Contrast-enhanced ultrasonography and spiral computed tomography in the detection and characterization of portal vein thrombosis complicating hepatocellular carcinoma

Macroscopic Portal Vein Thrombosis in HCC Patients

Macroscopic portal vein invasion (PVT) by hepatocellular carcinoma (HCC) in the liver is one of the most important negative prognostic factors for HCC patients. The characteristics of a large cohort of such patients were examined. We found that the percent of patients with PVT significantly increased with increasing maximum tumor diameter (MTD), from 13.7% with tumors of MTD <5cm to 56.4% with tumors of MTD >10cm. There were similar numbers of HCC patients with very large tumors with and without PVT. Thus, MTD alone was insufficient to explain the presence of PVT, as were high AFP levels, since less than 50% of high AFP patients had PVT. However, the percent of patients with PVT was also found to significantly increase with increasing blood alpha-fetoprotein (AFP) levels and tumor multifocality. A logistic regression model that included these 3 factors together showed an odds ratio of 17.9 for the combination of MTD>5.0cm plus tumor multifocality plus elevated AFP, compared to low levels of these 3 parameters. The presence or absence of macroscopic PVT may therefore represent different HCC aggressiveness phenotypes, as judged by a significant increase in tumor multifocality and AFP levels in the PVT positive patients. Factors in addition to MTD and AFP must also contribute to PVT development.

Portal vein thrombosis in cirrhosis: diagnosis, natural history, and therapeutic challenges

Portal vein thrombosis (PVT) is a frequent complication in cirrhosis and its prevalence increases with disease severity. Several factors are involved in the development and progression of PVT. The challenge for the management of PVT is the precise evaluation of the bleeding risk as opposed to life-threatening extension of thrombosis. Nevertheless, the impact on the progression and outcome of liver disease is unclear. A critical evaluation of the available data discloses that treating PVT in cirrhotics is safe and effective. However, there are open issues, such as which anticoagulant could represent a safer therapeutic option, and when and for how long this treatment should be administered to cirrhotic patients with PVT.

Tumor thrombus: incidence, imaging, prognosis and treatment

Intravascular tumor extension, also known as tumor thrombus, can occur in many different types of cancer. Those with the highest proclivity include Wilm's tumor, renal cell carcinoma (RCC), adrenal cortical carcinoma (ACC) and hepatocellular carcinoma (HCC). The presence of tumor thrombus markedly worsens prognosis and impacts treatment approach. Imaging plays a key role in its diagnosis. Endovascular methods also play a large role in treatment.

Hepatocellular Carcinoma with Macrovascular Invasion: Defining the Optimal Treatment Strategy

BACKGROUND

Tumoral macrovascular invasion (MVI) of hepatic and/or portal vein branches is a common phenomenon in hepatocellular carcinoma (HCC) and is associated with poorer prognosis when compared to HCC without MVI.

SUMMARY

Current international guidelines for the management of HCC recommend sorafenib as the only treatment option in case of MVI. Despite guideline recommendations, several alternative options have been tested to manage HCC with MVI: surgery, transarterial chemoembolization, external or internal radiation, hepatic arterial infusion chemotherapy, percutaneous treatment, cryotherapy, or the combination of two or more of these strategies, with or without sorafenib. Here we will provide a comprehensive state-of-the-art review for the management of this challenging clinical entity based on the most recent available data.

KEY MESSAGES

There is a growing body of evidence suggesting that alternative strategies to standard-of-care sorafenib might improve survival in patients with advanced HCC with MVI but the level of evidence remains weak. Randomized phase III trials are ongoing and will hopefully provide information leading towards a more personalized treatment algorithm.

The clinical outcomes of patients with portal vein tumor thrombi after living donor liver transplantation

The purpose of this study was to evaluate the feasibility of living donor liver transplantation for treatment of patients with hepatocellular carcinoma and segmental portal vein tumor thrombus (PVTT) below the second-order branch. Between January 2005 and December 2015, we retrospectively analyzed 242 patients in a control group (n = 184), a microvascular invasion (MVI) group (n = 24), and a PVTT group (n = 34). To assess the risks associated with PVTT, we evaluated recurrence, the disease-free survival (DFS) rate, the overall survival (OS) rate, and various other factors based on the characteristics of patients and tumors. Of the 242 patients, 5-year DFS and OS rates were 79.5% and 70.7%. A total of 34 (14.0%) patients had PVTT, of whom 7 had lobar PVTT in first-order branches. The control, MVI, and PVTT groups significantly differed in terms of tumor morphology (maximal and total diameters) and biology (alpha-fetoprotein [AFP] and protein induced by vitamin K absence or antagonist II). The control, MVI, and PVTT groups significantly differed in terms of the recurrence, DFS, and OS rates. Especially, lobar PVTT reduced the 5-year DFS and OS rates to dismal and 14.3%, respectively, but segmental PVTT was associated with favorable 5-year DFS and OS rates (63.9% and 50.3%, respectively). We found no statistically significant difference in the DFS and OS rates of patients with MVI alone and segmental PVTT alone. In patients in the segmental PVTT group with AFP levels of <100 ng/mL, the 5-year DFS and OS rates were 90.9% and 71.3%, respectively. In conclusion, a tumor thrombus in a lobar portal vein remains a contraindication to liver transplantation. However, a segmental PVTT is acceptable, especially when the AFP level is <100 ng/mL. Liver Transplantation 23 1023-1031 2017 AASLD.

Remote malignant intravascular thrombi: EUS-guided FNA diagnosis and impact on cancer staging

BACKGROUND AND AIMS

Malignant vascular invasion usually results from gross direct infiltration from a primary tumor and impacts cancer staging, prognosis, and therapy. However, patients may also develop a remote malignant thrombi (RMT), defined as a malignant intravascular thrombus located remote and noncontiguous to the primary tumor. Our aim was to compare EUS, CT, and magnetic resonance imaging (MRI) findings of RMT and to explore the potential impact on cancer staging.

METHODS

Patients with RMT were identified from a prospectively maintained EUS database. Retrospective chart review was performed to obtain EUS, CT/MRI, clinical, and outcome data.

RESULTS

A median of 3 FNAs (range, 1-8) was obtained from RMT in 17 patients (60 ± 14.1 years, 56% men) between April 2003 and August 2016, with the finding of malignant cytology in 12 patients (70.6%; 10 positive, 2 suspicious). CT/MRI detected the RMT in 5 patients (29.4%), 4 of whom had positive or suspicious EUS-FNA cytology. Among the 8 newly diagnosed pancreatic adenocarcinoma (PaC) patients, CT did not detect the RMT in 5 (63%), of whom 3 patients had positive or suspicious intravascular EUS-FNA cytology. For newly diagnosed PaC patients (n = 8), the EUS-FNA diagnosis of a biopsy specimen-proven RMT upstaged 3 patients (37.5%) and converted 2 patients (25%) from CT resectable to unresectable disease. No adverse events were reported. The mean follow-up was 18.9 ± 27.7 months.

CONCLUSIONS

Our study demonstrates the ability and potential safety of intravascular FNA to detect radiographically occult RMT, which substantially impacts cancer staging and resectability.

Portal vein thrombosis: The role of imaging in the clinical setting

Portal vein thrombosis is an infrequent condition occurring in several different clinical scenarios. In the last years it has been increasingly recognised due to the broad use of radiological methods. In this review we underline the central role of imaging in diagnosing portal vein thrombosis, in clarifying its etiology, choosing the best therapeutic approach and screening possible complications. Special attention is given to the role of imaging to differentiate portal vein thrombosis from neoplastic invasion of the portal vein, and to new diagnostic methods available for clinical practice in this field.

Clinical implications for imaging of vascular invasion in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the second largest cause of cancer mortality in the world, with vascular invasion being one of the most important prognostic factors. HCC with tumor thrombus was traditionally considered to have very limited treatment options. However, multiple promising treatment strategies have emerged in recent years, with diagnostic and interventional radiologists playing a major role in patient management. We provide a comprehensive update on the diagnosis and management of HCC with vascular invasion and the role of the radiologist in this condition.

Dual-energy CT with iodine quantification in distinguishing between bland and neoplastic portal vein thrombosis in patients with hepatocellular carcinoma

AIM

To investigate the diagnostic accuracy of dual-energy multidetector computed tomography (MDCT) with iodine quantification compared to conventional enhancement measurements in distinguishing bland from neoplastic portal vein thrombosis in patients with hepatocellular carcinoma.

MATERIAL AND METHODS

Thirty-four patients (26 men, eight women; mean age, 62 years) with hepatocellular carcinoma and portal vein thrombosis underwent contrast-enhanced dual-energy MDCT during the late hepatic arterial phase for the assessment of portal thrombosis (bland, n=21; neoplastic, n=13). Datasets were analysed separately by two different readers. Interobserver correlation and variability were calculated and compared with the Bland-Altman method. Diagnostic accuracy of conventional enhancement measurements and iodine quantification was calculated by setting either histopathology (n=7) or a reference standard based on MDCT imaging criteria and thrombus evolutionary characteristics compared to a previous MDCT examination (n=27). For iodine quantification threshold determination receiver operating characteristic (ROC) curves were drawn. p-Values <0.05 were considered significant.

RESULTS

For conventional enhancement measurements and iodine quantification interobserver correlation was 98% and 96%. Enhancement measurement resulted in a sensitivity of 92.3%, specificity of 85.7%, positive predictive value (PPV) of 80%, and negative predictive value (NPV) of 94.7%. An iodine concentration of 0.9 mg/ml optimised discrimination between neoplastic and bland thrombi (area under the ROC [AUC] 0.993) resulting in a sensitivity of 100%, specificity of 95.2%, PPV of 92.9%, and NPV of 100%. The overall diagnostic accuracy of iodine quantification (97%) was significantly better than conventional enhancement measurements (88.2%; p<0.001).

CONCLUSION

Compared to conventional enhancement measurements, iodine quantification improves the characterisation of portal vein thrombi during the late hepatic arterial phase in patients with hepatocellular carcinoma.

Management of hepatocellular carcinoma with portal vein tumor thrombosis: Review and update at 2016

Portal vein tumor thrombosis (PVTT) is a common phenomenon in hepatocellular carcinoma (HCC). Compared to HCC without PVTT, HCC with PVTT is characterized by an aggressive disease course, worse hepatic function, a higher chance of complications related to portal hypertension and poorer tolerance to treatment. Conventionally, HCC with PVTT is grouped together with metastatic HCC during the planning of its management, and most patients are offered palliative treatment with sorafenib or other systemic agents. As a result, most data on the management of HCC with PVTT comes from subgroup analyses or retrospective series. In the past few years, there have been several updates on management of HCC with PVTT. First, it is evident that HCC with PVTT consists of heterogeneous subgroups with different prognoses. Different classifications have been proposed to stage the degree of portal vein invasion/thrombosis, suggesting that different treatment modalities may be individualized to patients with different risks. Second, more studies indicate that more aggressive treatment, including surgical resection or locoregional treatment, may benefit select HCC patients with PVTT. In this review, we aim to discuss the recent conceptual changes and summarize the data on the management of HCC with PVTT.

Low Alpha-Fetoprotein Levels Are Associated with Improved Survival in Hepatocellular Carcinoma Patients with Portal Vein Thrombosis

BACKGROUND

Macroscopic portal vein thrombosis (PVT) is a common and dire prognostic feature of patients with hepatocellular carcinoma (HCC) and often precludes many treatments as a result. Little is known about its causes or mechanisms or clinical associations.

AIMS

To examine patients with PVT in order to possibly identify prognostically different subsets.

METHODS

A large cohort of non-curable patients with advanced and biopsy-proven HCC in which survival was documented, were retrospectively examined.

RESULTS

We analyzed a large HCC cohort containing 366 (63.3%) PVT-positive patients and found that PVT is associated with patients having larger tumors and higher levels of alpha-fetoprotein (AFP) and des-gamma carboxyprothrombin (DCP). We identified in patients with normal bilirubin levels (≤ 2.0 mg/dl) two PVT-positive patients, having higher and lower AFP levels, respectively. They differed in the significantly better prognosis of the low AFP patients, which may be useful for patient management decisions.

CONCLUSIONS

Patients with PVT are heterogeneous with respect to AFP levels. AFP-negative patients have a significantly better survival than those who have elevated AFP.

Application of contrast-enhanced ultrasound after liver transplantation: Current status and perspectives

Liver transplantation is an effective treatment for patients with end-stage liver disease. Accurate imaging evaluation of the transplanted patient is critical for ensuring that the limited donor liver is functioning appropriately. Ultrasound contrast agents (UCAs), in combination with contrast-specific imaging techniques, are increasingly accepted in clinical use for the assessment of the hepatic vasculature, bile ducts and liver parenchyma in pre-, intra- and post-transplant patients. We describe UCAs, their technical requirements, the recommended clinical indications, image interpretation and the limitations for contrast-enhanced ultrasound applications in liver transplantation.

Portal Vein Thrombosis in Patients with Hepatocellular Carcinoma: Diagnostic Accuracy of Gadoxetic Acid-enhanced MR Imaging

Purpose To assess the diagnostic performance of gadoxetic acid-enhanced magnetic resonance (MR) imaging in the evaluation of portal vein thrombosis (PVT) in patients with hepatocellular carcinoma (HCC). Materials and Methods This retrospective study was approved by the institutional review board. The requirement to obtain informed consent was waived. A total of 366 patients with HCC who underwent gadoxetic acid-enhanced MR imaging between January 2007 and May 2013, including 134 with malignant PVT, 49 with benign PVT, and 183 without PVT matched for age and sex, comprised our study population. PVTs were complete in 125 patients and partial in 58 and were located in a major portal vein (n = 159) or segmental portal vein (n = 24). Two radiologists independently reviewed the MR images and assessed the sensitivity, specificity, and accuracy in the detection and characterization of PVT according to location (major vs segmental) and type (complete vs partial). The Fisher exact or χ(2) test was used to evaluate sensitivity difference between the subsets. Results Gadoxetic acid-enhanced MR imaging showed good sensitivity (reviewer 1, 84% [154 of 183 patients]; reviewer 2, 70% [129 of 183 patients]) and high specificity (reviewer 1, 89% [163 of 183 patients]; reviewer 2, 96% [176 of 183 patients]) in the detection of PVT. Diagnostic accuracy for differentiating malignant PVT from benign PVT was high (reviewer 1, 92% [141 of 154 patients]; reviewer 2, 95% [122 of 129 patients]). However, there was slightly lower sensitivity for detecting segmental PVT compared with that of major PVT in the malignant PVT group (reviewer 1, 95% [104 of 110 patients] vs 88% [21 of 24 patients]; reviewer 2, 82% [90 of 110 patients] vs 79% [19 of 24 patients]; P = .203 and .775 for reviewers 1 and 2, respectively). Conclusion Gadoxetic acid-enhanced MR imaging provided good diagnostic performance in the detection of PVT and the differentiation of malignant from benign PVT in patients with HCC. However, caution is needed when evaluating potential candidates for curative treatment because of the low sensitivity for segmental PVT in the malignant PVT group. (©) RSNA, 2016 Online supplemental material is available for this article.

Contrast-enhanced ultrasound in differentiating malignant from benign portal vein thrombosis in hepatocellular carcinoma

Portal vein thrombosis (PVT) may occur in liver cirrhosis patients. Malignant PVT is a common complication in cirrhotic patients with concomitant hepatocellular carcinoma (HCC) and, in some cases, it may be even the initial sign of an undetected HCC. Detection of malignant PVT in a patient with liver cirrhosis heavily affects the therapeutic strategy. Gray-scale ultrasound (US) is widely unreliable for differentiating benign and malignant thrombi. Although effective for this differential diagnosis, fine-needle biopsy remains an invasive technique. Sensitivity of color-doppler US in detection of malignant thrombi is highly dependent on the size of the thrombus. Contrast-enhanced computed tomography (CT) and contrast-enhanced magnetic resonance (MRI) can be useful to assess the nature of portal thrombus, while limited data are currently available about the role of positron emission tomography (PET) and PET-CT. In contrast with CT, MRI, PET, and PET-CT, contrast-enhanced ultrasound (CEUS) is a fast, effective, well tolerated and cheap technique, that can be performed even in the same session in which the thrombus has been detected. CEUS can be performed bedside and can be available also in transplanted patients. Moreover, CT and MRI only yield a snapshot analysis during contrast diffusion, while CEUS allows for a continuous real-time imaging of the microcirculation that lasts several minutes, so that the whole arterial phase and the late parenchymal phase of the contrast diffusion can be analyzed continuously by real-time US scanning. Continuous real-time monitoring of contrast diffusion entails an easy detection of thrombus maximum enhancement. Moreover, continuous quantitative analyses of enhancement (wash in - wash out studies) by CEUS during contrast diffusion is nowadays available in most CEUS machines, thus giving a more sophisticated and accurate evaluation of the contrast distribution and an increased confidence in diagnosis in difficult cases. In conclusion, CEUS is a very reliable technique with a high intrinsic sensitivity for portal vein patency assessment. More expensive and sophisticated techniques (i.e., CT, MRI, PET, and PET-CT) should only be indicated in undetermined cases at CEUS.

Hepatectomy for hepatocellular carcinoma larger than 10 cm: preoperative risk stratification to prevent futile surgery

OBJECTIVES

Appropriate patient selection is important to achieving good outcomes and obviating futile surgery in patients with huge (≥10 cm) hepatocellular carcinoma (HCC). The aim of this study was to identify independent predictors of futile outcomes, defined as death within 3 months of surgery or within 1 year from early recurrence following hepatectomy for huge HCC.

METHODS

The outcomes of 149 patients with huge HCCs who underwent resection during 1995-2012 were analysed. Multivariate logistic regression analysis was performed to identify preoperative independent predictors of futility.

RESULTS

Independent predictors of 3-month mortality (18.1%) were: total bilirubin level >34 μmol/l [P = 0.0443; odds ratio (OR) 16.470]; platelet count of <150 000 cells/ml (P = 0.0098; OR 5.039), and the presence of portal vein tumour thrombosis (P = 0.0041; OR 5.138). The last of these was the sole independent predictor of 1-year recurrence-related mortality (17.2%). Rates of recurrence-related mortality at 3 months and 1 year were, respectively, 6.3% and 7.1% in patients with Barcelona Clinic Liver Cancer (BCLC) stage A disease, 12.5% and 14% in patients with BCLC stage B disease, and 37.8% (P = 0.0002) and 75% (P = 0.0002) in patients with BCLC stage C disease.

CONCLUSIONS

According to the present data, among patients submitted to hepatectomy for huge HCC, those with a high bilirubin level, low platelet count and portal vein thrombosis are at higher risk for futile surgery. The presence of portal vein tumour thrombosis should be regarded as a relative contraindication to surgery.

Differentiating malignant from benign thrombosis in hepatocellular carcinoma: contrast-enhanced ultrasound

BACKGROUND

To determine the accuracy of contrast-enhanced ultrasonography (CEUS) in differentiating malignant and benign venous thrombosis complicating hepatocellular carcinoma (HCC).

METHODS

Fifty patients (M:F = 41:9; age range 46-83 years) with HCC and venous thrombosis [portal vein (PV) in 45 and hepatic vein (HV) in 5] detected on CT or MR scan were evaluated with CEUS. Reference standard of malignant and benign thrombosis was based on serial clinicoradiologic follow-up (n = 43) or pathology (n = 7). Two independent, blinded readers retrospectively recorded the enhancement features of the venous thrombosis and diagnosed as benign or malignant thrombosis with a five-point confidence scale. Receiver operating characteristic (ROC) curves were calculated to determine the diagnostic performance of CEUS in differentiating malignant from benign thrombosis. Confidence level ratings were also used to calculate the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for the diagnosis of malignant thrombosis. Inter-reader agreement was calculated using κ statistics in each assessed finding. Gray scale and Doppler characteristics of primary tumor and thrombosis were also assessed.

RESULTS

Of the 50 patients, 37 were malignant (33 with PV thrombosis and 4 with HV thrombosis) and 13 were benign (12 with PV thrombosis and 1 with HV thrombosis). In ROC curve analysis for differentiating malignant from benign thrombosis, Az was 0.947 (CI 0.841-0.991) for reader 1 and 0.958 (CI 0.861-0.995) for reader 2 with excellent inter-reader agreement (κ = 0.86). When the confidence level ratings of 1 or 2 were considered malignant thrombosis, the sensitivity, specificity, PPV, and NPV in differentiating malignant from benign thrombosis were 100%, 83%, 95%, and 100% for reader 1 and 100%, 92%, 97%, and 100% for reader 2.

CONCLUSION

CEUS is useful to differentiate malignant and benign venous thrombosis associated with HCC with high diagnostic accuracy.

Multimodality Imaging of Tumour Thrombus

Vascular thrombosis occurs commonly in cancer patients. Once the diagnosis of thrombosis is established, it is important to characterize the nature of thrombus, tumoural versus bland, as each have a different prognosis, clinical significance, and management. This review paper discusses the imaging spectrum of tumour thrombus and its clinical significance emphasizing the role of imaging in differentiating tumour from bland thrombus.

Portal vein thrombosis

Portal vein thrombosis is an important cause of portal hypertension. PVT occurs in association with cirrhosis or as a result of malignant invasion by hepatocellular carcinoma or even in the absence of associated liver disease. With the current research into its genesis, majority now have an underlying prothrombotic state detectable. Endothelial activation and stagnant portal blood flow also contribute to formation of the thrombus. Acute non-cirrhotic PVT, chronic PVT (EHPVO), and portal vein thrombosis in cirrhosis are the three main variants of portal vein thrombosis with varying etiological factors and variability in presentation and management. Procoagulant state should be actively investigated. Anticoagulation is the mainstay of therapy for acute non-cirrhotic PVT, with supporting evidence for its use in cirrhotic population as well. Chronic PVT (EHPVO) on the other hand requires the management of portal hypertension as such and with role for anticoagulation in the setting of underlying prothrombotic state, however data is awaited in those with no underlying prothrombotic states. TIPS and liver transplant may be feasible even in the setting of PVT however proper selection of candidates and type of surgery is warranted. Thrombolysis and thrombectomy have some role. TARE is a new modality for management of HCC with portal vein invasion.

Differentiation of bland from neoplastic thrombus of the portal vein in patients with hepatocellular carcinoma: application of susceptibility-weighted MR imaging

BACKGROUND

Neoplastic and bland portal vein thrombi (PVT) are both common in patients with hepatocellular carcinoma (HCC). The correct discrimination of them is essential for therapeutic strategies planning and survival predicting. The current study aims to investigate the value of susceptibility-weighted imaging (SWI) in differentiating bland from neoplastic PVT in HCC patients.

METHODS

20 HCC patients with bland PVT and 22 HCC patients with neoplastic PVT were imaged with non-contrast SWI at 3.0 Tesla MRI. The signal intensity (SI) of the PVT and HCC lesions in the same patients was compared on SW images. The phase values of the PVT were compared between neoplastic and bland thrombi cohorts. Receiver operator characteristics (ROC) analysis was conducted to evaluate the diagnostic ability of the phase values for neoplastic and bland thrombi discrimination.

RESULTS

20 of 22 neoplastic PVT were judged similar SI and 2 were judged lower SI than their HCC. For 20 bland PVT, 19 were judged lower SI and 1 was judged similar SI as their HCC (P<0.001). The average phase values (0.361 ± 0.224) of the bland PVT were significantly higher than those of the neoplastic PVT (-0.328 ± 0.127, P<0.001). The AUC for phase values in differentiating bland from neoplastic PVT was 0.989. The best cut-off value was -0.195, which gave a sensitivity of 95% and a specificity of 95.5%.

CONCLUSIONS

SW imaging appears to be a promising new method for distinguishing neoplastic from bland PVT. The high sensitivity and specificity suggest its high value in clinical practice.

Imaging in clinical decision-making for portal vein thrombosis

Thrombosis of the portal venous system is a frequent and potentially life-threatening condition that can take place in a number of different clinical settings including liver cirrhosis, hepatocellular carcinoma, other solid tumours, abdominal septic foci, acute pancreatitis, haematological malignancies and congenital or acquired prothrombotic disorders. Clinical decision-making in patients with thrombosis of the portal venous system is a particularly complex process owing to the heterogeneity of the population affected by this condition and the lack of high-quality evidence from randomized controlled trials for the use of anticoagulation therapy in these patients. This Review discusses the available data regarding how imaging can provide assistance to physicians involved in this decision-making process in different clinical settings. A flowchart illustrating how to use imaging in this setting, based on current evidence and on the experience of the Vascular Liver Diseases Group of the Hospital Clinic in Barcelona, is also presented.

Management of hepatocellular carcinoma: The role of contrast-enhanced ultrasound

Hepatocellular carcinoma (HCC) is the sixth most common neoplasm and the third cause of cancer death worldwide. Contrast enhanced ultrasound (CEUS) has been applied for more than ten years and plays increasingly important roles in the management of HCC. On the basis of the Guideline and Good Clinical Practice Recommendations for CEUS in the liver-update 2012 and related literature about the management of HCC, we summarize the main roles and applications of CEUS in the management of HCC, including HCC surveillance, diagnosis, CEUS-guided treatment, treatment response evaluation and follow-up. The diagnostic algorithm for HCC is also suggested. Meanwhile, the comparisons between CEUS and contrast enhanced computed tomography/magnetic resonance imaging (CECT/CEMRI) in these areas are made. Although CEUS is subject to the same limitation as ordinary US and is inferior to CECT/CEMRI in some aspects, CEUS has proved to be of great value in the management of HCC with inherent advantages, such as sufficient high safety profile making it suitable for patients with renal failure or allergic to iodine, absence of radiation, easy reproducibility and high temporal resolution. The tremendous application of CEUS to the diagnosis and treatment of HCC provides more opportunities for patients with HCC diagnosed at different stages.

Practical effect of sorafenib monotherapy on advanced hepatocellular carcinoma and portal vein tumor thrombosis

Background/Aims

We investigated the effects of sorafenib monotherapy on advanced hepatocellular carcinoma (HCC) and portal vein tumor thrombosis (PVTT) in a clinical setting.

Methods

In total, 143 consecutive patients with unresectable HCC were treated with sorafenib. Among these patients, 30 patients with advanced HCC and PVTT (Vp3 or 4) were treated with sorafenib monotherapy.

Results

All patients had a performance status of 1 to 2 (Eastern Cooperative Oncology Group 1/2, 20/10) and Child-Pugh class A or B (A/B, 17/13). Eleven patients had modified Union for International Cancer Control stage IVA tumors, whereas 19 had stage IVB tumors. All patients had PVTT (Vp3, 6; Vp4, 24). Following sorafenib monotherapy, three patients (10.0%) had a partial response with PVTT revascularization, and nine (30.0%) had stable disease, with a disease control rate of 33.3%. The median overall survival was 3.1 months (95% confidence interval [CI], 2.70 to 3.50), and the median progression-free survival was 2.0 months (95% CI, 1.96 to 2.05). Fatigue and hand-foot skin reactions were the most troublesome side effects.

Conclusions

A limited proportion of patients with advanced HCC and PVTT exhibited a remarkable outcome after sorafenib monotherapy, although the treatment results in this type of patient is extremely poor. Further studies to predict good responders to personalized therapy are warranted.

Patterns of appearance and risk of misdiagnosis of intrahepatic cholangiocarcinoma in cirrhosis at contrast enhanced ultrasound

AIM

Primary aim was to validate the percentage of intrahepatic cholangiocarcinomas (ICC) which have a contrast vascular pattern at contrast enhanced ultrasound (CEUS) at risk of misdiagnosis with hepatocellular carcinoma (HCC) and, secondary aim, to verify if any characteristics in the CEUS pattern helps to identify ICC.

METHODS

All ICC on cirrhosis seen in three Italian centres (Bologna, Milan and Pavia) between 2003 and 2011, in which CEUS and at least another imaging technique (CT or MRI) had been performed, were retrospectively identified. Those patients with ICC size comparable to the early HCC stage (Milan criteria, considered as small ICC) were enrolled for this study. The enhancement pattern at CEUS was analysed and compared with CT or MRI.

RESULTS

A total of 25 small ICC made this study group. CEUS was at risk of misdiagnosis of ICC for HCC in a significantly higher number of cases than in CT (performed in 24 ICC) (52% vs. 4.2%, P = 0.009) and MRI (11 ICC) (52% vs. 9.1%, P = 0.02). A different contrast pattern among all techniques was found in 6 of 10 ICC lesions submitted to the three imaging methods. In the arterial phase, ICC lacked global hyperenhacement in approximately 50% of cases at CEUS and the degree of intensity of wash-out in the late phase was marked in 24% of nodules.

CONCLUSIONS

CEUS misdiagnosed as HCC a significantly higher number of ICC lesions in cirrhotic patients than CT and MRI. However, some CEUS contrast features can help suspect ICC, especially in some cases with inconclusive CT or MRI.

Current consensus and guidelines of contrast enhanced ultrasound for the characterization of focal liver lesions

The application of ultrasound contrast agents (UCAs) is considered essential when evaluating focal liver lesions (FLLs) using ultrasonography (US). Microbubble UCAs are easy to use and robust; their use poses no risk of nephrotoxicity and requires no ionizing radiation. The unique features of contrast enhanced US (CEUS) are not only noninvasiveness but also real-time assessing of liver perfusion throughout the vascular phases. The later feature has led to dramatic improvement in the diagnostic accuracy of US for detection and characterization of FLLs as well as the guidance to therapeutic procedures and evaluation of response to treatment. This article describes the current consensus and guidelines for the use of UCAs for the FLLs that are commonly encountered in US. After a brief description of the bases of different CEUS techniques, contrast-enhancement patterns of different types of benign and malignant FLLs and other clinical applications are described and discussed on the basis of our experience and the literature data.

Prediction of the therapeutic effects of anticoagulation for recent portal vein thrombosis: a novel approach with contrast-enhanced ultrasound

OBJECTIVE

To examine whether intra-thrombus enhancement on contrast-enhanced sonograms can predict the recanalization by anticoagulation for recent portal thrombosis.

METHODS

This prospective study included 10 patients with a recent portal thrombosis and 20 controls (10 cirrhosis patients and 10 healthy subjects, all without thrombosis). The diagnosis of thrombosis was based on clinical and ultrasound findings. Pre-anticoagulation intra-thrombus enhancement on the contrast-enhanced sonogram was examined with respect to the post-anticoagulation results or portal enhancement in controls.

RESULTS

Complete recanalization was obtained in 4 patients with positive intra-thrombus enhancement. However, in 4 other patients who had a thrombosis showing positive enhancement concurrent with one showing negative enhancement, anticoagulation recanalized the former and failed to recanalize the latter. Mean onset time of contrast enhancement measured from the beginning of hepatic arterial enhancement was significantly longer in the thrombus (6.6 ± 4.3 s, 3-16 s) than in the portal vein of controls (cirrhosis, 4.3 ± 1.4 s, 2-8 s, P = 0.0035; healthy subjects, 2.4 ± 0.6 s, 1-3 s, P < 0.0001). Anticoagulation failed to achieve recanalization in 2 patients with negative intra-thrombus enhancement. Sensitivity and specificity of contrast enhancement for the prediction of post-treatment recanalization was 100%.

CONCLUSIONS

Intra-thrombus positive enhancement demonstrated on contrast-enhanced sonograms has promise as a successful predictor of recanalization for the recent portal thrombosis.

Differentiation of neoplastic from bland macroscopic portal vein thrombi using dual-energy spectral CT imaging: a pilot study

OBJECTIVES

To assess the feasibility and value of dual-energy spectral computed tomography (DESCT) imaging for differentiating neoplastic from bland macroscopic portal vein (PV) thrombi.

METHODS

Computed tomography (CT) images of 44 patients with macroscopic PV thrombus (bland group, n = 16; neoplastic group, n = 28) were reviewed. Iodine-based material decomposition images in the portal venous phase were reconstructed to compare the iodine indices between groups, including thrombus iodine density (I (T)), thrombus-aorta iodine density ratio (I (T)/I (A)), and thrombus-PV iodine density ratio (I (T)/I (P)). Differential diagnostic performances of DESCT were calculated in the subgroup of 21 patients with histopathological evidence (bland group, n = 12; neoplastic group, n = 9).

RESULTS

The iodine indices of the neoplastic group were significantly higher than those in the bland group (P < 0.001). A threshold I (T) of 1.14 mg/mL, I (T)/I (A) of 0.17, and I (T)/I (P) of 0.17 in the portal venous phase yielded 100 %, 88.9 %, and 100 % sensitivity, and 91.7 %, 91.7 %, and 83.3 % specificity, respectively, in differentiating neoplastic from bland PV thrombi.

CONCLUSIONS

DESCT imaging with quantification of thrombus iodine density in the portal venous phase appears to be a promising new method for distinguishing neoplastic from bland macroscopic PV thrombi.

KEY POINTS

• Differentiating the nature of portal vein thrombus is of great clinical significance. • Iodine-based material decomposition imaging reflects iodine distribution after contrast media administration. • Dual-energy CT with iodine quantification can distinguish bland from neoplastic PV thrombi.

Contrast-enhanced ultrasound in abdominal imaging

The administration of a contrast agent is considered an essential tool to evaluate abdominal diseases using Ultrasound. The most targeted organ is the liver, especially to characterize focal liver lesions and to assess the response to percutaneous treatment. However, the expanding abdominal indications of contrast-enhanced ultrasound make this technique an important tool in the assessment of organ perfusion including the evaluation of ischemic, traumatic, and inflammatory diseases.

Portal vein thrombosis with contrast-enhanced ultrasound in a patient with hepatocellular carcinoma: a case study

Portal vein thrombosis (PVT) is the presence of thrombus in the portal vein that causes partial or complete occlusion. It is prevalent in hepatocellular carcinoma (HCC), where it can be either bland or malignant depending on the presence of invasion. Recent studies have identified contrast-enhanced ultrasound (CEUS) as the most reliable method of imaging to make this distinction. The arterial neovascularisation that is evident in a neoplastic thrombus can be visualised on CEUS with enhancement and pulsation, witnessed in real-time. This case study describes the use of contrast-enhanced ultrasound used as a non-invasive method to define the bland and malignant components of portal vein thrombosis in a 76-year-old male with hepatocellular carcinoma and cirrhosis.

Extrahepatic spread of hepatocellular carcinoma: spectrum of imaging findings

OBJECTIVE

The purpose of this article is to describe the imaging findings of extrahepatic spread of hepatocellular carcinoma (HCC).

CONCLUSION

Detecting extrahepatic metastases in HCC is critical in determining the optimal treatment plan for patients. Identifying the presence of extrahepatic metastases in patients with advanced disease may eliminate unnecessary surgery, such as liver transplantation or partial hepatic resection, and help direct the appropriate therapy.

The role of poly(ethylene glycol) brush architecture in complement activation on targeted microbubble surfaces

Complement fixation to surface-conjugated ligands plays a critical role in determining the fate of targeted colloidal particles after intravenous injection. In the present study, we examined the immunogenicity of targeted microbubbles with various surface architectures and ligand surface densities using a flow cytometry technique. Targeted microbubbles were generated using a post-labeling technique with a physiological targeting ligand, cyclic arginine-glycine-asparagine (RGD), attached to the distal end of the poly(ethylene glycol) (PEG) moieties on the microbubble surface. Microbubbles were incubated in human serum, washed and then mixed with fluorescent antibodies specific for various serum components. We found that complement C3/C3b was the main human serum factor to bind in vitro to the microbubble surface, compared to IgG or albumin. We also investigated the effect of PEG brush architecture on C3/C3b fixation to the microbubble surface. RGD peptide was able to trigger a complement immune response, and complement C3/C3b fixation depended on microbubble size and RGD peptide surface density. When the targeting ligand was attached to shorter PEG chains that were shielded by a PEG overbrush layer (buried-ligand architecture), significantly less complement activation was observed when compared to the more traditional exposed-ligand motif. The extent of this protective role by the PEG chains depended on the overbrush length. Taken together, our results confirm that the buried-ligand architecture may significantly reduce ligand-mediated immunogenicity. More generally, this study illustrates the use of flow cytometry and microbubbles to analyze the surface interactions between complex biological media and surface-engineered biomaterials.

APASL and AASLD Consensus Guidelines on Imaging Diagnosis of Hepatocellular Carcinoma: A Review

Consensus guidelines for radiological diagnosis of hepatocellular carcinoma (HCC) have been drafted by several large international working groups. This article reviews the similarities and differences between the most recent guidelines proposed by the American Association for Study of Liver Diseases and the Asian Pacific Association for the Study of the Liver. Current evidence for the various imaging modalities for diagnosis of HCC and their relevance to the consensus guidelines are reviewed.

CT and MRI of hepatocellular carcinoma: an update

Hepatocellular carcinoma (HCC) is one of the most common malignancies worldwide and one of the few malignancies with an increasing incidence in the USA. Imaging plays a crucial role in early detection, accurate staging and planning management strategies. Contrast material-enhanced MRI or computed tomography (CT) are the best imaging techniques currently available for the noninvasive diagnosis of HCC. The diagnosis of HCC is strongly dependent on hemodynamic features (arterial hypervascularity and washout in the venous phase) on dynamic imaging, and biopsy is no longer recommended for tumors with classical imaging features prior to treatment. The major challenge for radiologists in imaging cirrhosis is the characterization of hypervascular nodules smaller than 2 cm, which often have nonspecific imaging characteristics. In this review, we discuss the role of CT and MRI in the diagnosis and staging of HCC. The strengths and current limitations of these imaging modalities are highlighted.

Criteria for diagnosing benign portal vein thrombosis in the assessment of patients with cirrhosis and hepatocellular carcinoma for liver transplantation

Malignant portal vein thrombosis is a contraindication for liver transplantation. Patients with cirrhosis and early hepatocellular carcinoma (HCC) may have either malignant or benign (fibrin clot) portal vein thrombosis. The aim of this study was to assess prospectively whether well-defined diagnostic criteria would enable the nature of portal vein thrombosis to be established in patients with HCC under consideration for liver transplantation. Benign portal vein thrombosis was diagnosed by the application of the following criteria: lack of vascularization of the thrombus on contrast-enhanced ultrasound and on computed tomography or magnetic resonance imaging, absence of mass-forming features of the thrombus, absence of disruption of the walls of veins, and, if uncertainty persisted, biopsy of the thrombus for histological examination. Patients who did not fulfill the criteria for benign thrombosis were not placed on the transplantation list. In this study, all patients evaluated at our center during 2001-2007 with a diagnosis of HCC in whom portal vein thrombosis was concurrently or subsequently diagnosed were discussed by a multidisciplinary group to determine their suitability for liver transplantation. The outcomes for 33 patients who met the entry criteria of the study were as follows: in 14 patients who were placed on the transplantation list and underwent liver transplantation, no malignant thrombosis was detected when liver explants were examined histologically; 5 patients who were placed on the transplantation list either remained on the list or died from causes unrelated to HCC; in 9 patients, liver transplantation was contraindicated on account of a strong suspicion, or confirmation, of the presence of malignant portal vein thrombosis; and 5 patients who were initially placed on the transplantation list were subsequently removed from it on account of progression of HCC in the absence of evidence of neoplastic involvement of thrombosis. In conclusion, for a patient with HCC and portal vein thrombosis, appropriate investigations can establish whether the thrombosis is benign; patients with HCC and benign portal vein thrombosis are candidates for liver transplantation.

Differentiation of malignant thrombus from bland thrombus of the portal vein in patients with hepatocellular carcinoma: application of diffusion-weighted MR imaging

PURPOSE

To investigate the utility of diffusion-weighted (DW) imaging in distinguishing bland thrombus from neoplastic thrombus in the portal vein in patients with hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

In this retrospective institutional review board-approved HIPAA-complaint study, the imaging results in 25 patients (16 men [average age, 62.3 years; range, 35-75 years] and nine women [average age, 58.4 years; range, 32-69 years]; overall average age, 60.1 years; range, 32-75 years) with HCC and portal vein thrombosis who were examined with both contrast material-enhanced computed tomography (CT) and 1.5-T magnetic resonance (MR) imaging were reviewed. Axial echo-planar two-dimensional DW imaging was performed by using b values of 50, 400, and 800 sec/mm(2). A thrombus was considered neoplastic if it expanded the vessel or enhanced on the dynamic CT and MR images; otherwise it was considered bland. The signal intensity (SI) of the thrombus and HCC lesions in the same patients was compared on DW images. The results were evaluated by using the Fisher exact test. The apparent diffusion coefficients (ADCs) of HCC and thrombus were used to compute the ratio of the ADC of the thrombus to the ADC of the tumor.

RESULTS

On DW images, 15 of 19 neoplastic thrombi demonstrated same SI and four showed lower SI than the primary HCC. Each of the six bland thrombi had lower SI than the primary HCC (P < .001). The mean ADC of HCC and thrombus in the neoplastic thrombus group was 0.87 x 10(-3) mm(2)/sec and 0.88 x 10(-3) mm(2)/sec, respectively (P = .45). The ADC of the bland thrombus was 2.89 x 10(-3) mm(2)/sec, significantly higher than the ADC of the HCC (1.0 x 10(-3) mm(2)/sec, P < .0003). The ratio of the ADC of the thrombus to the ADC of the tumor in the bland thrombus group was 2.9 compared with 0.998 in the neoplastic group (P = .0003).

CONCLUSION

DW imaging enables discrimination between bland and neoplastic portal vein thrombi when the ratio of the ADC of the thrombus to the ADC of HCC was lower than 2 and when the thrombi showed similar SI as the primary HCC when qualitative analysis was performed.

Review article: the modern management of portal vein thrombosis

BACKGROUND

Portal vein thrombosis (PVT) is an important cause of portal hypertension. It may occur as such with or without associated cirrhosis and hepatocellular carcinoma. Information on its management is scanty.

AIM

To provide an update on the modern management of portal vein thrombosis. Information on portal vein thrombosis in patients with and without cirrhosis and hepatocellular carcinoma is also updated.

METHODS

A pubmed search was performed to identify the literature using search items portal vein thrombosis-aetiology and treatment and portal vein thrombosis in cirrhosis and hepatocellular carcinoma.

RESULTS

Portal vein thrombosis occurs because of local inflammatory conditions in the abdomen and prothrombotic factors. Acute portal vein thrombosis is usually symptomatic when associated with cirrhosis and/or superior mesenteric vein thrombosis. Anticoagulation should be given for 3-6 months if detected early. If prothrombotic factors are identified, anticoagulation should be given lifelong. Chronic portal vein thrombosis usually presents with well tolerated upper gastrointestinal bleed. It is diagnosed by imaging, which demonstrates a portal cavernoma in place of a portal vein. Anticoagulation does not have a definite role, but bleeds can be treated with endotherapy or shunt surgery. Rarely liver transplantation may be considered.

CONCLUSION

Role of anticoagulation in chronic portal vein thrombosis needs to be further studied.

Portal vein thrombosis in the district general hospital: management and clinical outcomes

INTRODUCTION

Portal vein thrombosis (PVT) refers to a thrombosis that occurs in the extrahepatic portal venous system in the presence or absence of underlying liver disease. The clinical presentation of PVT is extremely variable and there is no absolute consensus on its investigation and management. A paucity of literature examining this clinical entity in the district general hospital is observed.

METHODS

We reviewed the experience of two medium-sized district general hospitals in the UK. Twenty-five patients, who were diagnosed with PVT, were identified from the electronic databases of the two hospitals from 1994 to 2007.

RESULTS

Fifty-six percent of patients were females with a median age of 59 years. Seventy-six percent of patients had an identifiable comorbidity at presentation, the most common being chronic liver disease. The most frequently presenting symptom was abdominal pain and distension (60%). Twenty-four percent of patients presented with upper gastrointestinal bleeding secondary to oesophageal and/or gastric varices. Abdominal ultrasound and computed tomographical imaging were the imaging modalities most commonly used to diagnose PVT, although abdominal ultrasound missed 12% of patients subsequently diagnosed by other methods. Fifty percent of patients, who had a thrombophilia screen, were found to have a coagulopathy. Twenty-eight percent of patients were anticoagulated with warfarin with no adverse bleeding events observed. Forty-four percent of patients were placed on an endoscopic variceal band ligation programme. Nine patients died over the study period from either upper gastrointestinal bleeding, end-stage liver failure or biliary sepsis. The acturial 5-year survival was 72%.

CONCLUSION

The mortality from PVT is low and survival is related to the underlying cause. Although the diagnosis of PVT remains uncommon outside the specialist centre, both specialist and nonspecialist physicians must remain mindful of this important condition.