Interstitial microwave transition from hyperthermia to ablation: historical perspectives and current trends in thermal therapy.
High frequency tumor therapy requests heating of a well defined area, whereas the surroundings should be unaffected. This sort of therapy should be more tolerable than a whole body heating. For this purpose a new developed microwave applicator (433.9 MHz) for local heat application was tested in animals. Using this rectally insertable applicator the prostate of dogs were irradiated. The temperature of the rectum, the urethra and the prostate were measured and recorded using specially developed thermistor probes. The effect of hyperthermia on the prostate and the surrounding tissue was analyzed macroscopically and micromorphologically. It was shown that local heating of the prostate of dogs is possible. The induced damages of the prostate and surrounding tissue is not severe enough to be untolerable.