Inclusion Criteria:

• Pathological evidence of GBM using WHO classification criteria
• > 18 years of age
• Received maximal debulking surgery and radiotherapy with Temozolomide
• Karnofsky scale ≥ 70
• Life expectancy at least 3 months
• Participants of childbearing age must use effective contraception
• All patients must sign written informed consent
• Treatment start date at least 4 weeks out from surgery
• Treatment start date at least 4 weeks out but not more than 7 weeks from last dose of adjuvant Temozolomide
• Treatment start date at least 4 weeks out from radiation therapy

Exclusion Criteria:

• Progressive disease (according to MacDonald Criteria)
• Actively participating in another clinical treatment trial
• Pregnant

• Significant co-morbidities at baseline which would prevent maintenance temozolomide treatment:

  1. Thrombocytopenia (platelet count < 100 x 103/μL)
  2. Neutropenia (absolute neutrophil count < 1.5 x 103/μL)
  3. CTC grade 4 non-hematological Toxicity (except for alopecia, nausea, vomiting)
  4. Significant liver function impairment - AST or ALT > 3 times the upper limit of normal
  5. Total bilirubin > upper limit of normal
  6. Significant renal impairment (serum creatinine > 1.7 mg/dL)
• Implanted pacemaker, defibrillator or deep brain stimulator, or documented clinically significant arrhythmias
• Infra-tentorial tumor
• Evidence of increased intracranial pressure (midline shift > 5mm, clinically significant papilledema, vomiting and nausea or reduced level of consciousness)
• History of hypersensitivity reaction to Temozolomide or a history of hypersensitivity to DTIC