Gadolinium-based contrast agents (GBCAs) in the macrocyclic category have proven safe enough in children to be considered the standard of care across pediatrics whenever contrast-enhanced MR imaging is indicated, according the authors of a European study published online June 21 in Radiology.

Led by Daniel Tibussek, MD, and Dirk Klee, MD, of the University of Düsseldorf in Germany, the researchers reviewed the cases of 24 brain-tumor patients between 5 and 18 years old who underwent serial GBCA-enhanced brain MRI exams from 2008 to 2015.

The GBCA patients had at least nine scans each, and the mean count across the cohort was 14.2 scans.

The team used a control group of brain-tumor patients, matched for age and sex, whose members had serial brain MRI without contrast.

The study’s key finding: As with the control group, the children who were imaged with the macrocyclic GBCAs gadoteridol and gadoterate meglumine showed no measurable effects to brain tissue—i.e., no increases in signal intensity—in any of five brain regions (dentate nucleus, pons, globus pallidus, substantia nigra and pulvinar thalami).

“Our results provide some evidence that brain gadolinium deposition does not occur to a measurable extent even after repeated administration” of these two commonly used macrocyclic GBCAs, the authors write in their discussion.

They list among their study’s limitations its small size and its reliance on children with brain tumors, which, along with treatment, must be considered possible confounders.

Until more definite data are available, “caution is still warranted,” they warn, “and the indications of GBCA administration in the pediatric population should always be carefully weighed.”

Previous studies have yielded similarly friendly findings with macrocyclic GBCAs, and, although the less-stable linear (“open chain”) agents have raised heightened concern, the FDA all but cleared both categories as safe in May.