Assessing Dynamic Magnetic Resonance (MR) Imaging in Patients With Recurrent High Grade Glioma Receiving Chemotherapy

The purpose of this study is to learn more about imaging changes induced by a new therapeutic agent, bevacizumab with the standard steroid, dexamethasone in patients with high grade glioma. Magnetic resonance imaging (MRI) will be used to evaluate the difference between the 2 treatments. The usual contrast agent (gadolinium) and an iron containing contrast agent called "ferumoxytol" may help us to evaluate the differences between bevacizumab and dexamethasone effects on imaging of a brain tumor called high grade glioma. For this purpose, after intravenous contrast agent injection, special MR scans (called: dynamic perfusion, blood-brain barrier (BBB) permeability measurement) will be performed to see the microvascular changes in the brain and tumor.

Adult patients (\>18 years old) with recurrent high grade glioma (confirmed by radiology and tissue sample), who have progressed on prior temozolomide + radiation therapy, will be recruited from the neurology, neurosurgery, or neuro-oncology clinics. Patients will be enrolled if they meet the study inclusion and exclusion criteria Patients will be scanned at four different time-points (4 MRI series) (1) before the beginning of the treatment (base line), (2) Three weeks after the first treatment, (3) Three weeks after the second treatment, and (4) at time of progression of the disease. Each MRI time-point will consist of a series of MRI's on three consecutive days. On the first day, gadolinium (0.1 mmol/kg) will be injected for the MRI scan. On the following day ferumoxytol (2 mg/kg) and on the third day, the MRI scan will be done without additional contrast agent, to see the delayed contrast enhancement of ferumoxytol. Subjects will be on treatment including a chemotherapeutic agent called carboplatin combined with either bevacizumab or dexamethasone; 6 patients will receive carboplatin-bevacizumab, followed by carboplatin-dexamethasone, another 6 patients will receive carboplatin- dexamethasone, followed by carboplatin-bevacizumab. After the 3rd time-point, all the patients will continue on carboplatin-bevacizumab treatment (which is currently not an FDA approved combination for brain tumors, however it is widely used throughout the country).There will be monthly clinical visits with clinical MRI until progression of the disease. There will be a follow up visit, 1 month after the last ferumoxytol injection.