Hearing Outcome After Linear Accelerator-Based Radiotherapy for Vestibular Schwannomas: A Retrospective Analysis of a Single Center

OBJECTIVE To report our results on hearing preservation after linear accelerator (LINAC)-based stereotactic radiotherapy for vestibular schwannomas (VS) in a tertiary referral center. METHODS All patients who presented with VS in our center between 2010 and 2018 and who were treated with LINAC-based radiotherapy were retrospectively analyzed. Pure tone average and speech discrimination score represented hearing outcome, pre- and postradiotherapy. A Gardner-Robertson grade I or II hearing represented functional hearing. RESULTS In total, 35 patients were treated with LINAC-based radiotherapy. Median age was 55 years (range 18-86 years), 22 (63%) were female. Sixteen patients had a Koos grade III or IV tumor. Twenty-four patients were treated with radiosurgery (1 or 5 fractions; stereotactic radiosurgery), and eleven patients were treated with fractionated stereotactic radiotherapy. Mean follow-up was 4.8 years (range 1.8-8.4 years). In 34 patients, hearing was assessed pre- and post-radiotherapy. In seventeen patients, hearing remained stable. In eleven patients, a decrease in GR scale was observed, of which seven patients showed a decrease from a functional to a non-functional level (4 GR III, 2 GR IV, and 1 GR V). Tumor control was 95% (34/35), and except for hearing loss, all post-radiation complications and morbidity were transient. CONCLUSION These data emphasize that although the rate of tumor control (the primary goal of radiotherapeutic treatment) is high, it is important to adequately manage patients' expectations regarding the outcomes of the secondary possibly positive outcome; hearing preservation.