Iodine I 131 and Pazopanib Hydrochloride in Treating Patients With Recurrent and/or Metastatic Thyroid Cancer Previously Treated With Iodine I 131 That Cannot Be Removed By Surgery

This phase I trial is studying the side effects and best dose of iodine I 131 when given together with pazopanib hydrochloride in treating patients with recurrent and/or metastatic thyroid cancer previously treated with iodine I 131 that cannot be removed by surgery. Radioactive drugs, such as iodine I 131, may carry radiation directly to cancer cells and not harm normal cells. Pazopanib hydrochloride may stop the growth of tumor cells by blocking some of the enzymes needed for cell growth. Giving iodine I 131 together with pazopanib hydrochloride may be an effective treatment for thyroid cancer.