Radiofrequency ablation of small hepatic malignancies guided by contrast enhanced ultrasonography

Abstract

Objective To investigate the value of contrast enhanced ultrasonography (CEUS) in the treatment of small hepatic malignancies with radiofrequency ablation(RFA). Methods Seventy patients with 104 pathologically proved malignant liver lesions treated by RFA (size 0.7 -2.7 cm) were divided into 2 groups including CEUS group and control group. In CEUS group,39 patients(54 lesions) were treated with RFA guided by CEUS, while in control group 31 patients (50 lesions) were guided by conventional ultrasonography. There was no significant difference between clinical data of the two groups. Results Seventeen tumors(among them,12 lesions were less than 1.5 cm in diameter) in 13 patients showed more clearly on CEUS image than on conventional ultrasonography image (31.5% ) in CEUS group. The tumor necrosis rate at one month after RFA was 100% in CEUS group,and 92% in control group ( P = 0. 034).The number of RFA sessions per tumor was 1.00± 0.00 in CEUS group,and 1.08 ± 0.27 in control group (P = 0.000). Local tumor progression rate was 0 in CEUS group and 4% in control group ( P = 0. 138)during the period of 8 - 52 months follow-up (average 21 months). Conclusions CEUS can not only improve the display of small hepatic malignancies but also provide precise guidance in contrast with conventional ultrasonography. Compared with control group, RFA of small hepatic malignancies guided by CEUS lower the number of RFA sessions, enhance the tumor necrosis rate, decrease post-RFA local progression and therefore it has extensive clinical value. Key words: Ultrasonography; Microbubbles; Liver neoplasms; Catheter ablation