Management of Meningiomas
Complete surgical resection with removal of the dural attachment is the optimal treatment for symptomatic meningiomas when feasible, while asymptomatic small lesions (<30 mm) should be observed with serial MRI surveillance. 1
Diagnostic Approach
MRI with contrast is the gold standard imaging modality for meningiomas, demonstrating characteristic homogeneous dural-based enhancement with a "dural tail sign," CSF cleft between tumor and brain, and possible calcifications. 1 Post-contrast T1-weighted sequences provide the most critical information for tumor detection and characterization. 1
- Typical MRI features include: isointense or hypointense masses on T1-weighted images, hyperintense on T2-weighted images, with strong uniform contrast enhancement 2
- Calcifications occur in up to 50% of cases, more commonly in pediatric patients 2, 1
- Somatostatin receptor (SSTR) PET imaging should be considered when tumor extension is unclear or to differentiate recurrence from post-treatment changes 1
Treatment Algorithm by Clinical Presentation
Asymptomatic Small Meningiomas (<30 mm)
Observation with serial MRI every 6-12 months is recommended for most asymptomatic small meningiomas. 1 Surgery should only be considered if the tumor is accessible and potential neurological consequences exist. 1
Symptomatic Meningiomas
Surgery is the primary treatment when the tumor is accessible and surgical risk is acceptable. 1 The goal is complete resection including the involved dura. 1, 3
Key surgical considerations:
- Modern image-guided surgery (frameless stereotaxy) improves precision and reduces surgical morbidity 1
- Deep-seated meningiomas carry 5-18% postoperative morbidity risk 1
- Brainstem meningiomas have significant early morbidity in nearly half of cases 1
Adjuvant Radiation Therapy Indications
External beam radiation therapy (EBRT) is indicated for:
- WHO grade 3 (malignant) meningiomas after surgery 1
- Subtotally resected WHO grade 2 (atypical) meningiomas 1
- Residual or recurrent tumors, particularly those <3 cm in diameter (stereotactic radiosurgery preferred) 4
For larger meningiomas or those with pre-existing edema, fractionated stereotactic radiotherapy may be preferred over single-fraction radiosurgery. 4
Location-Specific Management
Meningiomas arise from arachnoid cells and can occur anywhere meninges exist, including unusual sites like nasal cavity, paranasal sinuses, and middle ear. 2
- 90% of pediatric meningiomas are supratentorial or intraventricular, most commonly on the convexity of hemispheres 2
- Posterior fossa and torcular meningiomas may present with difficult-to-describe headaches and require careful surgical planning due to venous sinus involvement 4
- For tumors with extensive venous sinus involvement, subtotal resection followed by stereotactic radiosurgery is recommended when complete resection carries high risk 4
Common Presenting Symptoms
Symptoms depend on tumor location and include:
- Raised intracranial pressure (headaches, drowsiness, vomiting) 2
- Focal neurological deficits affecting limbs 2
- Cranial nerve palsies 2
- Epilepsy in up to 30% of pediatric cases 2
- Visual deficits, hearing loss, ataxia, or spinal cord compression signs 2
Advanced Treatment Options
Peptide receptor radionuclide therapy (PRRT) using radiolabeled somatostatin receptor ligands shows promising results for treatment-refractory meningiomas. 1 SSTR PET imaging must be performed prior to PRRT to confirm target expression. 1
Post-Treatment Surveillance
MRI without and with contrast every 6-12 months is recommended for WHO grade 1 meningiomas. 1 After achieving stable disease (typically 5-10 years), follow-up intervals can be extended. 4
Critical pitfall: Recurrence rates for completely resected benign meningiomas can reach 20% within 25 years, necessitating long-term surveillance. 1 Subtotal resection carries higher recurrence rates, requiring adjuvant radiation therapy. 4
Special Populations
Pediatric meningiomas differ from adult tumors: