Diagnostic Accuracy of Contrast-Enhanced Ultrasound Compared with Contrast-Enhanced Computed Tomography in the Follow-Up of Hepatocellular Carcinoma Treated with Radiofrequency Ablation

Background: Contrast-enhanced computed tomography (CECT) is considered the gold standard for assessing therapeutic response in hepatocellular carcinoma (HCC) following locoregional treatments. More recently, contrast-enhanced ultrasound (CEUS) has emerged as a promising, cost-effective alternative, although evidence supporting its use in this context remains limited. This study aimed to evaluate the diagnostic performance of CEUS compared to CECT in assessing local response of HCC nodules treated with radiofrequency ablation (RFA). Methods: We retrospectively analyzed a consecutively enrolled cohort of patients undergoing RFA for HCC at IRCCS San Matteo Hospital, Pavia, between January 2017 and January 2022. Follow-up imaging included both CEUS and CECT at predefined time points. Imaging follow-up, MRI, and/or histological results were used as the reference standard to compare CEUS and CECT. Results: A total of 55 patients (mean age 74 years, 64% male) with 79 HCC nodules were included. Complete response was observed in 57 nodules (72%), all correctly identified by CEUS, whereas 4 cases were misclassified by CECT. Among the 22 nodules (28%) with residual disease, CEUS correctly identified 15 cases, while 17 were detected by CECT; notably, CEUS identified 4 lesions missed by CECT, which identified 6 missed at CEUS. Combined, the two modalities detected 21 (96%) out of 22 residual tumors. CEUS showed a sensitivity of 68.1%, specificity of 100%, and diagnostic accuracy of 91.1%, compared to 68.0%, 98.1%, and 88.6%, respectively, for CECT, with no significant differences. Conclusions: CEUS is a reliable, non-inferior, and complementary modality to CECT for evaluating treatment response of HCC following RFA. Larger prospective studies are warranted to further define its role in clinical practice.