Heat in Tumor Therapy

Abstract

To the Editor.— Le Veen et al (235:2198, 1976) describe their experience in treating 21 cancer patients with hyperthermia induced by radiofrequency (RF) diathermy. Their clinical results, though anecdotal, are consistent with the conclusion that if the temperature of tumors are elevated above the thermal death point for tissue, necrosis will result. This is not a surprising conclusion, and is in fact the basis of electrocautery. These results should not be confused with hyperthermic cancer therapy in the range of 42 to 45 C, in which destruction of tumor cells can be achieved without necrosis.1 The authors imply that their technique of heating is unique. This is hardly the case. An RF heating system for localized hyperthermia has been described by Gerner et al2and is actively used by that group. Furthermore, an RF unit specifically for tumor hyperthermia and operating at precisely the frequency described by Le