Contrast-Enhanced Ultrasound in the Short-Term Evaluation of Hepatocellular Carcinoma after Locoregional Treatment

Abstract

Background: Contrast-enhanced ultrasound (CEUS) with second-generation contrast agents performed 1 month after hepatocellular carcinoma (HCC) treatment is almost as sensitive as contrast-enhanced computed tomography (CECT) in depicting the residual tumor. However, the efficacy of CEUS performed early after the procedure is still debated. Aim: We evaluated the diagnostic accuracy (DA) of CEUS for the assessment of tumor response shortly after locoregional therapy in patients with unresectable HCC. Methods: Ninety-four patients with 104 HCC lesions who were scheduled to receive percutaneous ethanol injection, radiofrequency ablation, transcatheter arterial chemoembolization, or combined treatment were enrolled in this study. With CECT at 1-month as the reference standard, the DA of CEUS performed 48-h after the procedure was evaluated. Patients were followed-up to look for tumor or disease progression. Results: Based on CECT findings, 43/104 lesions were diagnosed as having residual viability after 1 month. CEUS performed 48 h after treatment detected residual tumor in 34/43 nodules with treatment failure at CECT with a sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of 79.1, 96.7, 94.4, 86.8, and 89%, respectively. There was a high degree of concordance between CEUS and CECT (kappa coefficient = 0.78). A hyperemic halo was detectable in 35 lesions without a statistically significant difference between concordant and discordant cases. In patients with uninodular disease responders according to 48 h CEUS had a significantly longer mean overall survival and time to progression compared to nonresponders. Conclusion: CEUS performed 48 h after treatment can be considered a reliable modality for the evaluation of the real extent of necrosis and has prognostic value in the assessment of HCC.