Fractionated stereotactic radiotherapy for acoustic neuroma: single-institution experience at The Princess Margaret Hospital

BACKGROUND: The clinical outcome and toxicity of fractionated stereotactic radiotherapy (FSRT) was assessed for acoustic neuroma in 60 patients treated in a single institution. METHODS: Between October 1996 and February 2005, 60 patients received FSRT for acoustic neuroma (AN). The mean total dose applied was 50 Gy in single daily 2-Gy fractions over 5 weeks. The median irradiated tumor volume was 4.9 cm(3) (range, 0.3-49.0 cm(3)). The median follow-up period was 31.9 months. RESULTS: FSRT was well tolerated in all patients. The 5-year actuarial local control rate was 96.2% (95% CI: 91.1%-100.0%). Five-year actuarial progression-free survival was 92.8% (95% CI: 84.8%-100.0%). The overall hearing preservation rate was 77.3%. Five of 6 patients with initial cranial nerve V (CNV) numbness remained stable post-FSRT. Two of 3 patients with baseline trigeminal neuralgia improved with the remaining patient stable. All 3 patients with nonsurgically related facial nerve weakness either improved or achieved stability in function. There were no cases of new cranial nerve toxicity post-FSRT. CONCLUSIONS: FSRT for the treatment of AN is safe, effective, and well tolerated. FSRT should thus be considered as an effective alternative treatment modality when compared with microsurgical resection or single fraction stereotactic radiosurgery.