In an adult with a large hypervascular skull‑base meningioma causing mass‑effect symptoms who refuses surgery, is embolization alone an appropriate treatment?

Embolization Alone for Meningioma Mass Effect in Surgery-Refusing Patients

Embolization alone is not recommended as definitive treatment for a large hypervascular skull-base meningioma causing mass-effect symptoms, even when the patient refuses surgery. 1

Why Embolization Alone is Inadequate

The evidence clearly demonstrates that embolization is designed as an adjunctive procedure, not a standalone therapy for meningiomas:

• Embolization effects are temporary: The radiographic and clinical effects of embolization may be transient, with recanalization and partial revascularization observed in 30% of embolized vessels within 7 days, and collaterals developing rapidly to reduce effectiveness. 1

• No evidence for symptom durability: When embolization is performed for palliative purposes in tumors, presenting symptoms and their regression should be measured as efficacy, but the guidelines emphasize this is only meaningful when part of a multimodality treatment plan. 1

• Risk of catastrophic complications: Transarterial embolization for meningiomas and other vascular skull-based tumors can lead to dramatic tumor infarction, swelling, and herniation—particularly dangerous when not followed by immediate surgical decompression. 1

Recommended Alternative Treatment Pathway

For a patient refusing surgery with a large symptomatic skull-base meningioma, stereotactic radiosurgery (SRS) should be strongly recommended as the primary alternative treatment. 2

Radiation Therapy Options:

• Stereotactic radiosurgery (SRS): The American Association of Neurological Surgeons recommends SRS as primary treatment for benign intracranial meningiomas in patients who are not surgical candidates, with recommendation level II evidence. 2

• Tumor size considerations: SRS is ideal for tumors less than 3 cm, with marginal doses of 12-15 Gy in a single fraction providing durable local control of WHO grade I meningiomas. 2

• Hypofractionated stereotactic radiotherapy (HSRT): For larger tumors exceeding 3 cm, HSRT with a common schedule of 25 Gy in 5 fractions may be used. 2

• Long-term efficacy: SRS provides 10-year local control rates ranging from 71% to 100% for benign meningiomas, with 10-year progression-free survival rates of 55% to 97%. 2

Critical Pitfalls to Avoid

• Do not perform embolization without a definitive treatment plan: The complication rate of embolization ranges from 1.5% to 5.6%, including permanent neurological deficits and death (3.5%), making it unjustifiable without subsequent curative intervention. 3, 4

• Hemorrhagic complications are the primary risk: Ten of 11 complications in one series were hemorrhagic, with 6 requiring emergency surgery; 2 patients died and 5 became dependent. 4

• Small particle size increases risk: The use of small polyvinyl alcohol particles (45-150 μm) significantly increases complication risk (OR 10.21) and should be avoided. 4

Clinical Decision Algorithm

1. Patient refuses surgery + symptomatic large meningioma → Counsel strongly for SRS as primary treatment 2

2. Tumor <3 cm → Single-fraction SRS (12-15 Gy) 2

3. Tumor ≥3 cm → Hypofractionated SRT (25 Gy in 5 fractions) 2

4. Patient also refuses radiation → Surveillance with MRI every 6-12 months, with clear documentation of informed refusal and discussion of untreated survival (49% at 3 months, 25% at 15 years versus 93% and 79% with treatment) 5

5. Never perform embolization alone → No role as monotherapy for mass-effect symptoms 1