Histopathogical changes of the normal liver by local hyperthermia were studied in rabbits. Hyperthermia was administered by an RF current heating divece with needle type applicators. Rabbits were allocated into 3 heated groups according to the treatment temperature and one control group. At laparotomy the left medial lobe of the liver was heated for 30 min at 38-39, 40-41 and 42-43 °C respectively. The livers were excised for the histopathological examination 1, 3, 7, 30, 90, and 180 days after the treatment. Irreversible changes did not occur after heating at lower than 41 °C. Extensive necrosis developed 1-7 days after heating at 42-43 °C and the necrotic area was gradually absorbed and replaced by fibrosis 30-180 days after heating.
These rusults indicate that the effect of local hyperthermia on the normal rabbit liver depends on temperatures and the irreversible change seems to occur when the liver is heated at higher than 42-43 °C.
