 4. Patients must be at first or second relapse and clinically require reoperation for tumor progression within 4 to 6 weeks. Note: Relapse is defined as progression following initial therapy i.e., radiation, chemotherapy, or radiation chemotherapy. If the participant had a surgical resection for relapsed disease and no antitumor therapy instituted for up to 12 weeks, this is considered one relapse. For participants who had prior therapy for a low grade glioma, the surgical diagnosis of a high grade glioma will be considered first relapse. 