Fractionated stereotactic radiation therapy and single high-dose radiosurgery for acoustic neuroma: Early results of a prospective clinical study

Purpose: To prospectively assess the local control and toxicity rate in aco ustic neuroma patients treated with linear accelerator-based radiosurgery a nd fractionated stereotactic radiation therapy. Methods and Materials: We evaluated 37 consecutive patients treated with st ereotactic radiation therapy for acoustic neuroma. All patients had progres sive tumors, progressive symptoms, or both. Mean tumor diameter was 2.3 cm (range 0.8-3.3) on magnetic resonance (MR) scan. Dentate patients were give n a dose of 5 x 4 Gy or 5 x 5 Gy and edentate patients were given a dose of 1 x 10 Gy or 1 x 12.50 Gy prescribed to the 80% isodose, All patients were treated with a single isocenter, Results: With a mean follow-up period of 25 months (range 12-61), the actua rial local control rate at 5 years was 91% (only 1 patient failed). The act uarial rate of hearing preservation at 5 years was 66% in previously-hearin g patients. The actuarial rate of freedom from trigeminal nerve toxicity wa s 97% at 5 years. No patient developed facial nerve toxicity or other compl ications. Conclusion: In this unselected series, fractionated stereotactic radiation therapy and linear accelerator-based radiosurgery give excellent local cont rol in acoustic neuroma, It combines a high rate of preservation of hearing with a very low rate of other toxicity, although follow-up is relatively s hort. (C) 2000 Elsevier Science Inc.