1. Have the appearance of high-grade glioma on magnetic resonance (MR) imaging if allowed to consent and will undergo the procedure if the frozen is consistent with glioblastoma or gliosarcoma OR Patients with a history of histologically confirmed diagnosis of World Health Organization Grade glioblastoma or gliosarcoma that are undergoing repeat resection of a recurrent tumor as identified on preoperative MR imaging
2. Aged ≥ 18 years old
3. Contrast-enhancing tumor volume of at least 10 cc on the preoperative, volumetric MRI within 1 month prior to surgery
4. Provision of signed and dated informed consent form by participant or legally authorized representative (LAR), if applicable
You may not be if
1\. Has a history or current evidence of any medical condition, therapy, or laboratory abnormality that might confound the results of the study or is not in the best interest of the participant, in the opinion of the treating investigator.
