Comparison between observation policy and fractionated stereotactic radiotherapy (SRT) as an initial management for vestibular schwannoma

Purpose: To compare the use of an observation policy with that of stereotac tic radiotherapy (SRT) for treatment of vestibular schwannoma, Methods and Materials: The study group consisted of 27 patients who underwe nt observation as an initial treatment (observation group) and 50 who recei ved SRT (SRT group). The mean follow-up period was 35 months and 31 months, respectively. Stereotactic radiotherapy consisted of small-field fractiona ted radiotherapy (36-44 Gy in 20-22 fractions over 6 weeks) with or without a subsequent 4-Gy single irradiation boost, Results: Actuarial tumor control rate of the SRT group was significantly be tter than that of the observation group (p < 0.0001). The mean growth was 3 .87 mm/year in the observation group and -0.75 mm/year in the SRT group (p < 0.0001). Eleven patients (41%) in the observation group and 1 (2%) in the SRT group received salvage therapy (p < 0.001). There was no difference in the actuarial Gardner and Robertson's class preservation curves for 5 year s after the initial presentation. Conclusion: Stereotactic radiotherapy using a fractionated schedule provide s a better tumor control rate and a similar rate of deterioration for heari ng levels compared to an observation policy. Initial SRT may be a reasonabl e alternative to a wait-and-see policy. (C) 1999 Elsevier Science Inc.