NSF lawsuit discovery process may expose lax contrast documentation

A casual attitude toward keeping track of gadolinium-enhanced studies may come back to haunt radiology departments that have become involved in several federal lawsuits alleging a connection between cases of nephrogenic systemic fibrosis and gadolinium-based MR contrast agents.

In a 2007 study that examined allergic reactions to gadolinium-based agents in patients undergoing MR studies, Dr. Jonathan Dillman and colleagues noted a lack of record-keeping when it came to contrast administration.

The group from the Ann Arbor-based University of Michigan Health System found that when acute reactions occurred, the gadolinium-based contrast agent used for the MR study was not documented in 44% of the cases (AJR 2007;189:1533-1538).

Such habits may not sit well with Judge Dan A. Polster of the U.S. District Court, Northern District of Ohio, as he oversees the discovery process for numerous cases filed by NSF patients against the manufacturers of gadolinium-based MRI contrast. In February, a U.S. judicial panel on multidistrict litigation issued an order to centralize in Polster's court the discovery process in federal cases filed on behalf of patients with renal failure.

Accurate documentation is relevant in two key decisions thus far issued in the cases. Plaintiffs' demographics and health histories will be compiled through a plaintiff profile form and presented to defense counsel in a standardized format. And all healthcare providers, including the radiologists who conducted the MR studies, will be directed to provide information related to each MR procedure, such as the specific type of contrast agent used and its dosage.

NOT JUST 'GIVING GAD'

This may prove problematic if documentation is not readily available in patient records. Historically, gadolinium-based contrast agents have not always been handled like the regulated drugs that they are, said Dr. Emanuel Kanal, chair of the American College of Radiology's blue ribbon panel on MR safety. He emphasized that radiologists need to remember that they are working with prescription drugs.

"Gadolinium-based contrast agents are prescription drugs like any other drugs," Kanal said in an interview with Diagnostic Imaging. "Our almost universal 'radiology-speak' notwithstanding, we do not administer 'gadolinium' to patients. Gadolinium is an element, and a rather toxic one at that. We administer gadolinium-based MR contrast agents that are, and have always been, approved by the FDA as prescription drugs, which can only be prescribed by a physician who is duly licensed to practice in that particular (U.S.) state."

But gadolinium-based contrast agents have been lumped together and treated as a generic product, making documentation the exception rather than the rule.

"We often say, 'Give gad to this patient.' We've not giving 'gad.' We're giving a specific contrast agent. But we have until recently treated gadolinium-based contrast agents interchangeably. A contrast agent is a prescription drug, and we need to order it as we do any other prescription drug," said Kanal, who is also the director of Magnetic Resonance Services at the University of Pittsburgh Medical Center.

Kanal was the lead author on the 2007 ACR guidance document for safe MR practices. The guidelines state that written orders for gadolinium-enhanced MR studies in patients with renal insufficiency should come directly from a radiologist. At the very least, the order should specify patient name and brand of contrast agent, dose, route, and rate of administration, according to the guidelines.

Upcoming recommendations on managing gadolinium-based MR studies in patients with renal insufficiency will also address the issue of documentation, said Dr. Jeffrey Weinreb, chair of the ACR's commission on quality and safety.

In a 2008 essay in the Journal of the American College of Radiology, Weinreb detailed the procedures and policies that govern gadolinium-enhanced MR studies conducted at Yale-New Haven Hospital. At his institution, "the supervising radiologist has to write an explicit order for the intravenous contrast that states the amount of and the specific type of agent to be administered for a specific MRI examination," for patients at risk for NSF (2008;5:53-56).

Weinreb told Diagnostic Imaging that the MR staff at his institution accepted the new policy quite readily, partly because of the NSF threat.

"Good medical practice dictates that, if you give any drug to a patient, it needs to be documented," he said. "There really shouldn't be a discussion or debate about that."

ESTABLISHING CAUSATION

One goal of this product identification process will be to determine if a particular gadolinium-based product has a dominant association with these NSF cases, said attorney John Dalimonte of Karon & Dalimonte in Boston.

The court will review the latest technical and scientific information available on NSF with an eye toward clarifying a cause and effect link between gadolinium-based agents and NSF, he said.

"I think the judge is trying to streamline this to say, 'Let's cut through the causation issue first. If (NSF) is a signature disease like mesothelioma and asbestos exposure, we don't need to create all these issues relating to causation'," Dalimonte said. "Let's get all the parties on board and agree to (causation), and then we can focus on everything else."

Contrast agent manufacturers have steadfastly maintained that not all gadolinium products are created equal. In addition, recent research has proposed that other factors - kidney transplant, transmetallation - may also trigger NSF.

Studies present at the 2008 European Congress of Radiology in Vienna suggest that there is insufficient evidence to indict all gadolinium-based agents and there may not be a correlation between cumulative dose and the specific type of contrast agent used.

Papers presented in April at 2008 American Roentgen Ray Society meeting found that NSF is rare among patients with moderate renal insufficiency . Another study established a potential link between NSF and infection.

Additional discovery-related conferences are scheduled in Polster's court in May and June.