Intranodular signal intensity analysis of hypovascular high-risk borderline lesions of HCC that illustrate multi-step hepatocarcinogenesis within the nodule on Gd-EOB-DTPA-enhanced MRI

Nodule-in-nodule architecture of hepatocellular carcinomas: enhancement patterns in the hepatobiliary phase and pathological features

PURPOSE

This study aimed to evaluate the enhancement patterns in the hepatobiliary phase (HBP) and pathological features of nodule-in-nodule-type hepatocellular carcinoma (NIN-HCC) patients.

METHODS

In this single-institution retrospective study, 27 consecutive cirrhosis patients with 29 histologically confirmed NIN-HCCs who underwent preoperative examination via Gd-EOB-DTPA-enhanced MRI were enrolled from January 2016 to September 2023. Two blinded radiologists assessed the imaging features of both the inner and outer nodules in NIN-HCCs to reach a consensus on the Liver Imaging Reporting & Data System (LI-RADS) categories of the lesions. Based on the different enhancement patterns of the inner and outer nodules in the HBP, NIN-HCCs were classified into different groups and further divided into different types. Imaging features and LI-RADS categories were subsequently compared among the groups. Pathological findings for NIN-HCCs were also evaluated.

RESULTS

Among 29 NIN-HCCs, all inner nodules showed hypervascularity, with a maximum diameter of 13.2 ± 5.5 mm; 51.7% (15/29) showed "wash-in with washout" enhancement; and 48.3% (14/29) showed "wash-in without washout" enhancement. All outer nodules showed hypovascularity, with a maximum diameter of 25.6 ± 7.3 mm, and 51.9% (14/29) showed a washout appearance on PVP. Among all the lesions, the maximum diameter was 27.5 ± 6.8 mm; 12 (41.4%) lesions were LR-4, and 17 (58.6%) lesions were LR-5. NIN-HCCs were classified into hypointense (62.1%, 18/29) and isointense (37.9%, 11/29) groups based on the signal intensity of the outer nodules in the HBP. In the hypointense group, 2 (6.9%) of the inner nodules were hypointense (type A), 11 (37.9%) were isointense (type B), and 5 (17.2%) were hyperintense (type C) compared to the background hypointense outer nodules. In the isointense group, 9 (31.0%) of the inner nodules were hypointense (type D), 2 (6.9%) were isointense (type E), and no (0%) was hyperintense (type F) compared to the background isointense outer nodules. There were no significant differences in the diameter, dynamic enhancement patterns of the inner or outer nodules, or LI-RADS scores of the lesions between the hypointense group and the isointense group (all P > 0.05). Histologically, the inner nodules of NIN-HCCs were mainly composed of moderately differentiated HCC (75.9% 22/29), whereas the outer nodules consisted of either well-differentiated HCC or high-grade dysplastic nodules (HGDNs).

CONCLUSIONS

NIN-HCCs exhibit specific MRI findings closely associated with their pathological features. The spectrum of HBP enhancement patterns provides valuable insights into the underlying cell biological mechanisms of these lesions. NIN-HCC subtypes may be used as a morphologic marker in the early stage of multistep hepatocarcinogenesis.

Preoperative Gadoxetic Acid-Enhanced MRI Based Nomogram Improves Prediction of Early HCC Recurrence After Ablation Therapy

Purpose

This study aimed to identify preoperative gadoxetic acid-enhanced MRI features and establish a nomogram for predicting early recurrence (≤ 2 years) of hepatocellular carcinoma (HCC) after ablation therapy.

Methods

A total of 160 patients who underwent gadoxetic acid-enhanced MRI and ablation HCC therapy from January 2015 to June 2018, were included retrospectively and divided into a training cohort (n = 112) and a validation cohort (n = 48). Independent clinical risk factors and gadoxetic acid-enhanced MRI features associated with early recurrence were identified by univariate and multivariate logistic regression analysis and used for construction of a nomogram. The performance of the nomogram was evaluated by discrimination, calibration, and clinical utility.

Results

Alpha-fetoprotein (AFP) level, tumor number, arterial peritumoral enhancement, satellite nodule and peritumoral hypointensity at hepatobiliary phases in the training cohort were identified as independent risk factors for early recurrence after ablation. A new nomogram that was constructed with these five features showed an area under the curve (AUC) of 0.843 (95%CI 0.771-0.916) and 0.835 (95%CI 0.713-0.956) in the training and validation cohort, respectively. The calibration curve and decision curve analysis (DCA) suggested that the nomogram had good consistency and clinical utility.

Conclusions

A new nomogram that was constructed using four preoperative gadoxetic acid-enhanced MRI features and serum AFP level can predict the risk of early HCC recurrence after ablation therapy with AUC up to 0.843. The strong performance of this nomogram may help hepatologists to categorize patients' recurrent risk to guide selecting treatment options and improve postoperative management.

Hypovascular hepatic nodules as a predictive factor for transcatheter arterial chemoembolization refractoriness in hepatocellular carcinoma

AIM

Intermediate-stage hepatocellular carcinoma (HCC) targeted for transcatheter arterial chemoembolization (TACE) corresponds to a highly heterogeneous population for whom the factors predicting TACE efficacy have not been established. This study aimed to evaluate the impact of hypovascular hepatic nodules coexisting with intermediate-stage HCC as a significant predictive factor for TACE refractoriness.

METHODS

A total of 66 patients with intermediate-stage HCC who received initial TACE were retrospectively analyzed. Hypovascular hepatic nodules were detected by dynamic computed tomography or magnetic resonance imaging, as well as angiography, before all initial TACE. The time to TACE refractoriness (TTTR) was defined as the period from initial TACE until the diagnosis of TACE refractoriness.

RESULTS

Hypovascular hepatic nodules were detected in 36 patients (54.5%), 15 (41.7%) of whom had a single nodule, whereas 21 (58.3%) had multiple nodules, and the median size of the maximum nodule was 10 mm (range 5-80 mm). The median TTTR was 17.4 months for all patients, and 7.3 and 33.1 months for patients with and without hypovascular hepatic nodules, respectively. The TTTR was significantly shorter for patients with hypovascular hepatic nodules than that for the other patients. In the multivariate analysis, the presence of hypovascular hepatic nodules (HR 7.016, 95% CI 3.534-13.930; P < 0.001) and being out of the up-to-seven criteria (HR 2.861, 95% CI 1.493-5.486; P = 0.002) were independent risk factors for a short TTTR.

CONCLUSIONS

The presence of hypovascular hepatic nodules with intermediate-stage HCC represents a significant predictive risk factor for TACE refractoriness.

Gadoxetic acid-enhanced MR imaging for hepatocellular carcinoma: molecular and genetic background

Gadoxetic acid-enhanced magnetic resonance imaging (MRI) plays important roles in diagnosis of hepatic lesions because of its superiority in the detectability of small lesions, its differentiation ability, and its utility for the early diagnosis of hepatocellular carcinoma (HCC). In HCC, expression of organic anion transporting polypeptide (OATP) 1B3 correlates with the enhancement ratio in the hepatobiliary phase. Gadoxetic acid-enhanced MRI, an indirect molecular imaging method, reflects OATP1B3 expression in HCC. OATP1B3 expression gradually decreases from the dysplastic nodule stage to advanced HCC. Decreased expression is a sensitive marker of multistep hepatocarcinogenesis, especially in the early stages. Hypervascular HCCs commonly show hypointensity in the hepatobiliary phase corresponding to a decrease in OATP1B3; however, approximately 10% of HCCs show hyperintensity due to OATP1B3 overexpression. This hyperintense HCC shows less aggressive biological features and has a better prognosis than hypointense HCC. Hyperintense HCC can be classified into a genetic subtype of HCC with a mature hepatocyte-like molecular expression. OATP1B3 expression and the less aggressive nature of hyperintense HCC are regulated by the molecular interaction of β-catenin signaling and hepatocyte nuclear factor 4α, a tumor suppressor factor. Gadoxetic acid-enhanced MR imaging has the potential to be an imaging biomarker for HCC. KEY POINTS: • The hepatobiliary phase is a sensitive indirect indicator of organic anion transporting polypeptide1B3 (OATP1B3) expression in hepatocellular carcinoma (HCC). • The OATP1B3 expression, namely, enhancement in the hepatobiliary phase, decreases from the very early stage of hepatocarcinogenesis, contributing to early diagnosis of HCC. • HCC showing hyperintensity on the hepatobiliary phase is a peculiar genetic subtype of HCC with OATP1B3 overexpression, a less aggressive nature, and mature hepatocyte-like molecular/genetic features.

Hepatobiliary phase hypointense nodule without arterial phase hyperenhancement as a risk factor for late recurrence (>1 year) of hepatocellular carcinoma after surgery

AIM

To evaluate the value of magnetic resonance imaging (MRI) features, including liver stiffness measured by magnetic resonance elastography (MRE) and the presence of hepatobiliary phase (HBP) hypointense nodule without arterial phase hyperenhancement (APHE), for predicting late recurrence (>1 year) after surgery for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This retrospective study included 124 consecutive patients who had undergone surgery for HCC and preoperative MRI. After excluding patients with early recurrence within 1 year after surgery, 89 patients were analysed. Preoperative MRI images were reviewed by a radiologist to record imaging findings, including (1) liver stiffness by MRE, (2) size of the HCCs, (3) number of HCCs, and (4) presence of HBP hypointense nodule without APHE. Pathological findings included tumour grade, vascular/biliary/capsule invasion, and fibrosis stage of the liver. Considering imaging/pathological findings and patients' characteristics as dependent variables, Cox proportional hazards model analysis was performed to identify independent factors associated with late recurrence after surgery.

RESULTS

The median follow-up period was 37.3 months. During follow-up, 29 patients (32.5%) developed late recurrence after surgery. In multivariate analysis, underlying liver disease (viral hepatitis) and presence of HBP hypointense nodules without APHE (p=0.010 and 0.033, respectively) were independently associated with disease-free survival (DFS). Kaplan-Meier analysis revealed that patients with HBP hypointense nodules without APHE had a significantly lower DFS rate than those without the nodule (39.2% versus 74.1% at 3 years after surgery, p=0.008).

CONCLUSION

The presence of HBP hypointense nodules without APHE was an indicator of late recurrence after surgery for HCC.

Non-hypervascular Hypointense Nodules on Hepatocyte Phase Gadoxetic Acid-Enhanced MR Images: Transformation of MR Hepatobiliary Hypointense Nodules into Hypervascular Hepatocellular Carcinomas

Background/Aims

The annual risk of transformation of non-hypervascular magnetic resonance (MR) hepatobiliary phase imaging (HBPI) hypointense nodules into hypervascular hepatocellular carcinomas (HCCs) was evaluated.

Methods

Cirrhotic patients with non-hypervascular HBPI hypointense nodules were retrospectively analyzed if they were diagnosed as HCC and MR followed up longer than 1 year during the period from January 2010 to October 2016 with regular intervals of 3 to 6 months. Risk factors for transformation into hypervascular HCCs were analyzed using the Cox proportional hazard model.

Results

Among the 103 non-hypervascular HBPI hypointense nodules meeting the inclusion criteria, transformation into hypervascular HCCs occurred in 44 tumors (42.7%). The median follow-up period was 24 months. Multivariate analysis revealed that hyperintensity on T2-weighted images (T2WI) and diffusion-weighted images (DWI) were the two independent predictors of transformation into hypervascular HCCs (p=0.036 and p=0.041, respectively). Most tumors with hyperintensity on T2WI or DWI on the initial or follow-up MR were transformed into hypervascular HCCs within the first year. Among the 22 nodules (21.3%) showing a new change in dynamic phases during follow-up, 14 nodules (13.6%) showed malignant transformations.

Conclusions

The transformation rates of HBPI hypointense nodules into hypervascular HCCs could be predicted according to the initial or serial MRI findings.

Differentiation Between Hepatocellular Carcinoma Showing Hyperintensity on the Hepatobiliary Phase of Gadoxetic Acid-Enhanced MRI and Focal Nodular Hyperplasia by CT and MRI

OBJECTIVE

The purpose of this study is to identify points useful in the imaging differentiation of hepatocellular carcinoma (HCC) showing hyperintensity on the hepatobiliary phase of gadoxetic acid-enhanced MRI and focal nodular hyperplasia (FNH) and FNH-like nodules.

MATERIALS AND METHODS

We enrolled consecutive 51 pathologically diagnosed HCCs that were hyperintense on hepatobiliary phase imaging (47 patients, including 44 with cirrhosis) and 10 FNHs and eight FNH-like nodules (16 patients, including five with cirrhosis). Imaging findings of dynamic CT and gadoxetic acid-enhanced MRI were assessed by two radiologists and compared between HCC and FNH.

RESULTS

The apparent diffusion coefficient (ADC) was lower in hyperintense HCC than in FNH (p = 0.004). The enhancement patterns of hyperintense HCC and FNH at dynamic CT were significantly different (p < 0.0001), with 95.9% of HCCs and 22.2% of FNHs showing arterial phase enhancement with a washout pattern, and 4.1% of HCCs and 77.8% of FNHs showing arterial phase enhancement without a washout pattern. The frequency of coronalike enhancement was 84.3% in hyperintense HCCs versus 11.1% in FNHs (p < 0.0001). The signal distribution on the hepatobiliary phase was significantly different between hyperintense HCCs and FNHs (p = 0.0002). The frequency of a capsulelike rim was 88.2% versus 22.2%, that of a mosaic appearance was 72.5% versus 11.1%, and that of a central scar was 0% versus 55.6% in hyperintense HCCs versus FNHs (all p < 0.0001). Multivariate logistic regression analysis showed that ADC ratio (p = 0.03; odds ratio, 0.12) and enhancement pattern at dynamic CT (p = 0.04; odds ratio, 16.21) were the independent factors for differentiation between hyperintense HCC and FNH.

CONCLUSION

For the diagnosis of hyperintense HCC differentiated from FNH and FNH-like nodule, arterial phase enhancement and washout pattern at dynamic CT and decrease of ADC ratio would be important findings.

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.

Intrahepatic distant recurrence after radiofrequency ablation for hepatocellular carcinoma: precursor nodules on pre-procedural gadoxetic acid-enhanced liver magnetic resonance imaging

Background Intrahepatic distant recurrence (IDR) after radiofrequency (RF) ablation for hepatocellular carcinoma (HCC) is associated with poor overall survival outcome. Purpose To evaluate the incidence and findings on pre-procedural gadoxetic acid-enhanced liver magnetic resonance imaging (MRI) of precursor nodules for IDR after RF ablation for HCC. Material and Methods This study was approved by our institutional review board. Among 343 patients treated with RF ablation for HCC between 2009 and 2011, 141 patients who underwent pre-procedural gadoxetic acid-enhanced liver MRI and experienced IDR were enrolled. The presence of precursor nodules for IDR on pre-procedural imaging was assessed. Nodules were categorized based on hypervascularity in the arterial phase and signal intensity on hepatobiliary phase images. Time to recurrence was compared between patients with and without precursor nodules. Results In 46 (32.7%) of 141 patients (50 HCCs), there were precursor nodules on pre-procedural MRIs (median follow-up period, 4.39 years; range, 0.08-6.08). In three patients, HCCs were missed on imaging. In the remaining 43 patients, the 47 precursor nodules identified were non-hypervascular hypointense (n = 26), non-hypervascular isointense (n = 6), non-hypervascular hyperintense (n = 2), hypervascular hypointense (n = 10), and hypervascular isointense (n = 3). The mean time-to-recurrence was significantly shorter for patients with precursor nodules than for those without (16.6 versus 24.0 months, P = 0.011). Conclusion About one-third of patients with IDR after RF ablation for HCC had precursor nodules on pre-procedural gadoxetic acid-enhanced MRI, most commonly non-hypervascular hypointense nodules in the hepatobiliary phase.

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.

Diagnostic Performance of Gadoxetic Acid-enhanced Liver MR Imaging versus Multidetector CT in the Detection of Dysplastic Nodules and Early Hepatocellular Carcinoma

Purpose To compare the diagnostic performance of gadoxetic acid-enhanced liver magnetic resonance (MR) imaging with that of contrast material-enhanced multidetector computed tomography (CT) in the detection of borderline hepatocellular nodules in patients with liver cirrhosis and to determine the Liver Imaging Reporting and Data System (LI-RADS) categories of these detected nodules. Materials and Methods The institutional review board approved this retrospective study and waived the informed consent requirement. Sixty-eight patients with pathologically proven dysplastic nodules (DNs) (low-grade DNs, n = 20; high-grade DNs, n = 17), early hepatocellular carcinomas (HCCs) (n = 42), or progressed HCCs (n = 33) underwent gadoxetic acid-enhanced MR imaging and multidetector CT. An additional 57 patients without any DNs or HCCs in the explanted livers were included as control subjects. Three radiologists independently graded the presence of liver nodules on a five-point confidence scale and assigned LI-RADS categories by using imaging findings. Jackknife alternative free-response receiver operating characteristics (JAFROC) software was used to compare the diagnostic accuracy of each modality in lesion detection. Results Reader-averaged figures of merit estimated with JAFROC software to detect hepatocellular nodules were 0.774 for multidetector CT and 0.842 for MR imaging (P = .002). Readers had significantly higher detection sensitivity for early HCCs with MR imaging than with multidetector CT (78.6% vs 52.4% [P = .001], 71.4% vs 50.0% [P = .011], and 73.8% vs 50.0% [P = .001], respectively). A high proportion of overall detected early HCCs at multidetector CT (59.4%) and MR imaging (72.3%) were categorized as LI-RADS category 4. Most early HCCs (76.2%) and high-grade DNs (82.4%) demonstrated hypointensity on hepatobiliary phase images. In total, 30 more LI-RADS category 4 early HCCs were identified with MR imaging than with multidetector CT across all readers. Conclusion Gadoxetic acid-enhanced MR imaging performed significantly better in the detection of high-risk borderline nodules, especially early HCCs, than did multidetector CT. ^© RSNA, 2017 Online supplemental material is available for this article.

Presence of non-hypervascular hypointense nodules on Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging in patients with hepatocellular carcinoma

BACKGROUND AND AIMS

Gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) performed before curative therapy for hepatocellular carcinoma (HCC) can distinguish between intrahepatic distant recurrence and hypervascularization. This study aimed to retrospectively evaluate the presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI as a risk factor of the intrahepatic distant recurrence of early stage HCC following radiofrequency ablation (RFA).

METHODS

A total of 132 patients who underwent preprocedural Gd-EOB-DTPA-enhanced MRI followed by initial RFA were retrospectively analyzed. Post-RFA intrahepatic distant recurrence, which excluded the hypervascularization of non-hypervascular hypointense nodules detected by preprocedural Gd-EOB-DTPA-enhanced MRI, was evaluated according to the presence of non-hypervascular hypointense nodules on preprocedural Gd-EOB-DTPA-enhanced MRI.

RESULTS

Intrahepatic distant recurrence rates following RFA were higher in patients with non-hypervascular hypointense nodules (1-year: 22.5%, 2-year: 52.1%, 5-year: 89.1%) compared with in patients without non-hypervascular hypointense nodules (1-year: 7.0%, 2-year: 28.8%, 5-year: 48.7%). The presence of non-hypervascular hypointense nodules was associated with markedly increased cumulative recurrence rates of both identical and different subsegment intrahepatic distant recurrence, being an independent risk factor for post-RFA identical and different subsegment intrahepatic distant recurrence (identical: HR = 2.365, P = 0.027; different: HR = 3.276, P < 0.001).

CONCLUSION

The presence of non-hypervascular hypointense nodules on hepatobiliary phase images from Gd-EOB-DTPA-enhanced MRI obtained prior to RFA is an important predictive factor of intrahepatic distant recurrence following RFA of HCC.

Diffusion-weighted magnetic resonance imaging predicts malignant potential in small hepatocellular carcinoma

BACKGROUND

Poor differentiation and microvascular invasion are indicators of poor outcome after hepatectomy for patients with small hepatocellular carcinoma (HCC).

AIMS

We investigated whether gadoxetic acid-enhanced and diffusion-weighted magnetic resonance imaging (MRI) could predict these factors before hepatectomy.

METHODS

Between July 2008 and April 2012, 75 patients who underwent hepatectomy for small HCCs (diameter: ≤3cm, tumor number: ≤3) were consecutively enrolled. In gadoxetic acid-enhanced MRI, the signal intensity in the tumor was corrected to that in the paraspinous muscles, and the relative enhancement was calculated. In diffusion-weighted imaging, we measured the apparent diffusion coefficient (ADC). We then investigated the correlations between relative enhancement or ADC and histological grade, microvascular invasion and recurrence-free survival.

RESULTS

Poorly differentiated HCCs showed significantly lower ADC than well-differentiated and moderately differentiated HCCs. There was no significant difference in the hepatobiliary phase. Only ADC was an independent predictor of microvascular invasion, and the best cut-off point of its prediction was 1.175×10(-3)mm(2)/s. Additionally, the recurrence-free survival was significantly shorter in low-ADC group than in high-ADC group.

CONCLUSION

ADC is useful for predicting poorly differentiated HCCs and microvascular invasion, and low ADC is associated with increased recurrence risk for small HCCs after hepatectomy.

Latest developments in precancerous lesions of hepatocellular carcinoma

Hepatocarcinogenesis in human chronic liver diseases is a multi-step process in which hepatic precancerous lesions progress into early hepatocellular carcinoma (HCC) and progressed HCC, and the close surveillance and treatment of these lesions will help improve the survival rates of patients with HCC. The rapid development and extensive application of imaging technology have facilitated the discovery of nodular lesions of ambiguous significance, such as dysplastic nodules. Further investigations showed that these nodules may be hepatic precancerous lesions, and they often appear in patients with liver cirrhosis. Although the morphology of these nodules is not sufficient to support a diagnosis of malignant tumor, these nodules are closely correlated with the occurrence of HCC, as indicated by long-term follow-up studies. In recent years, the rapid development and wide application of pathology, molecular genetics and imaging technology have elucidated the characteristics of precancerous lesions. Based on our extensive review of the relevant literature, this article focuses on evidence indicating that high-grade dysplastic nodules are more likely to transform into HCC than low-grade dysplastic nodules based on clinical, pathological, molecular genetic and radiological assessments. In addition, evidence supporting the precancerous nature of large cell change in hepatitis B virus-related HCC is discussed.

Differentiation of lipid poor angiomyolipoma from hepatocellular carcinoma on gadoxetic acid-enhanced liver MR imaging

PURPOSE

To investigate magnetic resonance (MR) findings of angiomyolipoma (AML) on gadoxetic acid-enhanced MR imaging, and to identify features that differentiate AML from hepatocellular carcinoma (HCC) in patients with a low risk of HCC development.

METHODS

This retrospective study was institutional review board approved, and the requirement for informed consent was waived. Twelve patients with hepatic AML who underwent gadoxetic acid-enhanced MRI with no risk factors for HCC development were recruited. Twenty-seven patients with HCC under the same inclusion criteria were recruited as control. Two radiologists analyzed the images in consensus for morphologic features, enhancement patterns, and hepatobiliary phase (HBP) findings. All results were analyzed using the Mann-Whitney test, two-tailed Fisher exact test, and chi-square test.

RESULTS

Patients with AML were younger than those with HCC (48.8 ± 15 years for AML vs. 62.7 ± 14.2 years for HCC, p = 0.008) with female predominance, while most HCC patients were male (75% (9/12) vs. 15% (4/27), p < 0.001). The most prevalent enhancement pattern was arterial enhancement followed by hypointensity at portal or transitional phases for both AMLs (58% (7/12)) and HCCs (74% (20/27)) (p = 0.455). However, during the HBP, AMLs frequently showed more homogeneous hypointensity than HCCs (83% (10/12) vs. 41% (11/27), p = 0.018). When compared with the signal intensity of the spleen, the mean relative signal intensity of the AML was 91.2 ± 15.4%, while in HCCs, it was 128.7 ± 40% (p < 0.001).

CONCLUSIONS

Although AMLs showed similar enhancement patterns to HCCs during the dynamic phases of gadoxetic acid-enhanced MRI, using characteristic MR features of AML during the HBP and demographic differences, one can better differentiate AML from HCC.

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.

Non-hypervascular hepatobiliary phase hypointense nodules on gadoxetic acid-enhanced MRI: risk of HCC recurrence after radiofrequency ablation

BACKGROUND & AIMS

Hepatobiliary phase images (HBPI) of gadoxetic acid-enhanced MRI can depict borderline hepatocellular nodules that have the potential to progress into hypervascular hepatocellular carcinomas (HCCs), as non-hypervascular hypointense nodules. We retrospectively evaluated the impact of the presence of non-hypervascular hypointense nodules at HBPI of gadoxetic acid-enhanced MRI on the patient's prognosis after radiofrequency ablation (RFA) for early stage HCCs.

METHODS

A total of 139 patients who underwent pre-procedural gadoxetic acid-enhanced MRI followed by RFA were included. After a mean follow-up of 44.6±13.2 months, we compared the results of tumor recurrence as well as overall and recurrence-free survival (RFS) with the presence of non-hypervascular hypointense nodules on HBPI.

RESULTS

The presence of non-hypervascular hypointense nodules on HBPI did not affect overall survival (p=0.136). However, the estimated 5-year RFS rate was 71.3% in 29 patients without non-hypervascular hypointense nodules on HBPI compared to 27.9% in 110 patients with non-hypervascular hypointense nodules on HBPI, indicating a significant difference (hazard ratio=2.84 [1.39-5.98], p=0.006). When we classified recurrence into local tumor progression [LTP], intrahepatic distant recurrence [IDR], and extra-hepatic metastasis [EM], five-year cumulative incidences (CI) of IDR in patients with non-hypervascular hypointense nodules on HBPI were significantly higher than those in patients without non-hypervascular hypointense nodules on HBPI (17.9% vs. 67.5%, p<0.001). Five-year CIs of LTP and EM showed no significant difference (p>0.05).

CONCLUSIONS

The presence of non-hypervascular hypointense hepatocellular nodules on HBPI of gadoxetic acid-enhanced MRI taken prior to RFA is a significant predictive factor of recurrence after RFA of early stage HCCs, particularly IDR.

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.

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.

Magnetic resonance imaging in cirrhosis: what's new?

Cirrhosis is the main risk factor for the development of hepatocellular carcinoma (HCC). The major causative factors of cirrhosis in the United States and Europe are chronic hepatitis C infection and excessive alcohol consumption with nonalcoholic steatohepatitis emerging as another important risk factor. Magnetic resonance imaging is the most sensitive imaging technique for the diagnosis of HCC, and the sensitivity can be further improved with the use of diffusion-weighted imaging and hepatocyte-specific contrast agents. The combination of arterial phase hyperenhancement, venous or delayed phase hypointensity "washout feature," and capsular enhancement are features highly specific for HCC with reported specificities of 96% and higher. When these features are present in a mass in the cirrhotic liver, confirmatory biopsy to establish the diagnosis of HCC is not necessary. Other tumors, such as cholangiocarcinoma, sometimes occur in the cirrhotic at a much lower rate than HCC and can mimic HCC, as do other benign lesions such as perfusion abnormalities. In this article, we discuss the imaging features of cirrhosis and HCC, the role of magnetic resonance imaging in the diagnosis of HCC and other benign and malignant lesions that occur in the cirrhotic liver, and the issue of nonspecific arterially hyperenhancing nodules often seen in cirrhosis.

Evaluation of eligibility criteria in living donor liver transplantation for hepatocellular carcinoma by α-SMA-positive cancer-associated fibroblasts

The eligibility criteria of liver transplantation (LT) for hepatocellular carcinoma (HCC) must clearly confirm the prognosis not only from pathological diagnosis but also from pre-operative imaging diagnosis. In the present study, we evaluated published eligibility criteria for LT based on both pre-operative imaging diagnosis and pathological diagnosis using living donor liver transplantation (LDLT) recipients at our hospital by α-smooth muscle actin (SMA)-positive cancer-associated fibroblasts (CAFs) in HCC. The Up-to-seven (Up-to-7), Asan and Tokyo criteria were evaluated, in both overall survival and HCC disease-free survival, to be statistically significantly beneficial criteria to define post-LDLT prognosis. Recipients only within Up-to-7 criteria based on both pre-operative imaging diagnosis and pathological diagnosis survived without HCC recurrence. Recipients with proliferation of α-SMA-positive CAFs in HCC had significantly poorer prognosis. All survival recipients without HCC recurrence, who were above the Up-to-7 criteria in pathological diagnosis, had no proliferation of α-SMA-positive CAFs. As a result of multivariate analysis, the significant independent factors defining prognosis of recipients after LDLT for HCC were Up-to-7 criteria and proliferation of α-SMA-positive CAFs. The ideal eligibility criteria for LDLT with HCC is Up-to-7 criteria and α-SMA-positive CAFs was considered to be an important factor in HCC recurrence. LDLT should be limited to recipients within Up-to-7 criteria or without proliferation of α-SMA-positive CAFs.