Tumor Control After Radiosurgery in Sporadic and Neurofibromatosis Type 2 Vestibular Schwannomas

Introduction: The tumor control rate after stereotactic radiosurgery (SRS) for neurofibromatosis type 2-associated vestibular schwannomas (NF2-VSs) compared to sporadic vestibular schwannomas (S-VSs) remains unclear. This nationwide, multicenter, retrospective study (KGKRS-21-001) aimed to clarify this issue. Methods: A total of 4718 patients treated with SRS for vestibular schwannomas were analyzed from 13 nationwide institutions in Korea. NF2-VS cases were propensity score-matched with S-VS cases at a ratio of 1:1, based on age, tumor volume, and marginal dose, resulting in 122 cases in each group. Results: No significant differences in age, tumor volume, or marginal dose were observed between the matched cohorts. The overall tumor control rates at 1, 3, and 10 years after SRS were 93.3%, 87.7%, and 80.7%, respectively, with no significant difference between NF2-VS and S-VS groups (p = 0.63). Subgroup analysis showed that age ≤ 19 years was a significant negative prognostic factor for tumor control in NF2-VS patients (p < 0.001), whereas no such correlation was found in the S-VS cohort (p = 0.78). Conclusions: SRS provides comparable tumor control for NF2-VSs and S-VSs. However, among NF2-VS patients, younger age (≤ 19 years) was associated with poorer tumor control, suggesting that age may be a critical factor in treatment decisions.