Ketogenic Diet Adjunctive to HD-MTX Chemotherapy for Primary Central Nervous System Lymphoma

Inclusion Criteria: 1. Age 18-70 2. Histopathologically confirmed PCNSL 3. No systemic involvement 4. Ability and willingness to sign informed consent 5. Normal liver and kidney function 6. Karnofsky Performance Score of 60 or more Exclusion Criteria: 1. Any systemic involvement of the tumor 2. Systemic illness or medical condition may pose additional risk, including cardiac, metabolic or endocrine disorders; incompensated renal or liver disfunction; history of renal calculi, hyperuricemia, hyper calcemia, mitochondrial disease, known disorder of fatty acid metabolism, porphyria, carnitine deficiency and pancreatitis 3. Uncontrolled hyperlipidemia or hyperglycemia 4. Human immunodeficiency virus positive, or hepatitis C positive 5. Pregnancy of breastfeeding 6. Inability or unwillingness to give written informed consent.