The present invention is related to a method of realizing percutaneous (transperineal) ablation of prostate tumor regions, using a radio frequency based coiled device. A bipolar electrode assembly comprising an outer helical electrode and an inner electrode arranged concentric with the outer helical electrode, wherein prior to applying radio frequency energy, at least the outer helical electrode is inserted percutaneously into the prostate. An image of the prostate and of the outer helical electrode as inserted is acquired, such that the outer helical electrode is visualized on the image. A graphical representation of a target position of the bipolar electrode assembly is superposed on the image.
