Vestibular schwannoma: An understanding of growth should influence management decisions

Background: Treatments for vestibular schwannomas include surgical removal and radiotherapy. Observation is a reasonable alternative, given the slow growth of these tumors. The goal of this study was to determine the 5-year no-growth rate in patients managed initially by observation in attempts to define indications for treatment. Study Design: Retrospective chart analysis of prospectively collected patient database. Methods: Patients with unilateral vestibular schwannomas who presented in the last 10 years were reviewed, Those managed initially by observation were reviewed. At least 2 consecutive imaging studies were required. The following information was recorded from the charts: age, sex, tumor size at presentation and subsequent follow-up Sessions, treatment in the event of growth, and time interval between presentation and last imaging available. The institutional ethics committee approved the study. Results: One hundred ten patients were included. There were 65 male patients and 45 female patients. The mean age was 62.4 years (range, 32-91 yr). The mean follow-up was 31.4 months (range, 6-156 mo). Twenty-three patients demonstrated evidence of growth, with an overall 5-year no-growth rate of 70.6%. Despite growth, the 5-year no-intervention rate was 81.3%. Interestingly, 11 patients (10%) demonstrated tumor regression. Patients with intracanalicular tumors had a 5-year no-growth rate of 89.8% compared with 73.9% and 45.2% for Grade I and Grade II or larger tumors, respectively. The difference between intracanalicular and Grade II or larger tumors was statistically significant (p = 0.0196). Conclusion: Our data Suggest that treatment can be delayed in a large proportion of vestibular schwannoma patients and that this is particularly true in patients with small tumors. Despite growth, only a small percentage of patients require intervention. Thus, we recommend a period of observation to determine the need for treatment in patients without indications for urgent intervention.