Clinicians identify tactics that minimize risk of NSF

February 1, 2009 Diagnostic Imaging. Vol. 31 No. 2 Clinicians identify tactics that minimize risk of NSF New York City hospitals using standard doses of gadolinium-based contrast media avoid new cases By James Brice Studies examining the clinical histories of patients who developed nephrogenic systemic fibrosis after treatment at distinguished teaching hospitals in New York City and Vienna suggest that gadoliniumbased contrast dose and post-MRI hemodialysis are keys to controlling the rare but deadly skin disorder. NSF is possibly associated with gadolinium-based MRI agents administered to kidney disease patients. The first case was documented in early 1997. The International Center for Nephrogenic Fibrosing Dermopathy Research at Yale University had identified more than 300 confirmed cases as of January 2009. It is not clear if any new cases were reported last year, according to Dr. Emanuel Kanal, a professor of radiology at the University of Pittsburgh. Some medical device and pharmaceutical companies report that no new cases arose, he said in an interview, but NSF patients have said during online discussions that they are aware of new cases. Studies presented at the 2008 RSNA meeting shed light on how to avoid NSF, according to Dr. Martin Prince, a professor of radiology at Weill Medical College of Cornell University. “Though we don't fully understand NSF, we have learned enough to virtually eliminate it as a concern,” he said in an interview. Prince presented results at RSNA 2008 from case reviews involving 83,121 patients at Columbia Presbyterian Medical Center and Cornell New York Hospital from January 1997 to July 2007. Of 31 biopsy-confirmed NSF cases at the two hospitals, Prince identified 15 in which the patient received gadolinium contrast at one of the two facilities. On the basis of that evaluation, Prince found that a single dose of gadolinium-based contrast media is safe. No NSF cases were associated with 74,124 patients who received a single dose. For dialysis patients who have estimated glomerular filtration rates (eGFR) of less than 15 mL/min, no new cases appeared after the hospitals began administering 0.1 mmol/kg doses of gadolinium-based contrast when a contrast agent was recommended for MRI and same-day dialysis was performed on these patients. The study found that the NSF incidence rate dropped from 8.8% to 0.4% for patients with an eGFR of less than 15 mL/min when dialysis was performed within two days of contrast administration. High contrast dose was also a major contributor. Ten cases were associated with the administration of a single dose of at least 32 mmol/kg to 5119 patients at the two hospitals. Their incidence rate was 0.2%. No cases were reported for the 5725 patients who received a standard dose. In a separate study, researchers at the Medical University of Vienna Medical Center established a positive association between cumulative dose of gadolinium-based MR contrast media and NSF from a 10-year review of records for 552 patients with endstage renal disease. Dr. Gertraud Heinz-Peer and colleagues examined the prevalence of NSF among 195 dialysis patients exposed to gadolinium-based contrast in 325 MR procedures. Six patients (1.6%) developed NSF. Five cases followed gadoliniumenhanced MR. They developed symptoms an average of 5.4 months after their last gadolinium infusion. Diagnosis was confirmed with a deep skin biopsy or medical or histopathological records. Four of six patients were on hemodialysis. One patient showed NSF symptoms 18 months before CE-MRI. One patient died. The researchers established no correlation between NSF onset and patient age or gender; underlying kidney disease; type of therapy; serum phosphate, calcium, or iron concentrations; number of gadolinium contrast administrations; and mean residual renal clearance. Mean dose, however, was a factor. Patients who developed NSF were administered an average 63 mL of contrast compared with 30 mL for patients who did not develop the disease. Other significant cofactors were a history of thrombosis, recent surgery, and a combination of hemodialysis and peritoneal dialysis, Heinz- Peer said. Even with additional experience with NSF, Kanal argues that more information about the disease is needed before physicians can count on preventive strategies to eradicate it. In contrast to Prince's position, Kanal disputed that single dosing and hemodialysis guarantee patient protection. Numerous exceptions appear in the peer-reviewed literature showing that NSF can arise after a single dose or among patients who underwent dialysis within 24 hours of contrast administration, Kanal said. International consensus emphasizes avoiding the use of gadoliniumbased agents for kidney disease patients if contrast is not necessary and minimizing its use when it is required, Kanal said. In addition to partial dosing, dialysis patients should be dialyzed immediately following MRI. It is also commonly thought that patients with reduced kidney function who are administered macrocylic agents, such as ProHance, are less likely to develop NSF than patients who received linear gadolinium-based compounds, such as Omniscan or Magnevist, the two agents associated with most of the NSF cases. Overall, physician vigilance has proven to be the most powerful medicine preventing NSF, Kanal said. Though acute renal failure can still escape detection, radiologists are generally more aware about the presence of renal disease and more willing to either reduce dosages or perform noncontrast MRI for such patients, or to switch to an agent that appears to be less closely associated with NSF development. “I think that these factors have played crucial roles in the marked decrease in the incidence of this disease that we have seen to date,” he said.

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