[Hyperthermia in malignant tumors of the extremities--experimental heating by a radiofrequency applicator and its clinical significance].

We studied hyperthermia for malignant tumors of the extremities, and obtained the following findings. In osteosarcoma cultured cells from OST (Human) and Dunn (Mouse), proliferation was clearly inhibited on being heated to 42 approximately 43 degrees C. On heat-treating the femurs of pigs, a rise in temperature to 42.5 degrees C or above was observed so that an antitumor effect could be anticipated. Moreover, no abnormal rise in temperature in the tissues surrounding the bone and light microscopy revealed no particular abnormalities. Clinically, a rise in temperature above 42.5 degrees C was observed in the majority of the malignant bone tumors (4 cases of osteosarcoma and 1 case of chordoma) and soft tissue tumors (1 case of epithelioid sarcoma, malignant fibrous histiocytoma, rhabdomyosarcoma, malignant melanoma and osteosarcoma) of which 2 cases were metastatic tumors. Before administration, 7 patients complained of pain, 4 of whom (57%) experienced an alleviation following treatment. Also in 5 (50%) out of 10 cases a shrinking of the tumor was observed and especially, in the case of soft tissue tumors a tendency towards a softening of tumor texture was seen.