A proactive response to gadolinium concerns

Responding to risks in healthcare is tricky business, and more often than not leads to lengthy and sometimes heated debate. See the conversation over breast cancer screening, as one prominent example, where some argue that the risks of false-positives and overdiagnosis are reason enough to urge a more conservative screening strategy.

This week’s top story, on the continuing developments in the study of gadolinium contrast retention, offers another such dilemma.

To recap: Several studies have been published in recent months indicating that some amount of gadolinium is retained in patients who underwent MRI with certain gadolinium-based contrast agents (GBCAs). Japanese researchers led by Tomonori Kanda, MD, PhD, of Hyogo Cancer Center, first showed a connection between abnormal T1 shortening in the brains of patients and repeated prior administration of some GBCAs in a study published last year. Researchers at the Mayo Clinic then found evidence of gadolinium deposits in postmortem brains of a small group of patients who had undergone four or more GBCA-enhanced MRIs.  A study from the University of Heidelberg Medical Center seemed to suggest that abnormal T1 shortening and related gadolinium retention was related to the specific class of GBCA, as patients in that study who had undergone scans exclusively using GBCAs with a linear molecular structure had increased MRI signal intensity and those imaged with macrocyclic GBCAs did not.

Given these provocative findings, the medical imaging community must take notice. This doesn’t mean hitting the panic button, but until we know the exact clinical impact of this GBCA retention, caution should be the order of the day. In an editorial published this week in Radiology, Emanuel Kanal, MD, director of magnetic resonance services and professor of radiology and neuroradiology at the University of Pittsburgh Medical Center; and Michael F. Tweedle, PhD, the Stefanie Spielman Professor of Cancer Imaging at The Ohio State University, make the case for a response that is urgent and proactive but also measured.

“Of all of the possible endings to this story, one of the worst would be for us to unnecessarily deprive our patients of crucial, even life-saving, medical data from GBCA-enhanced MR imaging,” wrote Kanal and Tweedle. “Another would be for us to ignore these new findings and continue prescribing them as we have until now, without change.”

They called for extra diligence in confirming that requested contrast-enhanced MRIs are indeed indicated, while considering the potential impact of “residual gadolinium in our decisions as to which agent to administer, how much to administer, and whether to administer it at all.” Kanal and Tweedle also acknowledged the need for further study to determine whether there are any significant toxic effects that come with residual gadolinium in the brains of patients. Kanal echoed these thoughts in an exclusive Q&A with Health Imaging.

These will be tough questions to study and answer, but a dedication to care requires they be confronted. The questions from the patients themselves will be much tougher.

-Evan Godt
Editor – Health Imaging