Purpose: To compare the use of an observation policy with that of stereotactic radiotherapy (SRT) for treatment of vestibular schwannoma.
Methods and materials: The study group consisted of 27 patients who underwent observation as an initial treatment (observation group) and 50 who received SRT (SRT group). The mean follow-up period was 35 months and 31 months, respectively. Stereotactic radiotherapy consisted of small-field fractionated 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 better 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 years after the initial presentation.
Conclusion: Stereotactic radiotherapy using a fractionated schedule provides a better tumor control rate and a similar rate of deterioration for hearing levels compared to an observation policy. Initial SRT may be a reasonable alternative to a wait-and-see policy.