Radiofrequency Ablation is a special needle electrode is placed in the tumor under the guidance of an imaging method such as ultrasound or computed tomography (CT) scanning. A radiofrequency current then is passed through the electrode to heat the tumor tissue near the needle tip and ablate-or eliminate-it. The heat from radiofrequency energy also closes up small blood vessels, thereby minimizing the risk of bleeding. In general, radiofrequency ablation causes only minimal discomfort and may be done as an outpatient procedure without general anesthesia. Admission to the hospital is not usually necessary.