Contrast-enhanced ultrasound for screening hepatocellular carcinoma: an implemented program at a semi-rural academic center

Performance of contrast-enhanced ultrasound liver imaging reporting and data system for differentiation of patients at risk of hepatocellular carcinoma and liver metastasis

BACKGROUND

Hepatocellular carcinoma (HCC) and metastatic liver tumors (MLT) are the most common malignant liver lesions, each requiring distinct therapeutic approaches. Accurate differentiation between these malignancies is critical for appropriate treatment planning and prognostication. However, there is limited data on the performance of contrast-enhanced ultrasound liver imaging reporting and data system (CEUS-LI-RADS) in this differentiation.

OBJECTIVE

To evaluate the diagnostic efficacy of the CEUS-LI-RADS in distinguishing between HCC and MLT in an expanded population at risk for both tumors.

METHODS

Between June 2017 and January 2022, 108 patients with HCC and 138 patients with MLT who were pathologically diagnosed, where included in this retrospective study. Two radiologists independently reviewed the CEUS features and liver imaging reporting and data system (LI-RADS) categories of the lesions, and based on their consensus, we calculated the diagnostic performance, including the area under the receiver operating characteristic curve, sensitivity, specificity, and accuracy of the CEUS-LI-RADS criteria.

RESULTS

The sensitivity, specificity, and accuracy of CEUS LI-RADS category 5 (CEUS-LR-5) for predicting HCC were 49.1% [95% confidence interval (CI)) 39.3-58.9], 97.1% (95% CI 92.7-99.2), and 76%, respectively, whereas the corresponding values for LI-RADS category M (LR-M) for diagnosing MLT were 89.1% (95%CI 82.7-93.8), 72.2% (95%CI 62.8-80.4), and 81.7%, respectively. Based on current LR-M criteria, a small proportion of HCCs were classified as LR-M due to the presence of early cessation (45-60s). In the analysis of the MLT subgroup, we found that the tumor size affects the distribution of LI-RADS (LR) classification in the subgroup (p = 0.037), and LI-RADS category 3 (LR-3) classification was observed more frequently in tumors of small size (≤3cm) than those of larger size. In addition, LR-3 metastases were more frequently characterized by hypovascular supply.

CONCLUSIONS

CEUS-LI-RADS demonstrates high specificity in distinguishing HCC from MLT, providing a reliable noninvasive diagnostic tool that can enhance clinical decision-making. These findings are clinically significant as they can improve patient management and treatment outcomes, and they underscore the need for future research to refine and expand the use of CEUS-LI-RADS in diverse clinical settings.

Occult liver nodules: their detection and characterization with CEUS

OBJECTIVES

Contrast enhanced ultrasound (CEUS) now joins the ranks of CT and MRI for noninvasive diagnosis of hepatocellular carcinoma (HCC). CEUS LI-RADS provides greater than 95% specificity for diagnosis within LR-5. Unlike CT/MRI, CEUS is nodule based. Currently, LI-RADS does not recommend CEUS of nodules occult or invisible on pre-contrast ultrasound except by experts. This study addresses our ability to find occult nodules using CEUS and to characterize them with CEUS LI-RADS.

METHODS

100 patients at risk for HCC, 81 with cirrhosis, with occult lesions were retrospectively identified from our archived patient logs. All patients had CEUS examination. Three specialized CEUS techniques (blindshot injection, portal venous (PVP) sweep of the liver, and on-top injection) are used to evaluate nodules.

RESULTS

There were 114 occult lesions in 100 patients. The origin of 78(68%) lesions was an MRI (n = 69) or CT scan (n = 9) with an observation of abnormal enhancement, generally arterial phase hyperenhancement (APHE). All these patients had blindshot CEUS injection looking for a correlate with APHE. The remainder of occult lesions (n = 36)(32%) were first detected during CEUS, generally as washout foci on PVP sweeps or incidental APHE or washout nearby other targets. All washout areas had subsequent on-top injection to assess for APHE. Application of CEUS LI-RADS algorithm categorized 26 LR-5, 34 LR-4, and 5 LR-M. CEUS upgraded LI-RADS category of 24/50(48%) occult lesions reported on CT/MRI. 29(25%) occult lesions were offered treatment and from categories LR-5 and LR-M, 5 had biopsy confirmation and 15 were treated. From both sources, MR/CT and CEUS, there were 12 occult lesions scanned for treatment response, categorized as 7 LR-TR viable, 1 LR-TR nonviable, and 4 LR-TR equivocal on CEUS.

CONCLUSION

Our study shows we can find and characterize occult nodules using CEUS techniques and CEUS LI-RADS algorithm, with positive impact on clinical management.

Abbreviated magnetic resonance imaging in hepatocellular carcinoma surveillance: A review

Hepatocellular carcinoma (HCC) is one of the most common primary malignancies of the liver and a leading cause for cancer-related deaths worldwide. HCC surveillance aims at early detection. The recommended strategy for screening HCC is biannual ultrasound with or without alpha-fetoprotein. However, this strategy is associated with sub-optimal sensitivity. Abbreviated magnetic resonance imaging (AMRI) is a promising alternative to ultrasound (US) for surveillance of HCC. The data regarding the role of AMRI in HCC screening is evolving. There are different AMRI protocols, each having its merits and disadvantages. In this review, we discuss the need for AMRI, protocols of AMRI and hindrances to widespread adoption of AMRI.

Addition of contrast in ultrasound screening for hepatocellular carcinoma

Objective

Screening ultrasound for hepatocellular carcinoma (HCC) identifies lesions which require further characterization by a contrast-enhanced exam to non-invasively diagnose HCC. While ultrasound is recommended in screening, some HCC can be occult on grayscale imaging. The purpose of this study was to determine if the addition of ultrasound contrast (sulfahexafluoride) to screening ultrasound for HCC can identify more HCC lesions than grayscale sonographic imaging alone.

Methods

All HCC screening ultrasounds that also had contrast were evaluated in this retrospective study. Patients with a focal lesion seen only after administration of contrast (OAC) were noted, as well as any follow-up imaging or pathology results. Additional variables collected included patient demographics, cirrhosis type, and laboratory values.

Results

230 unique patients were included, of which 160 had imaging or pathology follow-up. 18 of these patients had an OAC lesion, of which 17 had follow-up. Among these OACs, there was one LIRADS M lesion (1/18, 5.6 %) and one bland portal vein thrombus identified, which were both confirmed on follow-up imaging. All LIRADS 4 OAC lesions were downgraded. No additional HCC were identified on follow-up imaging or pathology of these patients.

Conclusion

Addition of contrast to screening ultrasound did identify additional lesions, portal vein thrombus, and high grade malignancy. However, as the incidence of OAC lesions was low (7.8 %, 18/230) and most of the lesions were not malignant, addition of post contrast sweeps through the liver is of low value in the low to medium at-risk cirrhotic population in identifying occult HCC.

Contrast-enhanced ultrasound for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease

BACKGROUND

Hepatocellular carcinoma occurs mostly in people with chronic liver disease. Worldwide, it ranks sixth in terms of incidence of cancer, and fourth in terms of cancer-related deaths. Contrast-enhanced ultrasound (CEUS) is used as an add-on test to confirm the presence of focal liver lesions suspected as hepatocellular carcinoma after prior diagnostic tests such as abdominal ultrasound or measurement of alpha-foetoprotein, or both. According to guidelines, a single contrast-enhanced imaging investigation, with either computed tomography (CT) or magnetic resonance imaging (MRI), may show the typical hepatocellular carcinoma hallmarks in people with cirrhosis, which will be sufficient to diagnose hepatocellular carcinoma. However, a significant number of hepatocellular carcinomas show atypical imaging features, and therefore, are missed at imaging. Dynamic CEUS images are obtained similarly to CT and MRI images. CEUS differentiates between arterial and portal venous phases, in which sonographic hepatocellular carcinoma hallmarks, such as arterial hyperenhancement and subsequent washout appearance, are investigated. The advantages of CEUS over CT and MRI include real-time imaging, use of contrast agents that do not contain iodine and are not nephrotoxic, and quick image acquisition. Despite the advantages, the use of CEUS in the diagnostic algorithm for HCC remains controversial, with disagreement on relevant guidelines. There is no clear evidence of the benefit of surveillance programmes in terms of overall survival as the conflicting results can be a consequence of an inaccurate detection, ineffective treatment, or both. Therefore, assessing the diagnostic accuracy of CEUS may clarify whether the absence of benefit could be related to underdiagnosis. Furthermore, an assessment of the accuracy of CEUS for the diagnosis of hepatocellular carcinoma is needed for either diagnosing hepatocellular carcinoma or ruling it out in people with chronic liver disease who are not included in surveillance programmes.

OBJECTIVES

1. To assess the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma of any size and at any stage in adults with chronic liver disease, in a surveillance programme or in a clinical setting. 2. To assess the diagnostic accuracy of CEUS for the diagnosis of resectable hepatocellular carcinoma in people with chronic liver disease and identify potential sources of heterogeneity in the results.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The last date of search was 5 November 2021.

SELECTION CRITERIA

We included studies assessing the diagnostic accuracy of CEUS for the diagnosis of hepatocellular carcinoma in adults with chronic liver disease, with cross-sectional designs, using one of the acceptable reference standards, such as pathology of the explanted liver, and histology of resected or biopsied focal liver lesion with at least a six-month follow-up.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods to screen studies, extract data, and assess the risk of bias and applicability concerns, using the QUADAS-2 checklist. We used the bivariate model and provided estimates of summary sensitivity and specificity. We assessed the certainty of the evidence using GRADE. We presented uncertainty-of-the-accuracy estimates using 95% confidence intervals (CIs).

MAIN RESULTS

We included 23 studies with 6546 participants. Studies were published between 2001 and 2021. We judged all 23 studies at high-risk of bias in at least one domain, and 13/23 studies at high concern for applicability. Most studies used different reference standards to exclude the presence of the target condition. The time interval between the index test and the reference standard was rarely defined. We also had major concerns on their applicability due to the characteristics of the participants. - CEUS for hepatocellular carcinoma of any size and stage: sensitivity 77.8% (95% CI 69.4% to 84.4%) and specificity 93.8% (95% CI 89.1% to 96.6%) (23 studies, 6546 participants; very low-certainty evidence). - CEUS for resectable hepatocellular carcinoma: sensitivity 77.5% (95% CI 62.9% to 87.6%) and specificity 92.7% (95% CI 86.8% to 96.1%) (13 studies, 1257 participants; low-certainty evidence). The observed heterogeneity in the results remains unexplained. The sensitivity analyses, including only studies with clearly prespecified positivity criteria and only studies in which the reference standard results were interpreted with no knowledge of the results about the index test, showed no differences in the results.

AUTHORS' CONCLUSIONS

We found that by using CEUS, as an add-on test following abdominal ultrasound, to diagnose hepatocellular carcinoma of any size and stage, 22% of people with hepatocellular carcinoma would be missed, and 6% of people without hepatocellular carcinoma would unnecessarily undergo further testing or inappropriate treatment. As to resectable hepatocellular carcinoma, we found that 23% of people with resectable hepatocellular carcinoma would incorrectly be unresected, while 8% of people without hepatocellular carcinoma would undergo further inappropriate testing or treatment. The uncertainty resulting from the high risk of bias of the included studies, heterogeneity, and imprecision of the results and concerns on their applicability limit our ability to draw confident conclusions.