Radiologic surveillance of acoustic neuromas.

OBJECTIVE: This study aimed to define the incidence and rate of tumor growth of acoustic neuromas (ANs) in patients who have undergone radiologic surveillance. DATA SOURCES: MEDLINE literature searches covering the period of January 1966-June 1997 were performed as well as a review of the bibliographies of the studies that were found. STUDY SELECTION: Criteria for inclusion of a study in this metaanalysis were: a defined group of patients diagnosed with an AN for whom radiologic surveillance was the selected strategy of management, limited inclusion of patients with neurofibromatosis type II (NF II) ANs, no recurrent ANs, data that could be extracted and pooled with other studies, and no duplication of patient populations between studies. Thirteen studies were selected. DATA EXTRACTION: Quality of the studies was determined by the design of each study and the ability to combine the data with the results of other studies. All of the studies were biased by their retrospective, nonrandomized nature. DATA SYNTHESIS: Paired t-tests (p < 0.05) and correlation coefficients were used to assess pooled data.
CONCLUSIONS: A total of 571 ANs were studied, with an average patient age of 64 years. Given an average follow-up period of 3 years, 54% of patients showed evidence of radiologic growth. No reliable predictors of tumor growth have been identified. The authors suggest that radiologic surveillance may best be applied to those patients who refuse treatment, who have a tumor in the only-hearing ear, or who are medically unable to undergo treatment. Small tumor size and advanced age should not be viewed as absolute contraindications for treatment.