NASHVILLE—Gadolinium-based contrast agents (GBCAs) are necessary for the accurate initial diagnosis of patients experiencing a first clinical attack of symptoms consistent with multiple sclerosis (MS) and for following patients with highly active disease or sudden, unexpected declines, according to a guideline issued by the Consortium of MS Centers (CMSC).
GBCAs are optional, although helpful, in many other clinical scenarios, especially when noncontrast MRI can provide answers.
“The key is that there is an optional role for gadolinium,” said David Li, MD, Professor of Radiology and Associate Member in Neurology at the University of British Columbia in Vancouver, at the 2018 CMSC Annual Meeting.
David Li, MD
Although a GBCA is still “essential” for some clinical scenarios in clinically isolated syndrome and MS, standard, high-quality MRI without contrast can adequately identify the majority of new MS lesions over time, the new guideline suggests. If a neurologist needs to monitor ongoing, current activity in settings of acute change, then gadolinium is still necessary, said Dr. Li.
The guideline, which was described at the meeting, is an update of the CMSC’s 2015 document, which endorsed a more liberal use of GBCAs. This more conservative stance reflects new research on the agents and an update in 2017 from the FDA that required a class-wide warning about gadolinium retention.
The agency began investigating gadolinium in 2015. In May 2017, it issued a statement confirming that gadolinium accumulates in neural tissue and can be retained for an extended period. In reviewing the evidence, however, the FDA found no concerning safety signals. Despite the presumed lack of toxicity, the agency issued the warning and recommended limiting the contrast agents’ use. The CMSC’s new MRI protocol guideline reflects these regulatory actions.
“While there is no known CNS toxicity, these agents should be used judiciously, recognizing that gadolinium continues to play an invaluable role in specific circumstances related to the diagnosis and follow-up of individuals with MS,” the document noted.
“It remains indispensable in patients presenting with their first clinical attack, as [its] use allows for an earlier diagnosis by demonstrating lesion dissemination in time in addition to lesion dissemination in space, which are the hallmarks of the diagnosis of MS. Early diagnosis leads to early treatment, which may help in preventing disease progression and improve long-term prognosis,” said Dr. Li. He had no disclosures relevant to gadolinium.
—Michele G. Sullivan