PURPOSE: To evaluate and compare outcomes for patients with vestibular 
schwannoma (VS) treated in a single institution with linac-based stereotactic 
radiosurgery (SRS) or by fractionated stereotactic radiotherapy (SRT).
METHODS AND MATERIALS: One hundred and nineteen patients (SRS = 78, SRT = 41) 
were treated. For both SRS and SRT, beam shaping is performed by a 
mini-multileaf collimator. For SRS, a median single dose of 12.5 Gy (range, 
11-14 Gy), prescribed to the 80% isodose line encompassing the target, was 
applied. Of the 42 SRT treatments, 32 treatments consisted of 10 fractions of 
3-4 Gy, and 10 patients received 25 sessions of 2 Gy, prescribed to the 100% 
with the 95% isodose line encompassing the planning target volume. Mean largest 
tumor diameter was 16.6 mm in the SRS and 24.6 mm in the SRT group. Local tumor 
control, cranial nerve toxicity, and preservation of useful hearing were 
recorded. Any new treatment-induced cranial nerve neuropathy was scored as a 
complication.
RESULTS: Median follow-up was 62 months (range, 6-136 months), 5 patients 
progressed, resulting in an overall 5-year local tumor control of 95%. The 
overall 5-year facial nerve preservation probability was 88% and facial nerve 
neuropathy was statistically significantly higher after SRS, after prior 
surgery, for larger tumors, and in Koos Grade ≥3. The overall 5-year trigeminal 
nerve preservation probability was 96%, not significantly influenced by any of 
the risk factors. The overall 4-year probability of preservation of useful 
hearing (Gardner-Robertson score 1 or 2) was 68%, not significantly different 
between SRS or SRT (59% vs. 82%, p = 0.089, log rank).
CONCLUSION: Linac-based RT results in good local control and acceptable clinical 
outcome in small to medium-sized vestibular schwannomas (VSs). Radiosurgery for 
large VSs (Koos Grade ≥3) remains a challenge because of increased facial nerve 
neuropathy.