Contrast-enhanced US with Perfluorobutane(Sonazoid) used as a surveillance test for Hepatocellular Carcinoma (HCC) in Cirrhosis (SCAN): an exploratory cross-sectional study for a diagnostic trial

Abstract

BackgroundUltrasonography (US) is widely used as a standard surveillance tool for patients who are at a high risk of having hepatocellular carcinoma (HCC); however, conventional B-mode US appears to be insufficient in order to ensure the early detection of HCC. Perfluorobutane allows very stable Kupffer phase imaging for at least 60 min, which is tolerable for examinations of the entire liver. The purpose of our study is to evaluate the added value of contrast-enhanced US using perfluorobutane to that of conventional B-mode US as an HCC surveillance tool for patients with liver cirrhosis.Methods/DesignSCAN (Sonazoid-US for surveillance of hepatoCellulArcarciNoma) is a prospective, multi-institutional, diagnostic trial using an intra-individual comparison design in a single arm of patients. This study was approved by our five institutional review board and informed consent was obtained from all participating. We obtained consent for publication of these data (contrast enhanced US images, CT or MRI images, laboratory findings, age, sex) from all participating patients. All patients will undergo conventional B-mode US immediately followed by contrast-enhanced US. The standardized case report forms will be completed by operating radiologists after B-mode US and contrast-enhanced US, respectively. If any lesion(s) is detected, the likelihood of HCC will be recorded. The primary endpoints are a detection rate of early-stage HCC and a false referral rate of HCC. Intra-individual comparison using Mcnemar’s test will be performed between B-mode US and contrast-enhanced US. The study will include 523 patients under HCC surveillance in five medical institutions in Korea.DiscussionSCAN is the first study to investigate the efficacy of contrast-enhanced US in surveillance using two reciprocal endpoints specialized for the evaluation of a surveillance test. SCAN will provide evidence regarding whether patients can truly benefit from contrast-enhanced US in terms of the detection of early stage HCC while avoiding additional unnecessary examinations. In addition to the study protocol, we elaborate on potentially debatable components of SCAN, including the design of an intra-individual comparison study, study endpoints, composite reference standards, and indefinite imaging criteria regarding the likelihood of HCC.Trial registrationThe date of trial registration (ClincalTrials.gov: NCT02188901) in this study is July 3, 2014. The last patient enrolled in August 30, 2016 and follow up to see the primary end point is still ongoing. All authors have no other relationships/conditions/circumstances that present a potential conflict of interest of relationships. Our study protocol has undergone peer-review by the funding body (GE Healthcare). No other relationships/conditions/circumstances that present a potential conflict of interest. Also, we clearly stated in the 'competing interests' section of my manuscript.

The AFSUMB Consensus Statements and Recommendations for the Clinical Practice of Contrast-Enhanced Ultrasound using Sonazoid

“…However, the specificity of Sonazoid CEUS was significantly higher than that of B-mode US, 0.982 (272/277) and 0.978 (271/277) versus 0.892 (247/277) and 0.949 (263/277). Similar trends were observed in prospectively collected data from five tertiary centers in Korea [77,78]. The detection rate of early-stage HCC of Sonazoid CEUS was 1.0% (95% confidence interval [CI], 0.3% to 2.2%; 5 of 524 patients) and that of B-mode US was 0.6% (95% CI, 0.1% to 1.7%; 3 of 524 patients), without a statistically significant difference (P=0.16).…”

Contrast-enhanced US with Perfluorobutane for Hepatocellular Carcinoma Surveillance: A Multicenter Diagnostic Trial (SCAN)

“…In performing US, the radiologists followed the guidelines of the Korean Society of Ultrasound in Medicine (16). The detailed technique used to perform perfluorobutane-enhanced US and the machine parameters have been reported elsewhere (17).…”

The AFSUMB consensus statements and recommendations for the clinical practice of contrast-enhanced ultrasound using sonazoid

“…Similar trends were observed in prospectively collected data from five tertiary centers in Korea. [ 77 78 ] The detection rate of early-stage HCC of Sonazoid CEUS was 1.0% (95% CI: 0.3%–2.2%; 5 of 524 patients) and that of B-mode US was 0.6% (95% CI: 0.1%–1.7%; 3 of 524 patients), without a statistically significant difference ( P = 0.16). However, the false referral rate with Sonazoid CEUS was 1.3% (95% CI: 0.5%–2.7%; 7 of 524 patients) and that with B-mode US was 4.6% (95% CI: 3.0%–6.7%; 24 of 524 patients), which was statistically significant ( P < 0.001).…”