Patent ID: 8880195

Claim:
A method of delivering an electric field to destroy cancerous cells of a prostate tissue of a patient including positioning of an elongate urethral probe comprising a proximal end and a distal portion having an expandable member, and one or more conductive electrode elements disposed on an outer surface of the expandable member, the method comprising: advancing the distal portion of the probe through the patient's urethra so as to position the expandable member at a target location in the patient's urethra; expanding the expandable member at the target location so as to position the conductive electrode elements in contact with an inner surface of the patient's urethra at the target location; positioning one or more secondary electrodes such that a current transfer region of each of the one or more secondary electrodes is disposed within or adjacent to the prostate tissue and spaced from the electrode elements of the expandable member, thereby at least partially defining a treatment volume; and establishing an alternating electrical current flow between the electrode elements of the expandable member and the one or more secondary electrodes by delivering electrical current from at least one of (a) at least one of the one or more conductive electrode elements and (b) at least one of the one or more current transfer regions, and through tissue of the treatment volume, so as to preferentially destroy cancerous cells of the prostate tissue in the treatment volume relative to non-cancerous cells in the treatment volume.