• Biopsy-proven benign or malignant brain tumor requiring tumor bed or tumor irradiation. This may include, but is not limited to, low-grade or favorable high-grade glioma, pituitary adenoma, vestibular schwannoma (acoustic neuroma), and meningioma as the most common diagnoses. Other tumor types that require irradiation and are deemed appropriate for proton radiation therapy are also eligible. Patients with a presumed diagnosis based on imaging and clinical characteristics will be permitted on this trial without pathological diagnostic confirmation if it is within standard of care to offer radiation therapy without a biopsy.

• Participants must otherwise be indicated for proton radiation therapy

• Age 18 years or older

• Karnofsky performance status ≥ 60 (see Appendix A)

• Participants may have had any extent of prior surgery and/or chemotherapy.

• Must be able to speak and comprehend English

• Ability to understand and willingness to sign a written informed consent document

• The effects of proton radiation therapy on the developing human fetus are known to be teratogenic. For this reason, women of child-bearing potential and men must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry, for the duration of study treatment, and 4 months after completion of proton therapy. Should a woman become pregnant or suspect she is pregnant while she or her partner is participating in this study, she should inform her treating physician immediately. Men treated or enrolled on this protocol must also agree to use adequate contraception prior to the study, for the duration of study treatment, and 4 months after completion of proton therapy.

• Life expectancy greater than or equal to 6 months.