Vestibular schwannoma: an understanding of growth should influence management decisions

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.

Retrospective chart analysis of prospectively collected patient database.

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.

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).

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.