Clinical results of thermoradiotherapy for recurrent lung cancers--comparison of results with radiotherapy alone

From October 1986 through December 1989, 18 patients with locally recurrent lung cancer were treated by local hyperthermia combined with radiotherapy at the Kawasaki Medical School Hospital. Nine patients were initially treated by radiotherapy for inoperable lung cancer or as adjunct postoperative therapy. The other 9 were initially treated by chemotherapy or operation. Local heat was applied with a 13.56 MHz radiofrequency (RF) capacitive heating equipment, twice a week after radiotherapy, for 45-60 minutes per session. The results were compared with 17 patients with locally recurrent tumors which were treated by radiation therapy alone between January 1981 and September 1986. Tumor temperatures of two patients were measured directly by thermocouples inserted into the tumors which partially attached to the chest wall. As we were unable to measure tumor temperatures in the other 16 because of the anatomical difficulty, we measured the temperatures of the esophagus as near as possible to these lesions. Based on thermometry results, it was estimated that the maximum tumor temperatures were about 40-41 degrees C. The local response rates (CR + PR) were 25% in patients treated with combined therapy and 7% in those with RT alone. The median survivals after onset of retreatment were 10.7 months and 5.0 months, a statistically significant difference being demonstrated. Severe complications were not seen in this treatment.