Stereotactic radiosurgery for facial nerve schwannomas: A preliminary assessment and review of the literature

Abstract

Objective. Facial nerve schwannomas (FNS) are rare tumors, and their appropriate management remains the subject of considerable debate. This report details the results of a series of patients with FNS treated with stereotactic radiosurgery (SRS) at the University of Virginia. Methods. We performed a retrospective review of the clinical and imaging outcomes of 5 patients who underwent Gamma Knife RS (GKRS) for small-to-medium-sized (< 5 mL) FNS at our institution. The study population consisted of 3 males and 2 females with a median age of 35 years. All patients presented with varying degrees of facial palsy and/or hearing dysfunction. Tumor volumes at GKRS ranged from 0.1 to 5 (median = 0.8) mL. The median maximum radiosurgical dose and tumor margin dose were 24 Gy and 12 Gy, respectively. Results. After a median follow-up period of 12 (range, 6–36) months, three tumors were radiographically smaller and two remained stable. Facial function improved in three patients, remained stable in one patient, and slightly declined from House–Brackmann grade I to II in one patient. Hearing function was preserved in three patients and deteriorated in two patients, one from Gardner–Robertson grade I to II and the other from serviceable hearing grade II to III. Conclusion. SRS appears to offer a reasonable rate of facial nerve preservation and tumor control for patients with small-to-medium-sized FNS. Considering the published outcomes achieved with resection, RS may be the preferred first-line treatment for these tumors.