PRE-CLINICAL TRIAL OF A RADIANT-HEAT DEVICE FOR WHOLE-BODY HYPERTHERMIA USING A PORCINE MODEL

Abstract

After review of the published clinical experience with systemic hyperthermia [for cancer therapy] a simple system which controls radiant heat balance to supplement metabolic heat might provide several advantages including the following: decreased morbidity; elimination of the requirement for general anesthesia; improved patient comfort; favorable cost-benefit considerations. A prototype radiant heart device for whole-body hyperthermia (WBH) in patients with disseminated cancer was tested. From preclinical evaluation of this device, the lightly anesthetized pig was found to be an ideal model for WBH; this species has physiological characteristics closely resembling those of humans. The pig''s core, pulmonary artery, liver, rectal and esophageal tempertures were raised to 41.8.degree. In 80-90 min. The air temperatures near the chamber wall never exceeded 65.degree.; the air temperature adjacent to the animal was 46.degree. C. Skin temperatures were .apprx. 42.5.degree. C at a core temperature of 41.8.degree. C. Once the core temperature is raised to 41.8% C, this temperature is maintainable for .apprx. 3.5 h without additional external heating if evaporative losses are controlled. Prolonged WBH was accomplished with light sedation and without the requirement for endotracheal intubation. No significant acute toxicity was encountered in a series of 6 pigs undergoing 9 separate exposures to WBH. This radiant heat apparatus is apparently feasible for clinical trials. The use of the pig as an appropriate animal model for further physiological and pharmacological WBH studies is strongly recommended.