Radiosurgery Plus NovoTTF-200A for Metastatic Small Cell Lung Cancer to the Brain

Inclusion Criteria: * All subjects must have history of histologically confirmed small cell lung cancer. Brain biopsy is not required unless diagnosis is judged to be in doubt by the treating physician. * Brain metastases that have not received radiotherapy previously (metastases on post-contrast MRI obtained within six weeks of study entry) deemed to be amenable to SRS. * Longest diameter \< 4 cm * Prior prophylactic cranial irradiation (PCI) is allowed. The maximum allowed dose is 25Gy in 10 fractions. * Prior systemic therapy is allowed after diagnosis of brain metastases provided that restaging MRI shows measurable intracranial disease. * Karnofsky Performance Status (KPS) of greater than or equal to 70. * Age greater than or equal to 18 years. * Life expectancy greater than 3 months. * Must receive optimal therapy for extracranial disease and may continue on systemic therapy during TTF administration. * Ability to operate the NovoTTF-200A device independently or with caregiver aid. * Previous clinical trial enrollment is allowed. * Subjects given written informed consent. Exclusion Criteria: * History of prior brain metastases. * Patients with significant edema leading to risk of brain herniation. * History of prior whole brain radiotherapy (WBRT) other than prophylactic cranial radiation. Prophylactic cranial radiation with a maximum dose of 25 Gy delivered as 10 fractions is allowed. WBRT in excess of 25 Gy (anything over 25 Gy) is not allowed. * Diffuse Leptomeningeal metastases with radiographic involvement in the brain and/or spinal cord. This does not include local leptomeningeal involvement which is defined as leptomeningeal enhancement within direct contact of targetable metastases. * Implantable electronic device in the brain. * Implanted pacemaker, programmable shunts, defibrillator, deep brain stimulator, other implanted electronic devices in the brain, or documented clinically significant arrhythmias. * Evidence of increased intracranial pressure (midline shift \> 5mm, clinically significant papilledema, vomiting and nausea, or reduced level of consciousness). * Known allergies to medical adhesives or hydrogel. * Currently pregnant or breastfeeding. * Concurrent brain-directed therapy. * Insufficient recovery from all active toxicities of prior therapies. * Women of childbearing potential who are not using an effective method of contraception are excluded.