Fibrose systémique néphrogénique

[Non-iodinated contrast media nephrotoxicity]

The development of interventional radiology techniques regularly exposes patients to the potential renal toxocity of iodinated contrast media. Faced with this risk of nephrotoxicity, gadolinium-based contrast agents have long been considered as a safe alternative to iodinated contrast media, especially in sensitive or at risk patients. However, these gadolinium-based contrast agents are not devoid of nephrotoxicity and present another risk, a complication related to renal failure, the nephrogenic systemic fibrosis. European and US recommendations from health agencies have recently come closer, defining groups of patients at risk of nephrogenic systemic fibrosis according to their level of renal function and the type of gadolinium-based contrast agent used. What are the real renal risks for these products? How to evaluate the benefit-risk balance of the patient to choose a radiological examination in an informative, effective and safe way? This article focuses on the description of the risks of gadolinium-based contrast agents, reviews existing recommendations and best practices to guide the choice of clinicians.

Incidence of nephrogenic systemic fibrosis in patients undergoing dialysis after contrast-enhanced magnetic resonance imaging with gadolinium-based contrast agents: the Prospective Fibrose Nephrogénique Systémique study

BACKGROUND

Nephrogenic systemic fibrosis (NSF) has been related to the use of gadolinium-based contrast agents (GBCAs) in patients undergoing dialysis. The Prospective Fibrose Nephrogénique Systémique study, a French prospective study supported by the French drug regulatory agency (Agence Nationale de Sécurité du Médicament) and the French Societies of Nephrology, Dermatology, and Radiology, aimed at determining the incidence of NSF in patients undergoing long-term dialysis.

MATERIALS AND METHODS

Adult patients undergoing long-term dialysis receiving a magnetic resonance imaging (MRI) examination prescribed between January 15, 2009 and May 31, 2011, with or without GBCA were included. The methodology was based on a patient form intended to detect any dermatological event (DE) that may occur within 4 months after the examination. Further investigations were planned with their physicians if a DE was reported.

RESULTS

A total of 571 patients were included. A total of 50.3% received GBCA. Among them, 93.4% received a macrocyclic GBCA, usually gadoteric acid (88.9%). All in all, 22 patients (3.9%) reported a DE. Dermatological diagnoses did not reveal any evidence of NSF.

CONCLUSIONS

The incidence of NSF after a single dose of a macrocyclic GBCA is null in our sample of 268 patients undergoing dialysis (hemodialysis and peritoneal dialysis). This incidence is just lower than 0.5%. When contrast-enhanced MRI can be essential, or even decisive, to the diagnosis, these results are important and reassuring if physicians need to perform contrast-enhanced MRI in patients undergoing dialysis.

[Renal toxicity of contrast agents in oncologic patients]

Cancer patients frequently undergo imaging examinations to diagnosis but also to evaluate their responses to treatment. These patients are also at high risk of kidney impairment before considering the possible nephrotoxicity of their chemotherapy. In this context, it is overriding to know contrast agents induced risks and what are the good practices to avoid them. Renal function evaluation takes a major part in there. The X-ray radiology using iodinated contrast agent (ICA) exposes patients to acute renal failure. This induced nephropathy is prevented by adequate hydration prior to injection when the glomerular filtration rate (GFR) of the patient is less than 60 ml/min/1.73 m(2). For hardly nephrotoxic, gadolinium-based contrast agents (GBCA) injected in magnetic resonance imaging, were considered for a long as a safe alternative to ICA. Yet they may induce nephrogenic systemic fibrosis (NSF). The recommendations of European and U.S. drugs safety agencies have recently converged defining groups at risk of NSF based on the level of patients GFR and the type of GBCA used. How to assess the risk-benefit balance of the cancer patient for whom you should choose an informative, effective and safe imaging examination?