Clinical outcome of neurofibromatosis type 2-related vestibular schwannoma: treatment strategies and challenges

To discuss the appropriate treatment strategy for NF2-related vestibular schwannoma (VS) according to our experiences, we analyzed long-term clinical and radiological data focusing on NF2-related VS patients. Seventeen NF2-related VS patients were included. Based on their first management modality for VS, we classified these patients into the following four groups: microsurgery (MS), fractionated gamma knife radiosurgery (f-GKS), single session gamma knife radiosurgery (s-GKS), and conservative management (CM). Each patient was assessed for each separate ear. Changes of tumor volume and hearing status for 32 ears in 17 patients according to their first treatment modality were evaluated. The mean follow-up duration and tumor volume of the MS (4 ears, 4 patients), f-GKS (12 ears, 10 patients), s-GKS (8 ears, 7 patients), and CM (8 ears, 7 patients) groups were 3.9 years and 1.6 mL; 5.1 years and 11.1 mL; 8.4 years and 5.6 mL; and 6.1 years and 1.6 mL, respectively. Relatively lower local control rates were observed in the MS and the CM group (0 and 12.5 %, respectively). On the other hand, better local control rates for follow-up periods of 5.1 and 8.4 years were achieved in the f-GKS and the s-GKS groups (75 and 50 %, respectively). However, hearing preservation in all treatment modalities could not be achieved effectively. Long-term preservation of hearing in at least one serviceable ear as well as tumor control should be considered for each patient. Therefore, a proper treatment option should be selected at the appropriate time according to clinical characteristics of individual patients.