Clinical use of a waveguide hyperthermia system for superficial tumors with deep infiltration

We have developed a new double waveguide system (AMC-2 system) for hyperthermia treatment (i.e heating tumor tissue to 40-43°C) of superficial tumors with deep infiltration. The system consists of two opposing rectangular 70 MHz rotatable waveguides. The aperture size of the bottom antenna is 20×34cm. The top antenna is interchangeable and antennas with an aperture size of 20×34cm, 15×34cm and 8.5×34cm can be selected. Clinical use of this system was demonstrated for a patient with a recurrent breast tumor. Four weekly hyperthermia sessions were applied in combination with a standard radiotherapy scheme. In order to gradually increase treatment complexity, in the first two sessions only one antenna was used and the last two sessions were performed with two antennas. Results show that appropriate phase steering can substantially improve tumor heating and thereby treatment quality. Clinical hyperthermia with this system was shown feasible.