CONSERVATIVE MANAGEMENT OF ACOUSTIC NEUROMA - AN OUTCOME STUDY

OBJECTIVE: This study analyzed selection criteria, clinical outcome, a nd tumor growth rates in patients with acoustic neuromas in whom the i nitial management strategy was observation. METHODS: A retrospective r eview of patients with conservatively managed unilateral acoustic neur omas was conducted. Minimum follow-up was 6 months. Patients with neur ofibromatosis Type II were excluded. Differences in tumor growth rates were analyzed by use of the Wilcoxon rank sum test. RESULTS: Sixty-ei ght patients (31 men and 37 women) with a mean age of 67.1 years were followed for an average of 3.4 years after diagnosis. The reasons for a trial of observation included advanced age (55%), patient preference (21%), minimal symptoms (9%), poor general medical condition (7%), as ymptomatic tumor (4%), and tumor in the only hearing ear (4%). Fifty-e ight patients (85%) were successfully managed with of observation alon e. Ten patients (15%) ultimately required treatment (nine received mic rosurgical treatment and one patient underwent radiosurgical intervent ion) at a mean time interval of 4.0 years after diagnosis. Forty-eight tumors (71%) showed no growth and 20 (29%) enlarged during the study period. The mean tumor growth rate at the 1-year follow-up was signifi cantly higher in the group requiring treatment (3.0 mm) than in the gr oup not requiring treatment (0.36 mm) (P < 0.0001). Thus, the tumor gr owth rate at the 1-year follow-up was a strong predictor of the eventu al need for treatment. CONCLUSION: Observation is a reasonable managem ent strategy in carefully selected patients with acoustic neuromas. Di ligent follow-up with serial magnetic resonance imaging is recommended , because some tumors will enlarge to the point at which active treatm ent is required.