• Grades 2-5 acute (≤ 90 days from start of radiotherapy) adverse events (e.g., neurologic, ocular/visual, dermatologic/skin [excluding alopecia], or other adverse event) as assessed by NCI CTCAE v3.0 [ Designated as safety issue: Yes ]
• Grades 2-5 late (> 90 days from start of radiotherapy) adverse events (e.g., neurologic, ocular/visual, dermatologic/skin [excluding alopecia], or other adverse event) as assessed by NCI CTCAE v3.0 [ Designated as safety issue: Yes ]
• Overall survival [ Designated as safety issue: No ]
• MRI imaging predictors as assessed by central neuroradiology review at diagnosis, at any failure, and at 3 years [ Designated as safety issue: No ]
• Adherence to protocol-specific target and normal tissue radiotherapy parameters [ Designated as safety issue: No ]
• Concordance between central and parent institution histopathologic grading and subtyping [ Designated as safety issue: No ]

• Grades 2-5 acute (≤ 90 days from start of radiotherapy) adverse events (e.g., neurologic, ocular/visual, dermatologic/skin [excluding alopecia], or other adverse event) as assessed by NCI CTCAE v3.0 [ Designated as safety issue: Yes ]
• Grades 2-5 late (> 90 days from start of radiotherapy) adverse events (e.g., neurologic, ocular/visual, dermatologic/skin [excluding alopecia], or other adverse event) as assessed by NCI CTCAE v3.0 [ Designated as safety issue: Yes ]
• Overall survival [ Designated as safety issue: No ]
• MRI imaging predictors as assessed by central neuroradiology review at diagnosis, at any failure, and at 3 years [ Designated as safety issue: No ]
• Adherence to protocol-specific target and normal tissue radiotherapy parameters [ Designated as safety issue: No ]

RATIONALE: Sometimes a tumor may not need treatment until it progresses. In this case, observation may be sufficient. Specialized radiation therapy that delivers a high dose of radiation directly to the tumor, such as 3-dimensional conformal radiation therapy and intensity-modulated radiation therapy, may kill more tumor cells and cause less damage to normal tissue. It is not yet known whether observation is more effective than radiation therapy in treating patients with meningioma.

PURPOSE: This phase II trial is studying observation to see how well it works compared with radiation therapy in treating patients with grade I, grade II, or grade III meningioma.

OBJECTIVES:

Primary

• To estimate the rates of progression-free survival at 3 years in patients with low-risk meningioma undergoing observation and in patients with intermediate- or high-risk meningioma undergoing radiotherapy.

Secondary

• To study the concordance, or lack thereof, between central and parent institution histopathologic diagnosis, grading, and subtyping.
• To estimate the rates of overall survival at 3 years in these patients.
• To estimate the incidence rates of acute and late adverse events ≥ grade 2 in patients with intermediate- or high-risk meningioma undergoing radiotherapy.
• To evaluate MRI imaging predictors by central neuroradiology review at diagnosis, at any failure, and at 3 years.
• To evaluate adherence to protocol-specific target and normal tissue radiotherapy parameters.

OUTLINE: This is a multicenter study. Patients are assigned to 1 of 3 groups according to risk.

• Group 1 (low-risk disease): Patients undergo observation.
• Group 2 (intermediate-risk disease): Patients undergo 3-dimensional conformal radiotherapy or intensity-modulated radiotherapy (IMRT) once daily 5 days a week for 6 weeks.
• Group 3 (high-risk disease): Patients undergo IMRT once daily 5 days a week for 6 weeks.

After completion of study treatment, patients are followed up every 3-6 months for 3 years and then annually for 10 years.

• Other: clinical observation
  Patients undergo observation.
• Radiation: 3-dimensional conformal radiation therapy
  Given once daily 5 days a week for 6 weeks
• Radiation: intensity-modulated radiation therapy
  Given once daily 5 days a week for 6 weeks

• No Intervention: Group 1
  Patients undergo observation.
  Intervention: Other: clinical observation
• Experimental: Group 2
  Patients undergo 3-dimensional conformal radiotherapy or intensity-modulated radiotherapy (IMRT) once daily 5 days a week for 6 weeks.
  Interventions:

  • Radiation: 3-dimensional conformal radiation therapy
  • Radiation: intensity-modulated radiation therapy
• Experimental: Group 3
  Patients undergo IMRT once daily 5 days a week for 6 weeks.
  Intervention: Radiation: intensity-modulated radiation therapy

DISEASE CHARACTERISTICS:

• Histologically confirmed meningioma, meeting 1 of the following criteria:

  • Low-risk disease, as defined by the following:

    • Newly diagnosed, WHO grade I disease that was gross totally resected (Simpson's grade I, II, or III resection with no residual nodular enhancement on postoperative imaging) or subtotally resected (residual nodular enhancement or Simpson grade IV or V resection)

  • Intermediate-risk disease, as defined by the following:

    • Newly diagnosed, WHO grade II disease that was gross totally resected OR recurrent WHO grade I disease irrespective of the resection extent

  • High-risk disease, as defined by 1 of the following:

    • Newly diagnosed or recurrent WHO grade III disease of any resection extent
    • Recurrent WHO grade II disease of any resection extent
    • Newly diagnosed, WHO grade II disease that was subtotally resected
• Patients with newly diagnosed disease must have had a histologic diagnosis within the past 6 months AND have undergone pre- and post-operative MRIs within the past 3 months
• Patients with recurrent/progressive intermediate- or high-risk disease who have not undergone recent surgery must have documentation of recurrence or progression by MRI within the past 3 months
• No extracranial or multiple meningioma and/or hemangiopericytoma

PATIENT CHARACTERISTICS:

• Zubrod performance status 0-1
• Negative pregnancy test (for patients enrolled in groups 2 or 3)
• Fertile patients must use effective contraception (for patients enrolled in groups 2 or 3)
• Able to receive gandolinium
• No other invasive malignancy within the past 3 years except for nonmelanoma skin cancer or carcinoma in situ of the breast, oral cavity, or cervix

• No severe, active comorbidity including, but not limited to, any of the following:

  • Unstable angina and/or congestive heart failure requiring hospitalization
  • Transmural myocardial infarction within the past 6 months
  • Acute bacterial and/or fungal infection requiring IV antibiotics
  • Chronic obstructive pulmonary disease exacerbation or respiratory illness requiring hospitalization or that would preclude study treatment
  • Hepatic insufficiency resulting in clinical jaundice and/or coagulation defects
  • Known HIV positivity or AIDS, based upon the current CDC definition
  • No evidence of active connective tissue disorders (e.g., lupus erythematosus and/or scleroderma) (for patients enrolled in groups 2 or 3)
• No other major medical illness or psychiatric impairment that, in the investigator's opinion, would preclude study treatment or informed consent

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• No prior radiotherapy to the scalp, cranium, brain, or skull base