Interstitial implant with interstitial hyperthermia.

A Phase I Pilot Study combining interstitial or intracavitary irradiation using 192Ir or 137Cs and interstitial hyperthermia in advanced or recurrent tumors is underway at the City of Hope National Medical Center. Hyperthermia is performed using 0.5 megahertz RF (500 kilohertz) radiofrequency localized current fields. In the implanted volume, a temperature of 41 degrees to 45 degrees C is maintained for 30 to 40 minutes. Hyperthermia is performed prior to irradiation in all patients. All patients had either failed previous conventional treatments, including surgery, chemotherapy and/or radiation therapy, or had advanced malignant tumors which were not felt to be controllable by conventional means. Sixteen lesions were implanted in 15 patients. Of the 16 lesions, 11/16 (68%) achieved complete response, and three had no response or recurred locally. The six patients (100%) receiving interstitial implant and hyperthermia as the primary therapy achieved complete response. Normal tissue complications were minimal. Range of response was three to 13 months. Interstitial thermoradiotherapy appears to be a safe and promising mode of therapy in advanced or recurrent accessible malignant tumors.