Treatment plan for parotid metastasis (No.1). The upper row (A-C) shows the 3-D model with the bone (white), tumor (yellow), blood vessels (red), and electrodes (black) shown for clarity. Lower row (D-F) shows the electric field strength according to the treatment plan. Blue color indicates tumor covered above 400 V/cm, while violet indicates normal tissue above 350 V/cm. Care was taken to ensure electrodes would avoid the major blood vessels and the bone.