Contrast-Enhanced Ultrasound with Perfluorobutane for Hepatocellular Cancer Surveillance: Our Initial Local Experience

Introduction:Ultrasound is the most commonly used modality for hepatocellular cancer (HCC) surveillance in Hong Kong but has limitations in lesion characterisation.A second-generation perfluorobutane (PFB) ultrasound contrast agent allows for lesion characterisation through the usual vascular enhancement phases and provides an additional late Kupffer phase.We reviewed current evidence of PFB use in HCC care and investigated the value of contrast-enhanced ultrasound with PFB (PFB-CEUS) compared with brightness mode (B-mode) ultrasound in surveillance for HCC in high-risk patients in Hong Kong.Methods: This prospective single-centre study assessed 50 high-risk patients under HCC surveillance undergoing B-mode ultrasound and PFB-CEUS, followed by gadoxetic acid-enhanced magnetic resonance imaging (MRI) within 3 weeks of the initial ultrasound scan.The MRI findings were considered the reference standard for the diagnosis of HCC.Detection rates of all and small (≤ 2 cm) HCCs on both modalities and the adverse event rate for each modality were evaluated. Results:The detection rate of small HCCs was 4% by B-mode ultrasound and 6% by PFB-CEUS.A total of four small HCCs were identified in our cohort.The immediate (day 0), short-term (day 7), and long-term (day 90) adverse event rates were 0%, 12% and 6%, respectively.All adverse events were mild and self-limiting, with an uncertain causal relationship to PFB administration.Conclusion: PFB-CEUS is emerging as a useful imaging modality in evaluation of liver lesions and HCC detection.Our initial local experience provides positive agreement with the literature and identifies areas requiring further investigation.