• Histopathologically proven diagnosis of glioblastoma or gliosarcoma prior to registration by pathology report;

• The tumor must be confined to the supratentorial compartment

• The Formaldehyde Fixed-Paraffin Embedded tumor tissue block must be available to be sent for retrospective central pathology review after registration).

• History/physical examination within 7 days prior to registration

• Karnofsky performance status ≥ 60 within 7 days prior to registration

• Adequate Organ Function Laboratory Values

‣ Absolute neutrophil count (ANC) ≥1,500/mcL

⁃ Platelets ≥100,000/mcL

⁃ Hemoglobin ≥9.0 g/gL or ≥5.6 mmol/L, without recent transfusion

⁃ Creatine ≤1.7 x upper limit of normal (ULN) or Measure or Calculated creatinine clearance ≥ 60.0mL/min for subject with creatinine levels \> 1.5 X institutional ULN (GFR can also be used in place of creatinine or CrCl)

⁃ Total bilirubin ≤ 1.5 x ULN or Direct bilirubin ≤ ULN for subjects with total bilirubin levels \> 1.5 x ULN

⁃ AST (SGOT) and ALT (SGPT) ≤ 2.5 x ULN or ≤ 5 x ULN for subjects with liver metastases

⁃ International Normalized Ratio (INR) or Prothrombin Time (PT) ≤ 1.5 x ULN unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants

⁃ Activated Partial Thromboplastin Time (aPTT) ≤ 1.5 x ULN unless subject is receiving anticoagulant therapy as long as PT or PTT is within therapeutic range of intended use of anticoagulants

• Adequate hematologic function based on complete blood count (CBC)/differential within 7 days prior to registration defined as follows:

‣ Absolute neutrophil count ≥ 1,500 cells/mm3;

⁃ Platelet count ≥ 100,000 cells/mm3

⁃ Hgb \> 9 g/dL (can be achieved with transfusion)

• Adequate renal function within 7 days prior to registration defined as follows:

‣ Blood Urea Nitrogen (BUN) ≤ 30 mg/dl and

⁃ Serum creatinine ≤ 1.7 mg/dl

• Adequate hepatic function within 7 days prior to registration defined as follows:

‣ Total bilirubin (except patients with Gilbert's Syndrome, who are eligible for the study but exempt from the total bilirubin eligibility criterion) ≤ 2.0 mg/dl and

⁃ Alanine Aminotransferase (ALT) and Aspartate Amino Transferase (AST) ≤ 2.5 x ULN

• The patient must have completed chemoradiation with Radiotherapy and Temozolomide of the primary tumor according to standards of care

• The treating physician expects that the patient will not require more than physiologic replacement dose of steroids defined as 4 mg of dexamethasone per day or its equivalent.

• Patients must have received no more than 3 prior therapies for Recurrent High Grade Glioma

• Subjects must have the ability to understand and the willingness to sign a written informed consent document.

• Female subject of childbearing potential should have a negative urine or serum pregnancy test within 72 hours prior to receiving the first dose of study medication. If the urine test is positive or cannot be confirmed as negative, a serum pregnancy test will be required.

• Female subjects of childbearing potential should be willing to use 2 methods of birth control or be surgically sterile, or abstain from heterosexual activity for the course of the study through 120 days after the last dose of study medication. Subjects of childbearing potential are those who have not been surgically sterilized or have not been free from menses for \> 1 year.

• Male subjects should agree to use an adequate method of contraception starting with the first dose of study therapy through 120 days after the last dose of study therapy.

• Tumor diameter in the plane perpendicular to LITT trajectory must be ≤ 6.0 cm in diameter

• It must be the surgeon's expectation that ≥ 90 of the tumor can be treated with LITT to the yellow thermal damage threshold (TdT) line (ie, 43 degrees for 2 min)

• Tumor must be Unifocal \& Unilateral-Two enhancing nodules within the same FLAIR hyperintense region are still eligible; 1-2 secondary enhancing or non-enhancing lesions may be present as long as they have been radiologically stable for greater than or equal to 3 months.