Pretreatment Microbubble-Induced Enhancement in Hepatocellular Carcinoma Predicts Intrahepatic Distant Recurrence After Radiofrequency Ablation

Abstract

The purpose of this study is to examine whether pretreatment findings in hepatocellular carcinoma (HCC) using contrast-enhanced ultrasound can predict local or distant recurrence after radiofrequency ablation (RFA). Subjects of the prospective study were 54 patients with HCC lesions treated by RFA. Intensity differences between lesion and liver parenchyma at early arterial (4 seconds) and peak enhancement times and washout at late phase were provided on contrast-enhanced sonograms with perflubutane microbubble agent. The pretreatment findings were examined with respect to intrahepatic local and distant recurrence. Univariate analysis showed that intensity differences at the early arterial time (hazard ratio [HR], 2.2; 95% CI, 1.0-4.6; p = 0.042) and lesion frequency (HR, 2.3; 95% CI, 1.0-5.0; p = 0.044) were risk factors for distant recurrence. Multivariate analysis showed that intensity differences at the early arterial time (HR, 2.7; 95% CI, 1.2-5.8; p = 0.014) and lesion frequency (HR, 2.9; 95% CI, 1.3-6.5; p = 0.015) were risk factors for distant recurrence. The cumulative distant recurrence rate for patients with intensity differences at the early arterial time was greater at less than 10 dB than at 10 dB or higher (33.3% and 91.3% vs 23.9% and 65.1% at 1 and 2 years, respectively; p = 0.035). The cumulative distant recurrence rate was 16.5% and 61.1% at 1 and 2 years, respectively, in patients with solitary lesions and 54.7% and 77.4% at 1 and 2 years, respectively, in patients with multiple lesions (p = 0.0296). No pretreatment findings were predictive for local recurrence. HCC lesions with gradual enhancement in the early arterial time displayed potential distant recurrence risk after RFA, requiring careful posttreatment surveillance.