GAMMA KNIFE RADIOSURGERY FOR FACIAL SCHWANNOMAS

Abstract

Patients who have a schwannoma of the facial nerve (facial schwannoma, facial neuroma) can be managed with observation, surgical resection, stereotactic radiosurgery, or fractionated radiotherapy. Attempted complete resection is associated with facial weakness. The role of radiosurgery in these patients remains to be defined. We reviewed the clinical and imaging outcomes in patients who underwent gamma knife radiosurgery for a facial schwannoma. Six patients had radiosurgery and were followed for a mean and median of 46.6 and 61.5 months, respectively (21–85 months). Three had a previous resection, and in 3 the diagnosis was made based on clinical and imaging criteria. All patients had facial nerve symptoms (5 had weakness and 1 had muscle twitching). House-Brackmann grades before radiosurgery were as follows: 1 (n = 1), 2 (n = 3), 3 (n = 1), and 6 (n = 1). The radiosurgery margin dose was 12 or 12.5 Gy. On later imaging, 3 tumors had regressed (with the longest follow-up duration) and 3 were unchanged. All patients had preservation of their preradiosurgery facial function. No other adverse effects were noted and all patients maintained their preradiosurgery level of hearing. Over a mean of almost 4 years of follow-up, radiosurgery was shown to be a safe and effective management for residual and newly diagnosed facial schwannomas.