Natural course of hypovascular nodules detected on gadoxetic acid-enhanced MR imaging: presence of fat is a risk factor for hypervascularization

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.

An overview of risk assessment and monitoring of malignant transformation in cirrhotic nodules

Cirrhotic liver nodules can progress to hepatocellular carcinoma (HCC) through a multi-step carcinogenesis model, with dysplastic nodules being particularly high risk. Currently, monitoring the progression of non-HCC cirrhotic nodules is primarily through dynamic observation, but there is a lack of sensitive, efficient, and convenient methods. Dynamic monitoring and risk evaluation of malignant transformation are essential for timely treatment and improved patient survival rates. Routine liver biopsies are impractical for monitoring, and imaging techniques like ultrasound, computed tomography, and magnetic resonance imaging are not suitable for all patients or for accurately assessing subcentimeter nodules. Identifying serum biomarkers with high sensitivity, specificity, and stability, and developing a multi-index evaluation model, may provide a more convenient and efficient approach to monitoring pathological changes in cirrhotic nodules.

Liver Lesions at Risk of Transformation into Hepatocellular Carcinoma in Cirrhotic Patients: Hepatobiliary Phase Hypointense Nodules without Arterial Phase Hyperenhancement

Recent technical advances in liver imaging and surveillance for patients at high risk for developing hepatocellular carcinoma (HCC) have led to an increase in the detection of borderline hepatic nodules in the gray area of multistep carcinogenesis, particularly in those that are hypointense at the hepatobiliary phase (HBP) and do not show arterial phase hyperenhancement. Given their potential to transform and advance into hypervascular HCC, these nodules have progressively attracted the interest of the scientific community. To date, however, no shared guidelines have been established for the decision management of these borderline hepatic nodules. It is therefore extremely important to identify features that indicate the malignant potential of these nodules and the likelihood of vascularization. In fact, a more complete knowledge of their history and evolution would allow outlining shared guidelines for their clinical-surgical management, to implement early treatment programs and decide between a preventive curative treatment or a watchful follow-up. This review aims to summarize the current knowledge on hepatic borderline nodules, particularly focusing on those imaging features which are hypothetically correlated with their malignant evolution, and to discuss current guidelines and ongoing management in clinical practice.

Hypervascular transformation of hepatobiliary phase hypointense nodules without arterial phase hyperenhancement on gadoxetic acid-enhanced MRI: long-term follow-up in a surveillance cohort

OBJECTIVES

With the increasing use of gadoxetic acid-enhanced MRI for HCC surveillance, hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE) are frequently encountered. We investigated the rate of these nodules with hypervascular transformation, which suggests hepatocarcinogenesis, by using a prospectively collected longitudinal surveillance cohort data.

METHODS

This study included 382 prospectively enrolled patients at high risk for developing HCC who underwent 1-3 rounds of bi-annual surveillance gadoxetic acid-enhanced MRI. MRI was analyzed to detect HBP hypointense nodules without APHE. Follow-up dynamic CTs and MRIs were evaluated to detect hypervascular transformation of the nodules. Cox proportional hazards regression analyses were used to find predictors for hypervascular transformation.

RESULTS

A total of 76 HBP hypointense nodules without APHE were found in 48 patients, giving a prevalence of 12.6% (48/382). The mean nodule size was 10.8 mm, with 43.4% (33/76) being ≥ 10 mm. Over a median follow-up of 78.6 months, 19 nodules (25.0%) showed hypervascular transformation, all of which demonstrated typical imaging features of HCC. On multivariable Cox-regression analysis, size (≥ 10 mm) was the only independent predictor of hypervascular transformation (hazard ratio, 3.31; 95% confidence interval, 1.21-9.05). The cumulative incidence of hypervascular transformation at 12 and 60 months of nodules ≥ 10 mm was 12.3% and 50.4%, respectively, while that of nodules < 10 mm was 2.5% and 13.9%, respectively.

CONCLUSIONS

About half of the HBP hypointense nodules ≥ 10 mm without APHE transformed to HCC at 5 years of follow-up, indicating the necessity for cautious monitoring with an augmented and extended follow-up schedule for these nodules.

KEY POINTS

• The prevalence of HBP hypointense nodules without APHE was 12.6% in a prospectively recruited population at high risk of developing HCC. • Nodule size ≥ 10 mm was significantly associated with hypervascular transformation, and approximately half of the HBP hypointense nodules ≥ 10 mm without APHE transformed to HCC during 5 years of follow-up. • Given the risk of malignant transformation, HBP hypointense nodules ≥ 10 mm without APHE should be closely monitored.

Can modified LI-RADS increase the sensitivity of LI-RADS v2018 for the diagnosis of 10-19 mm hepatocellular carcinoma on gadoxetic acid-enhanced MRI?

PURPOSE

To evaluate whether the Liver Imaging Reporting and Data System (LI-RADS) v2018 LR-5 criteria can be modified to increase sensitivity without reducing specificity for diagnosing 10-19 mm hepatocellular carcinoma (HCC) on gadoxetic acid-enhanced magnetic resonance imaging (MRI).

METHODS

A total of 133 high-risk consecutive patients with 174 small observations (10-19 mm) detected on gadoxetic acid-enhanced MRI were retrospectively studied. LI-RADS MRI major features (MFs) and ancillary features (AFs) were reviewed by two independent radiologists in consensus. Observations were categorized using LI-RADS v2018 MFs. Independently significant AFs were identified through logistic regression analysis. Upgraded LR-5 criteria were developed by combining independently significant AFs with MFs of LR-3 or LR-4 v2018. The sensitivity and specificity of the new diagnostic criteria were compared with those of LR-5 v2018 using McNemar's test.

RESULTS

Three of the AFs favoring malignancy [mild-moderate T2 hyperintensity, transitional phase (TP) hypointensity and fat in mass] were independently significant features for diagnosing 10-19 mm HCC. The upgraded LR-5 criteria (mLI-RADS VII: LR-4 + mild-moderate T2 hyperintensity/TP hypointensity or LR-3 + fat in mass) yielded a significantly greater sensitivity than that of the LR-5 v2018 criteria (70.4% vs 55.1%; p < 0.001), whereas the specificity was not significantly different (94.7% vs 98.7%, p = 0.250).

CONCLUSIONS

Independently significant AFs may be used to upgrade an observation from LR-3/LR-4 to LR-5, which can improve the sensitivity without impairing the specificity for diagnosing 10-19 mm HCC on gadoxetic acid-enhanced MRI.

Risk Factors for Hypervascularization in Hepatobiliary Phase Hypointense Nodules without Arterial Phase Hyperenhancement: A Systematic Review and Meta-analysis

RATIONALE AND OBJECTIVES

To perform a systematic review and meta-analysis to determine risk factors for hypervascularization in hepatobiliary phase (HBP) hypointense nodules without arterial phase hyperenhancement (APHE) in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Pubmed and EMBASE databases were searched up to May 7, 2020. Studies which evaluated radiologic and clinical risk factors for hypervascularization in HBP hypointense nodules without APHE were included. Hazard ratios were meta-analytically pooled using random-effects model. Methodological quality of included studies was assessed using Quality in Prognostic Studies (QUIPS) tool.

RESULTS

Sixteen studies with 934 patients were included. HBP hypointense nodules without APHE with baseline size greater than 10 mm, T2 hyperintensity, and restricted diffusion showed risk for hypervascularization with pooled HRs of 2.95 (95% confidence interval [CI], 1.94-4.20), 4.21 (95% CI, 1.15-15.40), 5.83 (95% CI, 1.42-23.95), respectively. Previous HCC history contributed to hypervascularization of the nodules with hazard ratio of 2.06 (95% CI, 1.23-3.44). T1 hyperintensity, intralesional fat, Child-Pugh Class B, sex, alfa-fetoprotein, hepatitis B or C infection were not significant risk factors for hypervascularization (p ≥0.05). Study quality was generally moderate.

CONCLUSION

HBP hypointense nodules without APHE on gadoxetic acid-enhanced MRI with baseline size greater than 10 mm, T2 hyperintensity, restricted diffusion and previous hepatocellular carcinoma history pose higher risk for hypervascularization. Proper patient management in patients with HBP hypointense nodules without APHE on gadoxetic acid-enhanced MRI may need to be tailored according to these risk factors.

Direct-Acting Antiviral Agents Reduce the Risk of Malignant Transformation of Hepatobiliary Phase-Hypointense Nodule without Arterial Phase Hyperenhancement to Hepatocellular Carcinoma on Gd-EOB-DPTA-Enhanced Imaging in the Hepatitis C Virus-Infected Liver

BACKGROUND AND AIMS

Hepatobiliary phase-hypointense nodules without arterial phase hyperenhancement (HHNs without APHE) on gadolinium-ethoxybenzyl-diethylenetriamine-enhanced magnetic resonance imaging (Gd-EOB-DTPA-enhanced MRI) are considered to be dysplastic nodules or early hepatocellular carcinoma (HCC) and have high risk of undergoing malignant transformation and progression to hypervascular HCC. The aim of this study was to evaluate the clinical outcome of HHNs without APHE diagnosed by Gd-EOB-DTPA-enhanced MRI before the eradication of HCV by direct-acting antiviral agents (DAAs).

METHODS

We retrospectively investigated 221 consecutive patients with HCV infection who were treated with DAAs. Thirty patients with 65 HHNs without APHE were enrolled in a sustained virologic response (SVR) cohort and 22 with 43 HHNs without APHE who did not receive DAAs or had failed HCV eradication therapy were enrolled in a non-SVR cohort. Fifty-seven percent of patients in the SVR group and 64% of those in the non-SVR group had a history of HCC. The primary endpoint of this study was the development of hypervascular HCC from HHNs without APHE detected on imaging. The cumulative incidence and relative risk of progression to hypervascular HCC in relation to clinical characteristics were compared between the two cohorts.

RESULTS

The 2-year cumulative incidence of progression to hypervascular HCC was 8.5 and 21.9% in the SVR and non-SVR cohorts, respectively. There was a significant reduction in progression of HHNs without APHE to HCC after the eradication of HCV (p = 0.022, log-rank test). Multivariate Cox regression analysis identified hyperintensity on T2-weighted images (relative risk 14.699, p < 0.001) and achieving SVR (relative risk 0.290, p = 0.043) as independent factors associated with the risk of HCC. During follow-up, 6 (9.2%) of the HHNs without APHE in the SVR cohort became undetectable on hepatocyte-phase images.

CONCLUSIONS

Eradication of HCV by DAAs could reduce the hypervascularization rate of HHNs without APHE, and some of these nodules disappeared.

Precision pathology analysis of the development and progression of hepatocellular carcinoma: Implication for precision diagnosis of hepatocellular carcinoma

Outcomes for patients with hepatocellular carcinoma (HCC) remain poor because the condition is often unresponsive to the available treatments. Consequently, the early and precise diagnosis of HCC is crucial to achieve improvements in prognosis. For patients with chronic liver disease, the assessment of liver fibrosis is also important to ascertain both the staging of fibrosis and the risk of HCC occurrence. Early HCC was first described in 1991 in Japan and was defined internationally in 2009. As the concept of early HCC spread, the multistage hepatocarcinogenesis process became accepted. Consequently, improvements in imaging technology made the early diagnosis of HCC possible. At present, the most appropriate therapeutic strategy for HCC is determined using an integrated staging system that assesses the tumor burden, the degree of liver dysfunction and the patient performance status; however, pathological and molecular features are not taken into account. The recent introduction of several new therapeutic agents will change the treatment strategy for HCC. Against this background, HCC subclassification based on tumor cellular and microenvironmental characteristics will become increasingly important. In this review, we give an overview of how pathological analysis contributes to understanding the development and progression of HCC and establishing a precision diagnosis of HCC.

Hypervascular Transformation of Hypovascular Hypointense Nodules in the Hepatobiliary Phase of Gadoxetic Acid-Enhanced MRI: A Systematic Review and Meta-Analysis

OBJECTIVE

The purpose of this study is to evaluate the outcomes of hypovascular hypointense nodules in the hepatobiliary phase of gadoxetic acid-enhanced MRI and the risk factors for the hypervascular transformation of the nodules through a systematic review and meta-analysis.

MATERIALS AND METHODS

We searched the Ovid-MEDLINE and EMBASE databases for published studies of hypovascular hypointense nodules in patients with chronic liver disease. The pooled proportions of the overall and cumulative incidence rates at 1, 2, and 3 years for the transformation of hypovascular hypointense nodules into hypervascular hepatocellular carcinomas (HCCs) were assessed by using random-effects modeling. Metaregression analysis was performed.

RESULTS

Sixteen eligible studies with 944 patients and 1819 hypovascular hypointense nodules in total were included. The pooled overall rate of hypervascular transformation was 28.2% (95% CI, 22.7-33.6%; I² = 87.46%). The pooled 1-, 2-, and 3-year cumulative incidence rates were 18.3% (95% CI, 9.2-27.4%), 25.2% (95% CI, 12.2-38.2%), and 30.3% (95% CI, 18.8-41.9%), respectively. The metaregression analysis revealed that the mean initial nodule size (cutoff value, 9 mm) was a significant factor affecting the heterogeneity of malignant transformation.

CONCLUSION

Hypovascular hypointense nodules detected in the hepatobiliary phase of gadoxetic acid-enhanced MRI carry a significant potential of transforming into hypervascular HCCs. The size of nodules is a significant risk factor for hypervascular transformation.

Asia-Pacific clinical practice guidelines on the management of hepatocellular carcinoma: a 2017 update

There is great geographical variation in the distribution of hepatocellular carcinoma (HCC), with the majority of all cases worldwide found in the Asia–Pacific region, where HCC is one of the leading public health problems. Since the “Toward Revision of the Asian Pacific Association for the Study of the Liver (APASL) HCC Guidelines” meeting held at the 25th annual conference of the APASL in Tokyo, the newest guidelines for the treatment of HCC published by the APASL has been discussed. This latest guidelines recommend evidence-based management of HCC and are considered suitable for universal use in the Asia–Pacific region, which has a diversity of medical environments.

Assessment of clinical and magnetic resonance imaging features of de novo hypervascular hepatocellular carcinoma using gadoxetic acid-enhanced magnetic resonance imaging

AIM

To clarify the clinical and magnetic resonance imaging (MRI) features of de novo hypervascular hepatocellular carcinoma (HCC) using serial gadoxetic acid-enhanced MRI.

METHODS

The institutional review board approved this retrospective study. After review of 1007 MRI examinations in 240 patients with chronic liver disease, 17 newly developed hypervascular HCCs in 16 patients detected by follow-up from initial MRI examination without hepatocellular nodules were evaluated. The clinical and MRI findings such as previous treatment history for HCC, period to hypervascular HCC onset, presence or absence of hypovascular hypointense nodules on hepatobiliary phase before hypervascularization, and intralesional fat component were recorded or evaluated. Statistical evaluations included Fisher's exact test, χ² -test, and Mann-Whitney U-test.

RESULTS

In 17 HCCs, 12 (71%) were de novo hypervascular HCC without showing hypovascular hypointense nodule on hepatobiliary phase before hypervascularization (de novo group) and 5 (29%) were hypervascularized HCC developed during multistep hepatocarcinogenesis (multistep group). The incidence of previous treatment history for HCC in the de novo group (91%) was significantly higher than that in the multistep group (20%) (P = 0.013). The duration to hypervascular HCC onset from initial examination was shorter in the de novo group (mean, 291 days) than in the multistep group (mean, 509 days) (P = 0.035). The incidence of fat-containing lesion in the de novo group (0%) was lower than that in the multistep group (40%) (P = 0.074).

CONCLUSION

De novo hypervascular HCC is characterized by rapid growth, patients with previous treatment history for HCC, and lack of intralesional fat, compared to hypervascular HCC with multistep progression.

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.

Percutaneous real-time sonoelastography as a non-invasive tool for the characterization of solid focal liver lesions: A prospective study

BACKGROUND

Real-time sonoelastography is currently used for the characterization of superficial solid lesions such as thyroid and breast masses. This study evaluates the usefulness of percutaneous sonoelastography for the characterization of solid focal liver lesions.

METHODS

30 out of 43 patients with 38 known liver lesions were included in a prospective, diagnostic study. Qualitative analysis (pattern of deformation, elasticity type of liver tumour) and semi-quantitative measurements (strain ratio, hardness percentage, histogram) were evaluated. Sensitivity, specificity, positive and negative predictive values were calculated and the area under the receiver operating characteristics curve was constructed.

RESULTS

Patterns A and C-D are specific of benign lesions and metastases respectively. The patterns for haemangiomas, focal nodular hyperplasia and metastases were significantly different to each other in terms of strain ratio, hardness percentage and histogram (p<0.05). A statistically significant difference (p<0.001) was observed between the median values of the 3 measured parameters for benign (1.02; 12%; 47) and malignant lesions (1.66; 65%; 20.5) respectively. The area under the receiver operating characteristics curve values for strain ratio, hardness percentage and histogram were 0.88, 0.89, and 0.86 respectively for cut-off values of 1.2, 45, and 30.

CONCLUSIONS

By percutaneous sonoelastography it is possible to differentiate benign versus malignant focal liver lesions, metastases in particular, with good diagnostic performance.

Hypovascular hypointense nodules on hepatobiliary phase without T2 hyperintensity on gadoxetic acid-enhanced MR images in patients with chronic liver disease: long-term outcomes and risk factors for hypervascular transformation

PURPOSE

To evaluate the long-term outcomes and imaging features associated with hypervascularization of hypovascular nodules that show T2 iso-/hypointensity and hypointensity on hepatobiliary phase (HBP) of gadoxetic acid-enhanced magnetic resonance (MR) images in patients with chronic liver disease.

MATERIALS AND METHODS

Sixty patients and 114 nodules, which were hypovascular and iso-/hypointense on T2-weighted images and hypointense on HBP of gadoxetic acid-enhanced MRI, were included. We evaluated the effect of baseline clinical features, baseline MR features and growth rate on subsequent hypervascularization.

RESULTS

Twenty-seven nodules in 21 patients transformed to hypervascular hepatocellular carcinoma (HCC). Using multivariate Cox analysis, T1 hyperintensity (hazard ratio [HR] = 2.69, P = 0.021), previous history of HCC (HR = 2.64, P = 0.021), and initial nodule size (HR = 1.09, P = 0.046) were identified to be associated with hypervascularization. The growth rate of nodules was a more powerful determinant of subsequent hypervascularization than baseline clinical and MR features. At long-term follow-up after >3 years, only one nodule with T1 isointensity showed hypervascularization.

CONCLUSION

Careful follow-up or diagnostic procedures, such as biopsy, should be considered for up to 3 years after detection of hypointense nodules on HBP with T1 hyperintensity or a higher growth rate.

KEY POINTS

• T1 hyperintensity is a baseline MR predictive factor for subsequent hypervascularization. • A higher growth rate is a more powerful determinant of subsequent hypervascularization. • Management of patients with these predictive factors requires more attention.

Challenges of Clinical Research on Hepatocellular Carcinoma

Challenges of clinical practice and research on hepatocellular carcinoma (HCC) were reviewed. There are several differences in clinical practice between Japan and the Western countries such as tumor markers, understanding of pathological early HCC, imaging diagnosis, treatment strategy, staging system and subclassification of HCC. Further studies are warranted for the clinical practices of Japan to be adopted in the rest of the world.

Surveillance, diagnosis, treatment, and outcome of liver cancer in Japan

BACKGROUND

Hepatocellular carcinoma (HCC) is the fifth most common type of cancer and the third leading cause of cancer-related death worldwide. HCC is most common in Asia, but its prevalence is rapidly increasing in Western countries; consequently, HCC is a global medical issue that urgently needs to be addressed. Japan is the only developed country that has experienced both hepatitis B-related and hepatitis C-related HCC and has a long history of innovation when it comes to new diagnostic and therapeutic modalities, such as computed tomography angiography, anatomical resection, ablation, and transarterial chemoembolization. Among these innovations, a nationwide surveillance program was well established by the 1980s, and such a long-term national program does not exist anywhere else in the world.

SUMMARY

More than 60% of the initially detected HCCs in Japan are Barcelona Clinic Liver Cancer stage 0 or A, which can undergo curative therapies such as resection, ablation, or transplantation. The recent 5-year survival rate of HCC patients in Japan was 43% and the median survival time was 50 months. In addition, both incidence and mortality rates are drastically declining as a result of the successful surveillance program, careful diagnostic flow, and extensive repeated treatments.

KEY MESSAGE

Japan's successful model in the surveillance, diagnosis, and treatment of HCC should be adopted as widely as possible to improve the survival of HCC patients worldwide.

Nonhypervascular Hypointense Nodules at Gadoxetic Acid-enhanced MR Imaging in Chronic Liver Disease: Diffusion-weighted Imaging for Characterization

PURPOSE

To compare the diagnostic performance of magnetic resonance (MR) imaging features, including those on diffusion-weighted (DW) and T2-weighted images, in differentiating between hypovascular hepatocellular carcinoma (HCC) and dysplastic nodules seen as hypointense nodules at hepatobiliary phase gadoxetic acid-enhanced MR imaging.

MATERIALS AND METHODS

The institutional review board approved this retrospective study and waived the need to obtain informed patient consent. There were 53 patients (39 men and 14 women; age range, 32-75 years) with histologically proven hypovascular HCCs (n = 25) and/or dysplastic nodules (n = 31) who underwent gadoxetic acid-enhanced MR imaging at 3.0-T between March 2011 and January 2014. Images of 25 HCCs and 31 dysplastic nodules were analyzed for nodule size; signal intensity on T1- and T2-weighted, portal venous phase, and DW (b value = 800 sec/mm(2)) images; and intralesional fat. Correlations between the hyperintensity grade of lesions and the liver-to-lesion signal intensity ratio at T2-weighted and DW imaging were determined by means of analysis with generalized estimating equations.

RESULTS

Hyperintensity at T2-weighted and DW imaging and hypointensity in the portal venous phase were significant features for differentiating hypovascular HCCs from dysplastic nodules (P < .05). The sensitivity of DW imaging tended to be higher than that of T2-weighted imaging (72.0% [18 of 25] vs 40.0% [10 of 25]; P = .008 for grade 2 and 3 hyperintensity). Use of the parameter of hyperintensity similar to or slightly lower than the signal intensity of the spleen on DW images (b value = 800 sec/mm(2)) yielded a specificity of 100% (31 of 31) for the diagnosis of hypovascular HCC by differentiating it from a dysplastic nodule.

CONCLUSION

Hyperintensity at DW imaging could be a useful MR imaging feature for differentiating hypovascular HCCs from dysplastic nodules seen as hypointense nodules at gadoxetic acid-enhanced MR imaging.

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.

OATP1B3 expression is strongly associated with Wnt/β-catenin signalling and represents the transporter of gadoxetic acid in hepatocellular carcinoma

BACKGROUND & AIMS

In the current era of emerging molecular targeted drugs, it is necessary to identify before treatment the specific subclass to which a tumour belongs. Gadoxetic acid is a liver-specific contrast agent that is preferentially taken up by hepatocytes. Therefore, gadoxetic acid-enhanced magnetic resonance imaging (EOB-MRI) should provide precise molecular information about hepatocellular carcinomas (HCCs). The aim of this study was to investigate the transporters of gadoxetic acid in HCC comprehensively and to analyse the molecular regulatory mechanism of such transporters.

METHODS

Expression levels of transporters, transcriptional factors and Wnt target genes in clinical samples were examined by quantitative real-time reverse transcription polymerase chain reaction and immunohistochemistry. LiCl treatment of the HCC cell line KYN-2 was conducted in vitro to assess the effects of Wnt signalling activity.

RESULTS

Comprehensive analyses of transporter mRNAs and protein expressions revealed that the organic anion transporting polypeptide 1B3 (OATP1B3) had the strongest correlation with tumour enhancement in hepatobiliary-phase images of EOB-MRI. Association analysis with OATP1B3 expression revealed significant correlation with the expression of Wnt/β-catenin target genes. Further, LiCl treatment induced OATP1B3 mRNA expression in KYN-2 cells, indicating a strong association between OATP1B3 expression and Wnt/β-catenin signalling. The sensitivity and specificity to predict Wnt/β-catenin-activated HCC using tumour enhancement in EOB-MRI were 78.9% and 81.7%, respectively.

CONCLUSIONS

OATP1B3 was confirmed as the most important transporter mediating HCC enhancement in EOB-MRI. OATP1B3 expression showed a strong association with the expression of Wnt/β-catenin target genes, therefore, OATP1B3-upregulated HCC likely represents a specific subclass of Wnt/β-catenin-activated HCC.

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.

Hepatobiliary MR contrast agents in hypovascular hepatocellular carcinoma

Hepatocellular carcinoma (HCC) develops via multistep hepatocarcinogenesis, during which hypovascular/early HCC precedes the typical hypervascular HCC. The hypovascular HCC lacks the typical hallmark imaging features of HCC, such as late arterial phase enhancement and portal venous washout, limiting early detection using conventional extracellular contrast agents for dynamic magnetic resonance imaging (MRI) or computed tomography (CT) imaging. In recent years, gadolinium-based contrast agents with hepatobiliary uptake have garnered interest from radiologists and hepatologists due to their potential for improved detection of HCC during hepatobiliary phase MRI. Lesions with reduced or absent hepatocyte function appear hypointense in the hepatobiliary phase of gadoxetic acid-enhanced MRI. This behavior can be exploited for earlier detection of hypovascular HCC. This review describes the general characteristics and advantages of gadoxetic acid for the diagnosis of HCC with a particular focus on hypovascular/early HCC.