Maintaining that the evidence is “weak,” on June 7 the American College of Radiology refuted a recent FDA recommendation that children have their thyroid function monitored after exposure to intravenous iodinated contrast.
The ACR statement comes on the heels of a safety communication from the U.S. Food and Drug Administration that was released in March 2022. In that communication, the FDA recommended that providers monitor the thyroid function of children aged three years and younger after the administration of intravenous iodinated contrast media (ICM). The statement indicated that certain children—newborns, those with low birth weight or those with cardiac conditions—are at an increased risk of a temporary decrease in thyroid hormone levels.
To back this warning, the FDA cited 11 research studies that had been published from 1987 to 2020. After a deep dive into the details of these studies, the ACR published a statement suggesting that the FDA’s guidance on thyroid monitoring in this population of patients may be well-intentioned, but it lacks convincing supportive evidence.
“At this time, the evidence is weak to support thyroid function monitoring in very low birth weight preterm infants, neonates, and infants with congenital heart disease," corresponding author of the statement Jonathan R. Dillman, MD, MSc, of the Cincinnati College of Medicine and Department of Radiology at Cincinnati Children’s Hospital Medical Center, and co-authors wrote. "The majority of existing studies suggest that any depression in thyroid function is usually transient and of uncertain clinical significance."
The statement also brought to light some of the unintended consequences of the FDA’s safety warning—increased parental anxiety, increased use of gadolinium-based contrast for MRI procedures that could require pediatric sedation, and delayed diagnosis for patients who undergo unenhanced CT due to the perceived risk of iodinated contrast use.
As of now, the ACR believes the risk of thyroid dysfunction after ICM to be low in the pediatric population. However, the college indicates support for further research—including research conducted by ICM manufacturers themselves—to continue to evaluate ICM in a “rigorous, scientifically sound manner in order to ensure the safe use of these agents in young children.”
Read the full statement in the Journal of the American College of Radiology.
Carolyn L. Wang, Daniella Asch, Joseph Cavallo, Jonathan R. Dillman, James H. Ellis, Monica M. Forbes-Amrhein, Leah A. Gilligan, Pranay Krishnan, Robert J. McDonald, Jennifer S. McDonald, Brian L. Murphy, Benjamin M. Mervak, Jeffrey Newhouse, Jay K. Pahade, Alisa Sumkin, Jeffrey C. Weinreb, Stefanie Weinstein, Matthew S. Davenport. "ACR Statement on Use of Iodinated Contrast Material for Medical Imaging in Young Children and Need for Thyroid Monitoring." Journal of the American College of Radiology, June 7, 2022.