to the editor: We found the article on brain tumors in adults to be informative and comprehensive. The authors stated that gadolinium-enhanced magnetic resonance imaging (MRI) is the preferred method for evaluating brain tumors. They provide several reasons why MRI is superior to computed tomography (CT) for this evaluation, including the negligible risk of allergic reaction to gadolinium. We agree that MRI is preferred to CT in this situation, but would like to point out that MRI with gadolinium does have some risks, specifically the risk of nephrogenic systemic fibrosis (NSF).

The diagnosis of NSF is relatively new, with the first cases being reported in 1997.¹ NSF is a fibrosing disorder in patients with chronic kidney disease that has been linked to the use of gadolinium for enhanced MRI. More than 95 percent of the cases reported to the International NSF Registry involved patients who had been exposed to gadolinium within two to three months of disease onset.² Manifestations of NSF are thickening of the skin, and fibrosis of the dermis and deeper structures including the muscle, fascia, lungs, and heart.³ NSF is a rare diagnosis with only 200 reported cases as of January 2008.² The exact pathogenesis is not completely understood, but it is related to fibrocyte overproduction of collagen in response to gadolinium deposition in tissues.

The U.S. Food and Drug Administration recommends using gadolinium only when clearly necessary in patients with stage 4 and 5 renal disease, which it defines as a glomerular filtration rate lower than 30 mL per minute per 1.73 m². If patients with renal insufficiency receive gadolinium, then hemodialysis should be promptly started after the imaging study is completed.⁴ Treatments for NSF are limited but include renal transplantation, extracorporeal photopheresis, ultraviolet A phototherapy, and plasmapheresis.