Clinical radiofrequency hyperthermia: a review

Localized radiofrequency (RF) hyperthermia is being investigated for potential use in cancer therapy, both as a single agent and in combination with radiation therapy and chemotherapy. Standard capacitive and inductive heating techniques and new technology, including magnetrode magnetic-loop induction, are being compared for safety and efficacy. Clinical trials suggest that effective localized RF hyperthermia may be administered safely to both superficial and deep visceral tumors with proper equipment. Temperatures of 42 degrees C or greater appear to be tumoricidal, though higher temperatures and longer and multiple treatments seem most beneficial. Effective heating of tumors has been independent of histology but could be related to size and blood flow. Combined with radiation therapy and chemotherapy, hyperthermia appears to have a synergistic or additive effect. These trials indicate that localized RF hyperthermia may soon provide a significant contribution to our armamentarium against cancer.