The mass is enhancing both with gadoteridol and ferumoxytol

The mass is enhancing both with gadoteridol and ferumoxytol. cerebral blood volume (rCBV). All 26 lesions showed 24-hourT1-weighted ferumoxytol enhancement; 16 also hadT2-weighted hypointensities. In 6 patients, ferumoxytol-induced signal changes were noted in areas with no gadoteridol enhancement. Significantly greater (P< .0001) SI changes were seen with gadoteridol, and qualitative analyses (lesion border delineation, internal morphology, contrast enhancement) also showed significant preferences (P= .0121;P= .0015;P< .0001, respectively) for this agent. There was no significant difference in lesion enhancement volumes between contrast materials. The ferumoxytol-rCBV values were significantly higher (P= .0016) compared with the gadoteridol-rCBV values. In conclusion, ferumoxytol Aplaviroc provides important information about tumor biology that complements gadoteridol imaging. The rCBV measurements indicate areas of tumor undergoing rapid growth, whereas the 24-hour scans mark the presence of inflammatory cells. Both of these functions provide useful information about tumor response to treatment. We suggest that dynamic and anatomical imaging with ferumoxytol warrant further assessment in brain tumor therapy. Keywords:brain tumors, ferumoxytol, magnetic resonance imaging, ultrasmall superparamagnetic iron oxide nanoparticles The most commonly used gadolinium-based contrast agents (GBCAs) are low-molecular-weight extracellular substances with a short plasma half-life. GBCAs are relatively safe when administered in clinically recommended doses (0.10.3 mmol/kg). However, emerging evidence linking GBCAs to nephrogenic systemic fibrosis has changed medical practice patterns toward avoiding gadolinium-enhanced MRI in patients with glomerular filtration rates (GFR) < 30 mL/min/1.73m2.1 Ultrasmall superparamagnetic iron oxide nanoparticles (USPIOs), such as ferumoxytol (Feraheme, AMAG Pharmaceuticals Inc.), developed for iron-replacement therapy primarily in patients with kidney disease, are promising contrast materials for brain tumor MRI due to theirT1andT2relaxation timeshortening effects.2,3The semisynthetic carbohydrate-coated ferumoxytol, which has a hydrodynamic diameter of 30 nm, shows little uptake by circulating monocytes, resulting in a long blood half-life (14 hours).4Ferumoxytol can be safely given Aplaviroc as a short intravenous bolus for dynamic MRI where it serves as a true blood pool agent at early time points (minutes) and is useful for measurement of the relative cerebral blood volume (rCBV).5,6Over a period of hours, ferumoxytol undergoes uptake in reactive astrocytes and tissue macrophages.7Consequently, ferumoxytol has the potential for imaging of both tumor vasculature and inflammation in central nervous system (CNS) malignancies.7,8 A 1.02-g treatment course of ferumoxytol (2 510 mg) was used for iron-replacement therapy in a large number of patients without significant Aplaviroc adverse effects.9So far, the highest given dose of ferumoxytol as an MRI contrast agent was 4 mg/kg (280 mg for a 70-kg patient).3A total dose of 510 mg (the maximum FDA-approved dose) of ferumoxytol administered in this study has not been investigated for MR imaging SLIT1 before. This study aims to qualitatively and quantitatively compare gadoteridol (ProHance, Bracco Diagnostic Inc.) with high-dose ferumoxytol for contrast-enhanced and perfusion-weighted (PW) MRI in patients with intracranial tumors. == Subjects and Methods == == Study Population == Between March 2008 and February 2010, 36 patients with intracranial tumors were enrolled in this prospective study. Patients who were younger than 18 years; were pregnant or lactating; showed clinical symptoms and signs of herniation (e.g. acute pupillary enlargement, rapidly developing motor changes, rapidly decreasing level of consciousness) or hemodynamic instability; had contraindications to MRI procedures (e.g. pacemaker); or had known allergic or hypersensitivity reactions to parenteral iron, dextran, iron-dextran or iron-polysaccharide preparations; had known or suspected iron overload (e.g. hemochromatosis, history of multiple transfusions); or had hepatic insufficiency or liver cirrhosis were excluded. HIV-positive patients on combination antiretroviral therapy were also ineligible because of the potential for pharmacokinetic interactions with ferumoxytol. The study was sponsored by the National Institutes of Health and was approved by the Oregon Health and Science University Institutional Review Board (eIRB #1562). All participants provided written informed consent. == MRI Examination == All MRI scans were performed on a 3T whole-body MRI system (TIM Trio, Siemens) with a body radio frequency (RF) coil transmit and a 12-channel phased-array head RF receiver coil. Aplaviroc The imaging protocol consisted of 3 consecutive days. On the first day, localizer scout images, axialT1- andT2-weighted pre- and 18.5-minute (range, 1621 minutes) postcontrast images, and first-pass dynamic susceptibility-weighted contrast-enhanced (DSC) perfusion MRI were acquired using gadoteridol gadolinium (III) chelate. On the following day, the same MRI sequences were obtained with ferumoxytol. On the third day, at least 22 hours (mean, 24.3 hours; range, 2228 hours) after the USPIO agent administration, the anatomical images were repeated in identical spatial orientations to detect delayed ferumoxytol-induced signal changes. Subjects with renal insufficiency (GFR < 30 mL/min/1.73m2) underwent only a 2-day MRI with USPIO, without gadoteridol. Gadoteridol was injected at a dose of 0.1 mmol/kg of body weight. Ferumoxytol was given over 20 minutes in a constant volume of 17.