Accuracy of Contrast-Enhanced Ultrasound for Hepatocellular Carcinoma post Transcatheter Arterial Chemoembolization

Purpose This prospective pilot study was performed to evaluate non-inferiority between CEUS and the clinical gold standard of CECT/MRI in patients with HCC following TACE in a United States population using Lumason® contrast agent and Liver Reporting and Data System (LIRADS). Methods Following institutional review board protocols, adult patients with a first-time diagnosis of HCC were identified and consented for inclusion. Follow-up CT/MRI was directed by referring clinicians and CEUS was performed on the same day. CEUS evaluated for treated lesion(s), any new lesion(s), and portal vein thrombus before and after Lumason®. Any subsequent follow-up imaging was reviewed. Results In the 26 enrolled patients, 33 target lesions were identified, size ranging between 0.9 and 16.8 cm (mean 3 cm); 26 were LIRADS-5 or -M. CEUS identified 19 cases of residual tumor, 12 with no viable disease; while CT/MRI identified 17 cases of residual tumor, 16 with no viable disease (p = 0.617). Both CEUS and CT/MRI identified 5 portal vein thrombi, 2 lesions were missed or miscategorized on CEUS, while 6 were missed or miscategorized on CT/MRI (p = 0.289). Six new lesions were identified on both CEUS and CT/MRI ranging between 0.7 and 3.3 cm (mean 1.6 cm) on CEUS, and 0.7 and 2.8 cm (mean 1.7 cm) on CT/MRI. Of these new lesions, 4 were identified only on CT/MRI and 3 only by CEUS. Post-TACE, there was no significant difference in detecting residual tumor and no viable tumor between CEUS and CT/MRI (p = 0.617). Conclusion CEUS is non-inferior to CT/MRI performed at identical follow-up interval, in evaluating for residual versus treated HCC following first-time TACE. CEUS may represent an option for patients with contrast allergies or contraindications to MRI. CEUS can be used to examine small or isoechoic tumors after treatment.