Utility of iron oxide nanoparticles in the radiographic diagnosis of CNS lymphoma and inflammatory diseases.

2077 Background: Ferumoxytol, an ultrasmall superparamagnetic iron oxide nanoparticle (USPIO), is approved for intravenous treatment of iron deficiency in chronic renal failure. The package insert warns of potential alterations of magnetic resonance imaging (MRI). Our initial animal studies provided evidence of USPIO uptake by macrophages and lymphoreticular cells suggesting its potential in CNS lymphoma (CNSL), post transplant lymphoproliferative disease, or CNS inflammation (i.e. multiple sclerosis). The mechanism of USPIO enhancement differs from gadolinium-based contrast agents (GBCA), which optimally image areas of increased vascular permeability. Methods: USPIO was administered as an MRI contrast agent to 20 patients with presumptive or de facto diagnosis of CNSL or CNS inflammation. Seventeen of 20 patients underwent both USPIO- and gadolinium-based MRI. Three patients received only USPIO due to risk of nephrogenic systemic fibrosis (NSF) with GBCA exposure. In the pilot phase of the study, patient...