The probe is inserted into the tumor during surgery, or through small incisions (left). Prongs are extended (middle), and electrical current is applied (right). The current heats up the tumor, and destroys it.
Currently available probes from Boston Scientific (left), Rita (middle) and Radionics (right).
Computer simulation can estimate the temperature inside the tumor, and help design better devices. (red=90°C, light blue=50°C).