Hearing Outcomes Using Fractionated Proton Radiation Therapy for Vestibular Schwannoma

Inclusion Criteria: * MRI confirmed unilateral vestibular schwannoma within 8 weeks prior to study entry * Measurable disease, defined as a lesion that can be accurately measured in at least one dimension * No prior radiotherapy with dose delivered to structures in proximity to the internal acoustic canal is allowable * Participants must have baseline "useful hearing" defined at the discretion of the treating physician in the irradiated ear * 18 years of age or older * Life expectancy of greater than 60 months * Karnofsky performance status 60 or greater * Diagnosis of neurofibromatosis 2 (NF2) is permitted * Women of child-bearing potential and men must agree to use adequate contraception during the interval of irradiation * Able to tolerate the supine position as required for the radiation treatment unit and able to tolerate rotation needed for treatment delivery * Able to tolerate the standard immobilization device that typically utilizes a dental impression mouth piece and thus requires breathing through the nasal passage. * Willing and able to comply with comprehensive audiologic testing, at baseline prior to radiation therapy, at 6 months from treatment completion, and at annual timepoints for 5 years after completion * Baseline Systolic Blood Pressure (BP) \> 100mm Hg. This is based on the average of two values - separate seated, resting measurements taken five minutes apart. BP does not need to be checked in both arms unless a reading is below 110 mm Hg, in which cas…