Radiation Therapy and Stereotactic Radiosurgery With or Without Temozolomide or Erlotinib in Treating Patients With Brain Metastases Secondary to Non-Small Cell Lung Cancer

This randomized phase III trial is studying whole-brain radiation therapy and stereotactic radiosurgery with or without temozolomide or erlotinib to see how well they work compared to whole-brain radiation therapy and stereotactic radiosurgery in treating patients with brain metastases secondary to non-small cell lung cancer. Radiation therapy uses high-energy x-rays to kill tumor cells. Stereotactic radiosurgery may be able to deliver x-rays directly to the tumor and cause less damage to normal tissue. Drugs used in chemotherapy, such as temozolomide, work in different ways to stop tumor cells from dividing so they stop growing or die. Erlotinib may stop the growth of tumor cells by blocking the enzymes necessary for their growth and by blocking blood flow to the tumor. It is not yet known whether radiation therapy and stereotactic radiosurgery are more effective with or without temozolomide or erlotinib in treating brain metastases.