Functional outcomes in retrosigmoid approach microsurgery and gamma knife stereotactic radiosurgery in vestibular schwannoma

Although vestibular schewannomas (VSs) are relatively rare as compared to other intracranial tumors, growing attention is required to achieve better outcomes with less morbidities among patients. In this retrospective study, we compared functional outcomes of retrosigmoid approach microsurgery (RSAMS) and gamma knife stereotactic radiosurgery (GKSRS) in VSs patients with serviceable hearing. Forty-six patients in inclusion criteria, who underwent RSAMS (n = 15) or GKSRS (n = 31) between January 2004 and June 2009 were reviewed. We evaluated symptoms at initial presentation, pre- and posttreatment pure-tone audiometry, speech discrimination score, tumor size, pre- and posttreatment assessments of facial nerve function, and pre- and posttreatment tinnitus, dizziness and facial paresthesia in vestibular schwannoma patients, who were treated with RSAMS or GKSRS. Hearing disturbance was the most common presenting symptom in both the groups. The hearing preservation rates in the RSAMS and GKSRS patients were 7% (1/15) and 45% (14/31), respectively. Two RSAMS patients and one GKSRS patient developed new facial neuropathy, defined as a temporary or permanent decline in House-Brackmann facial nerve grade. Tumor recurrence was observed in one RSAMS patient, whereas tumor size increase was observed in one GKSRS patient (3%). Tinnitus score was decreased after the treatment in both the groups. The results imply that GKSRS for vestibular schwannoma can possibly preserve hearing preservation with proper indication and treatment planning.