The purpose of this observational chart review study is to evaluate the efficacy and safety of Radiofrequency Ablation (RFA) for treatment of indeterminate thyroid nodules before and after RFA procedure. This is a data collection study in which the investigators ask patients to give access to information generated before and after RFA treatment of their condition. The RFA procedure uses image guidance to place an electrode through the skin into the target area. In RFA, high-frequency electrical currents are passed through an electrode, creating a small region of heat to treat the lesion.