What are the treatment options for meningioma?

Treatment Options for Meningioma

Treatment of meningiomas should be based on tumor size, location, symptoms, and WHO grade, with observation being preferred for small asymptomatic tumors and surgery being the primary treatment option for symptomatic or large tumors. 1

Initial Assessment and Classification

Meningiomas are classified according to the WHO grading system:

• WHO grade 1: Benign meningioma
• WHO grade 2: Atypical meningioma
• WHO grade 3: Malignant (anaplastic) meningioma 1

Diagnostic evaluation should include:

• Brain MRI (standard imaging)
• SSTR PET imaging when tumor extension is unclear or to differentiate recurrence from treatment-related changes 1, 2

Treatment Algorithm Based on Presentation

Small Tumors (<30 mm)

• Asymptomatic:

  • Observation is preferred 1
  • Surgery if accessible and potential neurologic consequences exist
  • Follow with RT if WHO grade 3 or consider RT for subtotally resected WHO grade 2

• Symptomatic:

  • Surgery if accessible, followed by RT if WHO grade 3
  • RT alone if surgery not feasible 1

Large Tumors (≥30 mm)

• Asymptomatic:

  • Surgery if accessible, followed by RT if WHO grade 3
  • Consider RT if incomplete resection and WHO grade 1/2
  • Observation if surgery not feasible

• Symptomatic:

  • Surgery if accessible, followed by RT if WHO grade 3
  • Consider RT if incomplete resection and WHO grade 1/2
  • RT alone if surgery not feasible 1

Radiation Therapy Options

Radiation therapy can be delivered as:

1. Fractionated conformal radiotherapy:

   • WHO grade 1 and 2: 45-54 Gy
   • WHO grade 3: 54-60 Gy in 1.8-2.0 Gy fractions 1

2. Stereotactic radiosurgery (SRS):

   • Small WHO grade 1 meningiomas: 12-15 Gy in a single fraction 1
   • Particularly useful for residual tumor after subtotal resection 3

Advanced Treatment Options for Recurrent/Progressive Disease

When surgery and conventional radiation options are exhausted:

1. Peptide Receptor Radionuclide Therapy (PRRT):

   • For SSTR-positive meningiomas on PET imaging
   • Uses [177Lu]Lutetium or [90Y]Yttrium as β-emitters
   • Considered when other local therapy options are no longer applicable 1, 2
   • Requirements:
     • Positive SSTR expression on PET imaging within last 2 months
     • Karnofsky performance status >60% or ECOG 0-2
     • Brain MRI within 2 weeks prior to treatment 1

2. Systemic therapy options:

   • Limited data supporting efficacy
   • Hydroxyurea has shown modest success in recurrent cases 4
   • Clinical trials should be considered when available 1

Special Considerations

1. Optic nerve sheath meningiomas:

   • Fractionated conformal radiotherapy is preferred as primary treatment 3

2. Critically located meningiomas (e.g., cranial base):

   • Consider planned subtotal resection combined with SRS/RT 5

3. Post-radiation assessment:

   • Within first 3 months after radiation, diagnosis of recurrence can be indistinguishable from pseudoprogression
   • Consider MR spectroscopy, MR perfusion, or PET to rule out radiation necrosis 1, 2

Follow-up Recommendations

• Serial MRI scans every 2-4 months for 2-3 years, then less frequently 2
• Consider SSTR PET for response assessment after treatment (>25% reduction in uptake may indicate positive response) 1, 2
• Median growth rate for untreated meningiomas is approximately 4 mm per year 1

Treatment Pitfalls to Avoid

1. Misinterpreting post-radiation changes as recurrence within the first 3 months after treatment 1, 2

2. Overlooking SSTR PET for diagnosis and treatment planning, which provides superior detection sensitivity compared to MRI alone 1, 2

3. Delaying treatment for recurrence when multiple treatment options exist 2

4. Failing to consider PRRT for appropriate candidates with treatment-refractory meningioma 1, 2