New malignant grading system for hepatocellular carcinoma using the Sonazoid contrast agent for ultrasonography

Review of Clinical Applications of Sonazoid Ultrasound Contrast for Liver Evaluation

ABSTRACT

Sonazoid is a new ultrasound contrast agent with unique Kupffer phase imaging advantages and high mechanical index stability. This paper introduces the basic theories and advantages of Sonazoid ultrasound. Then, the application and latest advances of Sonazoid in the diagnosis and treatment of liver diseases are reviewed in detail. In addition, the advantages and disadvantages of Sonazoid ultrasound and its future directions are discussed. Sonazoid is expected to become an important tool for clinical ultrasound diagnosis and treatment.

Value of high frame rate contrast-enhanced ultrasound in predicting microvascular invasion of hepatocellular carcinoma

OBJECTIVES

To investigate the value of vascular morphology on high frame rate contrast-enhanced ultrasound (H-CEUS) and CEUS Li-RADS in predicting microvascular invasion (MVI), Ki-67 expression and recurrence of hepatocellular carcinoma (HCC).

METHODS

This retrospective study enrolled 78 patients with single HCC diagnosed by postoperative pathology between January 1, 2021, and June 30, 2022. All patients underwent ultrasound and H-CEUS examination before operation. H-CEUS image features and CEUS Li-RADS were compared in different MVI status and Ki-67 level. Multiple logistic regression analysis was performed to select independent variables for MVI. Differences in recurrence among different H-CEUS image features, MVI status and Ki-67 level were further analyzed.

RESULTS

Tumor shape, vascular morphology, LR-M category, necrosis and AFP level were different between the MVI-positive group and MVI-negative group (p < 0.05). Vascular morphology and LR-M category were independent risk factors related to MVI (p < 0.05). Vascular morphology was also different between the high Ki-67 expression group and low Ki-67 expression group (p < 0.05). Vascular morphology, MVI status and Ki-67 expression were different between the recurrence group and no recurrence group (p < 0.05).

CONCLUSION

The vascular morphology of HCC on H-CEUS can indicate the risk of MVI status, Ki-67 expression and recurrence, which provides a feasible imaging technique for predicting the prognosis before operation.

CRITICAL RELEVANCE STATEMENT

H-CEUS shows the different vascular morphology of HCC in arterial phase and indicates the risk of MVI, Ki-67 expression and recurrence, which provides a feasible imaging technique for clinician to judge the risk of MVI pre-operation and adopt appropriate treatment.

KEY POINTS

H-CEUS can clearly show different vascular morphology of HCC in arterial phase. Vascular morphology on H-CEUS is associated with MVI status, Ki-67 expression and HCC recurrence. Preoperative MVI and Ki-67 expression prediction could help surgeons choose a more appropriate treatment plan.

Assessment of arterial-phase hyperenhancement and late-phase washout of hepatocellular carcinoma-a meta-analysis of contrast-enhanced ultrasound (CEUS) with SonoVue® and Sonazoid®

OBJECTIVES

The recognition of arterial phase hyperenhancement (APHE) and washout during the late phase is key for correct diagnosis of hepatocellular carcinoma (HCC) with contrast-enhanced ultrasound (CEUS). This meta-analysis was conducted to compare SonoVue®-enhanced and Sonazoid®-enhanced ultrasound in the assessment of HCC enhancement and diagnosis.

METHODS

Studies were included in the analysis if they reported data for HCC enhancement in the arterial phase and late phase for SonoVue® or in the arterial phase and Kupffer phase (KP) for Sonazoid®. Forty-two studies (7502 patients) with use of SonoVue® and 30 studies (2391 patients) with use of Sonazoid® were identified. In a pooled analysis, the comparison between SonoVue® and Sonazoid® CEUS was performed using chi-square test. An inverse variance weighted random-effect model was used to estimate proportion, sensitivity, and specificity along with 95% confidence interval (CI).

RESULTS

In the meta-analysis, the proportion of HCC showing APHE with SonoVue®, 93% (95% CI 91-95%), was significantly higher than the proportion of HCC showing APHE with Sonazoid®, 77% (71-83%) (p < 0.0001); similarly, the proportion of HCC showing washout at late phase/KP was significantly higher with SonoVue®, 86% (83-89%), than with Sonazoid®, 76% (70-82%) (p < 0.0001). The sensitivity and specificity for the detection of APHE plus late-phase/KP washout detection in HCC were also higher with SonoVue® than with Sonazoid® (sensitivity 80% vs 52%; specificity 80% vs 73% in studies within unselected patient populations).

CONCLUSION

APHE and late washout in HCC are more frequently observed with SonoVue® than with Sonazoid®. This may affect the diagnostic performance of CEUS in the diagnosis of HCCs.

CLINICAL RELEVANCE STATEMENT

Meta-analysis data show the presence of key enhancement features for diagnosis of hepatocellular carcinoma is different between ultrasound contrast agents, and arterial hyperenhancement and late washout are more frequently observed at contrast-enhanced ultrasound with SonoVue® than with Sonazoid®.

KEY POINTS

• Dynamic enhancement features are key for imaging-based diagnosis of HCC. • Arterial hyperenhancement and late washout are more often observed in HCCs using SonoVue®-enhanced US than with Sonazoid®. • The existing evidence for contrast-enhanced US may need to be considered being specific to the individual contrast agent.

Analysis of Sonazoid contrast-enhanced ultrasound for predicting the risk of microvascular invasion in hepatocellular carcinoma: a prospective multicenter study

OBJECTIVES

The aim of this study was to evaluate the potential of Sonazoid contrast-enhanced ultrasound (SNZ-CEUS) as an imaging biomarker for preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC).

METHODS

From August 2020 to March 2021, we conducted a prospective multicenter study on the clinical application of Sonazoid in liver tumor; a MVI prediction model was developed and validated by integrating clinical and imaging variables. Multivariate logistic regression analysis was used to establish the MVI prediction model; three models were developed: a clinical model, a SNZ-CEUS model, and a combined model and conduct external validation. We conducted subgroup analysis to investigate the performance of the SNZ-CEUS model in non-invasive prediction of MVI.

RESULTS

Overall, 211 patients were evaluated. All patients were split into derivation (n = 170) and external validation (n = 41) cohorts. Patients who had MVI accounted for 89 of 211 (42.2%) patients. Multivariate analysis revealed that tumor size (> 49.2 mm), pathology differentiation, arterial phase heterogeneous enhancement pattern, non-single nodular gross morphology, washout time (< 90 s), and gray value ratio (≤ 0.50) were significantly associated with MVI. Combining these factors, the area under the receiver operating characteristic (AUROC) of the combined model in the derivation and external validation cohorts was 0.859 (95% confidence interval (CI): 0.803-0.914) and 0.812 (95% CI: 0.691-0.915), respectively. In subgroup analysis, the AUROC of the SNZ-CEUS model in diameter  ≤ 30 mm and ˃ 30 mm cohorts were 0.819 (95% CI: 0.698-0.941) and 0.747 (95% CI: 0.670-0.824).

CONCLUSIONS

Our model predicted the risk of MVI in HCC patients with high accuracy preoperatively.

CLINICAL RELEVANCE STATEMENT

Sonazoid, a novel second-generation ultrasound contrast agent, can accumulate in the endothelial network and form a unique Kupffer phase in liver imaging. The preoperative non-invasive prediction model based on Sonazoid for MVI is helpful for clinicians to make individualized treatment decisions.

KEY POINTS

• This is the first prospective multicenter study to analyze the possibility of SNZ-CEUS preoperatively predicting MVI. • The model established by combining SNZ-CEUS image features and clinical features has high predictive performance in both derivation cohort and external validation cohort. • The findings can help clinicians predict MVI in HCC patients before surgery and provide a basis for optimizing surgical management and monitoring strategies for HCC patients.

HCC treated with immune checkpoint inhibitors: a hyper-enhanced rim on Sonazoid-CEUS Kupffer phase images is a predictor of tumor response

OBJECTIVES

We aimed to evaluate the efficacy of anti-programmed cell death 1 (PD-1)/programmed death-ligand 1 (PD-L1) antibody therapy by assessing the hyper-enhanced rim phenomenon of hepatocellular carcinoma (HCC) on Sonazoid-contrast-enhanced ultrasound (CEUS) Kupffer phase images.

METHODS

This retrospective study included 61 patients with HCC who received anti-PD-1/PD-L1 antibody therapy from August 1, 2020, to January 31, 2022. We compared the progression-free survival (PFS) of patients with hyper-enhanced rim+ and hyper-enhanced rim-nodules and the time to nodule progression (TTnP) of hyper-enhanced rim+ and hyper-enhanced rim- nodules.

RESULTS

Thirty-nine patients received postoperative therapy, and 22 patients had unresectable HCC. The mean PFS was 11.8 months (95% confidence interval [CI]: 8.7-14.9) for patients with hyper-enhanced rim+ HCC nodules and 16.5 months (95% CI: 14.9-18.1) for patients with hyper-enhanced rim- HCC nodules in the surgery group (p = 0.017). The mean PFS was 9.2 months (95% CI: 3.6-14.8) for patients with hyper-enhanced rim+ HCC nodules and 17.8 months (95% CI: 14.9-20.6) for patients with hyper-enhanced rim- HCC nodules in the non-surgery group (p = 0.015). For hyper-enhanced rim+ HCC nodules, TTnP for each nodule exceeding the specified threshold was 10.1 months, whereas that for hyper-enhanced rim- HCC nodules was 17.6 months (p = 0 .018). The disease control rate was 42.9% (3/7) for hyper-enhanced rim+ HCC nodules and 85.7% (21/24) for hyper-enhanced rim- HCC nodules (p = 0.013).

CONCLUSIONS

The presence of hyper-enhanced rim on the Kupffer phase images obtained via the non-invasive Sonazoid-CEUS is a promising imaging biomarker for predicting unfavorable response with anti-PD-1/PD-L1 therapy in patients with HCC.

KEY POINTS

• The mean progression-free survival was 11.8 months for patients with hyper-enhanced rim+ HCC nodules and 16.5 months for patients with hyper-enhanced rim- HCC nodules in the surgery group. • The mean progression-free survival was 9.2 months for patients with hyper-enhanced rim+ HCC nodules and 17.8 months for patients with hyper-enhanced rim- HCC nodules in the non-surgery group. • The disease control rate was 42.9% for hyper-enhanced rim+ HCC nodules and 85.7% for hyper-enhanced rim- HCC nodules (p = 0.013).

Prediction of the Ki-67 marker index in hepatocellular carcinoma based on Dynamic Contrast-Enhanced Ultrasonography with Sonazoid

BACKGROUND

Ki-67 is widely used as a proliferative and prognostic factor in HCC. This study aimed to analyze the relationship between dynamic contrast-enhanced ultrasonography (DCE-US) parameters and Ki-67 expression.

METHODS

One hundred and twenty patients with histopathologically confirmed HCC who underwent DCE-US were included in this prospective study. Patients were classified according to the Ki-67 marker index into low Ki-67 (< 10%) (n = 84) and high Ki-67 (≥ 10%) groups (n = 36). Quantitative perfusion parameters were obtained and analyzed.

RESULTS

Clinicopathological features (pathological grade and microvascular invasion) were significantly different between the high and low Ki-67 expression groups (p = 0.029 and p = 0.020, respectively). In the high Ki-67 expression group, the peak energy (PE) in the arterial phase and fall time (FT) were significantly different between the HCC lesions and distal liver parenchyma (p = 0.016 and p = 0.025, respectively). PE in the Kupffer phase was significantly different between the HCC lesions and the distal liver parenchyma in the low Ki-67 expression group (p = 0.029). The difference in PE in the Kupffer phase between HCC lesions and distal liver parenchyma was significantly different between the high and low Ki-67 expression groups (p = 0.045). The difference in PE in the Kupffer phase between HCC lesions and distal liver parenchyma < - 4.0 × 10⁷ a.u. may contribute to a more accurate diagnosis of the high Ki-67 expression group, and the sensitivity and specificity were 82.9% and 38.7%, respectively.

CONCLUSIONS

The DCE-US parameters have potential as biomarkers for predicting Ki-67 expression in patients with HCC.

The value of preoperative 18F-FDG PET metabolic and volumetric parameters in predicting microvascular invasion and postoperative recurrence of hepatocellular carcinoma

BACKGROUND

Microvascular invasion (MVI) is very important in the evaluation of hepatocellular carcinoma (HCC), but diagnosis is determined by postoperative pathology; thus, preoperative noninvasive methods will play an active role. The purpose of the study was to assess the performance of metabolic parameters of preoperative 18F-fluorodeoxyglucose PET/computerized tomography (18F-FDG PET/CT) in the prediction of MVI and postoperative recurrence in primary hepatocellular carcinoma.

METHODS

We retrospectively collected 72 patients with HCC who have performed 18F-FDG PET/CT scan before partial hepatectomy between 2016 and 2019. We used both normal liver tissue and inferior vena cava as the reference background and combined with clinicopathological features, 18F-FDG PET/CT metabolic and volumetric indices to predict MVI and postoperative recurrence of primary HCC before surgery.

RESULTS

Twenty-one of the 72 patients recurred, in recurrent cases showed higher maximum standard uptake value (SUVmax), TNR (ratio of tumor SUVmax to mean SUV [SUVmean] of the background tissue), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) than nonrecurrence cases (P < 0.001). All 18F-FDG PET metabolic and volumetric indices for predicting postoperative HCC recurrence were significant on receiver-operating-characteristic (ROC) curve analyses (P < 0.05). TNRIVC, TNRNL, MTVIVC, MTVNL TLGIVC and TLGNL were significant factors for predicting MVI in HCC (P < 0.05). On multivariate analyses, MVI, SUVmax, TNRIVC, TNRNL, MTVIVC, MTVNL, TLGIVC and TLGNL (P < 0.05) are independent risk factors for predicting postoperative HCC recurrence. TNRIVC is the most relevant PET/CT parameter for predicting MVI in HCC, and MTVIVC is the most valuable for predicting postoperative HCC recurrence. Moreover, the PET/CT parameters are more accurate for prognosis with inferior vena cava as a reference background than with normal liver tissue.

CONCLUSION

18F-FDG PET/CT metabolic and volumetric indices are effective predictors, and could noninvasively provide more comprehensive predictive information on MVI and postoperative recurrence of primary HCC before surgery.

Management of Hepatocellular Carcinoma in Japan: JSH Consensus Statements and Recommendations 2021 Update

The Clinical Practice Manual for Hepatocellular Carcinoma was published based on evidence confirmed by the Evidence-based Clinical Practice Guidelines for Hepatocellular Carcinoma along with consensus opinion among a Japan Society of Hepatology (JSH) expert panel on hepatocellular carcinoma (HCC). Since the JSH Clinical Practice Guidelines are based on original articles with extremely high levels of evidence, expert opinions on HCC management in clinical practice or consensus on newly developed treatments are not included. However, the practice manual incorporates the literature based on clinical data, expert opinion, and real-world clinical practice currently conducted in Japan to facilitate its use by clinicians. Alongside each revision of the JSH Guidelines, we issued an update to the manual, with the first edition of the manual published in 2007, the second edition in 2010, the third edition in 2015, and the fourth edition in 2020, which includes the 2017 edition of the JSH Guideline. This article is an excerpt from the fourth edition of the HCC Clinical Practice Manual focusing on pathology, diagnosis, and treatment of HCC. It is designed as a practical manual different from the latest version of the JSH Clinical Practice Guidelines. This practice manual was written by an expert panel from the JSH, with emphasis on the consensus statements and recommendations for the management of HCC proposed by the JSH expert panel. In this article, we included newly developed clinical practices that are relatively common among Japanese experts in this field, although all of their statements are not associated with a high level of evidence, but these practices are likely to be incorporated into guidelines in the future. To write this article, coauthors from different institutions drafted the content and then critically reviewed each other's work. The revised content was then critically reviewed by the Board of Directors and the Planning and Public Relations Committee of JSH before publication to confirm the consensus statements and recommendations. The consensus statements and recommendations presented in this report represent measures actually being conducted at the highest-level HCC treatment centers in Japan. We hope this article provides insight into the actual situation of HCC practice in Japan, thereby affecting the global practice pattern in the management of HCC.

Enhanced patterns on intraoperative contrast-enhanced ultrasonography predict outcomes after curative liver resection in patients with hepatocellular carcinoma

PURPOSE

This study aimed to clarify what hepatocellular carcinoma (HCC) phenotype, as categorized by intraoperative contrast-enhanced ultrasonography (CEUS), showed a high risk of recurrence after hepatic resection.

METHODS

Patients who underwent initial curative hepatectomy with intraoperative CEUS for a single HCC nodule were retrospectively assigned to three patterns of fine (FI), vascular (VA), and irregular (IR) according to the maximum intensity projection pattern based on intraoperative CEUS. Staining was performed for Ki-67, pyruvate kinase type M2 (PKM2), and vascular endothelial growth factor (VEGF) to assess the tumor proliferative activity, tumor glucose metabolism, and angiogenesis, respectively.

RESULTS

Of 116 patients, 18, 50, and 48 were assigned to the FI, VA and IR patterns, respectively. IR patients demonstrated a significantly worse prognosis for both the recurrence-free survival (RFS) and overall survival (OS) (P = 0.0002, 0.0262, respectively) than did patients with other patterns. A multivariate analysis revealed an IR pattern in intraoperative CEUS to be an independent predictive factor for a poor RFS, and major hepatectomy and an IR pattern were independent predictive factors for a poor OS. An IR pattern was closely related to the tumor size (≥ 3.3 cm) and poor histological differentiation and showed a high Ki-67 index, low VEGF expression, and high PKM2 expression.

CONCLUSION

IR-pattern HCCs as classified by intraoperative CEUS may be associated with a higher risk of recurrence and worse outcomes in HCC patients after hepatic resection than other patterns.

Quantitative Ultrasound Image Analysis Helps in the Differentiation of Hepatocellular Carcinoma (HCC) From Borderline Lesions and Predicting the Histologic Grade of HCC and Microvascular Invasion

OBJECTIVES

Quantitative image analysis is one of the methods to overcome the lack of objectivity of ultrasound (US). The aim of this study was to clarify the correlation between the features from a US image analysis and the histologic grade and microvascular invasion (MVI) of hepatocellular carcinoma (HCC) and differentiation of HCC smaller than 2 cm from borderline lesions.

METHODS

We retrospectively analyzed grayscale US images with histopathologic evidence of HCC or a precancerous lesion using ImageJ version 1.47 software (National Institutes of Health, Bethesda, MD).

RESULTS

A total of 148 nodules were included (borderline lesion, n = 31; early HCC [eHCC], n = 3; well-differentiated HCC [wHCC], n = 16; moderately differentiated HCC [mHCC], n = 79; and poorly differentiated HCC [pHCC], n = 19). A multivariate analysis selected lower minimum gray values (odds ratio [OR], 0.431; P = .003) and a higher standard deviation (OR, 1.880; P = .019) as predictors of HCC smaller than 2 cm. Median (range) minimum gray values of borderline lesions, eHCC, wHCC, mHCC, and pHCC were 29 (0-103), 7 (0-47), 6 (0-60), 10 (0-53), and 2 (0-38), respectively, and gradually decreased from borderline lesions to pHCC (P < 0.001). The multivariate analysis showed a higher aspect ratio (OR, 2.170; P = .001) and lower minimum gray value (OR, 0.475; P = .043) as predictors of MVI. An anechoic area diagnosed by a subjective evaluation was correlated with the minimum gray value (P < .0001). The proportion of the anechoic area gradually increased from eHCC to pHCC (P = .031).

CONCLUSIONS

In a US image analysis, HCC smaller than 2 cm had features of greater heterogeneity and a lower minimum gray value than borderline lesions. Moderately differentiated HCC was smoother than borderline lesions, and the anechoic area correlated with histologic grading. Microvascular invasion was correlated with a slender shape and a lower minimum gray value.

Early hemodynamics of hepatocellular carcinoma using contrast-enhanced ultrasound with Sonazoid: focus on the pure arterial and early portal phases

To clarify the early hemodynamics of hepatocellular carcinoma (HCC), we defined the early portal phase of contrast-enhanced ultrasound (CEUS) and examined the reliability of this modality for determining HCC differentiation. Starting in 2007, we performed Sonazoid CEUS in 146 pathologically confirmed hepatic nodules; 118 HCC (8 poorly [Pd], 73 moderately [Md] and 37 well-differentiated [Wd]) and 28 benign nodules. We focused on the pure arterial and early portal phases up to 45 seconds after Sonazoid injection, and then the subsequent phase up to 30 minutes. We calculated covariance-adjusted sensitivities for nodule enhancement combinations of these three phases. Nodule enhancements were divided into hypo, iso and hyper. A positive predictive value of 100% was obtained for the following patterns: iso-iso-hypo, hypo-iso-iso, and hypo-hypo-hypo for Wd, hyper-iso-hypo and hyper-hypo-hypo for Md, hypo-hyper-hypo for Pd, and hyper-hyper-hyper for benign nodules. In Wd HCC (early HCC), there were seven enhancement patterns, thought to be characterized by various hemodynamic changes from early to advanced HCC. Two patterns allowing a diagnosis of Wd HCC were hypo in the pure arterial phase. Subsequent iso-enhancement in the early portal phase indicated a portal blood supply. Decreased enhancement in the early portal phase allows a diagnosis of Md HCC. However, gradual enhancement observed from the pure arterial to the early portal phase allows a diagnosis of Pd HCC. Therefore, even in the early portal phase, hemodynamic changes were visible not only in Wd but also in Md and Pd HCC. In conclusion, with division of the early phase hemodynamics into pure arterial and early portal phases, CEUS can provide information useful for determining the likely degree of HCC differentiation and for distinguishing early stage HCC from benign nodules.

Undifferentiated carcinoma of the liver demonstrated by contrast-enhanced ultrasonography

A 78-year-old man had received interferon therapy and achieved sustained virologic response for chronic hepatitis C 10 years before. He came to our hospital due to liver damage. Abdominal ultrasonography showed a 90-mm mass lesion in the liver. The echoic level was high in the central part and low in the edge of the tumor. Moreover, there was an accumulation of low echoic irregular mass lesions around the hepatic portal region. Cervical ultrasonography also revealed several 15-mm mass lesions on the left clavicle, the imaging character of which was similar to the liver tumor. The liver tumor seemed to be hypovascular on dynamic computed tomography, but contrast-enhanced ultrasonography showed hyperenhancement at the early vascular phase and at maximum intensity projection showed a treelike branch vascular structure that derived from the central part to the margin of the mass. A needle biopsy of the liver tumor and a cervical lymph node resection were performed, which led to the definitive diagnosis of undifferentiated carcinoma of the liver with multiple lymph node metastasis, upon histological analysis. Undifferentiated carcinoma of the liver is extremely rare and contrast-enhanced ultrasonography was the most useful device for evaluating vascular characteristics in this case.

Diagnostic Value of Imaging Methods in the Histological Four Grading of Hepatocellular Carcinoma

We attempted to establish an ultrasound (US) imaging-diagnostic system for histopathological grades of differentiation of hepatocellular carcinoma (HCC). We conducted a retrospective study of histopathologically confirmed 200 HCCs, classified as early (45 lesions), well- (31 lesions), moderately (68 lesions) or poorly differentiated (diff.) (56 lesions) HCCs. We performed grayscale US to estimate the presence/absence of halo and mosaic signs, Sonazoid contrast-enhanced US (CEUS) to determine vascularity (hypo/iso/hyper) of lesion in arterial and portal phase (PP), and echogenicity of lesion in post-vascular phase (PVP). All findings were of significance for the diagnosis of some (but not all) histological grades (p < 0.001–0.05). Combined findings with a relatively high diagnostic efficacy for early, poorly and moderately diff. HCC were a combination of absence of halo sign and isoechogenicity in PVP of CEUS (accuracy: 93.0%, AUC: 0.908), hypovascularity in PP (accuracy: 78.0%, area under the curve (AUC): 0.750), and a combination of isovascularity in PP and hypoechogenicity in PVP (accuracy: 75.0%, AUC: 0.739), respectively. On the other hand, neither any individual finding nor any combination of findings yielded an AUC of over 0.657 for the diagnosis of well-diff. HCC. Our study provides encouraging data on Sonazoid CEUS in the histological differential diagnosis of HCC, especially in early HCC, and the effectiveness of this imaging method should be further proved by prospective, large sample, multicenter studies.

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

The first edition of the guidelines for the use of ultrasound contrast agents was published in 2004, dealing with liver applications. The second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some nonliver applications. The third edition of the contrast-enhanced ultrasound (CEUS) guidelines was the joint World Federation for Ultrasound in Medicine and Biology-European Federation of Societies for Ultrasound in Medicine and Biology (WFUMB-EFSUMB) venture in conjunction with other regional US societies such as Asian Federation of Societies for Ultrasound in Medicine and Biology, resulting in a simultaneous duplicate on liver CEUS in the official journals of both WFUMB and EFSUMB in 2013. However, no guidelines were described mainly for Sonazoid due to limited clinical experience only in Japan and Korea. The new proposed consensus statements and recommendations provide general advice on the use of Sonazoid and are intended to create standard protocols for the use and administration of Sonazoid in hepatic and pancreatobiliary applications in Asian patients and to improve patient management.

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

The first edition of the guidelines for the use of ultrasound contrast agents was published in 2004, dealing with liver applications. The second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some nonliver applications. The third edition of the contrast-enhanced ultrasound (CEUS) guidelines was the joint World Federation for Ultrasound in Medicine and Biology-European Federation of Societies for Ultrasound in Medicine and Biology (WFUMB-EFSUMB) venture in conjunction with other regional US societies such as Asian Federation of Societies for Ultrasound in Medicine and Biology, resulting in a simultaneous duplicate on liver CEUS in the official journals of both WFUMB and EFSUMB in 2013. However, no guidelines were described mainly for Sonazoid due to limited clinical experience only in Japan and Korea. The new proposed consensus statements and recommendations provide general advice on the use of Sonazoid and are intended to create standard protocols for the use and administration of Sonazoid in hepatic and pancreatobiliary applications in Asian patients and to improve patient management.

Current role of ultrasound in the diagnosis of hepatocellular carcinoma

Ultrasonography (US) is a major, sustainable hepatocellular carcinoma (HCC) surveillance method as it provides inexpensive, real-time, and noninvasive detection. Since US findings are based on pathological features, knowledge of pathological features is essential for delivering a correct US diagnosis. Recent advances in US equipment have made it possible to provide more information, such as malignancy potential and accurate localization diagnosis of HCC. Evaluation of malignancy potential is important to determine the treatment strategy, especially for small HCC. Diagnosis of blood flow dynamics using color Doppler and contrast-enhanced US is one of the most definitive approaches for evaluating HCC malignancy potential. Recently, a new Doppler microvascular imaging technique, superb microvascular imaging, which can detect Doppler signals generated by low-velocity blood flow, was developed. A fusion imaging system, another innovative US technology, has already become an indispensable technology over the last few years not only for US-guided radiofrequency ablation but also for the detection of small, invisible HCC. This article reviews the evidence on the use of ultrasound and contrast-enhanced ultrasound with Sonazoid for the practical management of HCC.

Low expression levels of insulin-like growth factor binding protein-3 are correlated with poor prognosis for patients with hepatocellular carcinoma

Insulin-like growth factor binding protein-3 (IGFBP-3) has previously been identified as a putative tumor suppressor gene. The present study investigated the clinical and prognostic significance of IGFBP-3 expression levels in patients with hepatocellular carcinoma (HCC). Immunohistochemistry (IHC) probing for IGFBP-3 was performed on paraffin-embedded tissue samples obtained from 120 patients with HCC, including tissue samples from 120 primary cancer sites and 50 matched adjacent non-malignant sites. Receiver-operator curve (ROC) analysis was used to determine the cut-off scores for the presence of IGFBP-3-positive tumor cells and to estimate the survival time of the patients. The threshold for marking the positive expression of IGFBP-3 was 65%, based on the area under the ROC. Positive expression of IGFBP-3 was observed in 65/120 (54.2%) of the HCC tissues, and in 36/50 (72%) of the adjacent non-malignant liver tissues. Low levels of IGFBP-3 expression were correlated with tumor size (P=0.003), tumor multiplicity (P=0.044), node (P=0.008), metastasis (P=0.001) and clinical stage (P=0.001), as well as reduced survival time (P=0.015). Using univariate survival analysis, a significant direct correlation between high and low IGFBP-3 expression levels, and patient survival time (mean survival time high IGFBP-3, 39.4 vs. low IGFBP-3, 18.7 months) was identified. Kaplan-Meier analysis demonstrated that IGFBP-3 expression levels and patients survival time were significantly correlated (P<0.001). Multivariate analysis revealed IGFBP-3 expression to be an independent parameter (P=0.003). Therefore, low levels of IGFBP-3 expression are associated with advance clinicopathological classification and may be a predictor of poor survival in patients with HCC. Furthermore, these findings suggest that IGFBP-3 may serve as an independent molecular marker for the evaluation of prognosis in patients with HCC.

Preoperative Fluorine 18 Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography for Prediction of Microvascular Invasion in Small Hepatocellular Carcinoma

OBJECTIVES

This study aimed to assess the value of preoperative fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography (F-FDG PET-CT) for predicting microvascular invasion (MVI) in small hepatocellular carcinoma (HCC).

METHODS

We retrospectively examined 60 patients who received F-FDG PET-CT prior to hepatic resection for small HCC (≤30 mm) with subsequent MVI confirmation by histopathology. The associations between PET-positive status and tumor factors were assessed. Furthermore, independent predictors for MVI and diagnostic utility of each MVI predictor were assessed.

RESULTS

Multivariate analysis revealed the presence of MVI as an independent predictor of PET-positive status (P = 0.023). Maximum standardized uptake value (SUVmax) of 3.2 or greater (P = 0.017) and lens culinaris agglutinin a-reactive α-fetoprotein (AFP-L3) 19% or greater (P = 0.010) were independent predictors of MVI. Areas under the receiver operating characteristic curves for SUVmax of 3.2 or greater, AFP-L3 19% or greater, and both factors combined for predicting MVI were 0.712 (0.493-0.932), 0.755 (0.563-0.947), and 0.856 (0.721-0.991), respectively. The sensitivity and specificity for predicting MVI were 77.8% and 74.5% for SUVmax of 3.2 or greater, 66.7% and 84.3% for AFP-L3 19% or greater, and 88.9% and 82.4% for the combination.

CONCLUSIONS

F-FDG PET-CT and AFP-L3 may be useful for predicting MVI in small HCC, and the combination of the 2 factors provided reliable assessment for selection of suitable hepatic resection and liver transplantation candidates.

Utility of combined gray-scale and perflubutane contrast-enhanced ultrasound for diagnosing early hepatocellular carcinomas: Comparison of well differentiated and distinctly nodular types

AIM

To clarify the value of gray-scale ultrasound (US) combined with contrast-enhanced US (CEUS) with perflubutane in diagnosing early hepatocellular carcinoma (HCC).

METHODS

A total of 57 surgically resected, well differentiated HCCs were analyzed. Hepatocellular carcinomas were macroscopically diagnosed as vaguely nodular or distinctly nodular types, which correspond to early HCC or progressed HCC, respectively. Gray-scale US findings were evaluated in terms of shape (round or roundish, or irregular), border and contour (well-defined and smooth, or poorly defined), and intratumor echo levels (hyper, hypo, iso, heterogeneous, or mosaic). Contrast-enhanced US findings were evaluated during the arterial phase (vascularity [finely homogeneous, dendritic, or chaotic] and perfusion enhancement [homogeneous or heterogeneous]), portal phase (presence or absence of washout), and post-vascular phase (echo intensity level [defect, incomplete defect, or iso-enhancing]).

RESULTS

Eighteen HCCs were categorized as early HCCs and the remaining 39 were categorized as progressed HCCs. Receiver operating characteristic curve analysis for the diagnosis of early HCC yielded area under the receiver operating characteristic curve (A_z ) values for border and contour on gray-scale US and echo intensity level in the CEUS post-vascular phase of 0.782 and 0.828, respectively. Multiple logistic regression analysis also indicated that both of these gray-scale US and CEUS findings were independently associated with early HCC. The A_z value for the combination of border and contour and echo intensity for the diagnosis of early HCC was 0.907, corresponding to a high diagnostic value.

CONCLUSION

The combination of gray-scale US and CEUS can provide high-quality imaging assessment for diagnosing early HCC.

Irregular vascular pattern by contrast-enhanced ultrasonography and high serum Lens culinaris agglutinin-reactive fraction of alpha-fetoprotein level predict poor outcome after successful radiofrequency ablation in patients with early-stage hepatocellular carcinoma

Radiofrequency ablation (RFA) is considered the most effective treatment for early-stage hepatocellular carcinoma (HCC) patients unsuitable for resection. However, poor outcome after RFA has occasionally been reported worldwide. To predict such an outcome, we investigated imaging findings using contrast-enhanced ultrasonography (CEUS) with Sonazoid and serum tumor markers before RFA. This study included 176 early-stage HCC patients who had initially achieved successful RFA. Patients were examined using CEUS; their levels of alpha-fetoprotein (AFP), Lens culinaris agglutinin-reactive fraction of AFP (AFP-L3), and des-gamma-carboxy prothrombin before RFA were measured. Sonazoid provided parenchyma-specific contrast imaging and facilitated tumor vascular architecture imaging through maximum intensity projection (MIP). Kaplan-Meier analysis examined cumulative rates of local tumor progression, intrasubsegmental recurrence, and survival; factors associated with these were determined with Cox proportional hazards analysis. Local tumor progression (n = 15), intrasubsegmental recurrence (n = 46), and death (n = 18) were observed. Irregular pattern in MIP classification and serum AFP-L3 level (>10%) before RFA were identified as independent risk factors for local tumor progression and intrasubsegmental recurrence. These two factors were independently associated with poor survival after RFA (irregular pattern in MIP: hazard ratio, (HR) = 8.26; 95% confidence interval, (CI) = 2.24-30.3; P = 0.002 and AFP-L3 > 10%: HR = 2.94; 95% CI = 1.09-7.94; P = 0.033). Irregular MIP pattern by CEUS and high level of serum AFP-L3 were independent risk factors for poor outcome after successful RFA. The Patients with these findings should be considered as special high-risk group in early-stage HCC.

Effect of parenchymal uptake of perfluorobutane microbubbles (Sonazoid(®) ) on radiofrequency ablation of the liver: in vivo experimental study

BACKGROUND & AIMS

To investigate the differences in mechanical effects and ablation zone between radiofrequency (RF) ablation with and without Sonazoid uptake in an in vivo rabbit liver model.

METHODS

Our study was approved by the Institutional Animal Care and Use Committee. Twenty-five rabbits were randomly allotted to one of five ablation durations (i.e., 1, 2, 3, 6 and 12 min). For each rabbit, RF ablation was performed twice, before and 10 min after Sonazoid administration (i.e. control group vs. Sonazoid group), using a 1-cm internally cooled electrode (40W) equipped with a parallelly fixed pressure-monitoring device. During ablation, a 'popping' sound was perceived and recorded along with tissue pressure changes and RF ablation parameters. Then, the ablation volume and microscopic changes were compared.

RESULTS

Popping sounds were more frequently perceived in the control group (21/25 vs. 1/25, P < 0.001). The time to first pressure peak was shorter in the Sonazoid group (22.3 ± 1.1 s vs. 46.3 ± 4.4 s, P < 0.001) with similar pressures (39.8 ± 4.2 mmHg vs. 35.6 ± 4.1 mmHg, P = 0.350). Time to first roll-off and mean power output were significantly less in the Sonazoid group (17.6 ± 1.2 s vs. 71.2 ± 8.2 s, P < 0.001; 9.4 ± 0.3 W vs. 12.8 ± 0.5 W, P < 0.001). Consequently, the Sonazoid group had lower total energy and ablation volumes for all durations. Microscopically, the control group showed larger conflu-ent disruptions, whereas the Sonazoid group showed many smaller disruptions scattered throughout the ablation zones.

CONCLUSIONS

Radiofrequency ablation after Sonazoid uptake induces a smaller ablation zone than conventional RF ablation. However, it appears to ablate the liver tissue with less mechanical effects.

Use of vessel patterns on contrast-enhanced ultrasonography using a perflubutane-based contrast agent for the differential diagnosis of regenerative nodules from early hepatocellular carcinoma or high-grade dysplastic nodules in patients with chronic liver disease

OBJECTIVE

We evaluated the use of tumor vessel patterns observed during arterial-phase contrast-enhanced ultrasonography (US) to differentiate regenerative nodules (RN) from early hepatocellular carcinoma (HCC) or high-grade dysplastic nodules (HGDN) in patients with chronic liver disease.

SUBJECTS AND METHODS

Pathologically confirmed lesions (83 early HCC, 6 HGDN, and 13 RN with mean maximal diameters of 15.4, 15.3, and 16.2 mm, respectively) were enrolled in this retrospective study. We performed contrast-enhanced US using a perflubutane-based contrast agent. We then classified the tumor vessels observed during the arterial phase of contrast-enhanced US into two patterns: peripheral vessels (centripetal pattern) and central vessels (centrifugal pattern).

RESULTS

Eighty-one (97.6%) of the 83 early HCC exhibited various enhancement patterns (hypovascular, 44.6%; isovascular, 25.3%; and hypervascular, 27.7%) and a peripheral vessel pattern, while the remaining 2 lesions (2.4%) exhibited hypovascular enhancement and a central vessel pattern. All 6 HGDN lesions were hypovascular with a peripheral vessel pattern. Twelve (92.3%) of the 13 RN were hypovascular with a central vessel pattern, and the remaining one (7.7%) was hypervascular with a central vessel pattern. When lesions exhibiting a central vessel pattern during arterial-phase contrast-enhanced US were diagnosed as RN, the sensitivity, specificity, and accuracy of these diagnoses were 100%, 97.8%, and 98.0%, respectively.

CONCLUSION

The tumor vessel patterns observed during arterial-phase contrast-enhanced US may be useful for differentiating RN from early HCC or HGDN in patients with chronic liver disease.

Computer-aided diagnosis for estimating the malignancy grade of hepatocellular carcinoma using contrast-enhanced ultrasound: an ROC observer study

BACKGROUND & AIMS

We are developing a computer-aided diagnosis (CAD) system for estimating the malignancy grade of hepatocellular carcinoma (HCC) using contrast-enhanced ultrasound (CEUS). In this study, observers estimated the malignancy grade of HCC with and without the cues provided by CAD.

MATERIALS AND METHODS

Institutional review board approval was obtained and informed consent was waived. A total of 232 histologically confirmed HCCs were studied: 76 well-differentiated HCC (w-HCC), 133 moderately differentiated HCC (m-HCC), and 23 poorly differentiated HCC (p-HCC). In this observer study, CEUS vascular images acquired using the maximum intensity projection technique were displayed together with static B-mode and Kupffer-phase (defined as 10 min after injection) images. Five hepatologists independently assigned confidence ratings for the malignancy grade of each HCC. Each hepatologist first read each case without CAD and then immediately afterwards with CAD. The observers' rating data were evaluated by multireader multicase receiver operating characteristic (ROC) analysis.

RESULTS

The overall sensitivity of our CAD system for discrimination between three histological differentiation grades of HCC was 87.5% (203/232). For discrimination between w-HCC and m/p-HCC, the mean area under the ROC curve (AUC) for the five observers was significantly improved from 0.779 ± 0.074 to 0.872 ± 0.090 with CAD (P = 0.0069). For discrimination between m-HCC and p-HCC, the mean AUC was also significantly improved from 0.713 ± 0.107 to 0.863 ± 0.101 with CAD (P = 0.0321).

CONCLUSION

The use of our CAD system can significantly improve the diagnostic performance of hepatologists in discriminating between three histological differentiation grades of HCC using CEUS.

Therapeutic evaluation of sorafenib for hepatocellular carcinoma using contrast-enhanced ultrasonography: Preliminary result

The present study aimed to determine the usefulness of contrast-enhanced ultrasonography (CEUS) with Sonazoid in evaluating the therapeutic response to sorafenib for hepatocellular carcinoma (HCC). In total, 26 patients with advanced HCC who received sorafenib and were followed up by CEUS were enrolled in the present study. CEUS was performed prior to and within 2-4 weeks of treatment, and the images of the target lesion in the post-vascular phase with a re-injection method were analyzed. The presence (+) or absence (-) of intratumoral necrosis and the intratumoral vascular architecture on micro-flow imaging (MFI) were compared prior to and subsequent to treatment. Target lesions that exhibited non-enhancement after re-injection were considered to indicate intratumoral necrosis. The intratumoral vascular architecture was classified into three groups, as follows: Vd, the intratumoral vessels visually narrowed or decreased; Vnc, the vessels remained unchanged; and Vi, the vessels were thickened or increased. Survival curves were estimated using the Kaplan-Meier method and compared using the log rank test between the intratumoral necrosis (+) and (-) groups, and among the Vd, Vnc and Vi groups. P<0.05 was considered to indicate a statistically significant difference. The number of patients in the intratumoral necrosis (+) and (-) groups was 8 and 18 patients, respectively, and the median survival time (MST) was 7.2 months [95% confidence interval (CI), 2.2-12.2] and 9.5 months (95% CI, 5.1-13.8), respectively (P=0.44). The MFI findings were observed in 11 patients in the Vd group, 10 patients in the Vnc group and 5 patients in the Vi group. The MSTs in the Vd, Vnc and Vi groups were 15.6 months (95% CI, 5.0-23.3), 11.0 months (95% CI, 3.5-17.6) and 3.6 months (95% CI: 1.2-6.0), respectively. The P-value for the differences between the Vd and Vnc groups, Vd and Vi groups, and Vnc and Vi groups were 0.78, 0.016 and 0.047, respectively, which indicated that the survival time decreased significantly in the Vi group. Evaluation of intratumoral vascular architecture using MFI demonstrates promise for assessing the therapeutic response to sorafenib in patients with HCC.

Role of contrast-enhanced ultrasonography with Sonazoid for hepatocellular carcinoma: evidence from a 10-year experience

Hepatocellular carcinoma (HCC) represents primary liver cancer. Because the development of HCC limits the prognosis as well as the quality of life of the patients, its management should be properly conducted based on an accurate diagnosis. The liver is the major target organ of ultrasound (US), which is the simple, non-invasive, and real-time imaging method available worldwide. Microbubble-based contrast agents are safe and reliable and have become popular, which has resulted in the improvement of diagnostic performances of US due to the increased detectability of the peripheral blood flow. Sonazoid (GE Healthcare, Waukesha, WI, USA), a second-generation contrast agent, shows the unique property of accumulation in the liver and spleen. Contrast-enhanced US with Sonazoid is now one of the most frequently used modalities in the practical management of liver tumors, including the detection and characterization of the nodule, evaluation of the effects of non-surgical treatment, intraoperative support, and post-treatment surveillance. This article reviews the 10-year evidence for contrast-enhanced US with Sonazoid in the practical management of HCC.

Utility of Contrast-enhanced Ultrasonography with Perflubutane for Determining Histologic Grade in Hepatocellular Carcinoma

The purpose of this study was to clarify the diagnostic value of contrast-enhanced ultrasonography (CEUS) with perflubutane in determining the histologic grade in hepatocellular carcinoma (HCC). A total of 147 surgically resected HCCs were dichotomized as well differentiated HCC (wd-HCC) and moderately- or poorly-differentiated HCC (mp-HCC). CEUS findings were evaluated during the arterial phase (vascularity, level and shape of enhancement), portal phase (presence or absence of washout) and post-vascular phase (echo intensity and shape). Receiver operating characteristic (ROC) curve analysis for the diagnosis of mp-HCC yielded area under the ROC curve (Az) values for arterial phase vascularity and portal phase washout of 0.910 and 0.807, respectively. The Az value for the combination of vascularity and washout for the diagnosis of mp-HCC was 0.956 (95% confidence interval, 0.910-0.979), corresponding to high diagnostic value. In conclusion, CEUS can provide high-quality imaging assessment for determining the histologic grade of HCCs.

Enhanced ultrasonography using a nano/microbubble contrast agent for islet transplantation

Recent basic and clinical studies have assessed the use of highly sensitive imaging modalities for visualizing transplanted islets. We investigated the utility of enhanced ultrasonography, combined with fluorescent acoustic liposome nano/microbubbles (FALs), for evaluating angiogenesis and the endocrine function of transplanted islets. BALB/c mice were classified into three groups: Diabetic mice that underwent syngeneic islet transplantation into the subrenal capsule and achieved normoglycemia (Tx group); those that failed to achieve normoglycemia (Tx-DM group); and those not receiving any treatment (DM group). Mice were examined by FAL-enhanced high frequency ultrasonography. The echogenicity of the islets increased rapidly within the first minute after injection of FALs and remained at a higher level in the Tx group, while small increases were observed in the other two groups. In histological assessments, fluorescently stained erythrocytes could be seen in and around the transplanted islets, indicating that the transplanted islets were enhanced by infusion of FALs via vessel networks between the engrafted islets and tissue. Furthermore, the echogenicity correlated significantly with endocrine parameters, including blood glucose (BG), serum insulin, and the BG change in the glucose tolerance test. In conclusion, the echogenicity of the islets under FAS-enhanced ultrasonosonography correlated with the endocrine status of transplanted islets.

Contrast-Enhanced Endoscopic Ultrasonography for Pancreatic Tumors

OBJECTIVES

To investigate the usefulness of contrast-enhanced endoscopic ultrasonography (CE-EUS) for histological differentiation of pancreatic tumors.

METHODS

CE-EUS was performed for consecutive patients having a pancreatic solid lesion, and tumors were classified into three vascular patterns (hypervascular, isovascular, and hypovascular) at two time phases (early-phase and late-phase). Correlation between vascular patterns and histopathology of resected pancreatic cancer (PC) tissues was ascertained.

RESULTS

The final diagnoses of 147 examined tumors were PC (n = 109), inflammatory mass (n = 11), autoimmune pancreatitis (n = 9), neuroendocrine tumor (n = 8), and others (n = 10). In late-phase images, 104 of 109 PCs had the hypovascular pattern, for a diagnostic sensitivity and specificity of 94% and 71%, respectively. Of 28 resected PCs, 10 had isovascular, and 18 hypovascular, patterns on the early-phase image. Early-phase isovascular PCs were more likely to be differentiated than were early-phase hypovascular PCs (6 well and 4 moderately differentiated versus 3 well, 14 moderately, and 1 poorly differentiated, P = 0.028). Immunostaining revealed that hypovascular areas of early-phase images reflected heterogeneous tumor cells with fibrous tissue, necrosis, and few vessels.

CONCLUSION

CE-EUS could be useful for distinguishing PC from other solid pancreatic lesions and for histological differentiation of PCs.

Diagnosis of hepatocellular carcinoma nodules in patients with chronic liver disease using contrast-enhanced sonography: usefulness of the combination of arterial- and kupffer-phase enhancement patterns

OBJECTIVES

To determine the usefulness of contrast-enhanced sonography using the perfluorobutane contrast agent Sonazoid (Daiichi-Sankyo, Tokyo, Japan) for establishing the diagnosis and cellular differentiation of hepatocellular carcinoma in patients with chronic liver disease.

METHODS

Patients with chronic liver disease in whom hepatic nodules were detected during screening for hepatocellular carcinoma were examined by imaging modalities, including contrast-enhanced computed tomography (CT), contrast-enhanced sonography, and contrast-enhanced magnetic resonance imaging. Nodules with negative imaging findings were further investigated with core biopsy or followed at our hospital. Between April 2007 and March 2011, all patients with hepatic nodules who underwent core biopsy of the nodules or hepatic resection for hepatocellular carcinoma were reviewed. Fifty-nine nodules from 47 patients with 42 contrast-enhanced sonographic findings and 41 contrast-enhanced CT findings were examined. Arterial- and Kupffer-phase enhancement patterns of the nodules on contrast-enhanced sonography were compared with the diagnosis and cellular differentiation of hepatocellular carcinoma. Arterial- and late-phase enhancement patterns on contrast-enhanced CT were also compared with histologic findings.

RESULTS

The combination of hyperenhancement in the arterial phase and hypoenhancement in the Kupffer phase on contrast-enhanced sonography (n = 11) correlated with moderately differentiated hepatocellular carcinoma (P = .0028, Fisher exact test). The combination of hypoenhancement in the arterial phase and isoenhancement in the Kupffer phase on contrast-enhanced sonography (n = 14) correlated with well-differentiated hepatocellular carcinoma (P = .0006, Fisher exact test). The combination of high density in the arterial phase and low density in the late phase on contrast-enhanced CT (n = 21) correlated with moderately differentiated hepatocellular carcinoma (P = .0059, Fisher exact test), but no enhancement pattern combination on contrast-enhanced CT correlated with well-differentiated hepatocellular carcinoma.

CONCLUSIONS

Sonazoid contrast-enhanced sonography is useful for diagnosis of well-differentiated hepatocellular carcinoma.

Enhanced reactive oxygen species overexpression by CuO nanoparticles in poorly differentiated hepatocellular carcinoma cells

Copper oxide nanoparticles (CuO NPs) are known to exhibit toxic effects on a variety of cell types and organs. To determine the oxidative impact of CuO NPs on hepatocellular carcinoma (HCC) cells, well-differentiated (HepG2) and poorly differentiated (SK-Hep-1) cells were exposed to CuO NPs. Cell viability assay showed that the median inhibition concentration (IC50) for SK-Hep-1 and HepG2 cells was 25 μg ml(-1) and 85 μg ml(-1), respectively. Cellular fluorescence intensity using DCFH-DA staining analysis revealed significant intracellular reactive oxygen species (ROS) generation of up to 242% in SK-Hep-1 cells, compared with 86% in HepG2 cells. HPLC analysis demonstrated that a CuO NP treatment caused cellular GSH depletion of 58% and a GSH/GSSG ratio decrease to ∼0.1 in SK-Hep-1 cells. The oxidative stress caused by enhanced superoxide anion production was observed in both HepG2 (146%) and SK-Hep-1 (192%) cells. The Griess assay verified that CuO NPs induced NO production (170%) in SK-Hep-1 cells. Comet assay and western blot further demonstrated that CuO NPs induced severe DNA strand breakage (70%) in SK-Hep-1 cells and caused DNA damage via increased γ-H2AX levels. These results suggest that well-differentiated HepG2 cells possess a robust antioxidant defense system against CuO NP-induced ROS stress and exhibit more tolerance to oxidative stress. Conversely, poorly differentiated SK-Hep-1 cells exhibited a deregulated antioxidant defense system that allowed accumulation of CuO NP-induced ROS and resulted in severe cytotoxicity.

Proposal of objective morphological classification system for hepatocellular carcinoma using preoperative multiphase computed tomography

BACKGROUND

To establish a preoperative morphological classification system for hepatocellular carcinoma using multiphase computed tomography.

METHODS

All consecutive patients who were diagnosed with hepatocellular carcinoma between 2004 and 2009 were enrolled, for a total of 232 patients. The concavity and convexity of each outer contour of hepatocellular carcinoma acquired from multiphase computed tomography were analyzed, and the area and depth of each indentation were quantified. The indentation area to tumor area ratio (s:S) and the s:S ratio multiplied by the indentation depth to indentation base ratio (s:S × d:t) were used as feature values reflecting the individual shapes.

RESULTS

Using a hierarchical cluster analysis, the shapes were classified into three groups: Type I (smooth: n = 158), Type II (jagged: n = 63), and Type III (rough: n = 11). The 5-year survival rates for Types I, II, and III were 64, 53, and 0 %, respectively (I vs. II, P = 0.038; I vs. III, P = 0.001; II vs. III, P = 0.002). The 5-year disease-free survival rates for Types I, II, and III were 27, 23, and 0 %, respectively (I vs. III, P = 0.0003 and II vs. III, P = 0.008). Microscopic portal venous invasion was significantly more likely with Type III than with Type I or II (P < 0.001 and P = 0.001, respectively).

CONCLUSIONS

The newly developed semiautomatic computed tomography-based morphological classification system appears to provide a promising additional criterion for the prognostic categorization of patients with hepatocellular carcinoma.

Utility of contrast-enhanced ultrasound with perflubutane for diagnosing the macroscopic type of small nodular hepatocellular carcinomas

OBJECTIVE

To clarify the diagnostic value of contrast-enhanced ultrasound (CEUS) with perflubutane in the macroscopic classification of small nodular hepatocellular carcinomas (HCCs).

METHODS

A total of 99 surgically resected nodular HCCs with a maximum diameter of 3 cm or less were analysed. HCCs were macroscopically categorized as simple nodular (SN) and non-SN. CEUS findings were evaluated during the arterial phase (vascularity, level and shape of enhancement), portal phase (presence or absence of washout) and post-vascular phase (echo intensity and shape).

RESULTS

Sixty-eight HCCs were categorized as SN and the remaining 31 were categorized as non-SN. For diagnosis of non-SN HCC, the areas under the receiver operating characteristic curve (A z) value for the shape of enhancement in the late arterial phase and the shape of the post-vascular image were 0.824 (95 % confidence interval [CI] 0.721-0.895) and 0.878 (95 % CI 0.788-0.933), respectively. The A z value for the combination of the shape of enhancement in the late arterial phase and the shape of the post-vascular image for the diagnosis of non-SN HCC was 0.907 (95 % CI 0.815-0.956), corresponding to a high diagnostic value.

CONCLUSION

CEUS can provide high-quality imaging assessment for determining the macroscopic classification of small nodular HCCs.

KEY POINTS

• Non-SN is one of the poor prognostic factors in patients with HCC • Assessment of macroscopic type provides valuable information for the management of HCC • CEUS can provide high-quality imaging assessment for macroscopic classification of HCC • For non-SN HCC diagnosed using CEUS, hepatectomy is preferred as curative treatment.