Dietary Methionine Restriction Plus Temozolomide for Recurrent GBM

Objectives: 1. To determine the safety, tolerability and efficacy of dietary methionine restriction for 7 days alternating with Temodar® (Temozolomide) given once a day for seven days and this repeated for up to one year in the treatment of patients with recurrent and/or progressive glioblastoma. 2. To determine the short- and long-term toxicity of dietary methionine restriction combined with Temodar® in glioblastoma patients. 3. To measure and correlate patients' tumor responses and progression-free survival with: serum methionine and peripheral blood lymphocyte methylation levels. In any patient undergoing surgery, to measure tumor alkylguanyl transferase (AGT) and methionine levels and compare to control specimens.