Observation or Radiation Therapy in Treating Patients With Newly Diagnosed Grade II Meningioma That Has Been Completely Removed by Surgery

Inclusion Criteria:

   - PRIOR TO STEP 1 REGISTRATION:

   - The patient must have a newly diagnosed unifocal intracranial meningioma, gross
   totally resected, and histologically confirmed as WHO grade II based upon pathology
   findings at the enrolling institution; WHO grade will be assigned according to WHO
   2016 criteria

   - Gross total resection (GTR) will be interpreted as modified Simpson grade 1-3 without
   gross residual dural-based or extradural tumor; GTR must be confirmed both by modified
   Simpson grade and by post-operative magnetic resonance imaging (MRI) findings

   - Step 1 registration must occur within 180 days of the initial surgery; within this 180
   day interval, a second surgery is permitted in order to achieve GTR, but even with a
   second surgery, step 1 registration must occur within 180 days of the initial
   resection

   - For step 1 registration the operating neurosurgeon must provide the modified Simpson
   grade

   - GTR must be confirmed on post-operative imaging following the most recent surgery;
   submission of both pre-operative and post-operative MRIs is required for patients; if
   a second surgery is performed, submission of post-operative MRI is required and
   pre-operative MRI is required only if obtained; all sequences obtained in the pre- and
   post-operative MR imaging are to be submitted to National Radiology Group (NRG)
   Oncology for study registration; imaging subsequent to enrollment must include pre and
   post gadolinium contrast-enhanced three-dimensional spoiled gradient (SPGR),
   magnetization-prepared rapid gradient echo (MP-RAGE), or turbo field echo (TFE) MRI
   scan and an axial T2 fluid attenuated inversion recovery (FLAIR) sequence; to yield
   acceptable image quality, the gadolinium contrast-enhanced three-dimensional SPGR,
   MP-RAGE, or TFE axial MRI scan should use the smallest possible axial slice thickness
   not exceeding 1.5 mm; the post-operative MRI must be completed within sufficient time
   to permit step 1 registration within 180 days of the initial resection; these same
   conditions apply in the setting of a second surgical procedure, although if a second
   surgery is completed, step 1 registration must still occur with 180 days of initial
   surgery; computed tomography (CT) imaging is not required, but may be obtained if
   desired clinically, for instance to assess calcifications or hyperostosis

   - The patient or a legally authorized representative must provide study-specific
   informed consent prior to study entry

   - If the patient is a primary English speaker, the patient must participate in the NCF
   and patient reported outcomes part of the study; if the patient is a primary French or
   Spanish speaker, the patient must participate in the patient reported outcomes part of
   the study

   - NOTE: Central pathology review must occur between steps 1 and 2 of registration; once
   appropriate pathology specimens are received, central pathology review will occur
   within 15 days, and must confirm WHO grade II meningioma before the patient can
   proceed to step 2 registration and randomization

   - PRIOR TO STEP 2 REGISTRATION:

   - Histologically confirmed diagnosis of WHO grade II meningioma confirmed by central
   pathology review prior to step 2 registration

   - History/physical examination, including neurologic examination within 60 days prior to
   step 2 registration

   - Post-operative Zubrod performance status 0-1 within 60 days prior to step 2
   registration

   - If the patient is a woman is of childbearing potential, a serum pregnancy test,
   obtained within 14 days prior to step 2 registration, must be negative, and, if
   randomized to receive radiation therapy, the woman must agree to use contraception

Exclusion Criteria:

   - Optic nerve sheath meningioma, spinal or other extracranial meningioma, multiple
   meningiomas, hemangiopericytoma

   - Definitive evidence of metastatic meningioma

   - Prior invasive malignancy (except non-melanomatous skin cancer) unless disease free
   for a minimum of 3 years (carcinoma in situ of the breast, oral cavity, cervix,
   melanoma in situ, or other non-invasive malignancies are permissible)

   - Previous radiotherapy to the scalp, cranium, brain, or skull base and
   radiation-induced meningiomas

   - Major medical illnesses or psychiatric impairments, which in the investigators
   opinion, will prevent administration or completion of the protocol therapy and/or
   preclude informed consent; these include, but are not restricted to:

      - Unstable angina and/or congestive heart failure requiring hospitalization at the
      time of step 2 registration

      - Transmural myocardial infarction within the last 6 months prior to step 2
      registration

      - Acute bacterial or fungal infection requiring intravenous antibiotics at the time
      of step 2 registration

      - Chronic obstructive pulmonary disease exacerbation or other respiratory illness
      requiring hospitalization or precluding study therapy at the time of step 2
      registration

      - Type II neurofibromatosis (NF2)

      - Ailments entailing substantial increases in sensitivity and side effect risk from
      radiation therapy (ataxia telangiectasia, Nijmegen breakage syndrome, and human
      immunodeficiency virus (HIV) with CD4 count < 200 cells/microliter); HIV testing
      is not required for eligibility for this protocol, and known HIV positive
      patients are eligible, provided they are under treatment with highly active
      antiretroviral therapy (HAART) and have a CD4 count >= 200 cells/microliter
      within 30 days prior to step 2 registration

      - Inability to undergo MRI with and without contrast (e.g. claustrophobia, non-MRI
      compatible implant or foreign body, etc) or receive gadolinium; note that
      patients with severe claustrophobia are permitted on this study if they are
      willing and able to undergo MRI with adequate sedation or anesthesia

   - Pregnancy and/or nursing females