The role of quantitation of real-time 3-dimensional contrast-enhanced ultrasound in detecting microvascular invasion: an in vivo study

Histopathological diagnosis of microvascular invasion in hepatocellular carcinoma: Is it reliable?

BACKGROUND

Microvascular invasion (MVI) is a critical prognostic factor for postoperative hepatocellular carcinoma recurrence, but the reliability of its current pathological diagnosis remains uncertain.

AIM

To evaluate the accuracy of current 7-point sampling methods and propose an optimal pathological protocol using whole-mount slide imaging (WSI) for better MVI detection.

METHODS

We utilized 40 New Zealand white rabbits to establish VX2 liver tumor models. The entire tumor-containing liver lobe was subsequently obtained, following which five different sampling protocols (A-E) were employed to evaluate the detection rate, accuracy, quantity, and distribution of MVI, with the aim of identifying the optimal sampling method.

RESULTS

VX2 liver tumor models were successfully established in 37 rabbits, with an incidence of MVI of 81.1% (30/37). The detection rates [27% (10/37), 43% (16/37), 62% (23/37), 68% (25/37), and 93% (14/15)] and quantity (15, 36, 107, 125, and 395) of MVI increased significantly from protocols A to E. The distribution of MVI showed fewer MVIs farther away from the tumor, but the percentage of MVI detected quantity gradually increased from 6.7% to 48.3% in the distant nonneoplastic liver tissue from protocols A to E. Protocol C was identified as the optimal sampling method by comparing them in sequence. The sampling protocol of three consecutive interval WSIs at the tumor center (WSI3) was further screened to determine the optimal number of WSIs. Protocol A (7-point sampling method) exhibited only 46% accuracy and a high false-negative rate of 67%. Notably, the WSI3 protocol improved the accuracy to 78% and decreased the false-negative rate to 27%.

CONCLUSION

The current 7-point sampling method has a high false-negative rate in MVI detection. In contrast, the WSI3 protocol provides a practical and effective approach to improve MVI diagnostic accuracy, which is crucial for hepatocellular carcinoma diagnosis and treatment planning.

Research progresses of imaging studies on preoperative prediction of microvascular invasion of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the predominant form of primary liver cancer, accounting for approximately 90% of liver cancer cases. It currently ranks as the fifth most prevalent cancer worldwide and represents the third leading cause of cancer-related mortality. As a malignant disease with surgical resection and ablative therapy being the sole curative options available, it is disheartening that most HCC patients who undergo liver resection experience relapse within five years. Microvascular invasion (MVI), defined as the presence of micrometastatic HCC emboli within liver vessels, serves as an important histopathological feature and indicative factor for both disease-free survival and overall survival in HCC patients. Therefore, achieving accurate preoperative noninvasive prediction of MVI holds vital significance in selecting appropriate clinical treatments and improving patient prognosis. Currently, there are no universally recognized criteria for preoperative diagnosis of MVI in clinical practice. Consequently, extensive research efforts have been directed towards preoperative imaging prediction of MVI to address this problem and the relative research progresses were reviewed in this article to summarize its current limitations and future research prospects.

A nomogram based on multi-modal ultrasound for prediction of microvascular invasion and recurrence of hepatocellular carcinoma

OBJECTIVE

To establish and validate a nomogram based on multi-modal ultrasound for preoperative prediction of microvascular invasion (MVI) in hepatocellular carcinoma (HCC), and to assess the ability thereof to stratify recurrence-free survival (RFS).

METHODS

A total of 287 HCC patients undergoing surgical resection were prospectively enrolled, including 210 patients in the training cohort and 77 patients in the test cohort. All patients underwent conventional ultrasound, contrast-enhanced ultrasonography, and shear wave elastography examinations within one week before surgery. Taking histopathological examination result as the reference standard, independent factors associated with MVI in HCC were determined by logistic regression and a nomogram was established and further evaluated. The Kaplan-Meier method was used to analyze the prognostic value of histologic MVI status and nomogram-predicted MVI status.

RESULTS

Multivariate analysis showed that tumor diameter, echogenicity, tumor shape, arterial phase peritumoral enhancement and enhancement level in portal venous phase were independent predictors of MVI (all p < 0.05). The nomogram based on these variables showed good discrimination and calibration with the areas under the receiver operating characteristic curve (AUC) of 0.821 (0.762-0.870) and 0.789 (0.681-0.874) in the training and test cohorts. There was a significant difference in RFS between the nomogram-predicted MVI positive and the nomogram-predicted MVI negative groups in training and test cohorts (p < 0.001 and p = 0.004 respectively).

CONCLUSIONS

The multimodal ultrasound features were effective imaging markers for preoperative prediction of MVI of HCC and the nomogram might be an effective tool to stratify the risk of recurrence and guide the individualized treatment of HCC.

Early evaluation of treatment response to transarterial chemoembolization in patients with advanced hepatocellular carcinoma: The role of dynamic three-dimensional contrast-enhanced ultrasound

BACKGROUND

Dynamic three-dimensional contrast-enhanced ultrasound (3D-CEUS) with quantitative analysis is available in recent years. It can reduce the quantitative sampling error caused by the inconsistency of different sections in order to evaluate local treatment response of hepatocellular carcinoma (HCC) accurately.

OBJECTIVE

To investigate the value of dynamic 3D-CEUS in evaluating the early response to transarterial chemoembolization (TACE) treatment in patients with advanced HCC lesions.

METHODS

In this prospective study, both two-dimensional (2D) CEUS and dynamic 3D-CEUS were performed on 40 HCC patients who scheduled for TACE at baseline (T0) and 1-3 days (T1) after treatment. Tumor microvascular perfusion changes were assessed by CEUS time-intensity curve (TIC) and quantitative parameters. According to contrast-enhanced computed tomography (CT) and magnetic resonance (MR) imaging 1 month after treatment results, patients were divided into responders and non-responders groups. The changes of perfusion parameters of both 2D-CEUS and 3D-CEUS were compared between responders and non-responders groups before and after TACE treatment.

RESULTS

Before and after TACE treatment, no significant difference in maximum diameter of HCC lesions between the two groups could be found. There were more significant differences and ratios of perfusion parameters in 3D-CEUS quantitative analysis than in 2D-CEUS. The mutual significant differences and ratios of 2D-CEUS and 3D-CEUS included peak intensity (PI) difference, PI ratio, ratio of area under the curve (A), ratio of area under the wash-out part (AWO) and slope (S) difference. The former 4 corresponding parameters were better on 3D-CEUS than on 2D-CEUS.

CONCLUSION

Dynamic 3D-CEUS can be used as a potential imaging method to evaluate early treatment response to TACE in advanced HCC patients.

Nomogram For Preoperative Prediction Of Microvascular Invasion Risk In Hepatocellular Carcinoma

Objective

To preoperatively predict the microvascular invasion (MVI) risk in hepatocellular carcinoma (HCC) using nomogram.

Methods

A retrospective cohort of 513 patients with HCC hospitalized at Xiangya Hospital between January 2014 and December 2018 was included in the study. Univariate and multivariate analysis was performed to identify the independent risk factors for MVI. Based on the independent risk factors, nomogram was established to preoperatively predict the MVI risk in HCC. The accuracy of nomogram was evaluated by using receiver operating characteristic (ROC) curve, calibration curve and decision curve analysis (DCA).

Results

Tumor size (OR=1.17, 95% CI: 1.11–1.23, p<0.001), preoperative AFP level greater than 155 ng/mL (OR=1.65, 95% CI: 1.13–2.39, p=0.008) and NLR (OR=1.14, 95% CI: 1.00–1.29, p=0.042) were the independent risk factors for MVI. Incorporating these 3 factors, nomogram was established with the concordance index of 0.71 (95% CI, 0.66–0.75) and well-fitted calibration curves. DCA confirmed that using this nomogram added more benefit compared with the measures that treat all patients or treat none patients. At the cutoff value of predicted probability ≥0.44, the model demonstrated sensitivity of 61.64%, specificity of 71.53%, positive predictive value (PPV) of 64.13%, and negative predictive value (NPV) of 69.31%.

Conclusion

Nomogram was established for preoperative prediction of the MVI risk in HCC patients, and better therapeutic choice will be made if it was applied in clinical practice.

Assessment of angiogenesis in rabbit orthotropic liver tumors using three-dimensional dynamic contrast-enhanced ultrasound compared with two-dimensional DCE-US

OBJECTIVES

To evaluate quantitative three-dimensional (3D) dynamic contrast-enhanced ultrasound (DCE-US) in the assessment of tumor angiogenesis using an orthotropic liver tumor model.

METHODS

Nine New Zealand white rabbits with liver orthotropic VX2 tumors were established and imaged by two-dimensional (2D) and 3D DCE-US after SonoVue^® bolus injections. The intraclass correlation coefficients of perfusion parameters, including peak intensity (PI), mean transit time, time to peak, and area under the curve, were calculated based on time-intensity curve. The percentage area of microvascular (PAMV) and the expression of vascular endothelial growth factor (VEGF) were both evaluated by immunohistochemical analysis and weighted by the tumor activity area ratio. Correlations between quantitative and histologic parameters were analyzed.

RESULTS

The reproducibility of 3D DCE-US quantitative parameters was excellent (ICC 0.91-0.99); but only PI showed high reproducibility (ICC 0.97) in 2D. None of the parameters of quantitative 2D DCE-US were significantly correlated with weighted PAMV or VEGF. For 3D DCE-US, there was a positive correlation between PI and weighted PAMV (r = 0.74, P = 0.04) as well as VEGF (r = 0.79, P = 0.02).

CONCLUSION

Quantitative parameters of 3D DCE-US show feasibility, higher reproducibility and accuracy for the assessment of tumor angiogenesis using an orthotropic liver tumor model compared with 2D DCE-US.

Feasibility of dynamic three-dimensional contrast-enhanced ultrasound in focal liver lesions: Image quality evaluation and correlation of quantification with two-dimensional contrast-enhanced ultrasound

BACKGROUND

Dynamic three-dimensional contrast-enhanced ultrasound (3D-CEUS) with quantitative analysis is updated in recent years.

OBJECTIVE

To explore the feasibility of dynamic 3D-CEUS in evaluation of dynamic vascular patterns of focal liver lesions (FLL), and to analyze the correlation of time-intensity curve (TIC) parameters between dynamic 3D-CEUS and two-dimensional CEUS (2D-CEUS).

METHODS

Dynamic 3D-CEUS and 2D-CEUS were both carried out in 106 FLL cases with SonoVue. Divided into arterial, portal and late phases, dynamic 3D-CEUS image quality of 106 FLLs were scored by 2 readers separately and graded according to the overall score. The 2D-CEUS and identical 3D-CEUS TIC parameters of the same FLL were compared and the correlation of these parameters were analyzed.

RESULTS

A satisfactory correlation (0.953) and a good inter-observer agreement (0.700) of 2 readers were achieved by using five-point score scale to image quality in 3 phases of dynamic 3D-CEUS. The boundaries of FLLs were clearest in arterial phase on dynamic 3D-CEUS. The depth and vascularization of FLLs only had influence on its image quality in only arterial phase (P = 0.002 and 0.000 respectively). The comparison of quantification between dynamic 3D-CEUS and 2D-CEUS of 56 FLLs were also underwent. Interclass correlation coefficient (ICC) of mean transit time (MTT) and time to peak (TP), were both 0.96, and Pearson correlation coefficients of all 5 TIC parameters were no less than 0.90 between dynamic 3D-CEUS and 2D-CEUS.

CONCLUSION

Dynamic 3D-CEUS is technically feasible and can be used for clinical evaluation of the perfusion of FLL avoiding adverse factors of sampling. Quantitative 3D-CEUS parameters are stable and reliable, and have good correlation with those of 2D-CEUS.