[Computer-assisted system for interstitial hyperthermia].

The combination of interstitial radiotherapy and interstitial hyperthermia is more promising in the treatment of tumors than one of these methods alone. The unit developed by us uses the afterloading needles for heating up the tumor tissue with ohm current and for controlling the distribution of temperature in the target volume. Up to twelve needles are provided by one commutator with the R.F. current controlled by the computer. The temperature is measured by three thermistors per needle which are arranged at an axial distance of 2 cm each. The linearization of the thermistor characteristics and the control of cummutator and R.F. generator is performed by the computer over an interface constructed by us. In order to achieve a homogeneous distribution of temperature in the target volume and to avoid hot spots, we have examined several needle configurations by measuring in an homogeneous phantom.