Human hyperthermic therapy: relation between tumor type and capacity to induce hyperthermia by radiofrequency

There is mounting evidence that hyperthermia of 42 degrees C or greater is tumoricidal to cell cultures and to animal and human tumors. However, temperatures of 45 degrees C or greater may have greater potential therapeutic benefit. The ability to selectively achieve such highintratratumor temperatures without injury to normal tissue may be due to the relatively poor blood flow in tumors compared with that in normal tissues. While vascularity and blood flow are known to vary significantly among tumors, we found that of 52 tumors evaluated, temperatures of 42 degrees C or greater in 42 tumors (81 per cent) and of 45 degrees C or greater in 23 tumors (44 per cent) appeared to be independent of the histologic type of tumor. Therefore, therapeutic hyperthermia may be possible for most varieties of human solid cancer.