| Image-guided radiofrequency ablation (RFA) and microwave ablation(MWA) are the main thermal ablations for the treatment of liver cancer. Since the beginning of the last century in 90s, radiofrequency ablation technology has been applied in clinical practice and rapidly become a first-line therapy for the local treatment of liver cancer. With technology innovation and application of the internal cooling electrode, microwave ablation has been more and more widely used in clinical therapy. According to the unresectable liver tumors, RFA and MWA are the ideal choice, which have been reported by bulk-case studies and multi-centre studies for their effectiveness and safety. RFA and MWA are minimally invasive treatment. With the application of the internal cooling electrode, low incidence of major complications occurs during the two thermal procedures. But there are some Serious complications such as liver abscess, hemorrhage, Intestinal perforation, pneumothorax, and Tumor Seeding et al. Of these, liver abscess is one of the most common complications. In clinical practice, it is import to choose the best thermal ablation and to avoid related serious complications. On the one hand,224 patients with Tumor diameter measuring 5cm or smaller treated by cool-tip RFA or MWA were enrolled to evaluate the effectiveness and safety. On the other hand, the clinical records of 691 patients with liver tumors who underwent RFA orMWA were retrospectively analyzed, in order to determine the incidence of liver abscesses and to identify the risk factors for liver abscess formation.Part I Cool-tip Radiofrequency versus Microwave Ablation Treatment for Hepatocellular Carcinoma Measuring 5cm in Greatest Diameter:A Comparison of Efficacy and SafetyObjective:To evaluate the short and long term efficacy and safety of cool-tip radiofrequency ablation compared with microwave ablation for hepatocellular carcinoma measuring 5cm in greatest diameter.Methods:This investigation was a retrospective case series study. From July 2006 to February 2011,224 patients with primary liver cancer underwent percutaneous cool-tip radiofrequency ablation or microwave ablation at Qilu hospital of Shandong University and Weihai Municipal hospital, including 154 male and 70 female patients. Among these patients,108 patients underwent RFA whereas 116 patients underwent MWA. Their clinical records were collected in this retrospective study. The inclusion criteria for the thermal ablation patients were as follow:primary liver cancer, child-pugh class A or class B cirrhosis, a solitary tumor of 5 cm in greatest diameter or smaller, three or fewer multiple tumors with a greatest diameter of 3 cm or less, no portal vein tumor thrombus or extrahepatic metastasis, no severe functional disorders or major organs, prothrombin activity above 40%, platelet count of>50 x 109/L. Local anesthesia or local anesthesia after intravenous anesthesia were done before percutaneous cool-tip RFA or MWA under ultrasound or CT guidance. All patients were followed up for at least 5 years. Ablation effects were evaluated by enhanced CT or enhanced MR examination. Complete ablation(CA) rates, local tumor recurrence (LTR) rates, tumor-free survival(TFS) rates, overall survival(OS) rates, and major complications(MC) were compared between group RFA and group MWA. Then the risk factors of survival rate were analyzed.Results:All patients were successfully treated by ultrasound or CT guided percutaneous RFA or MWA. The CA rate was 91.1% for RFA and 94.9% for MWA (x2=0.12, P=0.88). LTR was found in 10 of 123(8.1%) in RFA group and 9 of 139(10.1%) in MWA group (x2=0.25, P=0.70). The LTR of tumor diameters of 3.0cm or smaller was 4.2%(4/96) for RFA and 5.6%(6/106) for MWA(x2=0.23, P=0.63).The LTR of tumor diameters of 3.1-5.0 cm was22.2%(6/27) for RFA and 8.3%(3/36) for MWA(x2=1.80, P=0.08). The 1-,3-and 5-year recurrence-free survival rates were 84.3%,39.4% and 16.6% for RFA and 81.2%,40.5% and 19.2% for MW ablation, with no significant difference (log-rank Test,x2=0.30, P=0.584). There was no significant difference in the 1-,3-,and 5-year overall survival rates between the two groups (log-rank Test,x2=0.989, P=0.32), which were 97.2%,71.4% and 41.1% for the MWA group, and 81.2%,40.5% and 19.2% for the RFA group, respectively. In subgroup analyses, for patients with tumor diameters of 3.0 cm or smaller, there was no significant difference in the 1-,3-, and 5-year tumor-free survival rates (log-rank Test,%2=0.003, P=0.959) and the corresponding overall survival rates (x2=0.191, P=0.662), which were 86.2%,46.0% and 17.1% for the MWA group, and 80.2%, 39.4% and 18.2% for the RFA group, respectively. For patients with tumor diameters of 3.1-5.0 cm, the 1-,3-, and 5-year recurrence-free survival were 78.2%,20.8% and 16.4% for RFA and 83.4%,44.1%,20.3% for MWA, with no significant difference (log-rank Test,x2=1.173, P=0.279). For patients with tumor diameters of 3.1-5.0 cm, there was significant difference in the 1-,3-, and 5-year overall survival rates between the two groups (log-rank Test,x2=4.656, P=0.031), which were 86.3%,41.5% and 14.2% for the RFA group, and 88.4%,62.6% and 49.1% for the MWA group, respectively. Moreover, there was no significant difference(x2=0.69, P=0.39) in major complication rates between RFA group(4.6%) and MWA group (2.6%). From cox proportional hazard model, There was increased survival for patients treated with preoperative TACE and intraoperative combination with PEI with hazard ratios of 1.296 (95% confidence interval(CI),1.127-1.878; P=0.034) and 1.345 (95%CI, 1.33-1.984; P=0.016) respectively. There were no patient deaths due to treatment.Conclusion:Cool-tip RFA and MWA are both effective and safe methods in treating hepatocellular carcinoma measuring 5cm in greatest diameter, with no significant differences in complete ablation rates, local tumor recurrence rates, tumor-free survival rates, overall survival rates, and major complications. For HCC diameter of 3.1-5cm, longer survival time may be obtained for MWA than RFA, which are affected by preoperative TACE and intraoperative combination with PEI.PartⅡ Incidence and Risk Factors for Liver Abscess After Thermal Ablation of Liver NeoplasmObjectives:The objective of this study was to determine the incidence and risk factors of liver abscess formation after thermal ablation of liver cancer.Materials and Methods:The clinical data of 691 patients who underwent thermal ablation procedures for liver cancer were collected in order to retrospectively analyze the basic characteristics, incidence, and risk factors associated with liver abscess formation. Patients with multiple risk factors for liver abscess formation were enrolled in a risk factor group, and patients with no risk factors were enrolled in a control group. The chi-square test and multiple logistic regression analysis were used to analyze the relationship between the occurrence of liver abscesses and potential risk factors.Results:Three hundred and eighty five patients underwent RFA procedures, and 306patients underwent MWA procedures. This study’s patients included 569 males and 122 females between the ages of 23 and 79 years. Of the 691 patients analyzed, 172 were diagnosed by percutaneous biopsy; of these,108 had hepatocellular carcinoma and 64 had hepatic metastasis. Four hundred and nineteen patients were diagnosed with typical imaging examinations and the presence of tumor markers. The median diameter of the tumors was 3.2±2.3 cm (range 0.5-8.5 cm). The total incidence of liver abscesses was 1.7%, while the rates in the RFA group (1.8%) andMWA groups (1.6%) were similar (P> 0.05). The rates of liver abscesses in patients who had child-pugh class B and class C cirrhosis (P= 0.0486), biliary tract disease (P= 0.0305), diabetes mellitus (P= 0.0344), and porta hepatis tumors (P= 0.0123) were 4.0%,6.7%,6.5%, and 13.0%, respectively. There was a statistically significant difference between these four groups and the control group (all P< 0.05). The incidence of liver abscesses in the combined ablation and percutaneous ethanol injection (PEI) group (P= 0.0026) was significantly lower than that of the ablation group (P< 0.05).Conclusions:The incidence of liver abscesses after liver cancer thermal ablation is low. Child-Pugh Class B and Class C cirrhosis, biliary tract disease, diabetes mellitus, and porta hepatis tumors are four significant risk factors. Combined ablation with PEI reduces the rate of liver abscesses. |
PDF Full Text Request