We are seeking to enroll up to 30 subjects with newly diagnosed or recurrent GBM who will undergo a clinical brain MRI examination with and without contrast prior to surgery. Participants will also have a blood draw pre-operatively to collect samples for cfDNA and ctDNA analysis. MRI imaging will include an injection of intravenous infusion of 5 mg/kg ferumoxytol in addition to routine pre and post-contrast sequences after gadolinium injection. Subsequently, three different sites in the enhancing component of the tumor of each participant will be selected for intraoperative sampling based on hypointense signal on multi-echo gradient-recalled echo sequence that reflect ferumoxytol-induced signal drop.

You may be eligible for this study if you meet the following criteria:

• Conditions: GBM,Glioblastoma,recurrent GBM
• Age: 18 years - 99 years
• Gender: All