 Study patients: Adult patients n 20 with Group 1 compelling MRI evidence of a new primary brain tumor who have not yet undergone surgery or any tumor-directed therapy, or Group 2 newly diagnosed primary malignant brain tumors WHO Grade II-IV glial-based tumorswho have not had a complete surgical resection and by contrast MRI have residual tumor greater than 1.0 cm in diameter and will be receiving radiotherapy andor chemotherapy, or Group 3 patients with recurrent primary barin tumor as determined by standard clinical criteria and MRI imaging. Four to eight patients per year will be enrolled during the first 3 years, for a total of 20 patients. Enrollment will be weighted toward lower-grade tumors during year 1 in order to allow for longer followup times during the life of the project. Dr. Jensen or Dr. Colman will identify and recruit patients for participation and obtain informed consent. 