• Age ≥ 18 years.

• Patients with a histologically confirmed or suspected high-grade glioma (HGG) by MRI.

• a. For cases with suspected HGG, intraoperative frozen section diagnoses of HGG must be made by pathologists (Section 4.4.1).

• Uni-focal or butterfly gliomas that can receive ≥70% of lesion volume ablated as determined by the treating surgeon.

• Gliomas must be located or positioned where surgical resection is either not feasible or high-risk as deemed by a group of surgical neuro-oncologists.

• Preoperative Karnofsky score ≥ 70 (APPENDIX A).

• Patients must have demonstrable normal organ function as defined below within 14 days of surgery.

‣ Absolute neutrophil count (ANC) ≥ 1500 cells/mm3

⁃ Platelets ≥ 100,000 cells/mm3

⁃ Hemoglobin ≥ 9.0 g/dL. Use of transfusion or other intervention to achieve this hemoglobin level is acceptable.

⁃ Blood urea nitrogen (BUN) ≤ 35 mg/dL and creatinine ≤ 1.9 mg/dL and estimated glomerular filtration rate (eGFR) or creatinine clearance rate \> 50 mL per minute.

⁃ Electrocardiogram (ECG) without evidence of acute cardiac ischemia.

⁃ Prothrombin time (PT)/International Normalized Ratio (INR) \<1.4

⁃ Liver function tests: Aspartate aminotransferase (AST) and alanine transaminase (ALT) at or below 2.5 times the upper limit of normal (ULN).

⁃ Sodium level \> 130 mg/L. Use of salt resection or hypertonic saline to achieve this sodium level is acceptable.

• Patients must be able to understand and sign informed consent.