, on the CT dose data.
Conclusion
The new data collection rules aim to make imaging safer by requiring a more careful assessment of the dosing, quality, and necessity of CT scans. While some in the industry have expressed concerns about the regulations, many experts agree that the measures will help accelerate the transition towards always lower and lower doses. The debate highlights the importance of balancing the benefits of medical imaging with the risks of radiation exposure.
FAQs
- How many CT scans are performed every year in the United States?
- What is the estimated cancer risk from CT scans?
- What are the new data collection rules for hospitals and providers?
- How do industry associations react to the new rules?
About 93 million CT scans are performed every year in the United States.
The estimated cancer risk from CT scans is 2% of all cases diagnosed annually, although ongoing research suggests it may be higher.
The new rules require a more careful assessment of the dosing, quality, and necessity of CT scans and will be phased in over about three years.
The Leapfrog Group welcomed the new rules, while the American College of Radiology and other associations expressed concerns about the regulations’ potential impact on providers and costs.
