An electrical ablation apparatus comprises first and second electrodes. Each electrode comprises a first end configured to couple an energy source and a second end configured to couple to a tissue treatment region. An energy source is coupled to the first and second electrodes. At least one electrode is movable between a first position and a second position. A first necrotic zone having a first shape is created when the electrodes are energized in the first position and a second necrotic zone having a second shape is created when the electrodes are energized in the second position. At least one electrode may be pre-formed with a radius.
