Radiologic surveillance of acoustic neuromas

Objective: This study aimed to define the incidence and rate of tumor growt h or acoustic neuromas (ANs) in patients who have undergone radiologic surv eillance. Data Sources: MEDLINE literature searches covering the period of January 19 66-June 1997 were performed as well as a review of the bibliographies of th e studies that were found. Study Selection: Criteria for inclusion of a study in this meta-analysis we re: a defined group of patients diagnosed with an AN for whom radiologic su rveillance was the selected strategy of management, Limited inclusion of pa tients with neurofibromatosis type II (NF II) ANs, no recurrent ANs, data t hat 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 eac h study and the ability to combine the data with the results of other studi es. All of the studies were biased by their retrospective, nonrandomized na ture. Data Synthesis: Paired t-tests (p < 0.05) and correlation efficients were u sed to assess pooled data. Conclusions: A total of 571 ANs were studied, with an average patient age o f 64 years. Given an average follow-up period of 3 years, 54% of patients s howed 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 i n the only-hearing ear, or who are medically unable to undergo treatment. S mall tumor size and advanced agr should not be viewed as absolute contraind ications for treatment.