Gadolinium chelate administration is largely unnecessary for imaging pediatric tumors when performing MRI or combined PET/MR scans, according to a recent study published by the Journal of Nuclear Medicine.
Heike E. Daldrup-Link, MD, PhD, Stanford School of Medicine, and colleagues compared the accuracy of gadolinium chelate-enhanced and unenhanced MR images of 119 pediatric patients. They also compared the accuracy of gadolinium chelate-enhanced and unenhanced 18F-FDG PET/MR images for 36 pediatric patients.
Overall, the researchers found that gadolinium chelate administration made no significant difference in the diagnostic accuracy of MR or 18F-FDG PET/MR images of pediatric tumors.
“18F-FDG avidity and gadolinium chelate enhancement show a high degree of concordance in these tumors,” the authors wrote. “If gadolinium chelate enhancement of MR images does not provide additional information compared with 18F-FDG PET images, MR images for local staging can be streamlined and gadolinium chelates replaced by more specific MR contrast agents.”
There is one possible exception to this rule, however; the authors noted that gadolinium may still be beneficial when characterizing focal liver lesions.
“We therefore suggest that the administration of gadolinium chelates may be necessary only if equivocal liver lesions are identified on unenhanced sequences,” the authors wrote. “This could be especially useful in, for example, differentiation between focal nodular hyperplasia/adenomas and hepatoblastomas/metastases, which often requires a 2-step approach with a more specific contrast agent such as gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid. In such cases, obtaining unenhanced sequences might be advantageous by allowing the examiner to add more specific contrast agents in the same session.”
In recent years, numerous studies have produced evidence of gadolinium retention in the brains of MRI contrast patients, leading to an ongoing discussion about the risks of certain gadolinium-based contrast agents. Previous HealthImaging.com coverage of the topic can be found here, here, and here.