- Subjects must have findings on neuroimaging studies and clinical evaluation consistent with the diagnosis of a primary brain tumor in order to be offered enrollment in the study. Subsequently, in order to remain on study, they must have histologically or cytologically confirmed primary tumor of the brain. Intra-operative confirmation of histology (i.e. frozen section assessment or equivalent) is required for all subjects. Gliadel wafers will not be implanted without positive intraoperative histopathology consistent with a primary tumor of the brain. The final classification and evaluability determination will be made based on post-operative histological reports showing anaplastic astrocytoma or Glioblastoma multiforme. No central pathology review will be required.