A Feasibility, Dose-Escalation Study Using Intracerebral Microdialysis to Assess the Neuropharmacodynamics of Temsirolimus in Patients With Primary or Metastatic Brain Tumors

Inclusion Criteria Patients must be at least 18 years of age. Patients must have either a primary or metastatic brain tumor(s). Patients must be in need of a surgical debulking or a stereotactic biopsy for the purpose of diagnosis or differentiating between tumor progression and treatment-induced effects following radiation therapy + or - chemotherapy. For patients in cohort 2, treatment with temsirolimus must not be contraindicated. Patients in cohort 2 must not be taking any hepatic enzyme-inducing anticonvulsants (phenytoin, carbamazepine, phenobarbital, primidone, oxcarbazepine). Patients who are taking strong CYP3A4 inducers or inhibitors such as clarithromycin, itraconazole, ketoconazole, nefazodone, telithromycin, rifampin, rifabutin, rifampacin, or St. John's Wort must discontinue the medication beginning at least one week prior to surgery and lasting for the duration of the study. The only exception will be dexamethasone which can be used post-operatively as indicated. Patients must have a Karnofsky Performance Status \>= 60% or an ECOG/Zubrod score of\<= 2. Patients must have recovered from any toxicity of any prior therapy. Patients must have adequate bone marrow function (defined as an absolute neutrophil count of \>= 1500 cells/mm3 and platelet count ≥ 100,000 cells/mm3), liver function with total bilirubin \<= 2.0 mg/dl and AST (SGOT) \<= 4 times the institutional upper limit of normal, and serum creatinine \<=1.5 x the institutional upper limit of norm…