OBJECTIVE: To identify prognostic factors for preserving useful hearing (Gardner-Robertson class 1 or 2) 2 years after stereotactic radiosurgery (SRS) for vestibular schwannoma, with a focus on auditory brainstem response (ABR) and baseline auditory status. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Eighty-six patients treated between 2010 and 2019 with Gamma Knife SRS and presenting with serviceable hearing at diagnosis. All patients included had ABR pretreatment and pure tone and speech audiometry before treatment and at 2 years after radiosurgery. INTERVENTIONS: Stereotactic radiosurgery; audiological evaluation including ABR and pure tone and speech audiometry before treatment and at 2-year follow-up. MAIN OUTCOME MEASURES: Preservation of useful hearing (Gardner-Robertson class 1 or 2) using pure tone average and word recognition score at 2 years post-treatment. RESULTS: Useful hearing was preserved in 77.9% (pure tone audiometry) and 86.7% (speech audiometry) of patients at 2 years. Pathologic ABR Wave I and initial Gardner-Robertson class 2 were significantly associated with the likelihood of loss of useful hearing at 2 years. CONCLUSIONS: Auditory brainstem response and quality of audition at baseline are predictive factors of preservation of useful hearing at 2 years after SRS.Level of Evidence: Level 3.
Beharry et al. (Tue,) studied this question.