Amid a growing body of research that shows deposits of gadolinium-based contrast agents (GBCAs) remain in the brain after repeat MRI procedures, the FDA is investigating the products' safety and risks.
The agency will work with its National Center for Toxicological Research (NCTR), the research community and industry to find out why gadolinium deposits build up in the brain and to see whether it negatively affects patients' health. Recent medical literature has found that deposits of GBCAs stay in patients' brains after they undergo four or more contrast MRI scans, but it's unclear whether the deposits are harmful, the FDA said in a statement.
Until more is known about the issue, regulators are urging healthcare professionals to limit their use of GBCA products "to clinical circumstances in which the additional information provided by the contrast is necessary" and "reassess the necessity of repetitive GBCA MRIs in established treatment protocols," the FDA said in a statement.
|Courtesy of Mayo Clinic|
The FDA probe comes a few months after the Mayo Clinic discovered that GBCAs used in MRI exams leave deposit in the brains. Researchers looked at 13 cadavers that had undergone at least four MRI exams with GBCA agents, and compared the bodies with another 10 that never had the procedure. Scientists found that the former group had "measurable quantities" of gadolinium in their brain tissue, while the latter had none.
But there aren't any data suggesting that the deposits are harmful for patients, study author and Mayo Clinic radiologist Dr. Laurence Eckel said at the time. The Mayo Clinic team's findings "challenge our understanding" of how the agents move through the body after they're administered, but have already been used safely for a number of years, he added. And the Mayo Clinic Department of Radiology still recommends using GBCAs in MRI procedures.
"We now simply have a few more questions that the medical and scientific communities will seek to answer. Efforts are underway to do just that," Eckel said.
Meanwhile, the FDA continues to refine its position on GBCAs. In 2010, the agency slapped gadolinium-based imaging drugs from Bayer, GE Healthcare ($GE) and Covidien with warnings, requiring the companies to change their product labels to reflect the risk of a potentially fatal skin condition when taken by kidney disease patients. As of now, the FDA is not requiring GBCA manufacturers to change labels for the products, it said in a statement.
- read the FDA announcement