Conservative management versus stereotactic radiation for vestibular schwannomas: A meta-analysis of patients with more than 5 years' follow-up

OBJECTIVE: To compare the long-term outcome of hearing and tumor control of small vestibular schwannomas treated with conservative management or radiation therapy. DATA SOURCES: A thorough search for English-language publications and "in-process" articles dating from 1948 to January 2011 was performed using Ovid MEDLINE. STUDY SELECTION: The principal criteria were patients with no microsurgical intervention before their treatment, a follow-up of at least 5 years, and a useful hearing level at diagnosis. DATA EXTRACTION: Fourteen studies met our criteria. Hearing preservation outcome (worse, unchanged, and better) and tumor size outcome (growth, unchanged, and regression) data were collected from the articles, as well as all other significant observations. No studies using fractionated stereotactic radiotherapy met our criteria. Stereotactic radiation was the only radiation therapy analyzed. DATA SYNTHESIS: The data were analyzed using the Pearson χ test. CONCLUSION: Current data on conservative management and stereotactic radiation do not provide enough evidence to make a clear conclusion on the outcome of useful hearing preservation in a long-term manner. In this study, however, stereotactic radiation is shown to have better tumor control rates than conservative management. Additional studies reporting long-term follow-ups of patients are required so as to provide the medical field with a better understanding of vestibular schwannoma treatment therapies.