Computer controlled microwave system for clinical hyperthermia

A hyperthermia system which has been developed for clinical use is described. Different direct-contact applicators working at the ISM microwave frequency of 915 MHz are used for inducing heat in superficial tumours to a depth of about 3 cm. The system is a further development of an earlier prototype which worked at 2450 MHz. The microwave generator is controlled by a microcomputer governed by temperature measurements with thermistor probes inserted into the tissue. To minimise the influence of the interaction between the microwaves and the temperature probes, a pulsed irradiation technique is used. Up to July 1984, 80 superficial tumours had been treated with radiotherapy combined with local hyperthermia applied using this system.