DISEASE CHARACTERISTICS:

• Diagnosis of primary or metastatic brain tumor

• Completed a course of ≥ 30 Gy fractionated whole-brain irradiation or large-field partial-brain irradiation for primary or metastatic brain tumor ≥ 6 months prior to study entry

  • Meets the following criteria:

    • Single-fraction stereotactic radiosurgery as a boost after external-beam radiotherapy
    • No polifeprosan 20 with carmustine implant (Gliadel wafers), GliaSite®, or other type of brain brachytherapy
    • No convection-enhanced delivery of immunotoxins
    • No other investigational modalities as adjuvant therapy after external-beam radiotherapy
• Must have treatment records (total dose, dose per fraction, and isodose curves) available for all prior radiotherapy (external-beam radiotherapy, brachytherapy, and/or stereotactic radiosurgery)
• Patients receiving prophylactic cranial irradiation are eligible
• No radiographic evidence of brain disease OR stable brain disease, defined as no evidence of tumor progression within the past 3 months

• No brain metastases with progressive extracranial primary or metastatic disease

  • Extracranial primary or metastatic disease must be stable or have responded to local and/or systemic treatment within the past 3 months

PATIENT CHARACTERISTICS:

• Life expectancy ≥ 30 weeks
• Karnofsky performance status 60-100%
• Patients must have a phone
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception
• No sick sinus syndrome or supraventricular arrhythmias
• No hypersensitivity to donepezil hydrochloride

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• More than 2 weeks since prior and no other concurrent dementia drugs, cognitive enhancers, neuroleptics, and/or anti-parkinsonian agents
• Concurrent steroids, anti-cholinergics, anti-epileptics, anti-depressants, and/or sedatives/benzodiazepines allowed provided patient is on a stable or decreasing dose
• Concurrent narcotic analgesics allowed provided the patient is on a stable dose and/or prn basis

• No other planned therapy, including surgery, brain irradiation of any type, chemotherapy, or immunotherapy, for the next 30 weeks for brain or extracranial primary metastatic disease

  • Concurrent trastuzumab (Herceptin®) for breast cancer allowed
  • Concurrent hormonal therapy for breast or prostate cancer allowed
• No concurrent bethanechol, ketoconazole, quinidine, or succinylcholine

• No prior GliaSite or other type of brain brachytherapy, convection enhanced delivery of immunotoxins, and/or any other investigational modalities for treatment of brain tumor

  • Gliadel wafers allowed
• No concurrent chemotherapy