BACKGROUND: Vestibular schwannomas (VSs) related to neurofibromatosis type 2 (NF2) are challenging tumors. The increasing use of stereotactic radiosurgery (SRS) necessitates further investigations of its role and safety. OBJECTIVE: To evaluate tumor control, freedom from additional treatment (FFAT), serviceable hearing preservation, and radiation-related risks of patients with NF2 after SRS for VS. METHODS: We performed a retrospective study of 267 patients with NF2 (328 VSs) who underwent single-session SRS at 12 centers participating in the International Radiosurgery Research Foundation. The median patient age was 31 years (IQR, 21-45 years), and 52% were male. RESULTS: A total of 328 tumors underwent SRS during a median follow-up time of 59 months (IQR, 23-112 months). At 10 and 15 years, the tumor control rates were 77% (95% CI: 69%-84%) and 52% (95% CI: 40%-64%), respectively, and the FFAT rate were 85% (95% CI: 79%-90%) and 75% (95% CI: 65%-86%), respectively. At 5 and 10 years, the serviceable hearing preservation rates were 64% (95% CI: 55%-75%) and 35% (95% CI: 25%-54%), respectively. In the multivariate analysis, age (hazards ratio: 1.03 [95% CI: 1.01-1.05]; P = .02) and bilateral VSs (hazards ratio: 4.56 [95% CI: 1.05-19.78]; P = .04) were predictors for serviceable hearing loss. Neither radiation-induced tumors nor malignant transformation were encountered in this cohort. CONCLUSION: Although the absolute volumetric tumor progression rate was 48% at 15 years, the rate of FFAT related to VS was 75% at 15 years after SRS. None of the patients with NF2-related VS developed a new radiation-related neoplasm or malignant transformation after SRS.

Clinical Oncology Department Ain Shams University Cairo Egypt

Department of Neurological Surgery University of Miami School of Medicine Miami Florida USA

Department of Neurological Surgery University of Pittsburgh Medical Center Pittsburgh Pennsylvania USA

Department of Neurological Surgery University of Virginia Charlottesville Virginia USA

Department of Neurosurgery Koc University School of Medicine Istanbul Turkey

Department of Neurosurgery Max Rady College of Medicine University of Manitoba Winnipeg Manitoba Canada

Department of Neurosurgery Neurological Institute Taipei Veteran General Hospital Taipei Taiwan

Department of Neurosurgery Post Graduate Institute of Medical Education and Research Chandigarh India

Department of Neurosurgery Université de Sherbrooke Centre de recherche du CHUS Sherbrooke Quebec Canada

Department of Neurosurgery West Virginia University Morgantown West Virginia USA

Department of Radiation Oncology Beaumont Health System Royal Oak Michigan USA

Department of Radiology Centro Gamma Knife Dominicano and Radiology Department Cedimat Santo Domingo Dominican Republic

Gamma Knife Center Cairo Nasser Institute Hospital Cairo Egypt

Neurosurgery Department Ain Shams University Cairo Egypt

Neurosurgery Department Benha University Qalubya Egypt

Radiation Oncology Department National Cancer Institute Cairo University Cairo Egypt

Radiosurgery Unit Hospital Ruber Internacional Madrid Spain

School of Medicine National Yang Ming University Taipei Taiwan

Stereotactic and Radiation Neurosurgery Na Homolce Hospital Prague Czech Republic

Neurosurgery. 2023 Oct 1;93(4):e98-e99. doi: 10.1227/neu.0000000000002613. PubMed

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