Hepatocellular carcinoma: clinical significance of signal heterogeneity in the hepatobiliary phase of gadoxetic acid-enhanced MR imaging

Hepatobiliary and Pancreatic Neoplasms: Essential Predictive Imaging Features for Personalized Therapy

Tumor biologic characteristics encompassing histopathologic, immune microenvironmental, genetic, and molecular aspects are becoming indispensable factors to be considered in treatment strategies for patients with cancer. Innovations in oncologic treatment have broadened the range of therapeutic approaches and now hold promise for treatments personalized according to tumor biologic characteristics. Particularly for hepatobiliary and pancreatic neoplasms, the advent of cytostatic agents such as molecularly targeted agents and immune checkpoint inhibitors, which differ markedly from conventional cytotoxic agents, has contributed to advances in clinical practice. These cytostatic agents increase the potential for curative-intent treatment of unresectable cancers by reducing tumor volume. Radiologic examinations are of more interest than ever to noninvasively obtain information about tumor biologic features. Radiomics represents an invaluable research method for elucidating associations between tumor biologic characteristics and radiologic imaging findings, but their applicability in daily clinical practice remains challenging. Various radiologic predictive findings for tumor biologic characteristics have already been proposed for hepatobiliary and pancreatic neoplasms. Radiologists must gain familiarity with these findings and the roles they have in predicting the clinical prognosis and treatment efficacy. In addition, radiologists should explore the potential applications of these imaging findings to current treatment strategies for the coming era of personalized medicine. The authors describe predictive findings using CT and MRI for diagnosis of hepatocellular carcinoma, colorectal liver metastases, intrahepatic cholangiocarcinoma, and pancreatic adenocarcinoma, with correlations to pathologic, immunologic, molecular, and genetic background factors. ©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Ronot in this issue.

Vessels encapsulating tumor clusters contribute to the intratumor heterogeneity of HCC on Gd-EOB-DTPA-enhanced MRI

BACKGROUND

Vessels encapsulating tumor clusters (VETC) pattern is tumor vasculature of HCC and is a predictor of prognosis and therapeutic efficacy. Recent radiological studies have demonstrated the predictability of VETC from preoperative images, but the mechanisms of image formation are not elucidated. This study aims to determine the relationship between VETC and intratumor heterogeneity in Gd-EOB-DTPA-enhanced magnetic resonance imaging (EOB-MRI) and to provide its pathological evidence.

METHODS

Radiologists visually classified preoperative arterial- and hepatobiliary-phase EOB-MRI images of 204 surgically resected HCCs into patterns based on heterogeneity and signal intensity; these classifications were validated using texture analysis. Single and multiplex immunohistochemistry for CD34, h-caldesmon, and OATP1B3 were performed to evaluate VETC, arterial vessel density (AVD), and OATP1B3 expression. Recurrence-free survival was assessed using the generalized Wilcoxon test. The contribution of clinicoradiological factors to the prediction of VETC was evaluated by random forest and least absolute shrinkage and selection operator regression.

RESULTS

VETC was frequently found in tumors with arterial-phase heterogeneous hyper-enhancement patterns and in tumors with hepatobiliary-phase heterogeneous hyperintense/isointense patterns (HBP-Hetero). AVD and OATP1B3 expression positively correlated with signal intensity in the arterial and hepatobiliary phases, respectively. Intratumor spatial analysis revealed that AVD and OATP1B3 expression were lower in VETC regions than in tumor regions without VETC. Patients with HBP-Hetero tumors had shorter recurrence-free survival. Machine learning models highlighted the importance of serum PIVKA-II, tumor size, and enhancement pattern of arterial and hepatobiliary phase for VETC prediction.

CONCLUSIONS

VETC is associated with local reductions of both AVD and OATP1B3 expression, likely contributing to heterogeneous enhancement patterns in EOB-MRI. Evaluation of the arterial and hepatobiliary phases of EOB-MRI would enhance the predictability of VETC.

Predicting prognosis prior to the combination of atezolizumab and bevacizumab on unresectable HCC: Analysis and comparison of tumor heterogeneity at CT and Gd-EOB-DTPA hepatobiliary MR imaging

Since 2007, the combination of atezolizumab and bevacizumab, comprising an immune checkpoint inhibitor and a molecularly targeted agent, has become the first-line treatment for advanced hepatocellular carcinoma (HCC). Predicting prognosis prior to systemic chemotherapy remains a critical concern. This study included 84 advanced HCC patients who underwent enhanced computed tomography (CT) and Gd-EOB-DTPA magnetic resonance imaging (MRI) before the systemic therapy were included. In CT, the 2 radiologists measured mean CT Hounsfield unit (CTHU) value by drawing region of interest at the largest diameter of the tumor on arterial phage. The HU values were categorized into 5 groups: ≤ 0, 0 < HU ≤ 50, 50 < HU ≤ 100, 100 < HU ≤ 150, and HU > 150. The percentage of the entire tumor in each category was calculated. On MRI, hepatobiliary phase imaging features and relative enhancement ratio (RER) were also evaluated by 2 radiologists. Prognostic factors associated with progression-free survival were identified using statistical analysis. RER on HBP MRI correlated with prognosis in systemic chemotherapy. Conversely, other image features on HBP MRI and CT histogram provided consistent treatment effect.

Prediction of Efficacy for Atezolizumab/Bevacizumab in Unresectable Hepatocellular Carcinoma with Hepatobiliary-Phase Gadolinium Ethoxybenzyl-Diethylenetriaminepentaacetic Acid MRI

BACKGROUND

This study aimed to examine whether the coefficient of variation (CV) in the hepatobiliary-phase (HBP) of Gd-EOB-DTPA-MRI could be an independent predictive factor for tumor progression.

METHODS

Patients who underwent Gd-EOB-DTPA-MRI before Atezolizumab/bevacizumab therapy at six affiliated institutions between 2018 and 2022 were included. CV for each patient was calculated as the mean value for up to five tumors larger than 10 mm, and CV of the whole tumor was calculated using LIFEx software. The tumor response was evaluated within 6-10 weeks. The primary endpoint was to investigate the predictive factors, including CV, related to tumor progression using logistic regression analysis. The secondary endpoints were tumor response rate and progression-free survival (PFS) based on CV.

RESULTS

Of the 46 enrolled patients, 13 (28.3%) underwent early progressive disease. Multivariate analysis revealed that a high CV (≥0.22) was an independent predictive factor for tumor progression (p = 0.043). Patients with a high CV had significantly frequent PD than those with a low CV (43.5 vs. 13.0%, p = 0.047). Patients with a high CV tended to have shorter PFS than those with a low CV (3.5 vs. 6.7 months, p = 0.071).

CONCLUSION

Quantitative analysis using CV in the HBP of Gd-EOB-DTPA-MRI may be useful for predicting tumor progression for atezolizumab/bevacizumab therapy.

Hepatobiliary-phase gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid MRI for pretreatment prediction of efficacy-to-standard-therapies based on Barcelona Clinic Liver Cancer algorithm: an up-to-date review

Recent advances in systemic therapy have had major impacts on treatment strategies for hepatocellular carcinoma (HCC). The 2022 Barcelona Clinic Liver Cancer (BCLC) guidelines incorporate a new section on clinical decision-making for personalized medicine, although the first treatment suggested by the BCLC guidelines is based on solid scientific evidence. More than ever before, the appropriate treatment strategy must be selected prior to the initiation of therapy for HCC. Gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid magnetic resonance imaging (Gd-EOB-DTPA-MRI) is essential for liver imaging and the hepatobiliary phase (HBP) of EOB-MRI reflects the expression of organic anion transporting polypeptide (OATP) transporters. Molecules associated with OATP expression are relevant in the molecular classification of HCC subclasses, and EOB-MRI is becoming increasingly important with advances in the molecular and genetic understanding of HCC. In this review, we describe imaging findings for the pretreatment prediction of response to standard therapies for HCC based on the BCLC algorithm using the HBP of EOB-MRI, with specific attention to the molecular background of OATPs. A more complete understanding of these findings will help radiologists suggest appropriate treatments and clinical follow-ups and could lead to the development of more personalized treatment strategies in the future. CLINICAL RELEVANCE STATEMENT: In the coming era of personalized medicine, HBP of EOB-MRI reflecting molecular and pathological factors could play a predictive role in the therapeutic efficacy of HCC and contribute to treatment selection. KEY POINTS: • Imaging features of hepatobiliary phase predict treatment efficacy prior to therapy and contribute to treatment choice. • Wnt/β-catenin activation associated with organic anion transporting polypeptide expression is involved in the tumor immune microenvironment and chemo-responsiveness. • Peritumoral hypointensity of hepatobiliary phase reflecting microvascular invasion affects the therapeutic efficacy of locoregional to systemic therapy.

Radiomics nomogram for prediction of glypican-3 positive hepatocellular carcinoma based on hepatobiliary phase imaging

Introduction

The hepatobiliary-specific phase can help in early detection of changes in lesion tissue density, internal structure, and microcirculatory perfusion at the microscopic level and has important clinical value in hepatocellular carcinoma (HCC). Therefore, this study aimed to construct a preoperative nomogram for predicting the positive expression of glypican-3 (GPC3) based on gadoxetic acid-enhanced (Gd-EOB-DTPA) MRI hepatobiliary phase (HBP) radiomics, imaging and clinical feature.

Methods

We retrospectively included 137 patients with HCC who underwent Gd-EOB-DTPA-enhanced MRI and subsequent liver resection or puncture biopsy at our hospital from January 2017 to December 2021 as training cohort. Subsequently collected from January 2022 to June 2023 as a validation cohort of 49 patients, Radiomic features were extracted from the entire tumor region during the HBP using 3D Slicer software and screened using a t-test and least absolute shrinkage selection operator algorithm (LASSO). Then, these features were used to construct a radiomics score (Radscore) for each patient, which was combined with clinical factors and imaging features of the HBP to construct a logistic regression model and subsequent nomogram model. The clinicoradiologic, radiomics and nomogram models performance was assessed by the area under the curve (AUC), calibration, and decision curve analysis (DCA). In the validation cohort,the nomogram performance was assessed by the area under the curve (AUC).

Results

In the training cohort, a total of 1688 radiomics features were extracted from each patient. Next, radiomics with ICCs<0.75 were excluded, 1587 features were judged as stable using intra- and inter-class correlation coefficients (ICCs), 26 features were subsequently screened using the t-test, and 11 radiomics features were finally screened using LASSO. The nomogram combining Radscore, age, serum alpha-fetoprotein (AFP) >400ng/mL, and non-smooth tumor margin (AUC=0.888, sensitivity 77.7%, specificity 91.2%) was superior to the radiomics (AUC=0.822, sensitivity 81.6%, specificity 70.6%) and clinicoradiologic (AUC=0.746, sensitivity 76.7%, specificity 64.7%) models, with good consistency in calibration curves. DCA also showed that the nomogram had the highest net clinical benefit for predicting GPC3 expression.In the validation cohort, the ROC curve results showed predicted GPC3-positive expression nomogram model AUC, sensitivity, and specificity of 0.800, 58.5%, and 100.0%, respectively.

Conclusion

HBP radiomics features are closely associated with GPC3-positive expression, and combined clinicoradiologic factors and radiomics features nomogram may provide an effective way to non-invasively and individually screen patients with GPC3-positive HCC.

Quantitative Analysis of Signal Heterogeneity in the Hepatobiliary Phase of Pretreatment Gadoxetic Acid-Enhanced MRI as a Prognostic Imaging Biomarker in Transarterial Chemoembolization for Intermediate-Stage Hepatocellular Carcinoma

BACKGROUND

In the era of local and systemic therapies for intermediate-stage hepatocellular carcinoma (HCC), personalized therapy has become available. The aim of our study was to evaluate the usefulness of quantitative analysis of pretreatment gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) to predict prognosis following transarterial chemoembolization (TACE).

METHODS

This retrospective study included patients with treatment-naïve intermediate-stage HCC who underwent EOB-MRI before the initial TACE and were treated by initial TACE between February 2007 and January 2016. Signal heterogeneity in the hepatobiliary phase (HBP) of EOB-MRI was quantitatively evaluated by the coefficient of variation (CV). The cutoff CV value was determined using the Classification and Regression Tree algorithm.

RESULTS

A total of 64 patients were enrolled. In multivariate analysis, High CV (≥0.16) was significantly associated with poor prognosis (p = 0.038). In a subgroup analysis of patients within up-to-7 criteria, MST was significantly shorter in the High CV group than in the Low CV group (37.7 vs. 82.9 months, p = 0.024). In patients beyond up-to-7 criteria, MST was 18.0 and 38.3 months in the High CV and Low CV groups, respectively (p = 0.182). In both groups scanned at 1.5 T or 3.0 T, High CV was significantly associated with poor prognosis (p = 0.001 and 0.003, respectively).

CONCLUSION

CV of the tumor in the HBP of EOB-MRI is a valuable prognostic factor of TACE.

Evaluating the Role of Hepatobiliary Phase of Gadoxetic Acid-Enhanced Magnetic Resonance Imaging in Predicting Treatment Impact of Lenvatinib and Atezolizumab plus Bevacizumab on Unresectable Hepatocellular Carcinoma

Simple Summary

Atezolizumab plus bevacizumab therapy has high response rates in patients with unresectable hepatocellular carcinoma (HCC). The hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) has been reported to be useful as an imaging biomarker for detecting β-catenin mutations. We evaluated whether pretreatment in the hepatobiliary phase of EOB-MRI could predict the therapeutic effect of lenvatinib (n = 33) and atezolizumab plus bevacizumab (n = 35). The visual assessment and relative enhancement ratio (RER) of the largest HCC lesions were evaluated using the hepatobiliary phase of EOB-MRI. In the lenvatinib group, progression-free survival (PFS) was not differently stratified using EOB-MRI. In the atezolizumab plus bevacizumab group, the heterogeneous type had significantly shorter PFS than the homogenous type, and the hyperintensity (RER ≥ 0.9) type had significantly shorter PFS than the hypointensity type. Hence, the hepatobiliary phase of EOB-MRI was useful for predicting the therapeutic effect of atezolizumab plus bevacizumab therapy on unresectable HCC.

Abstract

Background: Atezolizumab plus bevacizumab therapy has high response rates in patients with unresectable hepatocellular carcinoma (HCC). The hepatobiliary phase of gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) has been reported to be useful as an imaging biomarker for detecting β-catenin mutations. We evaluated whether the pretreatment of the hepatobiliary phase of EOB-MRI could predict the therapeutic effect of lenvatinib and atezolizumab plus bevacizumab. Methods: This study included 68 patients (lenvatinib group (n = 33) and atezolizumab plus bevacizumab group (n = 35)). The visual assessment and relative enhancement ratio (RER) of the largest HCC lesions were evaluated using the hepatobiliary phase of EOB-MRI. Results: The hyperintensity type (RER ≥ 0.9) was 18.2% in the lenvatinib group and 20.0% in the atezolizumab plus bevacizumab group. In the lenvatinib group, progression-free survival (PFS) was not different between the heterogeneous and homogenous types (p = 0.688) or between the hyperintensity and hypointensity types (p = 0.757). In the atezolizumab plus bevacizumab group, the heterogeneous type had significantly shorter PFS than the homogenous type (p = 0.007), and the hyperintensity type had significantly shorter PFS than the hypointensity type (p = 0.012). Conclusions: The hepatobiliary phase of EOB-MRI was useful for predicting the therapeutic effect of atezolizumab plus bevacizumab therapy on unresectable HCC.

Therapeutic efficacy of lenvatinib for hepatocellular carcinoma with iso‑high intensity in the hepatobiliary phase of Gd‑EOB‑DTPA‑MRI

Previous studies have reported that hepatocellular carcinoma (HCC) harboring WNT/β-catenin mutations exhibits iso-high intensity by gadolinium ethoxybenzyl diethylenetriaminepentaacetic acid-enhanced magnetic resonance imaging (Gd-EOB-DTPA-MRI, i.e. EOB-MRI) during the hepatobiliary phase (HBP), thus indicating that EOB-MRI may help clinicians identify an immune exclusion class, which might not respond to treatment with immune checkpoint inhibitors. The present study analyzed the efficacy of lenvatinib for HCC with iso-high intensity during the HBP of EOB-MRI. Overall, 52 patients who underwent EOB-MRI for 140 HCC nodules were classified into iso-high-intensity and low-intensity groups during the HBP of EOB-MRI. The clinical and histological characteristics, and different responses to treatment of both groups were analyzed. The expression levels of β-catenin and glutamine synthetase, indicative of WNT/β-catenin mutations, were enhanced in the HCC with iso-high-intensity group. Nine patients had iso-high intensity, whereas 43 patients had low intensity. Tumor size was larger, and the levels of antagonist-II or vitamin K absence were higher in the iso-high-intensity group. Furthermore, 3/9 patients in the iso-high-intensity group had objective responses compared with 13/43 patients in the low-intensity group. Disease control was observed in 5/9 patients in the iso-high-intensity group and 26/43 patients in the low-intensity group. Median overall survival was 29.8 months for the iso-high-intensity group compared with 20.8 months for the low-intensity group. In the iso-high-intensity group, the median progression-free survival rate was 6.7 months compared with 5.6 months in the low-intensity group. No differences in best percentage change from baseline tumor size were observed in either group. Although few patients were included in this study, the present findings suggested that the efficacy of lenvatinib was unaffected by signal intensity during the HBP of EOB-MRI.

Liver MRI and clinical findings to predict response after drug eluting bead transarterial chemoembolization in hepatocellular carcinoma

To identify the gadoxetic acid (GA)-enhanced magnetic resonance imaging (MRI) and laboratory findings that enable prediction of treatment response and disease-free survival (DFS) after the first session of drug eluting bead transarterial chemoembolization (DEB-TACE) in patients with hepatocellular carcinoma (HCC). A total of 55 patients who underwent GA-enhanced MRI and DEB-TACE from January 2014 to December 2018 were included. All MRI features were reviewed by two radiologists. Treatment response was evaluated according to the modified Response Evaluation Criteria in Solid Tumors. Univariate and multivariate logistic regression analyses were used to determine predictive factors of treatment response and DFS, respectively. A total of 27 patients (49.1%) achieved complete response (CR) after one session of treatment. There were no significant differences between the two groups in terms of clinical and laboratory characteristics. Heterogeneous signal intensity in the hepatobiliary phase (HBP) was the only independent predictor of non-CR (odds ratio, 4.807; p = 0.048). Recurrent HCC was detected in 19 patients (70.4%) after CR. In the multivariate analysis, elevated serum alpha-fetoprotein (AFP) level (≥ 30 ng/mL) was the only significant parameter associated with DFS (hazard ratio, 2.916; p = 0.040). This preliminary study demonstrated that heterogeneous signal intensity in the HBP and high serum AFP were useful predictive factors for poor treatment response and short DFS after DEB-TACE, respectively.

Hepatobiliary MR contrast agent uptake as a predictive biomarker of aggressive features on pathology and reduced recurrence-free survival in resectable hepatocellular carcinoma: comparison with dual-tracer 18F-FDG and 18F-FCH PET/CT

OBJECTIVES

To compare the performance of the quantitative analysis of the hepatobiliary phase (HBP) tumor enhancement in gadobenate dimeglumine (Gd-BOPTA)-enhanced MRI and of dual-tracer 18F-FDG and 18F-fluorocholine (FCH) PET/CT for the prediction of tumor aggressiveness and recurrence-free survival (RFS) in resectable hepatocellular carcinoma (HCC).

METHODS

This retrospective, IRB approved study included 32 patients with 35 surgically proven HCCs. All patients underwent Gd-BOPTA-enhanced MRI including delayed HBP images, 18F-FDG PET/CT, and (for 29/32 patients) 18F-FCH PET/CT during the 2 months prior to surgery. For each lesion, the lesion-to-liver contrast enhancement ratio (LLCER) on MRI HBP images and the SUV_max tumor-to-liver ratio (SUV_T/L) for both tracers were calculated. Their predictive value for aggressive pathological features-including the histological grade and microvascular invasion (MVI)-and RFS were analyzed and compared using area under receiver operating characteristic (AUROC) curves and Cox regression models, respectively.

RESULTS

The AUROCs for the identification of aggressive HCCs on pathology with LLCER, 18F-FDG SUV_T/L, and 18F-FCH SUV_T/L were 0.92 (95% CI 0.78, 0.98), 0.89 (95% CI 0.74, 0.97; p = 0.70), and 0.64 (95% CI 0.45, 0.80; p = 0.035). At multivariate Cox regression analysis, LLCER was identified as an independent predictor of RFS (HR (95% CI) = 0.91 (0.84, 0.99), p = 0.022). LLCER - 4.72% or less also accurately predicted moderate-poor differentiation grade (Se = 100%, Sp = 92.9%) and MVI (Se = 93.3%, Sp = 60%) and identified patients with poor RFS after surgical resection (p = 0.030).

CONCLUSIONS

HBP tumor enhancement after Gd-BOPTA injection may help identify aggressive HCC pathological features, and patients with reduced recurrence-free survival after surgical resection.

KEY POINTS

• In patients with resectable HCC, the quantitative analysis of the HBP tumor enhancement in Gd-BOPTA-enhanced MRI (LLCER) accurately identifies moderately-poorly differentiated and/or MVI-positive HCCs. • After surgical resection for HCC, patients with LLCER - 4.72% or less had significantly poorer recurrence-free survival than patients with LLCER superior to - 4.72%. • Gd-BOPTA-enhanced MRI with delayed HBP images may be suggested as part of pre-surgery workup in patients with resectable HCC.

Intra-individual comparison of gadolinium-enhanced MRI using pseudo-golden-angle radial acquisition with gadoxetic acid-enhanced MRI for diagnosis of HCCs using LI-RADS

OBJECTIVES

To determine the usefulness of extracellular contrast agent (ECA)-enhanced multiphasic liver magnetic resonance imaging (MRI) using a pseudo-golden-angle radial acquisition scheme by intra-individual comparison with gadoxetic acid-MRI (EOB-MRI) with regard to image quality and the diagnosis of hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This prospective study enrolled 15 patients with 18 HCCs who underwent EOB-MRI using a Cartesian approach and ECA-MRI using the pseudo-golden-angle radial acquisition scheme (free-breathing continuous data acquisition for 64 s following ECA injection, generating six images). Two reviewers evaluated the arterial and portal phases of each MRI for artifacts, organ sharpness, and conspicuity of intrahepatic vessels and the hepatic tumors. A Liver Imaging Reporting and Data System category was also assigned to each lesion.

RESULTS

There were no differences in the subjective image quality analysis between the arterial phases of two MRIs (p > 0.05). However, ghosting artifact was seen only in EOB-MRI (N = 3). Six HCCs showed different signal intensities in the arterial phase or portal phase between the two MRIs; five HCCs showed arterial hyperenhancement on ECA-MRI, but not on EOB-MRI. The capsule was observed in 15 HCCs on ECA-MRI and 6 HCCs on EOB-MRI. Five and one HCC were assigned as LR-5 and LR-4 with ECA-MRI and LR-4 and LR-3 with EOB-MRI, respectively.

CONCLUSION

Free-breathing ECA-enhanced multiphasic liver MRI using a pseudo-golden-angle radial acquisition was more sensitive in detecting arterial hyperenhancement of HCC than conventional EOB-MRI, and the image quality was acceptable.

KEY POINTS

• The pseudo-golden-angle radial acquisition scheme can be applied to perform free-breathing multiphasic dynamic liver MRI. • Adopting the pseudo-golden-angle radial acquisition scheme can improve the detection of arterial enhancement of HCC. • The pseudo-golden-angle radial acquisition scheme enables motion-free liver MRI.

Combined hepatocellular cholangiocarcinoma: LI-RADS v2017 categorisation for differential diagnosis and prognostication on gadoxetic acid-enhanced MR imaging

OBJECTIVES

To investigate the performance of the Liver Imaging Reporting and Data System (LI-RADS) v2017 for combined hepatocellular cholangiocarcinoma (cHCC-CCA) in the differential diagnosis from hepatocellular carcinoma (HCC) and prediction of prognosis on gadoxetic acid-enhanced MRI (Gd-EOB-MRI).

METHODS

Patients at high risk of HCC with pathologically confirmed cHCC-CCAs (n = 70) and a matched control of HCCs (n = 70) who had undergone Gd-EOB-MRI were included. LI-RADS category was assigned for each lesion by two radiologists. Imaging features and surgical outcomes were compared between cHCC-CCAs of LR-M and LR-5/4 using the χ² test or Fisher's exact test. Recurrence-free survival (RFS) was estimated using Kaplan-Meier survival curves and compared using the log-rank test.

RESULTS

cHCC-CCAs and HCCs were categorised as LR-M, LR-5/4 and LR-TIV in 61.4% (43/70), 37.1% (26/70) and 1.4% (1/70) and 10.0% (7/70), 88.6% (62/70) and 1.4% (1/70), respectively. cHCC-CCAs of LR-5/4, in comparison to LR-M, showed significantly higher frequencies of major HCC features: arterial hyperenhancement (96.2% (25/26) vs. 58.1% (25/43), p = 0.001), washout appearance (80.8% (21/26) vs. 48.8% (21/43), p = 0.011) and enhancing capsule (34.6% (9/26) vs. 11.6% (5/43), p = 0.031). After curative surgery, patients with cHCC-CCAs of LR-M showed a higher early recurrence rate (≤ 6 months) than did those with LR-5/4 (27.8% (10/36) vs. 4.8% (1/21), p = 0.041), whereas no significant difference was observed in RFS (log-rank p = 0.084).

CONCLUSIONS

By using LI-RADS on Gd-EOB-MRI, a substantial proportion of cHCC-CCAs can be categorised as non-LR-M. In addition, cHCC-CCAs mimicking HCCs on imaging (LR-5/4) may indicate better surgical outcomes with regard to early recurrence than those of LR-M.

KEY POINTS

• cHCC-CCAs can be categorised as either LR-M or non-LR-M on Gd-EOB-MRI. • cHCC-CCAs of LR-5/4 frequently demonstrate major HCC imaging features. • LI-RADS categorisation may provide prognostic information after surgery in cHCC-CCAs.

Quantification of hepatocellular carcinoma heterogeneity with multiparametric magnetic resonance imaging

Tumour heterogeneity poses a significant challenge for treatment stratification. The goals of this study were to quantify heterogeneity in hepatocellular carcinoma (HCC) using multiparametric magnetic resonance imaging (mpMRI), and to report preliminary data correlating quantitative MRI parameters with advanced histopathology and gene expression in a patient subset. Thirty-two HCC patients with 39 HCC lesions underwent mpMRI including diffusion-weighted imaging (DWI), blood-oxygenation-level-dependent (BOLD), tissue-oxygenation-level-dependent (TOLD) and dynamic contrast-enhanced (DCE)-MRI. Histogram characteristics [central tendency (mean, median) and heterogeneity (standard deviation, kurtosis, skewness) MRI parameters] in HCC and liver parenchyma were compared using Wilcoxon signed-rank tests. Histogram data was correlated between MRI methods in all patients and with histopathology and gene expression in 14 patients. HCCs exhibited significantly higher intra-tissue heterogeneity vs. liver with all MRI methods (P < 0.030). Although central tendency parameters showed significant correlations between MRI methods and with each of histopathology and gene expression, heterogeneity parameters exhibited additional complementary correlations between BOLD and DCE-MRI and with histopathologic hypoxia marker HIF1α and gene expression of Wnt target GLUL, pharmacological target FGFR4, stemness markers EPCAM and KRT19 and immune checkpoint PDCD1. Histogram analysis combining central tendency and heterogeneity mpMRI features is promising for non-invasive HCC characterization on the imaging, histologic and genomics levels.

Recent Trends in the Management of Hepatocellular Carcinoma with Special Emphasis on Treatment with Regorafenib and Immune Checkpoint Inhibitors

Hepatocellular carcinoma (HCC) is the fifth most common cancer and the third leading cause of cancer deaths worldwide. Sonazoid-enhanced ultrasound and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI are the most important imaging modalities in diagnosing HCC. There are 2 non-contradictory HCC treatment algorithms in Japan. Hepatic arterial infusion chemotherapy plays an important role in the treatment of advanced HCC with main or branch portal vein invasion. Regorafenib, as a second-line systemic treatment, prolongs survival in patients with intermediate and advanced HCC who progressed on sorafenib. In recent clinical trials, immune check point inhibitors show promising results for the treatment of HCC. This review describes recent trends in the management of HCC.

MR-imaging features of hepatocellular carcinoma capsule appearance in cirrhotic liver: comparison of gadoxetic acid and gadobenate dimeglumine

PURPOSE

The purpose of the study is to compare the MR-imaging features of hepatocellular carcinoma (HCC) capsule appearance on gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging, using imaging-based presumptive diagnosis of HCC as the reference standard.

METHODS

Gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging of 51 patients with 71 HCCs were retrospectively reviewed. Three readers graded in consensus, using a five-point scale, the presence (score 4-5) of capsule appearance on images obtained during T1-weighted GRE portal venous phase (PVP), 3-min phase, and hepatobiliary phase (HBP). The Fisher's exact test and the t student unpaired test were performed.

RESULTS

A hyperintense capsule appearance was present either on PVP or 3-min phase in 11/46 and in 24/25 HCCs imaged with gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging, respectively (24% vs. 96% p < 0.001). A hypointense capsule appearance was present on HBP in 8/46 and 0/22 HCCs evaluated with gadoxetic acid and gadobenate dimeglumine-enhanced MR imaging, respectively (17% vs. 0% p = 0.046). A capsule appearance was detected either on PVP, 3-min phase, or HBP in 17/46 (37%) HCCs after gadoxetic acid injection and in 24/25 (96%) HCCs after gadobenate dimeglumine injection (p < 0.001).

CONCLUSIONS

A capsule appearance was more frequently seen on gadobenate dimeglumine-enhanced MR imaging when compared to gadoxetic acid-enhanced MR imaging.

Recent Advances in the Imaging Diagnosis of Hepatocellular Carcinoma: Value of Gadoxetic Acid-Enhanced MRI

Magnetic resonance imaging (MRI) using gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DPTA), or gadoxetic acid for short, is a hepatocyte-specific contrast agent which is now increasingly used for the detection and characterization of focal hepatic lesions, particularly in patients at high-risk of developing hepatocellular carcinomas (HCC). In fact, several recent guidelines now recognize gadoxetic acid-enhanced MRI (Gd-EOB-MRI) as the primary diagnostic imaging modality for the noninvasive diagnosis of HCC, although it must be noted that several major guidelines still include only extracellular contrast media-enhanced computed tomography and MRI. The primary merits of Gd-EOB-MRI lie in the fact that it can provide not only dynamic imaging, but also hepatobiliary phase (HBP) imaging which can lead to high lesion-to-liver contrast and give additional information regarding hepatocyte uptake via organic anion transporting polypeptides. This, in turn, allows higher sensitivity in detecting small HCCs and helps provide additional information regarding the multistep process of hepatocarcinogenesis. Indeed, many recent studies have investigated the diagnostic value of Gd-EOB-MRI for early HCCs as well as its role as a potential imaging biomarker in predicting outcome. We herein review the recent advances in the imaging diagnosis of HCCs focusing on the applications of Gd-EOB-MRI and the challenging issues that remain.

Selection of patients with hepatocellular carcinoma for liver transplantation: Past and future

The aim of liver transplantation (LT) for hepatocellular carcinoma (HCC) is to ensure a rate of disease-free survival similar to that of patients transplanted due to benign disease. Therefore, we are forced to adopt strict criteria when selecting candidates for LT and prioritizing patients on the waiting list (WL), to have clarified indications for bridging therapy for groups at risk for progression or recurrence, and to establish certain limits for downstaging therapies. Although the Milan criteria (MC) remain the standard and most employed criteria for indication of HCC patients for LT by far, in the coming years, criteria will be consolidated that take into account not only data regarding the size/volume and number of tumors but also their biology. This criteria will mainly include the alpha fetoprotein (AFP) values and, in view of their wide variability, any of the published logarithmic models for the selection of candidates for LT. Bridging therapy is necessary for HCC patients on the WL who meet the MC and have the possibility of experiencing a delay for LT greater than 6 mo or any of the known risk factors for recurrence. It is difficult to define single AFP values that would indicate bridging therapy (200, 300 or 400 ng/mL); therefore, it is preferable to rely on the criteria of a French AFP model score > 2. Other single indications for bridging therapy include a tumor diameter greater than 3 cm, more than one tumor, and having an AFP slope greater than 15 ng/mL per month or > 50 ng/mL for three months during strict monitoring while on the WL. When considering the inclusion of patients on the WL who do not meet the MC, it is mandatory to determine their eligibility for downstaging therapy prior to inclusion. The upper limit for this therapy could be one lesion up to 8 cm, 2-3 lesions with a total tumor diameter up to 8 cm, or a total tumor volume of 115 cm³. Lastly, liver allocation and the prioritization of patients with HCC on the WL should take into account the recently described HCC model for end-stage liver disease, which considers hepatic function, HCC size and the number and the log of AFP values. This formula has been calibrated with the survival data of non-HCC patients and produces a dynamic and more accurate assessment model.

Respiratory motion artefacts in dynamic liver MRI: a comparison using gadoxetate disodium and gadobutrol

OBJECTIVES

Our aim was to retrospectively evaluate the occurrence of respiratory motion artefacts in patients undergoing dynamic liver magnetic resonance (MR) either with gadoxetate disodium or gadobutrol.

METHODS

Two hundred and thirty liver MR studies (115 with gadobutrol, 115 with gadoxetate disodium) were analysed. Respiratory motion artefacts on dynamic 3D T1-weighted MR images (pre-contrast, arterial, venous, and late-dynamic phase) were assessed using a five-point rating scale. Severe motion was defined as a score ≥ 4. Mean motion scores were compared with the Mann-Whitney-U-test. The chi-squared-test was used for dichotomous comparisons.

RESULTS

Mean motion scores for gadoxetate disodium and gadobutrol showed no relevant differences for each phase of the dynamic contrast series (pre-contrast: 1.85 ± 0.70 vs. 1.88 ± 0.57, arterial: 1.85 ± 0.81 vs. 1.87 ± 0.74, venous: 1.82 ± 0.67 vs. 1.74 ± 0.64, late-dynamic: 1.75 ± 0.62 vs. 1.79 ± 0.63; p = 0.469, 0.557, 0.382 and 0.843, respectively). Severe motion artefacts had a similar incidence using gadoxetate disodium and gadobutrol (11/460 [2.4%] vs. 7/460 [1.5%]; p = 0.341).

CONCLUSIONS

Gadoxetate disodium is associated with equivalent motion scores compared to gadobutrol in dynamic liver MRI. In addition, both contrast agents demonstrated a comparable and acceptable rate of severe respiratory motion artefacts.

KEY POINTS

• Gadobutrol and gadoxetate disodium showed comparable motion scores in dynamic phase imaging. • The incidence of severe motion artefacts was pronounced in arterial phase imaging. • Adverse respiratory side effects were not recorded in 115 examinations with gadoxetate disodium.

Surveillance and diagnostic algorithm for hepatocellular carcinoma proposed by the Liver Cancer Study Group of Japan: 2014 update

Surveillance and diagnostic algorithms for hepatocellular carcinoma (HCC) have already been described in guidelines published by the American Association for the Study of Liver Diseases (AASLD), the European Association for the Study of the Liver and the European Organisation for Research and Treatment of Cancer (EASL-EORTC), and the Japan Society of Hepatology (JSH), but the content of these algorithms differs slightly. The JSH algorithm mainly differs from the other two algorithms in that it is highly sophisticated and considers the functional imaging techniques of gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid-enhanced MRI (EOB-MRI) and Sonazoid contrast-enhanced ultrasound (CEUS) to be very important diagnostic modalities. In contrast, the AASLD and EASL-EORTC algorithms are less advanced and suggest that a diagnosis be made based solely on hemodynamic findings using dynamic CT/MRI and biopsy findings. A consensus meeting regarding the JSH surveillance and diagnostic algorithm was held at the 50th Liver Cancer Study Group of Japan Congress, and a 2014 update of the algorithm was completed. The new algorithm reaffirms the very important role of EOB-MRI and Sonazoid CEUS in the surveillance and diagnosis of liver cancer and is more sophisticated than those currently used in the United States and Europe. This is now an optimized algorithm that can be used to diagnose early-stage to classical HCC easily and highly accurately.

JSH Consensus-Based Clinical Practice Guidelines for the Management of Hepatocellular Carcinoma: 2014 Update by the Liver Cancer Study Group of Japan

The Clinical Practice Guidelines for the Management of Hepatocellular Carcinoma proposed by the Japan Society of Hepatology was updated in June 2014 at a consensus meeting of the Liver Cancer Study Group of Japan. Three important items have been updated: the surveillance and diagnostic algorithm, the treatment algorithm, and the definition of transarterial chemoembolization (TACE) failure/refractoriness. The most important update to the diagnostic algorithm is the inclusion of gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging as a first line surveillance/diagnostic tool. Another significant update concerns removal of the term "lipiodol" from the definition of TACE failure/refractoriness.