CLINICAL-RESULTS OF RADIOFREQUENCY HYPERTHERMIA FOR MALIGNANT LIVER-TUMORS

Purpose: To evaluate thermometry and the clinical results of radiofreq uency (RF) hyperthermia for advanced malignant liver tumors. Methods a nd Materials: One hundred seventy-three patients with malignant liver tumors treated between 1983 and 1995 underwent hyperthermia. The 173 t umors consisted of 114 hepatocellular carcinomas (HCCs) and 59 non-HCC s (47 metastatic liver tumors and 12 cholangiocarcinomas). Eight-megah ertz RF capacitive heating equipment was used for the hyperthermia. Tw o opposing 25-cm electrodes were generally used for heating the liver tumors. Our standard protocol was to administer hyperthermia 40-50 min twice a week for a total of eight sessions. The liver tumor temperatu re was measured by microthermocouples when possible. Transcatheter art erial embolization, radiotherapy, immunotherapy, and chemotherapy were combined with hyperthermia treatment in accordance crith each patient 's liver function. Results: One hundred forty (81%) of the 173 patient s who underwent more than four sessions of hyperthermia were evaluated in this study. Thermometry was performed in 77 (55%) of these 140 pat ients. The maximum tumor temperature, average tumor temperature, and m inimum tumor temperature in the HCC were (mean +/- standard error) 41. 2 +/- 0.2 degrees C, 40.3 +/- 1.3 degrees C, and 40.1 +/- 0.2 degrees C, respectively. The same thermometry results for non-HCC were 42.3 +/ - 0.2 degrees C, 41.2 +/- 0.2 degrees C, and 40.9 +/- 0.2 degrees C, r espectively. The maximum and minimum temperatures (41.8 +/- 0.2 degree s C and 40.3 +/- 0.4 degrees C) in the patients with a complete or par tial response (CR or PR) were higher than those in the patients with n o response or progressive disease (NR or PD) (41.3 +/- 0.5 degrees C a nd 39.8 +/- 0.4 degrees C), but the difference was not significant. Of the 73 cases with HCC who were evaluated by computed tomography (CT), CR was achieved in 7 (10%), PR in 15 (21%), NR in 37 (51%), and PD in 14 (19%). Of the 45 cases involving liver metastases evaluated by CT, CR was achieved in 3 (7%), PR in 17 (38%), NR in 12 (27%), and PD in 13 (29%). The I-gear cumulative survival rate for HCC patients was 30. 0%, and the 5-year survival rate was 17.5%. The 1-year survival of non -HCC patients was 32.5%, and the longest survival was 30 months. The s equelae of hyperthermia included focal fat necrosis in 20 patients (12 %), gastric ulceration in 4 (2%), and liver necrosis in 1 (1%). The se quelae of thermometry were severe peritoneal pain in seven patients (1 1%), intraperitoneal hematoma in one (1%), and pneumothorax in one (1% ). Conclusion: Even though the thermometry results for liver tumors we re not satisfactory, the treatment results are promising. Further clin ical trials of RF capacitive hyperthermia for the treatment of advance d liver tumors should be encouraged. (C) 1997 Elsevier Science Inc.