Study on Radiation Therapy With or Without Temozolomide for Treating Low-Grade Glioma

DISEASE CHARACTERISTICS:

• Histologically confirmed* supratentorial low-grade glioma, including 1 of the following:

  • Grade 2 astrocytoma
  • Grade 2 oligodendroglioma
  • Grade 2 oligoastrocytoma (mixed glioma containing astrocytoma and oligodendroglioma)

• 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; no pathological diagnosis of grade 3 or 4 glioma at any time

• Paraffin-embedded tumor specimen available for submission for confirmation of pathological review and determination of 1p and 19q deletion status

• Patients must currently meet ≥ 1 of the following criteria*:

  • Uncontrolled symptoms, defined as any of the following:

    • Headaches associated with mass effect
    • Uncontrolled seizures despite two different antiepileptic drug regimens (i.e., two antiepileptic drugs tested either sequentially or in combination)
    • Focal neurological symptoms
    • Cognitive symptoms or deficits

  • Tumor progression by serial MRIs, defined as any of the following:

    • New or progressive enhancement
    • New or progressive T2 or FLAIR signal abnormality

  • Age ≥ 40 years

• NOTE: *Patients < 40 years of age 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 not eligible.

• Patients who have undergone gross total resection and have no detectable residual disease are eligible

• No pilocytic astrocytoma, ganglioglioma, pleomorphic xanthoastrocytoma, or dysembryoplastic neuroepithelial tumors

PATIENT CHARACTERISTICS:

• Karnofsky performance status 60-100%
• WBC ≥ 3,000/mm^3
• ANC ≥ 1,500/mm^3
• Platelet count ≥ 100,000/mm^3
• Hematocrit ≥ 30%
• Bilirubin ≤ 2 times upper limit of normal (ULN)
• AST and ALT ≤ 3 times ULN
• Creatinine ≤ 2.0 times ULN
• Not pregnant or nursing
• Negative pregnancy test
• Able to undergo MRI with and without contrast
• No other malignancy within the past 5 years, except for nonmelanoma skin cancer or cervical carcinoma in situ
• No uncontrolled infection
• No known HIV positivity
• No medical disorder that would increase risks associated with radiotherapy and temozolomide
• No other disorder that would limit life expectancy to < 5 years

PRIOR CONCURRENT THERAPY:

• No prior radiotherapy, cytotoxic chemotherapy, radiosurgery, or investigational therapy directed at the brain tumor

  • Any number of prior surgical procedures for the brain tumor allowed

• No prior radiotherapy to the head unless the radiotherapy ports entirely excluded the brain

• At least 2 weeks since any prior brain surgery (e.g., stereotatic biopsy, open biopsy, or resection)

• At least 6 weeks since prior MRI and chest x-ray

  • If resection is performed, an MRI after surgery is required