A total of 267 patients with hepatocellular carcinoma underwent ultrasound-guided radiofrequency ab-lation (RFA) in Peking University School of Oncology between1999 and 2005 (421 RFAsessions). Among them,254 patients were candidates for RFA treatment and the selective criteria were: (1) the greatest diameter of tumor≤8.0 cm;(2) tumor number≤4; (3) no obvious invasion into adjacent structures;(4) absence of extensivetumor thrombus in large vessels; (5) prothrombin time ratio greater than 60% and platelet count greater than 50×109/L. Of the 256 HCC patients, 206 were male and 50 were female (mean age, 56.8 years; range, 24 -80years). The mean size of the tumors was 3.8 cm (range, 1.2 -8.0 cm). Among the 256 HCC patients, 207(80.8%) were not amenable for surgery due to impairment of liver function, post-operative recurrence, multipletumors, senile, serious cardiac/respiratory damage or diabetes. According to the UICC-TNMstaging system, 61,90, 45, and 8 patients were in stagesⅠ,Ⅱ,Ⅲ, andⅣ, respectively. Fifty-two patients had recurrentHCC aftersurgical resection. Of these 256 HCC patients, their Child-Pugh grades of A, B and C were 150, 94, and 12, re-spectively. Of all the subjects,151 patients had solitary tumors and 105 had multiple tumors, and 65, 127,and 64patients had tumors sized≤3 cm, 3.1 -5 cm, and >5 cm, respectively.According to tumor size, shape and loca-tion, we adopted a defined treatment strategy, which consisted of a mathematical protocol, an individualized proto-col and adjunctive measures. And several methods were also used to prevent and deal with complications in tumorswith different features. In this series the tumor complete necrosis rate (CR)was95.2% (356/374 tumors). It washigher in≤3.5 cmtumors with a CR of98.5% (200/203 tumors) than in >3.5 cmtumors with a CR of91.3%(156/171 tumors). CR were 95.6% (44/46 tumors) for tumors near the gallbladder, 92.9%(79/85 tumors)fortumors near the diaphragm, 90.9%(40/44 tumors) for tumors near the gastrointestinal tract, 91.2% (31/34tumors)
