Temperature controlled microwave ring radiator for hyperthermia therapy

The authors have constructed a dual therapy plaque applicator for simultaneous thermoradiotherapy of small tissue volumes requiring a high degree of treatment localization. The applicator consists of a 1-cm diameter copper tubing ring which is embedded in dielectric potting resin inside a top-hat-shaped copper plaque. The ring is driven with a 10-W 2450-MHz power source while at the same time water is circulated in the tubing to adjust heating at the tissue surface relative to that at depth. Temperature distributions from the plaque applicator were characterized with 2-mm incremental mapping in two different tissue volumes, one with high and one with low blood perfusion. The results show that tissue regions up to 8-10 mm in depth can be heated to 42.5-45.0 degrees C while surface temperatures are maintained below 42.5 degrees C.<>