Retrospective Evaluation of the Effect of Surgery and CyberKnife on Recurrence and Neurological Deficits in Cases Diagnosed as Vestibular Schwannoma

INTRODUCTION: We aimed to investigate the effects of treatment with microsurgical resection and CyberKnife, on local control and functional neurological loss in patients diagnosed as vestibular schwannoma and to choose the best treatment method for the benefit of the patient.
METHODS: Thirty-one patients were included in the study. Microsurgical resection was performed in 15 (Group 1) patients, and CyberKnife treatment was performed in 16 (Group 2) patients. Microsurgical resection with retrosigmoid approach was performed as a surgical method for Group 1 patients, accompanied by electrophysiological studies. Stereotaxic radiosurgery was performed with CyberKnife in Group 2 patients whom with tumors smaller than 3 cm and risk of additional morbidity. All patients were followed up clinically and radiologically.
RESULTS: The mean tumor diameter was 32.7±8.02 mm in Group 1 patients and 17.6±6.1 mm in Group 2 patients. The mean follow-up period was 33.8±16.3 months in Group 1 and 16.4±7.5 months in Group 2. The local control success of microsurgical resection in vestibular schwannomas was 100%, and the CyberKnife treatment was 93.75%. Good to moderate facial nerve function was preserved in 80% of Group 1 patients. In Group 2, the rate of complete preservation of facial nerve functions is 100%. While the rate of complete loss of hearing function was 6.67% in Group 1, no deterioration in hearing function was observed in Group 2.
DISCUSSION AND CONCLUSION: Microsurgical resection is inevitable in large-sized vestibular schwannomas due to the mass effect. The application of surgery accompanied by electrophysiological studies reduces neurological deficits. Functional losses may occur even in the presence of electrophysiological studies. In large and giant tumors, applying microsurgical resection with electrophysiological studies and providing local control with CyberKnife as an adjuvant treatment in the presence of residual tumor are seen as the ideal treatment method.