Gamma-Knife Radiosurgery for Type 2 Neurofibromatosis Vestibular Schwannomas

Eum, Dong Woong; Kim, Moo Seong; Kim, Sung Tae; Lee, Kun Soo; Paeng, Sung Hwa; Pyo, Se Young; Jeong, Young Gyun; Jung, Yong Tae; Jeong, Hae Woong; Kim, Yang Weon; Kim, Sang Jin

Original article

Journal of the Korean Society of Stereotactic and Functional Neurosurgery 2012;8(2):70-73.
Published online September 30, 2012.

Gamma-Knife Radiosurgery for Type 2 Neurofibromatosis Vestibular Schwannomas

Dong Woong Eum, Moo Seong Kim, Sung Tae Kim, Kun Soo Lee, Sung Hwa Paeng, Se Young Pyo, Young Gyun Jeong, Yong Tae Jung, Hae Woong Jeong, Yang Weon Kim, Sang Jin Kim

Department of Neurosurgery, Diagnostic Radiology, Emergency Medicine, Neurology, Inje University, Busan Paik Hospital, Busan, Korea

Abstract

Objective
The goal of radiosurgery is to arrest tumor growth while preserving neurological function. Patients having vestibular schwannomas associated with type 2 neurofibromatosis represent a special challenge because of the risk of complete deafness. The authors retrospectively analysed the clinical features, and radiologic results to evaluate the result of stereotactic radiosurgery treating vestibular schwannomas secondary to type 2 neurofibromatosis. Material and Methods: 10 patients underwent Gamma knife radiosurgery. Of these 10 patients, 9 underwent first stage radiosurgery, and one patient pwas subjected to second stage radiosurgery. The mean tumor volume at radiosurgery was 13.3mL, and the mean marginal dose was 10.8Gy (range 10-12Gy) Result: During the mean follow-up period of 54.7 months, 7 patients (70%) showed regression in their tumors, 2 patients (20%) showed no change, and one patient (10%) showed an increase in tumor size. In two tumor patients among regression group after radiosurgery, new tumors grew , and additional radiosurgery was performed for new lesion. Hearing was preserved in 8 (80%) of patients. Facial nerve function was preserved in all patients.
Conclusion
Radiosurgery is a valuable minimally invasive treatment for vestibular schwannomas secondary to type 2 neurofibromatosis.

Key Words: Radiosurgery, Vestibular schwannoma, Type 2 neurofibromatosis.