3D versus 2D contrast-enhanced sonography in the evaluation of therapeutic response of hepatocellular carcinoma after locoregional therapies: preliminary findings

Objective: To investigate diagnostic performance of 3D contrast-enhanced ultrasound (CEUS) compared with 2D CEUS in the assessment of therapeutic response of hepatocellular carcinoma (HCC) treated with locoregional therapies (LRT). Materials and methods: Twenty-three consecutive patients (13 men and 10 women; mean age 65.5years) with 23 HCCs (size range 1.2–7.2cm; mean size 2.9±1.4cm) treated by means of radiofrequency ablation (RFA n=9), transarterial chemoembolization (TACE n=8), combined RFA and TACE (n=3), percutaneous alcoholization (n=2), and wedge resection (n=1) underwent 2D and 3D CEUS 1month (30±2days) after treatment. Magnetic resonance (n=17) and computed tomography (n=6) acted as standard of reference (SOR). Two radiologists assessed the absence (complete response CR) or presence (residual tumor RT) of any nodular arterially enhancing area within or along the margin of the treated HCC. Results: Both 2D and 3D CEUS observed CR in 10/23 (43.5%) HCCs and RT in 11/23 (47.8%) HCCs. In 1/23 (4.3%) HCC, RT was documented by SOR and 2D CEUS, but it was not appreciable at 3D CEUS. In 1/23 (4.3%) HCC, the presence of peripheral residual tumor was suspected by both 2D and 3D CEUS, but it was not confirmed by SOR. No statistically significant difference between 2D and 3D CEUS in depicting either CR or RT was found (p>0.05). Sensitivity, specificity, positive and negative predictive values, and accuracy of 3D CEUS were 91.7% [95% confidence interval (CI) 0.760–1.073], 90.9% (95% CI 0.739–1.079), 91.7, 90.9, and 91.3%, respectively. Conclusion: 2D and 3D CEUS provided similar diagnostic performance in the assessment of therapeutic response of HCC treated with LRT.