Effect of Radiofrequency Induced Local Hyperthermia on Normal Canine Liver

간조직에 온열치효를 시행시 출현하는 조직병리학적 소견 및 혈액의 생화학적 소견을 관찰하고자 13마리의 정상 간에 8MHz 라디오파를 이용한 온열치료를 시행하였다. 42.5±0.5°C로 30분간 온열치료를 받은 군 (제1군, n=5), 45±0.5°C로 30분간 온열치료를 받은 군 (제2군, n=5) 및 온열치료를 받지않은 대조군(n=3)으로 나누어 분석하였을때, 혈액의 SGOT의 SGPT는 온열치료를 시행한 두군 공히 증가된 소견을 보였고 제 1군에서는 간세포의 부종소견의 특이한 조직병리학적소견이 관찰되지않아 가역성 변화로 생각되었지만 제2군에서는 간 세포의 심한 괴사소견이 관찰되어 있는 불가역성의 가조직 손상으로 생각되었다. 이상의 결론으로 유추할 때 임상에서 행하여지는 간암의 온열치료시에 정상 가조직의 손상을 가능한 방지하기위하여는 정확한 종괴의 구역에 치료온도의 주의깊은 관찰이 요구된다.

In order to assess the effects of radiofrequency-induced local hyperthermia on the normal liver, histopathologic findings and biochemical changes after localized hyperthermia in canine liver were studied. Hyperthemia was externally adminsitered using the Thermotron RF-8 (Yamamoto Vinyter Co., Japan; Capacitive type heating machine) with parallel opposed electrodes. Thirteen dogs were used and allocated into one control group (N=3) and two treatment groups according to the treatment temperature. Group I (N=5) was heated with 42.5±0.5°C for 30 minutes, and Group Ⅱ (N=5) was heated with 45±0.5°C for 15-30 minutes. Samples of liver tissue were obtained through a needle biopsy immediately after hyperthermia and 7, 14, and 28 days after treatment. Blood samples were obtained before treatment and 1, 3, 5, 7, 14 and 28 days after treatment and examined for SGOT, SGPT and alkaline phosphatase. Although SGOT and SGPT were elevated after hyperthermia in both groups (three of five in each group), there was no liver cell necrosis or hyperthermia related mortality in Group Ⅰ. A hydropic swelling of hepatocytes was prominent histologic finding. Hyperthermia with 45°C for 30 minutes was fatal and showed extensive liver cell necrosis. In conclusion, liver damage dy heat of 42.5±0.5°C for 30 minutes is reversible, and liver damage by heat of 45±0.5°C for 30 minutes can be fatal or irreversible. However, these results cannot be applied directly to human trial. Therefore, in order to apply hyperthermic treatment on human liver tumor safely, close observation of temperature with proper thermometry is mandatory. Hyperthermic treatment should be confined to the tumor area while sparing a normal liver as much as possible.