Short-term efficacy of ultrasound-guided percutaneous ethanol injection enhanced single needle radiofrequency ablation in the treatment of liver cancer

Abstract

Objective To investigate the short-tern efficacy of ultrasound-guided percutaneous ethanol injection (PEI) enhanced single needle radiofrequency ablation ( RFA) in the treatment of liver cancer.Methods The clinical data of 71 patients who were admitted to the Xijing Hospital from June 2010 to June 2011 were retrospectively analyzed.All patients were divided into the RFA group (25 patients ) and RFA + PEI group (46 patients).In the RFA group,the needle of RFA was injected into the tumor for coagulation with the guidence of ultrasound.In the RFA + PEI group,95％ ethanol was injected into the tumor with the guidence of ultrasound,and then RFA was performed.The tumor necrosis volumes of the 2 groups were assessed by contrast-enhanced ultrasound at 2 weeks after RFA.The relationship between the average RFA energy and volume of ethanol applied and necrosis volume was analyzed.All data were analyzed by using the chi-square test,t test and Pearson correlation coefficient.Results The volume of coagulative necrosis of the RFA group was (22 ± 17) cm3,which was significantly smaller than (55 ± 44) cm3 of the RFA + PEI group (t =3.85,P ＜ 0.05 ).In the RFA + PEI group,the volume of ethanol injected was positively correlated with the volume of coagulative necrosis (r =0.615,t =5.86,P ＜ 0.05 ),but negatively correlated with the treatment efficacy ( r =- 0.709,t =- 7.52,P ＜ 0.05 ).The amount of required energy was positively correlated with the volume of coagulative necrosis (r =0.884,t =14.13,P ＜0.05 ),whereas no significant correlation was detected between the amount of required energy and the treatment efficacy ( r =- 0.225,t =- 1.72,P ＞ 0.05 ).The equation for calculating the volume of ethanol required was conducted:Y =2.526X - 2.693 [ Y:volume of ethanol required ( ml),X:diameter of the tumor (cm) ].Three patients in the RFA + PEI group were complicated by transient pain,flushing and cardiac acceleration after the operation,and the symptoms were alleviated by symptomatic treatment.The levels of transaninase were increased in the 3 groups,and then back to normal at 2 weeks after the treatment.No complications such as hepatic rupture,intestinal perforation,bile leakage or tumor implantation were detected in the 2 groups.The levels of alphafetoprotein (AFP) were significantly decreased.The AFP expressions of 20 patients (80％) in the RFA group and 39 patients (85％) in the RFA + PEI group changed to negative,with no significant difference between the 2 groups ( x2 =0.42,P ＞ 0.05 ).Conclusion PEI helps to increase the volume of coagulative necrosis and to reduce the energy requirement of routine RFA,and enhances the efficacy of single needle RFA. Key words: Liver neoplasms; Ultrasound guidence; Percutaneous ethanol injection; Radiofrequency ablation, single needle