What are the current guidelines for the treatment of meningioma?

Treatment Guidelines for Meningioma

For WHO grade 1 meningiomas, gross total resection including involved dura is the primary curative treatment, while stereotactic radiosurgery (12-15 Gy single fraction) is recommended as definitive evidence-based therapy for surgically inaccessible or residual tumors, achieving 71-100% 10-year local control 1, 2.

Treatment Algorithm by Clinical Scenario

Asymptomatic or Incidental Meningiomas

• Watch-and-scan strategy is appropriate, particularly for elderly patients or those with significant comorbidities 2
• Serial MRI monitoring without immediate intervention
• This approach is increasingly recognized as valid management for a significant proportion of cases

Symptomatic or Growing Tumors

Primary Treatment Hierarchy:

1. Surgical Resection (First-line)

   • Gross total resection including involved dura is curative 2
   • Simpson grade resection determines recurrence risk
   • Use preoperative and postoperative imaging to evaluate extent and osseous involvement 3

2. Stereotactic Radiosurgery (SRS) - For specific indications

   • Prescription dose: 12-15 Gy single fraction 1
   • Indications: Small tumors, surgically inaccessible locations, residual disease, elderly/medically inoperable patients
   • 10-year local control: 71-100% 1
   • Low toxicity profile
   • Requires tumor size and proximity to critical structures to be favorable

3. Fractionated Radiotherapy

   • For tumors too large or too close to critical structures for SRS
   • Used for inoperable or recurrent tumors requiring treatment 2

WHO Grade 2 (Atypical) Meningiomas - Critical Distinctions

Grade 2 meningiomas require more aggressive management than grade 1:

• After gross total resection: Conventionally fractionated RT to at least 59.4 Gy is standard of care 3
• After subtotal resection: Mandatory adjuvant RT with larger margins using preoperative and postoperative imaging 3
• SRS/hypofractionated SRT is less appropriate for grade 2 disease 3
• Consider SRS only for: patients unable to tolerate lengthy conventional RT, prior RT cases, or small residual tumors after careful discussion 3

Important Caveat for Grade 2 Disease

The majority of prospective data involves larger margins with conventional fractionation. Stereotactic approaches lack robust evidence in this setting and should be used cautiously 3.

Emerging Molecular-Guided Approaches

Peptide Receptor Radionuclide Therapy (PRRT) is an experimental option for progressive meningiomas 4, 2:

Eligibility criteria before PRRT:

• Positive SSTR expression on PET imaging within 2 months
• Karnofsky performance status >60% or ECOG 0-2
• Brain MRI within 2 weeks as baseline
• Adequate organ function (complete blood count, renal function with GFR, liver function)
• Pregnancy excluded in women of childbearing age

Key preparation:

• Discontinue somatostatin analogs: 4-6 weeks for long-acting formulations, 24 hours for short-acting 4
• Stop corticosteroids if not essential 4

Recurrent Disease Management

For suspected recurrence:

• SSTR-PET imaging has high accuracy differentiating recurrent disease from treatment-related changes (radionecrosis/scar tissue) 4
• Treatment options: repeat surgery if feasible, radiosurgery (if not previously irradiated and size appropriate), or fractionated RT
• Experimental systemic therapy: Bevacizumab or multikinase inhibitors targeting VEGF receptor show modest results, but no standard systemic treatment exists 2

Common Pitfalls to Avoid

1. Do not treat all meningiomas the same - WHO grade 2 requires more aggressive RT approach than grade 1
2. Do not use SRS margins for grade 2 meningiomas - larger margins with conventional fractionation are standard 3
3. Do not forget dural involvement - resection must include involved dura for cure 2
4. SSTR-PET pitfalls: Active inflammatory lesions (granulomatous inflammation, neurosarcoidosis) and other neoplasms (brain metastases, gliomas) may show uptake; rare meningiomas may have absent uptake 4

Multidisciplinary Team Composition

Essential team members include 5:

• Neurosurgery (resection, intraoperative decisions)
• Radiation oncology (adjuvant therapy guidance)
• Neuroradiology (imaging integration for surgical planning)
• Neuro-ophthalmology (for skull base tumors affecting vision)

This coordinated approach improves tumor control, preserves neurological function, and optimizes quality of life 5.