Biopsy of Liver Target Lesions under Contrast-Enhanced Ultrasound Guidance - A Multi-Center Study

PURPOSE

 To retrospectively characterize the prevalence and impact of contrast-enhanced ultrasound (CEUS) as a guidance technique for the biopsy of liver target lesions (LTLs) at six interventional ultrasound centers.

MATERIALS AND METHODS

 The six participating centers retrospectively selected all patients in whom biopsy needles were positioned in LTLs during CEUS. The prevalence of CEUS-guided biopsies at each center between 2005 and 2016, contrast agent consumption, procedure indications, diagnostic yield and complications were assessed. Informed consent was obtained for all patients.

RESULTS

 CEUS-guided biopsy of LTLs was carried out in 103 patients (68 M/35 F, median age: 69 yrs) with 103 liver target lesions (median size: 20 mm) using cutting needles (18 - 20 g) in 94 cases (91.2 %). CEUS-guided biopsy represented 2.6 % (range: 0.8 - 7.7 %) of 3818 biopsies on LTLs carried out at the participating centers. Indications to CEUS-guided biopsy were: a target lesion not visible on non-enhanced US (27.2 %), improvement of conspicuity of the target (33 %), choice of non-necrotic area inside the target (39.8 %). 26 patients (25.2 %) had a previously non-diagnostic cyto-histological exam. The diagnostic accuracy of the technique was 99 %. No major complications followed infusion of contrast agent or biopsy performance.

CONCLUSION

 The indications for CEUS-guided biopsy for LTLs are limited, but CEUS can be useful in challenging clinical scenarios, e. g. poorly visualized or invisible lesions or sampling of non-necrotic areas in the target lesions. There is also a potential advantage in using CEUS to guide repeat biopsies after unsuccessful sampling performed using the standard ultrasound technique.

Contrast ultrasound LI-RADS LR-5 identifies hepatocellular carcinoma in cirrhosis in a multicenter restropective study of 1,006 nodules

BACKGROUND & AIMS

The use of contrast enhanced ultrasound (CEUS) for the diagnosis of hepatocellular carcinoma (HCC) in cirrhosis was questioned because of the risk of a false positive diagnosis in cases of cholangiocarcinoma. The American College of Radiology has recently released a scheme (CEUS Liver Imaging Reporting and Data System [LI-RADS®]) to classify lesions at risk of HCC investigated by CEUS. The aim of the present study was to validate this LI-RADS scheme for the diagnosis of HCC.

METHODS

A total of 1,006 nodules from 848 patients with chronic liver disease at risk of HCC were collected in five Italian centers and retrospectively analyzed. Nodules were classified as LR-5, (HCC) if ≥1 cm with arterial phase hyperenhancement, and late washout (onset ≥60 s after contrast injection) of mild degree. Rim enhancement and/or early and/or marked washout qualified lesions as LR-M (malignant, but not specific for HCC). Other combinations qualified lesions at intermediate risk for HCC (LR-3) or probable HCC (LR-4). Diagnostic reference standard was CT/MRI diagnosis of HCC (n = 506) or histology (n = 500).

RESULTS

The median nodule size was 2 cm. Of 1,006 nodules, 820 (81%) were HCC, 40 (4%) were cholangiocarcinoma, 116 (11%) regenerative nodules (±dysplastic). The LR-5 category (52% of all nodules) was 98.5% predictive of HCC, with no risk of misdiagnosis for pure cholangiocarcinoma. Sensitivity for HCC was 62%. All LR-M nodules were malignant and the majority of non-hepatocellular origin. Over 75% of cholangiocarcinomas were LR-M. The LR-3 category included 203 lesions (HCC 96 [47%]) and the LR-4 202 (HCC 173 [87%]).

CONCLUSIONS

The CEUS LI-RADS class LR-5 is highly specific for HCC, enabling its use for a confident non-invasive diagnosis.

LAY SUMMARY

This is a retrospective study of approximately 1,000 focal lesions at risk for hepatocellular carcinoma (HCC). Herein, we demonstrate that the refined definition of the typical contrast enhanced ultrasound pattern of HCC introduced by the Liver Imaging Reporting and Data System (LI-RADS®) practically abolishes the risk of misdiagnosis of other malignant entities (e.g. cholangiocarcinoma) for HCC with negligible reduction in sensitivity. These data support the use of contrast enhanced ultrasound to diagnose HCC in cirrhosis.

Reverse time-dependent effect of alphafetoprotein and disease control on survival of patients with Barcelona Clinic Liver Cancer stage C hepatocellular carcinoma

AIM

To characterize the survival of cirrhotic patients with Barcelona Clinic Liver Cancer (BCLC) stage C hepatocellular carcinoma (HCC) and to ascertain the factors predicting the achievement of disease control (DC).

METHODS

The cirrhotic patients with BCLC stage C HCC evaluated by the Hepatocatt multidisciplinary group were subjected to the investigation. Demographic, clinical and tumor features, along with the best tumor response and overall survival were recorded.

RESULTS

One hundred and ten BCLC stage C patients were included in the analysis; the median overall survival was 13.4 mo (95%CI: 10.6-17.0). Only alphafetoprotein (AFP) serum level > 200 ng/mL and DC could independently predict survival but in a time dependent manner, the former was significantly associated with increased risk of mortality within the first 6 mo of follow-up (HR = 5.073, 95%CI: 2.159-11.916, P = 0.0002), whereas the latter showed a protective effect against death after one year (HR = 0.110, 95%CI: 0.038-0.314, P < 0.0001). Only patients showing microvascular invasion and/or extrahepatic spread recorded lower chances of achieving DC (OR = 0.263, 95%CI: 0.111-0.622, P = 0.002).

CONCLUSION

The BCLC stage C HCC includes a wide heterogeneous group of cirrhotic patients suitable for potentially curative treatments. The reverse and time dependent effect of AFP serum level and DC on patients’ survival confers them as useful predictive tools for treatment management and clinical decisions.

Nanoparticle-Based Receptors Mimic Protein-Ligand Recognition

The self-assembly of a monolayer of ligands on the surface of noble-metal nanoparticles dictates the fundamental nanoparticle's behavior and its functionality. In this combined computational-experimental study, we analyze the structure, organization, and dynamics of functionalized coating thiols in monolayer-protected gold nanoparticles (AuNPs). We explain how functionalized coating thiols self-organize through a delicate and somehow counterintuitive balance of interactions within the monolayer itself and with the solvent. We further describe how the nature and plasticity of these interactions modulate nanoparticle-based chemosensing. Importantly, we found that self-organization of coating thiols can induce the formation of binding pockets in AuNPs. These transient cavities can accommodate small molecules, mimicking protein-ligand recognition, which could explain the selectivity and sensitivity observed for different organic analytes in NMR chemosensing experiments. Thus, our findings advocate for the rational design of tailored coating groups to form specific recognition binding sites on monolayer-protected AuNPs.

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Synthesis and molecular simulations of AuNPs for chemosensing

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A rationale for the molecular recognition ability of functionalized AuNPs

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Functionalized coating ligands form transient protein-like binding pockets

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Toward the computational nanodesign of intelligent nanoreceptors for chemosensing

The functionalization of monolayer-protected nanoparticles is at the frontier of nanotechnology, such that innovative applications are emerging in fields such as nanomedicine, chemosensing, and even catalysis. Importantly, the nanoparticle's functionality is mainly defined by the nature of the ligands forming the coating monolayer. Here, we show how the self-organization of functionalized coating ligands in monolayer-protected gold nanoparticles (AuNPs) affects their solubility and molecular recognition abilities. We found that coating ligands form transient, protein-like binding pockets in functionalized AuNPs. Thus, we reveal that nanoparticle-based chemosensing operates through a recognition process that is similar to that for protein-ligand complex formation. These findings could now herald the arrival of the computational nanodesign of intelligent nanodevices with recognition abilities toward small molecules such as drugs, metabolites, illegal drugs, and small molecular markers for cancer.

HepPar1-Positive Circulating Microparticles Are Increased in Subjects with Hepatocellular Carcinoma and Predict Early Recurrence after Liver Resection

Circulating microparticles (MPs) are novel potential biomarkers in cancer patients. Their role in hepatocellular carcinoma (HCC) is under intensive investigation. In this study, we tested the hypothesis that MPs expressing the antigen HepPar1 are increased in the blood of subjects with HCC and may serve as markers of early recurrence after liver resection (LR). We studied 15 patients affected by HCC undergoing LR, and used flow cytometry to assess the number of circulating HepPar1+ MPs. Ten subjects without HCC (five with liver cirrhosis and five with healthy livers) were used as controls. After LR, HCC patients underwent a follow-up to check for early recurrence, which occurred in seven cases. The number of circulating HepPar1+ MPs was significantly higher in subjects affected by HCC, compared to individuals without cancer (p < 0.01). We also found that, among HCC patients, the number of circulating HepPar1+ MPs, measured before LR, was significantly higher in those who displayed early recurrence compared to those without recurrence (p = 0.02). Of note, other types of circulating MPs, such as those derived from endothelial cells (CD144+) or those produced by the activated endothelium (CD144+/CD62+), were not associated with HCC, nor could they predict HCC recurrence. HepPar1+ MPs deserve further investigation as novel biomarkers of disease and prognosis in HCC patients.

Lid domain plasticity and lipid flexibility modulate enzyme specificity in human monoacylglycerol lipase

Human monoacylglycerol lipase (MAGL) is a membrane-interacting enzyme that generates pro-inflammatory signaling molecules. For this reason, MAGL inhibition is a promising strategy to treat pain, cancer, and neuroinflammatory diseases. MAGL can hydrolyze monoacylglycerols bearing an acyl chain of different lengths and degrees of unsaturation, cleaving primarily the endocannabinoid 2-arachidonoylglycerol. Importantly, the enzymatic binding site of MAGL is confined by a 75-amino-acid-long, flexible cap domain, named 'lid domain', which is structurally similar to that found in several other lipases. However, it is unclear how lid domain plasticity affects catalysis in MAGL. By integrating extensive molecular dynamics simulations and free-energy calculations with mutagenesis and kinetic experiments, we here define a lid-domain-mediated mechanism for substrate selection and binding in MAGL catalysis. In particular, we clarify the key role of Phe159 and Ile179, two conserved residues within the lid domain, in regulating substrate specificity in MAGL. We conclude by proposing that other structurally related lipases may share this lid-domain-mediated mechanism for substrate specificity.

Induced Fit in Protein Multimerization: The HFBI Case

Hydrophobins, produced by filamentous fungi, are small amphipathic proteins whose biological functions rely on their unique surface-activity properties. Understanding the mechanistic details of the multimerization process is of primary importance to clarify the interfacial activity of hydrophobins. We used free energy calculations to study the role of a flexible β-hairpin in the multimerization process in hydrophobin II from Trichoderma reesei (HFBI). We characterized how the displacement of this β-hairpin controls the stability of the monomers/dimers/tetramers in solution. The regulation of the oligomerization equilibrium of HFBI will necessarily affect its interfacial properties, fundamental for its biological function and for technological applications. Moreover, we propose possible routes for the multimerization process of HFBI in solution. This is the first case where a mechanism by which a flexible loop flanking a rigid patch controls the protein-protein binding equilibrium, already known for proteins with charged binding hot-spots, is described within a hydrophobic patch.

Fungi proliferate by creating a complex hyphal network growing within a wet environment. However, for most fungi to colonize new territories, they must produce spores carried by aerial hyphae and spread them into the air. Aerial structures need to overcome the surface tension of the surrounding water in order to grow into the air. This process requires hydrophobins, a remarkable class of self-associating fungal proteins which lower the surface tension at the air/water interface by creating a thin amphipathic layer. In solution they form multimers in equilibrium with the interfacial layer. Due to their unique surface-activity properties, hydrophobins have been used for a variety of biotechnical applications. We used enhanced sampling molecular dynamics simulations methods to study the multimerization process in solution of a hydrophobin from Trichoderma reesei (HFBI). We clarified the fundamental role of a small flexible region within the HFBI monomer involved in the formation of multimers. A flexible loop flanking a rigid interaction patch is able to fine-tune the interaction energy. This mechanism, already known for charged binding patches, is described here for hydrophobic hot-spots. This result is remarkably important in order to clarify the mechanism of arranging at the interface and enhancing hydrophobin-based technological applications.

Presence of portal vein thrombosis in liver cirrhosis is strongly associated with low levels of ADAMTS-13: a pilot study

Portal vein thrombosis (PVT) dramatically changes the prognosis of cirrhotic patients, especially those waiting for liver transplantation. However, the possible contribution to PVT of von Willebrand factor (VWF) and ADAMTS-13 is poorly documented. The aim of our study was to assess the presence of alterations of VWF and ADAMTS-13 serum levels in cirrhotic patients with PVT. Twenty-four patients with PVT (group PVT) and 60 without PVT (group without PVT) were enrolled. A comprehensive analysis of biochemical and hemostatic parameters was performed. ADAMTS-13 activity was significantly lower in group A (median 16.8 vs. 69.1 %, p = 0.0047). Group PVT, compared to group without PVT, showed a significantly higher VWF:act, (median 308.4 vs 203.3 %, p = 0.032), whereas no difference was observed for VWF:Ag, FVIII level and the presence of risk factors for venous thromboembolism. No correlation was found between the Child-Pugh score and ADAMTS-13 activity. In multivariable logistic regression analysis performed on data concerning both group PVT and without PVT, only the ADAMTS-13 activity (p = 0.007) was independently and inversely associated with PVT. In conclusion, ADAMTS-13 activity is independently associated with PVT in cirrhotic patients.

An optimized polyamine moiety boosts the potency of human type II topoisomerase poisons as quantified by comparative analysis centered on the clinical candidate F14512

Combined computational-experimental analyses explain and quantify the spermine-vectorized F14512's boosted potency as a topoII poison. We found that an optimized polyamine moiety boosts drug binding to the topoII/DNA cleavage complex, rather than to the DNA alone. These results provide new structural bases and key reference data for designing new human topoII poisons.

Usefulness of contrast enhanced ultrasound in monitoring therapeutic response after hepatocellular carcinoma treatment

In the last years, the development in the oncology field has been huge and rapid. In particular, the evaluation of response to anti-tumour treatments has been being object of intense research, producing significant changes. Response assessment after therapy in solid neoplasias has always used radiological imaging techniques, with tumour size reduction representing a presumed therapeutic efficacy. However, with the introduction of anti-angiogenetic drugs the evaluation of tumour size has become unsuitable because some tumours, under treatment, show only tumour perfusion changes rather than lesion shrinkage. Between different imaging techniques with contrast-enhancement, contrast-enhanced ultrasound (CEUS) and, in particular, dynamic CEUS have arisen as a promising and non-invasive device for monitoring cancer treatments. Moreover, the introduction of perfusion software has even more refined the technique since it is able to provide quantitative parameters related to blood flow and blood volume that can be associated with tumour response and clinical outcome such as the progression free survival and the overall survival. Here, we give an overview of the current status of CEUS in monitoring hepatocellular carcinoma response to different kind of treatments.

Single hepatocellular carcinoma smaller than 2 cm: are ethanol injection and radiofrequency ablation equally effective?

BACKGROUND/AIM

The impact of radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) on survival in patients with small hepatocellular carcinoma (HCC) is unclear. We compared their efficacy in cirrhotics with single HCC ≤2 cm.

PATIENTS AND METHODS

Two hundred forty-four cirrhotics with single HCC ≤2 cm treated with PEI (108 cases) or RFA (136 cases) were enrolled in the study. Eighty-one patients in each group were selected for propensity score matching analysis.

RESULTS

The five-year survival was not significantly different (64.7% in PEI and 72.9% in RFA group) but the 5-year recurrence (73.3% in PEI and 49% in RFA group, p=0.023) and local tumor progression (49% in PEI and 30.1% in RFA group, p=0.018) were higher in the PEI group.

CONCLUSION

PEI and RFA are equally effective in treating HCCs smaller than 2 cm in terms of 5-year survival, despite higher cumulative and local recurrence rates, in patients treated with PEI.

Differentiating hepatocellular carcinoma from dysplastic nodules at gadobenate dimeglumine-enhanced hepatobiliary-phase magnetic resonance imaging

PURPOSE

We evaluated whether the addition of delayed phase imaging (DPI) gadobenate dimeglumine-enhanced MRI to dynamic postcontrast imaging improves the characterization of small hepatocellular carcinoma (HCC) and the differentiation between HCC, high grade dysplastic nodules (HGDN), and low grade dysplastic nodules (LGDN).

METHODS

Twenty-five cirrhotic patients with 30 nodules (16 HCC, 8 HGDNs, and 6 LGDNs; maximum size of 3 cm) were included in this retrospective study. The diagnostic reference standard was histology. All the patients underwent MRI both prior to and following intravenous administration of gadobenate dimeglumine. The lesions were classified as hypointense, isointense, hyperintense on DPI for qualitative assessment. In the quantitative analysis the relative tumor-liver contrast to noise ratio (CNR) of the lesions on DPI was calculated.

RESULTS

All HCCs were hypointense on DPI while only 8 (57.1%) of 14 DNs were hypointense and only 1 of 6 (16.6%) LGDNs was hypointense. There was a statistically significant difference in the hypointensity on DPI between HCCs and DNs (p = 0.003) in the qualitative analysis but not in the CNR values while there was a strong statistically significant difference in the hypointensity on DPI in the qualitative (p = 0.00001) and quantitative analysis (p < 0.05) between LGDNs and the group obtained by unifying HGDNs and HCCs.

CONCLUSION

DPI is helpful in differentiating HCCs and HGDNs from LGDNs. Demonstration of hypointensity on DPI should raise the suspicion of HGDN or hypovascular HCC in the case of nodules with atypical dynamic pattern.

Early prediction of response to sorafenib in patients with advanced hepatocellular carcinoma: the role of dynamic contrast enhanced ultrasound

BACKGROUND & AIMS

Sorafenib has become the standard first-line treatment for patients with advanced HCC and acts by inducing alterations in tumor vascularity. We wanted to evaluate the feasibility of dynamic CEUS (D-CEUS) as a predictor of early tumor response to sorafenib and to correlate functional parameters with clinical efficacy end points.

METHODS

Twenty-eight HCC patients treated with sorafenib 400mg bid were prospectively enrolled. CEUS was performed at baseline (T0) and after 15 (T1) and 30 (T2) days of treatment. Tumor vasculature was assessed in a specific harmonic mode associated with a perfusion and quantification software (Q-Lab, Philips). Variations between T1/T2 and T0 were calculated for five D-CEUS functional parameters (peak intensity, PI; time to PI, TP; area under the curve, AUC; slope of wash in, Pw; mean transit time, MTT) and were compared for responders and non-responders. The correlation between D-CEUS parameters, overall survival (OS), and progression-free survival (PFS) was also assessed. A p value <0.05 was considered statistically significant.

RESULTS

The percentage variation at T1 significantly correlated with response in three D-CEUS parameters (AUC, PI and Pw; p=0.002, <0.001, and 0.003, respectively). A decrease of AUC (p=0.045) and an increased/unchanged value of TP (p=0.029) and MTT (p=0.010) were associated with longer survival. Three D-CEUS parameters (AUC, TP, Pw) were significantly associated with PFS.

CONCLUSIONS

D-CEUS provides a reliable and early measure of efficacy for anti-angiogenic therapies and could be an excellent tool for selecting patients who will benefit from treatment.

A phase II study of sunitinib in advanced hepatocellular carcinoma

BACKGROUND

In 2007, sorafenib was the first drug able to improve overall survival in patients with advanced hepatocellular carcinoma.

AIM

In 2005 we designed a phase II study to assess safety and efficacy of sunitinib.

METHODS

This is a single arm, open-label, single-centre phase II trial. Eligibility criteria were advanced hepatocellular carcinoma; no prior chemotherapy, performance status 0-1; and Child≤B8. The treatment schedule was 50mg each day orally, 4 weeks on, 2 weeks off.

RESULTS

Between 10/2007 and 10/2010, 34 patients were enrolled. A significant worsening of liver functional reserve after sunitinib was observed. Grade 3/4 adverse effects occurred in 80% of patients and included fatigue (47%), nausea (15%), liver failure (15%), encephalopathy (12%) and upper gastrointestinal bleeding (12%). Six patients (18%) died within 60 days of enrolment. A partial response was observed in 4 patients (12%). Median time to tumour progression was 2.8 months and median overall survival was 5.8 months.

CONCLUSION

A dose of 50mg/d induces a high rate of severe adverse events. Toxicity remains a key concern also at the dose of 37.5mg/d. However, sunitinib is able to induce a prolonged response in some patients. Positron Emission Tomography/Computed Tomography scans may select good responders.

Nonalcoholic fatty liver disease is associated with increased GHBP and reduced GH/IGF-I levels

INTRODUCTION

Nonalcoholic fatty liver disease (NAFLD) has been described in adult GH deficiency syndrome. Furthermore, chronic liver disease can be associated with significant changes in levels of IGF-I, GH-binding protein (GHBP), IGF-binding proteins (IGFBPs) and acid-labile subunit (ALS). However, the effect of liver steatosis on the GHBP production has not been investigated yet.

AIM OF THE STUDY

To explore whether GH secretion and/or levels of IGF-I, IGFBP-3, ALS and GHBP could be altered in obese patients in relation to the presence of liver steatosis.

MATERIALS AND METHODS

A total of 115 obese patients (BMI > 30) were enrolled in the protocol (65 patients with liver steatosis and 50 age- and BMI-matched controls). In all patients, the following parameters were studied: serum levels of glucose, insulin, the HOMA index, IGF-I, GHBP, IGFBP-3, ALS and GH after GHRH and arginine stimulation test.

RESULTS

As expected, patients with NAFLD had blood glucose, insulin, HOMA-R significantly higher than controls, indicating a more severe insulin-resistance state in NAFLD. Furthermore, patients with NAFLD had higher levels of GHBP and IGFBP-3 and lower GH peak and IGF-I levels as compared to controls. No difference was found in ALS levels between the groups. In a multivariate analysis, GHBP was positively associated with hepatic steatosis while IGF-1 was negatively associated with hepatic steatosis.

CONCLUSIONS

This study demonstrates that in patients with NAFLD, the GHBP levels are increased, and that the GH/IGF-I axis is significantly altered probably leading to reduced IGF-I bioavailability at tissue level.

Construction of the Free Energy Landscape of Peptide Aggregation from Molecular Dynamics Simulations

To describe the structure and dynamics of oligomers during peptide aggregation, a method is proposed that considers both the intramolecular and intermolecular structures of the multimolecule system and correctly accounts for its degeneracy. The approach is based on the "by-parts" strategy, which partitions a complex molecular system into parts, determines the metastable conformational states of each part, and describes the overall conformational state of the system in terms of a product basis of the states of the parts. Starting from a molecular dynamics simulation of n molecules, the method consists of three steps: (i) characterization of the intramolecular structure, that is, of the conformational states of a single molecule in the presence of the other molecules (e.g., β-strand or random coil); (ii) characterization of the intermolecular structure through the identification of all occurring aggregate states of the peptides (dimers, trimers, etc.); and (iii) construction of the overall conformational states of the system in terms of a product basis of the n "single-molecule" states and the aggregate states. Considering the Alzheimer β-amyloid peptide fragment Aβ16-22 as a first application, about 700 overall conformational states of the trimer (Aβ16-22)3 were constructed from all-atom molecular dynamics simulation in explicit water. Based on these states, a transition network reflecting the free energy landscape of the aggregation process can be constructed that facilitates the identification of the aggregation pathways.