Stereotactic Radiosurgery and Erlotinib in Treating Patients With Non-Small Cell Lung Cancer and Brain Metastases

DISEASE CHARACTERISTICS:

• Histologically confirmed non-small cell lung cancer (NSCLC) meeting the following criteria:
• Fewer than 5 intraparenchymal brain metastases by gadolinium-enhanced MRI meeting the following criteria:
• Maximum diameter ≤ 4.0 cm
• If multiple lesions are present and one lesion is > 3.0 cm, the remaining lesions must be ≤ 3.0 cm in maximum diameter
• No metastases within 3 mm of the optic nerve or optic chiasm such that some portion of the optic nerve or chiasm would receive > 9 Gy from radiosurgery
• No metastases in the brainstem, midbrain, pons, or medulla
• No prior complete resection of a single brain metastasis or of all known brain metastases
• Subtotal resection allowed provided residual disease is ≤ 4.0 cm in maximum diameter
• No clinical or radiographic evidence of unstable systemic progression (other than the study lesion[s]) within the past month
• Patients with brain metastases at initial presentation do not require 1 month of scans documenting stable disease
• Isolated brain metastases with stable systemic disease allowed
• No leptomeningeal metastases by MRI and/or positive cerebrospinal fluid cytology

PATIENT CHARACTERISTICS:

• Karnofsky performance status 60-100%
• Life expectancy ≥ 3 months
• ANC > 1,000/mm³
• Platelet count > 100,000/mm³
• Hemoglobin > 10 g/dL
• PT and PTT normal
• AST < 2 times upper limit of normal (ULN)
• Alkaline phosphatase < 2 times ULN
• Total bilirubin < 2 times ULN
• Lactic dehydrogenase < 2 times ULN
• Serum creatinine < 1.5 times ULN
• Not pregnant or nursing
• Negative pregnancy test
• Fertile patients must use effective contraception during and for ≥ 2 weeks after completion of study therapy
• Neurologic function status 0-2
• No history of allergic reactions attributed to compounds of similar chemical or biologic composition to erlotinib hydrochloride
• No contraindication to MRI (e.g., cardiac pacemaker)
• No absolute contraindication to lumbar puncture

PRIOR CONCURRENT THERAPY:

• See Disease Characteristics
• Prior systemic therapy allowed
• No prior cranial radiotherapy
• Prior radiotherapy to noncranial sites allowed
• More than 1 week since prior intrathecal chemotherapy or prior treatment of leptomeningeal carcinoma
• No concurrent systemic therapy
• Prior or current erlotinib hydrochloride for treatment of systemic disease allowed provided systemic disease has not progressed while on erlotinib hydrochloride
• No concurrent enzyme-inducing anticonvulsant
• If patients are on an enzyme-inducing anticonvulsant (e.g., phenytoin, carbamazepine, or phenobarbital), the agent must be converted to a nonenzyme-inducing anticonvulsant before or at the start of erlotinib hydrochloride treatment
• No concurrent CYP3A4 inhibitors or inducers (e.g., Hypericum perforatum [St. John wort] or ketoconazole)
• No other concurrent investigational therapy