 Recently, new electrochemotherapy modalities have been developed for treatment of internal tumors using surgical procedures, endoscopic routes, or percutaneous approaches to gain access to the treatment area.When a biological cell is exposed to an electric field of sufficient strength, an increase in the transmembrane voltage is generated, which leads to rearrangements of the cell membrane structure.These changes result in an increase of the cell membrane permeability, which allows nonpermeant molecules to enter the cell.