|Inclusion Criteria:||1) Age >/= 18 years.|
2) Tumors must be supratentorially located.
3) Pathological diagnosis of astrocytoma grade 2, oligodendroglioma grade 2, or oligoastrocytoma grade 2 (mixed glioma containing astrocytoma and oligodendroglioma). Pilocytic astrocytoma, ganglioglioma, pleomorphic xanthastrocytoma, or dysembryoplastic neuroepithelial tumors are not eligible. NOTE: If the pathology from multiple procedures supports the diagnosis of a brain tumor, the qualifying pathology of grade 2 astrocytoma, oligodendroglioma, or oligoastrocytoma must be the most recent pathological diagnosis, and a pathological diagnosis of a grade 3 or grade 4 glioma must not have been made at any time.
4) Patients must have paraffin-embedded tumor specimen available for submission for pathological review and determination of 1p/19q deletion status. NOTE: It is recommended that patients not be Pre-registered until the required tumor specimens are on hand and ready for submission. If submission of tissue will be submitted more than 5 working days after pre-registration, immediately notify the Mayo Clinic Cytogenetics Laboratory.
5) The patient must currently have at least one of the following: 1) Uncontrolled symptoms, defined as any of the below: Headaches associated with mass effect; Uncontrolled seizures despite 2 different antiepileptic drug regimens (i.e., 2 antiepileptic drugs tested either sequentially or in combination); Focal neurological symptoms; Cognitive symptoms or deficits. OR 2) Tumor progression by serial MRIs, defined as any of the below: New or progressive enhancement; New or progressive T2 or FLAIR signal abnormality. OR 3) Age >/= 40 years. NOTE: Patients aged less than 40 whose only symptom of low-grade glioma is seizures that are well-controlled on antiepileptic drugs, and who have no evidence of radiographic progression, are ineligible.
6) Patient must be able to undergo MRI with and without contrast. Patients who are unable to undergo MRI are ineligible.
7) MRI and chest x-ray within 6 weeks prior to pre-registration. A postoperative MRI is required for all patients who underwent open biopsy, or resection, but is not mandatory following stereotactic biopsy.
8) Karnofsky performance status (KPS) >/= 60%.
9) Patients who have undergone gross total resection and have no detectable residual disease are eligible.
10) 1p/19q deletion status assessment as determined by the Mayo Cytogenetics Laboratory has been received.
11) Must be able to start treatment with RT within 2 weeks or 10 working days at a qualified center (to be defined by the Radiation Oncology chair) and to start TMZ prescribed at a participating center within 2 weeks or 10 working days of randomization.
12) CBC requirements within 14 days prior to randomization: White blood count (WBC) >/= 3,000 /mm3; Absolute neutrophil count (ANC) > 1,500 /mm3; Platelets >/= 100,000 /mm3; Hematocrit > 30%
13) Chemistry requirements within 14 days prior to randomization: Bilirubin </= 2 x upper limit of normal (ULN); AST </= 3 x ULN (SGOT); Creatinine </= 2.0 x ULN; ALT < 3 x ULN (SGPT)
14) Women must not be pregnant or breast-feeding due to known and potential teratogenic effects of radiotherapy and temozolomide and the uncertain safety of temozolomide in lactation. All females of childbearing potential must have a blood test or urine study within 2 weeks prior to randomization to rule out pregnancy.
15) Women of childbearing potential and sexually active males are strongly advised to use an accepted and effective method of contraception.
16) Patient must be at least two weeks post any brain surgery (whether stereotactic biopsy, open biopsy or resection) at the time of randomization.