Stereotactic radiosurgery and fractionated stereotactic radiosurgery for vestibular schwannomas: A comparison of clinical outcomes from the RSSearch patient registry.

PURPOSE: To compare clinical outcomes following stereotactic radiosurgery (SRS) and fractionated stereotactic radiosurgery (fSRS) for vestibular schwannomas (VS).

MATERIALS/METHODS: We identified 64 VS patients from the RSSearch Patient Registry (12 treated with SRS and 52 patients treated with fSRS). Potential factors predictive of local control (LC) and toxicity were estimated using the Kaplan-Meier method, Cox proportional hazards model, and binary logistic regressions with propensity score weighting.

RESULTS: SRS (100%) and fSRS (94.2%) resulted in similar LC (p = 0.33). fSRS was associated with a higher likelihood of experiencing toxicities (42.3% vs. 8.3%; p = 0.054 on time-to-event analysis) that was maintained following a propensity-score weighted binary logistic regression (p = 0.037) and propensity-score weighted Cox regression (p = 0.039; hazard ratio (HR) = 8.85 (95% CI: 1.1 - 70.1)).

CONCLUSION: In a multi-institutional analysis, we note equivalent LC but higher toxicity with fSRS compared to SRS for VS.