Visual Outcomes and Local Control After Fractionated Stereotactic Radiotherapy for Optic Nerve Sheath Meningioma

Purpose: To review the outcomes of patients with optic nerve sheath meningiomas (ONSM) treated with fractionated stereotactic radiotherapy. Methods: Patient characteristics, treatment, and outcomes were analyzed for all patients with primary and secondary ONSM treated from 2001 to 2012. Clinically significant visual acuity change was defined as a 2-line change on the Snellen eye chart from pre-fractionated stereotactic radiotherapy. Results: Forty-one patients were treated: 23 patients with primary ONSM and 18 patients with secondary ONSM. The median age at diagnosis was 56 years. The median visual follow up was 3.8 years and the median radiologic follow up was 4.4 years. At diagnosis, 36% had normal vision (20/20–20/40), 10% had mild impairment (