The value of three-dimensional contrast-enhanced ultrasound fusion imaging in evaluating the ablation margin of radiofrequency ablation for hepatocellular carcinoma

Abstract

Objective To compare three-dimensional contrast-enhanced ultrasound (3DCEUS) fusion imaging and computed tomography (CT) fusion imaging in evaluating ablation margin (AM) after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC). Methods The 3DCEUS images of 60 patients before and after RFA were collected. The AM was evaluated by the self-developed 3DCEUS fusion imaging technique. The consistency of AM evaluation was compared between 3DCEUS and CT fusion imaging. The risk factors of local tumor progression (LTP) including AM were analyzed. Results The registration success rate of 3DCEUS fusion imaging was 96.7% (58/60). Thirty-one cases were in the AM<5 mm group, and 27 cases were in the AM≥5 mm group. The consistency of AM evaluation between 3DCEUS and CT fusion imaging was good (Kappa coefficient=0.895, P<0.001). During a follow-up period ranging 4.2 to 18 months, LTP was identified in 5 tumors (8.6%, 5/58). The incidence of LTP with the AM<5 mm was higher than that with the AM≥5 mm(P=0.033). Conclusions 3DCEUS fusion imaging is feasible for AM evaluation immediately after RFA with high consistency with CT fusion imaging. AM<5 mm evaluated on 3DCEUS fusion immediately after RFA is a risk factor for LTP. Key words: Contrast-enhanced ultrasound, three-dimensional; Carcinoma, hepatocellular; Fusion imaging; Radiofrequency ablation