Background
Systematic review and meta-analysis. Microsurgery vs stereotactic radiation therapy (SRT: SRS or FSRT) for small vestibular schwannomas (Koos grade I–II, max diameter ≤30 mm). 57 studies (17 microsurgery, 32 SRT, 8 observational); literature through 2011.
Interventions and follow up
Arm A: Microsurgery (17 series)
Arm B: Stereotactic radiation therapy (32 SRS/FSRT series; 8 observational)
Primary endpoint: Local control, facial nerve function, hearing preservation, complication rates
mFollow up: Varied by study (range 2–10+ yr)
Arm B: Stereotactic radiation therapy (32 SRS/FSRT series; 8 observational)
Primary endpoint: Local control, facial nerve function, hearing preservation, complication rates
mFollow up: Varied by study (range 2–10+ yr)
Results
Local control: 95.3% (SRT) vs 91.6% (MS); P<.05 favoring SRT
Facial nerve preserved (HB I–II): 94.9% (SRT) vs 75.3% (MS); P<.001
Serviceable hearing preserved: 51.2% (SRT) vs 44.6% (MS); NS
Overall morbidity: Significantly lower with SRT
Facial nerve preserved (HB I–II): 94.9% (SRT) vs 75.3% (MS); P<.001
Serviceable hearing preserved: 51.2% (SRT) vs 44.6% (MS); NS
Overall morbidity: Significantly lower with SRT
Adverse events
Microsurgery: facial nerve palsy (any) 24.7%, CSF leak 8.4%, meningitis 2.3%, mortality 0.2%
SRT: facial nerve palsy 5.1%, trigeminal neuropathy 4.7%, symptomatic edema 3.2%, salvage surgery 3.2%
Mortality: None in SRT series
SRT: facial nerve palsy 5.1%, trigeminal neuropathy 4.7%, symptomatic edema 3.2%, salvage surgery 3.2%
Mortality: None in SRT series
Conclusions
For small vestibular schwannomas, SRT achieves equivalent/superior local control with significantly better facial nerve preservation vs microsurgery and comparable hearing preservation. Supports SRT as preferred upfront option unless surgical decompression needed.
Key Limitations
Pooled retrospective series, not randomized; heterogeneous follow-up, dose/technique, and hearing-assessment criteria; selection bias (larger/symptomatic tumors to surgery); no long-term QoL endpoints.
Clinical Context
Reinforces SRS/FSRT as a standard alternative to microsurgery for small VS; modality selection driven by tumor size, hearing status, and need for mass-effect decompression.