Radiofrequency ablation systems are comprised of three components: a radiofrequency generator, an active electrode, and dispersive electrodes. The RF energy is introduced into the tissue via the active electrode. As the RF energy (alternating current) moves from the active electrode to the dispersive electrode (i.e., the electrosurgical return pad) and then back to the active electrode, the ions within the tissue oscillate in an attempt to follow the change in the direction of the alternating current. This movement results in frictional heating of the tissue, and as the temperature within the tissue becomes elevated beyond 60°C, cells begin to die. It is this phenomenon that causes the region of necrosis surrounding the electrode.