Calculation of the electrical parameters in electrochemotherapy of solid tumours in mice.

Electrochemotherapy is a novel approach in chemotherapeutic drug delivery into tumours. Short intense direct current electric pulses are applied to tumour tissue causing electropermeabilisation thus enabling entrance of chemotherapeutic drugs into cells which otherwise do not easily penetrate. A three dimensional anatomically based finite element model of the mouse with injected subcutaneous solid tumour was built. The main goal of the study was to evaluate the influence of the electrode orientation on the distribution of electric field in the tumour and surrounding tissue during electrochemotherapy. Two electrode configurations, previously examined in experimental study, were modelled. Electric field distributions were calculated for each configuration. The main conclusion of our study is that changing electrode orientation strongly influences the distribution of the electric field inside the tumour in the electrochemotherapy of solid tumours in mice, which is in good agreement with the results of the experimental study. The efficacy of the electrochemotherapy depends on the magnitude of the electric field intensity inside tumour tissue.