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 as having hearing loss no
greater than grade 2 in the irradiated ear

- 18 years of age or older

- Life expectancy of greater than 60 months

- Karnofsky performance status 60 or greater

- 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

- 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

Exclusion Criteria:

- Participants who have had prior radiotherapy, with dose delivered to structures in
proximity to the internal acoustic canal

- Participants with tumors (or residual tumor after surgery) measuring > 3cm in
greatest dimension

- Participants with neurofibromatosis type 2 (NF2)

- Participants may not be receiving any other study agents

- History of adverse reaction to radiotherapy

- Participants receiving any medications or substances that are known to cause
ototoxicity are ineligible

- Uncontrolled intercurrent illness including, but not limited to ongoing or active
infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac
arrhythmia, or psychiatric illness/social situations that would limit compliance with
study requirements

- Pregnant women

- Individuals with a history of malignancy are ineligible except for the following
circumstances. Individuals with a history of malignancies are eligible if they have
been disease-free for at least 5 years and are deemed by the investigator to be a low
risk for recurrence of that malignancy. Individuals with the following cancers are
eligible if diagnosed and treated within the past 5 years: cervical cancer in situ,
and basal cell squamous cell carcinoma of the skin.

- HIV-positive individuals on combination antiretroviral therapy

- Patients with co-existing major ear disease, such as chronic otitis, Menieres
disease, or otosclerosis