Current role of ultrasound for the management of hepatocellular carcinoma

Hydralazine-augmented contrast ultrasound imaging improves the detection of hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) detection with B-mode and contrast-enhanced ultrasound (CUS) imaging often varies between subjects, especially in patients with background cirrhosis. Various factors contribute to this variability, including the tumor blood flow, tumor size, internal echoes, and its location in livers with diffuse fibro-cirrhotic changes.

OBJECTIVE

Towards improving lesion detection, this study evaluates a vasodilator, hydralazine, to enhance the visibility of HCC by reducing its blood flow relative to the surrounding liver tissue.

METHODS

HCC were analyzed for tumor visibility measured for B-mode, CUS, and hydralazine-augmented-contrast ultrasound (HyCUS) in an autochthonous HCC rat model. 21 tumors from 12 rats were studied. B-mode and CUS images were acquired before hydralazine injection. Rats received an intravenous hydralazine injection of 5 mg/kg, then images were acquired 20 min later. Four rats were used as controls. The difference in echo intensity of the lesion and the surrounding tissue was used to determine the visibility index (VI).

RESULTS

The visibility index for HCC was found to be significantly improved with the use of HyCUS imaging compared to traditional B-mode and CUS imaging. The visibility index for HCC was 16.5 ± 2.8 for HyCUS, compared to 5.3 ± 4.8 for B-mode and 4.1 ± 3.8 for CUS. The differences between HyCUS and the other imaging modalities were statistically significant, with p-values of 0.001 and 0.02, respectively. Additionally, when compared to control cases, HyCUS showed higher discrimination of HCC (VI = 6.4 ± 1.2) with a p-value of 0.003, while B-mode (VI = 6.7 ± 1.4, p = 0.5) and CUS (VI = 6.4 ± 1.2, p = 0.3) showed lower discrimination.

CONCLUSION

Vascular blood flow modulation by hydralazine enhances the visibility of HCC. HyCUS offers a potential problem-solving method for detecting HCC when B-mode and CUS are unsuccessful, especially with background fibro-cirrhotic liver disease. Future evaluation of the approach in humans will determine its translatability for clinical applications.

Contrast-enhanced ultrasound for assessing blood flow modulation of hepatocellular carcinoma by hydralazine

Modulating aberrant tumor microvasculature provides unique opportunities for enhancing ultrasound imaging of hepatocellular carcinoma (HCC). This study aims to use contrast-enhanced ultrasound to evaluate the potential of a potent vasodilator, hydralazine, to attenuate blood flow in HCC while enhancing it in the surrounding liver tissue. The "steel effect," where blood flow is diverted from the lesion to the surrounding tissue aims to enhance lesion-tissue contrast. Methods: HCC was induced in six rats by oral ingestion of diethylnitrosamine for 12 weeks. 10 tumors were studied to assess the enhancement in HCC tumors and surrounding tissue. Contrast-enhanced ultrasound images (CEUS) of each tumor were acquired before and after hydralazine injection. The enhancement of images was analyzed for the qualitative and quantitative assessment of HCC enhancement. Peak enhancement (PE) was calculated, representing the maximum signal intensity reached during the transit of the contrast bolus for both the tumor and the surrounding tissue. Intravenous administration of hydralazine significantly reduced CEUS signals in HCC tumors. The visual examination of images showed that the enhancement of tumors dramatically decreased after hydralazine injection. On the other hand, the surrounding tissue showed an increased enhancement. PE for the HCC changed from (71.8 ± 5) pre hydralazine to (28.7± 4.9), a 61.7% reduction after hydralazine injection, p=0.01. Future studies validating the technique in clinical settings for enhancing lesion-tissue contrast may allow physicians greater precision and accuracy in HCC surveillance for early detection of small tumors.

The clinical application of ultrasonography with superb microvascular imaging-a review

Superb microvascular imaging (SMI) is among the latest doppler ultrasound methods. It uses an advanced clutter filter to eliminate artifacts caused by breathing, movement and retains the low-speed blood signals in microvessels. The great advantage of SMI is that it can intuitively detect very slow blood signals in microvessels, providing clinicians with more significant information about flow distribution in the target area. Therefore, it is speculated that SMI has important application value. The purpose of this article is to outline the application of SMI in different parts of the body.

Is Doppler/Dopplex ultrasonography reliable in the assessment of percutaneous ablative therapies of hepatocellular carcinoma: a prospective cross-sectional study

INTRODUCTION

After hepatocellular carcinoma (HCC) interventional therapies, noninvasive vascular diagnostic imaging [duplex, Color/power Doppler ultrasonography, and triphasic computed tomography (CT)] determines the lesion complete/incomplete ablation. The aim was to analyze the usefulness of duplex, color/power Doppler ultrasonography in HCC ablation after percutaneous ablative therapies (PATs).

METHODS

We included 30 patients with 33 HCCs subjected to duplex/Doppler ultrasonography, ultrasound-guided fine-needle aspiration cytology (FNAC), and triphasic CT, all these before and after PATs.

RESULTS

One week after treatment ended, out of 21 lesions with pretreatment positive color-Doppler, signals disappeared in 19 (90.5%) lesions. Out of 29 lesions with pretreatment positive power-Doppler, signals disappeared in 24 (82.8%). Out of 13 lesions with pretreatment intralesional power/duplex arterial signals, signals disappeared in eight (61.5%). There was a significant correlation (P < 0.05) between power-Doppler arterial signals and FNAC. Before HCC ablation, power-Doppler demonstrated a sensitivity 40% and specificity 96% in HCC detection in relation to FNAC, it had a sensitivity 60% and specificity 85% in HCC detection compared to triphasic CT. After HCC ablation, power-Doppler had a sensitivity and specificity of 100% in viable malignancy detection in relation to FNAC. Power-Doppler had a sensitivity 89% and specificity 93% in residual malignancy detection in relation to triphasic CT.

CONCLUSION

Power-Doppler is a good positive test as intralesional arterial signals in a cirrhotic liver lesion is highly suggestive of HCC. Power-Doppler was sensitive in HCC ablation assessment in pretreatment positive cases only. Both triphasic CT and duplex/Doppler are complementary and the use of different diagnostic modalities after ablation is mandatory.

Application of new ultrasound techniques for focal liver lesions

Ultrasonography (US) has the overwhelming advantages of not entailing radiation exposure and being a noninvasive, real-time, convenient, easy-to-perform, and relatively inexpensive imaging modality. It is used as the first-line imaging modality for screening, detection, and diagnosis of focal liver lesions (FLLs) [small hepatocellular carcinomas (HCCs), in particular]. However, with the increasing demand for accurate and early diagnosis of small HCCs, newer radiologic methods need to be explored to overcome certain limitations of US. For example, the imaging is easily negatively affected by the presence of gas, rib cage, and subcutaneous fat, and is insensitive for capturing the subtle but vital information on the blood flow. It was in response to this need that new promising technologies such as contrast-enhanced ultrasound and fusion imaging were introduced for the detection of liver lesions. This paper presents an overview of the epidemiology and mechanisms of the development of HCCs, with an emphasis on the application of US in the diagnosis and treatment of FLLs. The aim of this article is to provide the state-of-the-art developments in the imaging diagnosis of FLLs and evaluation of ablation treatment of early HCCs. By keeping abreast of these recent advances, we hope that doctors and researchers working in the field of diagnosis/treatment of liver diseases will be able to discriminate benign FLLs such as regenerative nodules and focal nodular hyperplasia from HCCs, so as to avoid unnecessary repeated tumor biopsies and overtreatment. In particular, we expect that small HCCs or precancerous nodules (such as dysplastic nodules) can be accurately diagnosed and appropriately treated even at an early stage.

Superb microvascular imaging technique in depicting vascularity in focal liver lesions: more hypervascular supply patterns were depicted in hepatocellular carcinoma

Purpose

To investigate the capacity of Superb Microvascular Imaging (SMI) to detect microvascular details and to explore the different SMI features in various focal liver lesions (FLLs) and the correlation between SMI and microvessel density (MVD).

Method: Eighty-three liver lesions were enrolled in our study, including 35 hepatocellular carcinomas (HCCs) and 48 non-HCCs. All patients underwent color Doppler flow imaging (CDFI) and SMI examination and were categorized into subgroups according to Adler semiquantitative grading (grade 0–3) or the microvascular morphologic patterns (pattern a-f). The correlation between SMI blood flow signal percentage and MVD was assessed.

Results

Compared with CDFI, SMI detected more high-level blood flow signals (grade 2–3) and more hypervascular supply patterns (pattern e-f) in HCCs (p < 0.05). Furthermore, more hypervascular supply patterns and fewer hypovascular supply patterns were detected in HCC compared with non-HCC (p < 0.05). Based on Adler’s grading or microvascular morphologic patterns, the areas under the receiver operating characteristic curve were 0.696 and 0.760 for SMI, 0.583 and 0.563 for CDFI. The modality of “SMI-microvascular morphologic pattern” showed the best diagnostic performance. There was significant correlation between MVD and the SMI blood flow signal percentage (vascular index, VI) in malignant lesions (r = 0.675, p < 0.05).

Conclusion

SMI was superior to CDFI in detecting microvascular blood flow signals. More hypervascular supply patterns were depicted in HCC than in non-HCC, suggesting a promising diagnostic value for SMI in the differentiation between HCC and non-HCC. Meanwhile, we were the first to demonstrate that SMI blood flow signal percentage (VI) was correlated with MVD in malignant lesions.

Experimental Study of Retention on the Combination of Bifidobacterium with High-Intensity Focused Ultrasound (HIFU) Synergistic Substance in Tumor Tissues

High intensity focused ultrasound (HIFU) has been recently regarded to be a new type of technique for non-invasive ablation of local tumors and HIFU synergists could significantly improve its therapeutic efficiency. The therapeutic efficiency of HIFU is greatly limited by the low retention of HIFU synergists in the target area and short residence time. This study aimed to explore a method to increase the deposition of HIFU synergists in tumors. Cationic lipid nanoparticle can be used to enhance the HIFU ablation effect, but there is still a problem for it that the deposition amount in the tumor tissue is small and the residence time is short. Bifidobacterium is highly biosafe and can be selectively colonized in the hypoxic zone of tumor tissue. Cationic lipid nanoparticles can be observed in vitro by attachment to bifidobacterium by electrostatic adsorption. And the effect of the proliferation of bifidobacterium in tumor tissues on the retention amount and retention time of cationic lipid nanoparticles in vivo was evaluated. Results showed that the cationic lipid nanoparticles were linked to the surface of Bifidobacterium effectively in vitro, while in vivo, the retention amount and retention time of cationic lipid nanoparticles could be increased by Bifidobacterium in tumor tissues, which provided a new method for improving the therapeutic efficiency of HIFU.

A Glycomarker for Short-term Prediction of Hepatocellular Carcinoma: A Longitudinal Study With Serial Measurements

Objectives

Wisteria floribunda agglutinin-positive human Mac-2-binding protein (WFA⁺-M2BP) is a glycomarker. The present community-based long-term follow-up study repeatedly determined the serum WFA⁺-M2BP level and examined its short- and long-term associations with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC).

Methods

A total of 921 participants with antibodies against HCV seropositive, but seronegative for hepatitis B surface antigen were enrolled from seven townships in Taiwan during 1991–1992. The participants were regularly followed and their serum WFA⁺-M2BP levels were measured at baseline and follow-up. HCC was ascertained through active follow-up and computerized data linkage with the National Cancer Registration System until December 31, 2013. Cox proportional hazards and logistic regression models were applied to estimate the magnitude of associations between serum WFA⁺-M2BP levels and HCC.

Results

During a median follow-up of 21.7 years, 122 new-onset HCC cases were identified. Elevated serum WFA⁺-M2BP levels were associated with an increased risk of HCC (p < 0.001). Patients with increasing changes in serum WFA⁺-M2BP levels, relative to their baseline levels, had a 4.36-fold risk of HCC. The areas under receiver operating curves (AUROCs) of WFA⁺-M2BP for predicting HCC showed that the prediction efficacy was significantly higher while closer to HCC diagnosis (p = 0.024). The AUROC was 0.91 for predicting HCC within 1 year by including the predictors of age, sex, alanine aminotransferase, alpha-fetoprotein (AFP) and WFA⁺-M2BP.

Conclusions

Serum WFA⁺-M2BP level may elevate before HCC onset and is a short-term predictor of HCC among patients infected with HCV.

Echo Decorrelation Imaging of Rabbit Liver and VX2 Tumor during In Vivo Ultrasound Ablation

In open surgical procedures, image-ablate ultrasound arrays performed thermal ablation and imaging on rabbit liver lobes with implanted VX2 tumor. Treatments included unfocused (bulk ultrasound ablation, N = 10) and focused (high-intensity focused ultrasound ablation, N = 13) exposure conditions. Echo decorrelation and integrated backscatter images were formed from pulse-echo data recorded during rest periods after each therapy pulse. Echo decorrelation images were corrected for artifacts using decorrelation measured prior to ablation. Ablation prediction performance was assessed using receiver operating characteristic curves. Results revealed significantly increased echo decorrelation and integrated backscatter in both ablated liver and ablated tumor relative to unablated tissue, with larger differences observed in liver than in tumor. For receiver operating characteristic curves computed from all ablation exposures, both echo decorrelation and integrated backscatter predicted liver and tumor ablation with statistically significant success, and echo decorrelation was significantly better as a predictor of liver ablation. These results indicate echo decorrelation imaging is a successful predictor of local thermal ablation in both normal liver and tumor tissue, with potential for real-time therapy monitoring.

Superb microvascular imaging technology for ultrasound examinations: Initial experiences for hepatic tumors

PURPOSE

To explore whether superb microvascular imaging (SMI) technology could be helpful for the evaluation of hepatic tumors.

MATERIALS AND METHODS

Our institutional review board approved this study, and informed consent was obtained from all of the patients. Twenty-three patients with 29 hepatic tumors were enrolled in our study. The tumors consisted of hemangiomas (n=15), focal nodular hyperplasias (FNHs) (n=7), and hepatocellular carcinomas (n=7). All lesions were pathologically (n=2) or radiologically (n=27) confirmed. The mean tumor diameter was 1.9cm (range, 0.9cm to 5.0cm). Using SMI technology, all lesions were scanned and categorized into subgroups according to the flow pattern on the SMI.

RESULTS

The hemangiomas exhibited nodular rim patterns (33%) and spotty dot-like patterns (20%), and both of these findings were very specific for the diagnosis of hemangioma. The FNHs exhibited spoke-wheel patterns (43%) and radiating vessel patterns (29%) that were very specific findings for the diagnosis of FNH. The other tumors did not exhibit any specific patterns on SMI.

CONCLUSION

Evaluations of the inner vascularities of hepatic tumors with the SMI technique were feasible, and the SMI features were significantly different between the different types of hepatic tumors. These differences could aid the diagnoses of hepatic tumors with US.

The Research of Feature Extraction Method of Liver Pathological Image Based on Multispatial Mapping and Statistical Properties

We propose a new feature extraction method of liver pathological image based on multispatial mapping and statistical properties. For liver pathological images of Hematein Eosin staining, the image of R and B channels can reflect the sensitivity of liver pathological images better, while the entropy space and Local Binary Pattern (LBP) space can reflect the texture features of the image better. To obtain the more comprehensive information, we map liver pathological images to the entropy space, LBP space, R space, and B space. The traditional Higher Order Local Autocorrelation Coefficients (HLAC) cannot reflect the overall information of the image, so we propose an average correction HLAC feature. We calculate the statistical properties and the average gray value of pathological images and then update the current pixel value as the absolute value of the difference between the current pixel gray value and the average gray value, which can be more sensitive to the gray value changes of pathological images. Lastly the HLAC template is used to calculate the features of the updated image. The experiment results show that the improved features of the multispatial mapping have the better classification performance for the liver cancer.

Analysis of tissue changes, measurement system effects, and motion artifacts in echo decorrelation imaging

Echo decorrelation imaging, a method for mapping ablation-induced ultrasound echo changes, is analyzed. Local echo decorrelation is shown to approximate the decoherence spectrum of tissue reflectivity. Effects of the ultrasound measurement system, echo signal windowing, electronic noise, and tissue motion on echo decorrelation images are determined theoretically, leading to a method for reduction of motion and noise artifacts. Theoretical analysis is validated by simulations and experiments. Simulated decoherence of the scattering medium was recovered with root-mean-square error less than 10% with accuracy dependent on the correlation window size. Motion-induced decorrelation measured in an ex vivo pubovisceral muscle model showed similar trends to theoretical motion-induced decorrelation for a 2.1 MHz curvilinear array with decorrelation approaching unity for 3-4 mm elevational displacement or 1-1.6 mm range displacement. For in vivo imaging of porcine liver by a 7 MHz linear array, theoretical decorrelation computed using image-based motion estimates correlated significantly with measured decorrelation (r = 0.931, N = 10). Echo decorrelation artifacts incurred during in vivo radiofrequency ablation in the same porcine liver were effectively compensated based on the theoretical echo decorrelation model and measured pre-treatment decorrelation. These results demonstrate the potential of echo decorrelation imaging for quantification of heat-induced changes to the scattering tissue medium during thermal ablation.

Preoperative ultrasound features as prognostic factors for patients with hepatocellular carcinoma

PURPOSE

Ultrasound is the most common imaging tool used to scan the tumours of hepatic carcinoma patients. However, very few studies have been performed to evaluate ultrasound imaging features for predicting tumour prognosis. Therefore, the goal of the current study was to evaluate preoperative ultrasound characteristics as prognostic factors that could affect survival rate after liver resection for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

A total of 104 HCC patients who underwent resection were retrospectively reviewed with regard to their clinical data, preoperative ultrasound characteristics, and survival rate. Preoperative ultrasound parameters included cirrhosis, tumour site, size, echo pattern, portal vein thrombosis, intra-tumour blood flow signal, peak systolic velocity (V max), and resistance index (RI). The Kaplan-Meier method was used to calculate survival. Pre-resection prognostic factors were assessed using univariate log-rank test and a multivariate Cox proportional hazards model.

RESULTS

The median survival was 37 months. The 1-, 3-, and 5-year disease-free survival (DFS) rates were 78.85, 53.85, and 26.92 %, respectively, and the overall survival (OS) rates at 1, 3, and 5 years were 85.58, 69.23, and 46.15 %, respectively. On univariate analysis, shorter survival was associated with mixed echo pattern, larger tumour size, portal vein thrombus, affluent flow signal, and higher V max. Application of the Cox multivariate proportional hazards model indicated that tumour size and blood flow signal in the tumours were independent prognostic factors.

CONCLUSIONS

The overall survival for HCC patients undergoing hepatic resection can be stratified on a sonographic basis of tumour size and intra-nodular vasculature. These prognostic factors may be useful to determine appropriate treatment for HCC patients.

Tolerance of high-intensity focused ultrasound ablation in patients with hepatocellular carcinoma

Background

High-intensity focused ultrasound (HIFU) ablation is a relatively new, noninvasive way of ablation for treating hepatocellular carcinoma (HCC). Emerging evidence has shown that it is effective for the treatment of HCC, even in patients with poor liver function. There is currently no data on the safety limit of HIFU ablation in patients with cirrhosis. However, this information is vital for the selection of appropriate patients for the procedure. We analyzed HCC patients who had undergone HIFU ablation and determined the lower limit of liver function and other patient factors with which HCC patients can tolerate this treatment modality.

Methods

Preoperative variables of 100 patients who underwent HIFU ablation for HCC were analyzed to identify the risk factors in HIFU intolerance in terms of stress-induced complications. Factors that may contribute to postablation complications were compared.

Results

Thirteen (13 %) patients developed a total of 18 complications. Morbidity was mainly due to skin and subcutaneous tissue injuries (n = 9). Five patients had first-degree skin burn, one had second-degree skin burn, and three had third-degree skin burn. Four complications were grade 3a in the Clavien classification and 14 were below this grade. Univariate analysis showed that age (p = 0.022) was the only independent factor in HIFU intolerance.

Conclusions

HIFU ablation is generally well tolerated in HCC patients with cirrhosis. It is safe for Child-Pugh A and B patients and selected Child-Pugh C patients. With this new modality, HCC patients who were deemed unsalvageable by other surgical means in the past because of simultaneous Child-Pugh B or C disease now have a new hope.

Analysis of serum α-fetoprotein-L3% and des-γ carboxyprothrombin markers in cases with misleading hepatocellular carcinoma total α-fetoprotein levels

Serum fraction of α-fetoprotein L3 (AFP-L3%) and des-γ carboxyprothrombin (DCP) are proposed serum markers for the diagnosis of hepatocellular carcinoma (HCC). We evaluated their performance in two patient populations with total AFP levels non-diagnostic for HCC. From a cohort of 150 consecutive patients with HCC, 60 patients with total AFP <200 ng/ml were identified. Additionally, 50 patients with elevated AFP and no radiological evidence of HCC, for at least one year of follow-up, were included. AFP-L3% and DCP were measured by the Liquid Phase Binding Assay System (LiBASys). In cases where AFP-L3% was undetectable, a more sensitive method based on-chip electrokinetic reaction was applied. AFP-L3% was found to be positive in 22 (36.7%) of patients with HCC and 6 (12%) of non-HCC patients. DCP was found to be positive in 26 patients with HCC (43%) and in none of the non-HCC patients. Thirty-six out of sixty (60%) patients with HCC were positive for either AFP-L3% or DCP. With the on-chip technology, AFP-L3% was found to be positive in 10 patients with HCC and in 5 patients without HCC, who tested negative by LiBASys. The final sensitivity of combined AFP, AFP-L3% and DCP testing, in the entire cohort of patients with HCC, was 84%. The specificity of AFP-L3% and DCP in the studied population was 78.5 and 100%, respectively. The addition of AFP-L3% and DCP increased the sensitivity and specificity of total serum AFP for the diagnosis of HCC. The on chip AFP-L3% assay was more sensitive but less specific compared to LiBASys.

Contrast-enhanced ultrasound features of hepatocellular carcinoma of different sizes

AIM: To analyze the contrast-enhanced ultrasound (CEUS) features of hepatocellular carcinoma (HCC) of different sizes.

METHODS: A total of 75 consecutive patients with 90 HCC lesions were enrolled. HCC was examined by CEUS and confirmed by surgery and pathology. These patients were divided into two groups according to the maximum diameter of the lesion: small HCC (SHCC) group (diameter ≤3 cm) and large HCC (LHCC) group (>3 cm). The CEUS characteristics of HCC of different sizes were analyzed retrospectively.

RESULTS: Among 90 lesions, 39 were small HCC (SHCC) and 51 were large HCC (LHCC). During the arterial phase, all the 39 lesions in the SHCC group exhibited hyperenhancement, of which 37 (94.9%) were homogeneously and 2 (5.1%) were inhomogeneously enhanced. Comparatively, all the 51 lesions in the LHCC group exhibited hyperenhancement, of them 27 (52.9%) appeared as homogeneous enhancement, 21 (41.2%) as inhomogeneous enhancement and 6 (6%) as atypical patterns. The enhancement patterns had significant difference during the arterial phase between the two groups (P < 0.05). During the portal phase, 10 (25.6%) lesions were isoechoic and 29 (74.4%) were hypoechoic in the SHCC group, while 7 (13.7%) lesions were hyperechoic, 2 were isoechoic (3.9%), and 42 (82.4%) were hypoechoic in the LHCC group. A significant difference was also noted in enhancement patterns during the portal phase between the two groups (P < 0.05). During the late phase, hypoenhancement was visualized in all the SHCC lesions, while in the LHCC group, hypoenhancement was visualized in 50 (98%) lesions and isoenhancement in 1 (2%) lesion. No significant difference was observed in enhancement patterns during the late phase between the two groups.

CONCLUSION: Our study shows that the enhancement manifestations of HCC are related to lesion size. During the arterial phase, most SHCC lesions show homogeneous enhancement, while inhomogeneous enhancement patterns appear mostly in LHCC lesions. During the portal and late phases, SHCC lesions may be washed out earlier than LHCC ones.

[Malignant focal liver lesions]

Focal liver lesions are a very common occurrence. The detection and differentiation of such lesions is particularly important for the management of oncology patients and is a core task for radiology. The early and conclusive detection of malignant liver processes in a cost-efficient manner and with a low radiation dose for the patient requires systematic and skillful use of the various radiological methods. This review explains the application of current radiological methods for the detection and differentiation of malignant liver lesions and the typical appearance of the most commonly found liver malignancies.

Treatment of advanced hepatocellular carcinoma with very low levels of amplitude-modulated electromagnetic fields

Background:

Therapeutic options for patients with advanced hepatocellular carcinoma (HCC) are limited. There is emerging evidence that the growth of cancer cells may be altered by very low levels of electromagnetic fields modulated at specific frequencies.

Methods:

A single-group, open-label, phase I/II study was performed to assess the safety and effectiveness of the intrabuccal administration of very low levels of electromagnetic fields amplitude modulated at HCC-specific frequencies in 41 patients with advanced HCC and limited therapeutic options. Three-daily 60-min outpatient treatments were administered until disease progression or death. Imaging studies were performed every 8 weeks. The primary efficacy end point was progression-free survival ⩾6 months. Secondary efficacy end points were progression-free survival and overall survival.

Results:

Treatment was well tolerated and there were no NCI grade 2, 3 or 4 toxicities. In all, 14 patients (34.1%) had stable disease for more than 6 months. Median progression-free survival was 4.4 months (95% CI 2.1–5.3) and median overall survival was 6.7 months (95% CI 3.0–10.2). There were three partial and one near complete responses.

Conclusion:

Treatment with intrabuccally administered amplitude-modulated electromagnetic fields is safe, well tolerated, and shows evidence of antitumour effects in patients with advanced HCC.

Posterior acoustic enhancement in hepatocellular carcinoma

OBJECTIVES

The purpose of this study was to assess sonographic appearances of hepatocellular carcinoma with particular attention to posterior acoustic effects.

METHODS

We performed an Institutional Review Board-approved retrospective review of patients with hepatocellular carcinoma who had undergone sonographically guided procedures in our department between 2001 and 2010. A total of 247 masses thought to represent hepatocellular carcinoma were identified; 27 were excluded because of prior angioembolization (altering the sonographic appearance), alternate histologic diagnoses, and incomplete patient information or imaging. Ultimately, 220 masses in 185 patients (138 men and 47 women; average age, 59.1 years) constituted the study population. Preprocedure sonograms were reviewed in consensus by 3 abdominal radiologists; the liver echo texture, lesion echogenicity, and posterior acoustic effect were rated and correlated with patient data.

RESULTS

The average mass size was 3.1 cm (range, 0.7-17 cm). In total, 84.1% of the masses (n = 185) arose in abnormally echogenic/attenuating livers; 54.1% of the masses (n = 119) were predominantly hypoechoic, 23.2% (n = 51) isoechoic, and 22.7% (n = 50) hyperechoic. Target-type morphologic characteristics were noted in 41 masses. Many masses (52.7% [n = 116]) had no specific posterior acoustic effect, but nearly half (46.4%) had either mild (n = 64) or marked (n = 38) posterior acoustic enhancement. The remaining masses (0.9% [n = 2]) had posterior shadowing. Posterior acoustic enhancement was most common among hyperechoic masses (62% with posterior acoustic enhancement), target-type masses (63%), and masses larger than 5 cm (81.5%).

CONCLUSIONS

Posterior acoustic enhancement is present to some degree in almost half of hepatocellular carcinomas, which may relate to the tissue characteristics of the tumor or the cirrhotic liver itself. Attention to this finding, including scanning without spatial compounding, is recommended during sonographic screening for hepatocellular carcinoma in the growing population of patients with liver disease.

Role of contrast-enhanced ultrasound in assessing short-term therapeutic response to high-intensity focused ultrasound in patients with pancreatic carcinoma

AIM: To evaluate the role of contrast-enhanced ultrasound (CEUS) in assessing the short-term therapeutic response to high-intensity focused ultrasound (HIFU) in patients with pancreatic carcinoma.

METHODS: Twenty-nine patients with pancreatic carcinoma received HIFU treatment. CEUS was performed to monitor the response of tumor vessels to HIFU ablation before and after treatment. Meanwhile, 15 patients underwent magnetic resonance imaging (MRI) for comparison.

RESULTS: Before treatment, hypoenhancement was found on CEUS in 23 (79.3%) patients, and isoenhancement to hyperenhancement in 6 (20.7%) patients. Contrast agent washout was significantly faster in pancreatic carcinoma lesions than in normal pancreatic tissue in all cases. Complete non-enhancement area was noted in 8 cases after first HIFU therapy, in 12 cases after second therapy, and in 4 cases after third treatment. Five cases presented hypoenhancement at the boundary of the lesion even after third treatment and needed more treatments. The accuracy of CEUS was similar to that of MRI in assessing the response to HIFU therapy (86.7% vs 93.3 %, P > 0.05).

CONCLUSION: CEUS allows to accurately differentiate tumor necrosis and evaluate response to HIFU treatment in patients with pancreatic carcinoma.

Doppler signals observed during high temperature thermal ablation are the result of boiling

PURPOSE

To elucidate the causation mechanism of Spectral Doppler ultrasound signals (DUS) observed during high temperature thermal ablation and evaluate their potential for image-guidance.

METHODS

Sixteen ex vivo ablations were performed in fresh turkey breast muscle, eight with radiofrequency ablation (RFA) devices, and eight with a conductive interstitial thermal therapy (CITT) device. Temperature changes in the ablation zone were measured with thermocouples located at 1 to 10 mm away from the ablation probes. Concomitantly, DUS were recorded using a standard diagnostic ultrasound scanner. Retrospectively, sustained observations of DUS were correlated with measured temperatures. Sustained DUS was arbitrarily defined as the Doppler signals lasting more than 10 s as observed in the diagnostic ultrasound videos captured from the scanner.

RESULTS

For RFA experiments, minimum average temperature (T1 +/- SD) at which sustained DUS were observed was 97.2 +/- 7.3 degrees C, while the maximum average temperature (T2 +/- SD) at which DUS were not seen was 74.3 +/- 9.1 degrees C. For CITT ablation, T1 and T2 were 95.7 +/- 5.9 degrees C and 91.6 +/- 7.2 degrees C, respectively. It was also observed, especially during CITT ablation, that temperatures remained relatively constant during Doppler activity.

CONCLUSIONS

The value of T1 was near the standard boiling point of water (99.61 degrees C) while T2 was below it. Together, T1 and T2 support the conclusion that DUS during high temperature thermal ablation are the result of boiling (phase change). This conclusion is also supported by the nearly constant temperature histories maintained at locations from which DUS emanated.

[Diagnostic imaging for the screening of hepatocellular carcinoma]

The application of diagnostic imaging is of fundamental importance in the screening, diagnosis and therapy of hepatocellular carcinoma. Among the diagnostic imaging options, ultrasonography has leading role, as it is simple, non-invasive and enables real-time imaging. Screening and active follow up of patients at high risk of primary liver tumors is essential in their early detection. Screening/active follow up of patients at high risk of primary liver tumors means six monthly ultrasound examination. The diagnosis of hepatocellular carcinoma is based on the detection of its characteristic contrast enhancing dynamics, which is possible through dynamic diagnostic imaging procedures (contrast agent enhanced ultrasonography, triphasic CT, MRI). The diagnostic imaging procedure applied depends on the size of the lesions. Examination of the cirrhotic liver remains particularly difficult even with the modern diagnostic imaging procedures, especially concerning the recognition of small early stage hepatocellular carcinoma, and premalignant lesions.

Identification and expression analysis of the aldo-ketoreductase1-B10 gene in primary malignant liver tumours

BACKGROUND & AIMS

The aim of our study was to search for highly up-regulated genes in primary malignant liver tumours and to analyse their expression at the mRNA- and protein level.

METHODS

Using a random-based gene fishing approach (representational difference analysis coupled to array hybridisation) we identified 7 genes high abundantly expressed in hepatocellular carcinoma (HCC) as compared to non-neoplastic liver tissue, among them a gene fragment of the aldo-ketoreductase (AKR) superfamily. Full length cloning and sequencing of the gene fragment identified it as B10 gene of the AKR-family 1 (AKR1B10). For expression analysis on transcriptional level quantitative real-time RT-PCR was performed in 22 HCC and 22 non-neoplastic liver cirrhotic tissues.

RESULTS

Our data demonstrate significantly higher expression levels of AKR1B10-mRNA in HCC compared to non-tumourous cirrhotic liver tissue (p<0.0001). To evaluate its protein expression in primary malignant liver tumours, we investigated tissue arrays of 210 HCC and 51 cholangiocarcinomas (CC) by immunohistochemistry, using a monoclonal antibody against AKR1B10. Protein staining of AKR1B10 was significantly increased in well and moderately differentiated tumours compared to corresponding non-neoplastic liver tissue (p=0.023). However, AKR1B10-staining decreased in advanced, low differentiated tumours with a significant inverse correlation between AKR1B10-staining and tumour proliferation, indicated by Ki67 (MIB-1) staining (r=-0.89, p=0.02).

CONCLUSION

The over-expression of AKR1B10 in early stages of well and moderately differentiated tumours and its down-regulation in advanced tumour-stages with low grade of differentiation demonstrated that AKR1B10 may be a helpful marker for differentiation and proliferation of HCC and CC.

Surveillance and diagnosis of hepatocellular carcinoma in patients with cirrhosis

Early identification of hepatocellular carcinoma (HCC) is more frequent because of surveillance programs for HCC worldwide. The optimal strategy of surveillance in cirrhosis is a current topical issue. In terms of diagnosis, recent advances in non-invasive imaging technology, including various techniques of harmonic ultrasound, new ultrasound contrast agents, multi-slice helical computed tomography and rapid high quality magnetic resonance, have all improved the accuracy of diagnosis. Consequently the role of liver biopsy in diagnosis of HCC has declined. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. However, with recent advances in genomics and proteomics a great number of potential serum and tissue markers have been identified and are being developed as new candidate markers for both diagnosis and prognosis of hepatocellular carcinoma, and may increase the need for liver biopsy.

Contrast-enhanced ultrasound in assessment of the therapeutic efficacy of high intensity focused ultrasound in treating hepatocellular carcinoma

AIM: To evaluate the role of contrast-enhanced ultrasonography in assessing the short-term therapeutic response of hepatocellular carcinoma with high intensity focused ultrasound (HIFU).

METHODS: Thirty two patients with hepatocellular carcinoma (HCC) received HIFU treatments including 23 part-covered treatments and 9 full-covered treatments. Contrast-enhanced ultrasound (CEUS) imaging was performed to monitor the response of tumor vessels to HIFU ablation before the treatment and 1-4 d after the treatment separately. Simultaneously, all patients underwent routine US for comparison.

RESULTS: Compared with tumor images in the patients before HIFU which showed multiple blood flow signals, clinical images showed an abrupt interruption, followed by the cessation of blood flow within the tumor vessels after HIFU treatment, demonstrating that homogeneous coagulative necrosis occurred in the treatment area. According to the final diagnosis as gold standard, the accuracy of CEUS for HIFU was much better than the conventional ultrasonography (90.6% vs 46.9%, P < 0.05).

CONCLUSION: CEUS can accurately differentiate tumor necrosis and evaluate therapeutic efficacy of HIFU.

Imaging in liver transplantation

The aim of this study was to illustrate the role of non-invasive imaging tools such as ultrasonography, multi-detector row computed tomography, and magnetic resonance imaging in the evaluation of pediatric and adult liver recipients and potential liver donors, and in the detection of potential complications arising from liver transplantation.

Evidence-based diagnosis and locoregional therapy for hepatocellular carcinoma

Early identification of hepatocellular carcinoma (HCC) is crucial to improving the results of therapy and for patients to be eligible for liver transplantation. Recent advances in noninvasive imaging technology include various techniques of harmonic ultrasound, new ultrasound contrast agents, multislice helical computed tomography and rapid high-quality magnetic resonance. The imaging diagnosis relies on the hallmark of arterial hypervascularity with portal venous washout. Since the use of better radiological techniques has improved the accuracy of noninvasive diagnosis, the role of liver biopsy in the diagnosis of HCC has declined. With recent advances in genomics and proteomics, a great number of potential markers have been identified and developed as new candidate markers for HCC. Locoregional therapies currently constitute the best options for early nonsurgical treatment of HCC. Percutaneous ethanol injection shows similar results to resection surgery for single tumors less than 3 cm in diameter. Radiofrequency ablation is superior to percutaneous ethanol injection in terms of local recurrence. Transarterial chemoembolization is currently the most common approach for the management of HCC without curative options since it improves patient survival, but the optimal embolizing agent, length of interval between sessions and whether the chemotherapeutic agent has any effect have not yet been determined. Combining transarterial chemoembolization with antiangiogenic agents, as well as with other techniques, such as radiofrequency ablation, may improve the results. Injection of radioisotopes such as yttrium-90, via the hepatic artery, may be particularly useful in patients with portal vein thrombosis. Comparisons with other transarterial techniques are needed.

Novel therapeutic approaches for hepatocellulcar carcinoma: fact and fiction

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and accounts for 80%-90% of this class of malignancy. So far, understanding of its pathogenesis and effective therapeutic methods are rather limited. In this issue, 11 invited review articles are published to address current advance of underlying molecular mechanisms for the development of HCC, and novel therapeutic approaches for HCC. This series of review articles provide an in-depth unders-tanding of HCC that has led to or may lead to the development of novel therapies for HCC.