 This phase I trial is studying the side effects and best dose of cediranib maleate when given together with whole brain radiation therapy in treating patients with brain metastases from non-small cell lung cancer. Cediranib maleate may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth or by blocking blood flow to the tumor. Radiation therapy uses high-energy x-rays and other types of radiation to kill cancer cells and shrink tumors. Giving cediranib maleate together with radiation therapy may kill more tumor cells 