MRI assessment of hepatocellular carcinoma after locoregional therapy

Is intravoxel incoherent motion magnetic resonance imaging useful for predicting hepatocellular cancer recurrence and invasion of the peritumoral zone after transarterial chemoembolization?

PURPOSE

We evaluated the potential role of intravoxel incoherent motion (IVIM) in predicting the therapeutic response and peritumoral invasion in patients with hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE).

MATERIALS AND METHODS

We enrolled 47 patients previously treated with TACE between January 2018 and December 2021. We evaluated the IVIM-derived metrics [apparent diffusion coefficient (ADC), D, D*, f] in the TACE-treated, peritumoral, and parenchymal areas of the liver.

RESULTS

The ADCtace and Dtace values (1.13 ± 0.22 × 10-3 m2/s vs 0.95 ± 0.13 × 10-3 mm2/s, 1.28 ± 0.27 × 10-3 mm2/s vs 1.07 ± 0.3 × 10-3 mm2/s, P < 0.05) were higher in the non-progressing groups than in the progressing groups in the TACE-treated areas. Dpt represented the D values in the peritumoral area, which can distinguish between the progressive and non-progressive groups with an AUC of 0.73. The Dstd values, which represent the D values in the peritumoral area normalized by the D values in the liver parenchyma in the non-progressing groups (1.10 ± 0.14 × 10-3 mm2/s), were higher than those of the progressing groups (0.93 ± 0.17 × 10-3 mm2/s).

CONCLUSION

The ADCtace, Dtace, Dpt, and Dstd values reflect the changes in the microstructure of the progressive and non-progressive groups after TACE treatment, showing robust diagnostic performances in predicting the therapeutic response and peritumoral invasion.

Role of intravoxel incoherent motion (IVIM) imaging in response assessment of hepatocellular carcinoma after transarterial chemoembolization (TACE) - A prospective study

INTRODUCTION

Response evaluation of hepatocellular carcinoma (HCC) currently is based on arterial phase enhancement which doesn't take into microstructural changes in the tumor after trans-arterial chemoembolization (TACE).

AIM

This prospective study was conducted to assess the feasibility and efficacy of intravascular incoherent motion imaging (IVIM) in response evaluation of HCC after TACE. 39 cirrhotic patients with 48 HCC underwent MR imaging 1 week within and 6weeks after TACE. IVIM parameters like Dslow (true diffusion), Dfast (pseudodiffusion), perfusion fraction and ADC were measured prior to and postTACE. The pre and post TACE values in LR-TR (LIRADS - treatment response) nonviable and viable lesions were compared using paired t-tests. ROC curve analysis was done to calculate sensitivity and specificity and propose cut-off values.

RESULT

Non-viable lesions showed a significant increase in Dslow (1.208 ± 0.581 vs 1.560 ± 0.494, P-value -.0207) and ADC (1.37 ± 0.53 vs 1.65 ± 0.4287, P value .016) after TACE. There was also significant decrease in Dfast (33.7 ± 10.4 vs 23.75 ± 12.13, P value .0005) and f (19.92 ± 10.54 vs 12.9 ± 10.41, P value .012) values after TACE in non-viable lesions compared to viable lesions. The change in true diffusion had the highest AUC (0.741) among IVIM parameters with greater than 0.075 increase between preTACE and postTACE values having a sensitivity and specificity of 81.8% and 60% respectively for complete response.

CONCLUSION

IVIM imaging is feasible to assess the response in HCC after TACE. True diffusion is more sensitive and specific than apparent diffusion in evaluating the response.

Machine-Learning-Based Radiomic Features on Pre-Ablation MRI as Predictors of Pathologic Response in Patients with Hepatocellular Carcinoma Who Underwent Hepatic Transplant

Background: The aim was to investigate the role of pre-ablation tumor radiomics in predicting pathologic treatment response in patients with early-stage hepatocellular carcinoma (HCC) who underwent liver transplant. Methods: Using data collected from 2005–2015, we included adult patients who (1) had a contrast-enhanced MRI within 3 months prior to ablation therapy and (2) underwent liver transplantation. Demographics were obtained for each patient. The treated hepatic tumor volume was manually segmented on the arterial phase T1 MRI images. A vector with 112 radiomic features (shape, first-order, and texture) was extracted from each tumor. Feature selection was employed through minimum redundancy and maximum relevance using a training set. A random forest model was developed based on top radiomic and demographic features. Model performance was evaluated by ROC analysis. SHAP plots were constructed in order to visualize feature importance in model predictions. Results: Ninety-seven patients (117 tumors, 31 (32%) microwave ablation, 66 (68%) radiofrequency ablation) were included. The mean model for end-stage liver disease (MELD) score was 10.5 ± 3. The mean follow-up time was 336.2 ± 179 days. Complete response on pathology review was achieved in 62% of patients at the time of transplant. Incomplete pathologic response was associated with four features: two first-order and two GLRM features using univariate logistic regression analysis (p < 0.05). The random forest model included two radiomic features (diagnostics maximum and first-order maximum) and four clinical features (pre-procedure creatinine, pre-procedure albumin, age, and gender) achieving an AUC of 0.83, a sensitivity of 82%, a specificity of 67%, a PPV of 69%, and an NPV of 80%. Conclusions: Pre-ablation MRI radiomics could act as a valuable imaging biomarker for the prediction of tumor pathologic response in patients with HCC.

A Review of Quantitative Ultrasound-Based Approaches to Thermometry and Ablation Zone Identification Over the Past Decade

Percutaneous thermal therapy is an important clinical treatment method for some solid tumors. It is critical to use effective image visualization techniques to monitor the therapy process in real time because precise control of the therapeutic zone directly affects the prognosis of tumor treatment. Ultrasound is used in thermal therapy monitoring because of its real-time, non-invasive, non-ionizing radiation, and low-cost characteristics. This paper presents a review of nine quantitative ultrasound-based methods for thermal therapy monitoring and their advances over the last decade since 2011. These methods were analyzed and compared with respect to two applications: ultrasonic thermometry and ablation zone identification. The advantages and limitations of these methods were compared and discussed, and future developments were suggested.

Current Imaging Diagnosis of Hepatocellular Carcinoma

Simple Summary

The role of imaging in the management of hepatocellular carcinoma (HCC) has significantly evolved and expanded beyond the plain radiological confirmation of the tumor based on the typical appearance in a multiphase contrast-enhanced CT or MRI examination. The introduction of hepatobiliary contrast agents has enabled the diagnosis of hepatocarcinogenesis at earlier stages, while the application of ultrasound contrast agents has drastically upgraded the role of ultrasound in the diagnostic algorithms. Newer quantitative techniques assessing blood perfusion on CT and MRI not only allow earlier diagnosis and confident differentiation from other lesions, but they also provide biomarkers for the evaluation of treatment response. As distinct HCC subtypes are identified, their correlation with specific imaging features holds great promise for estimating tumor aggressiveness and prognosis. This review presents the current role of imaging and underlines its critical role in the successful management of patients with HCC.

Abstract

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer related death worldwide. Radiology has traditionally played a central role in HCC management, ranging from screening of high-risk patients to non-invasive diagnosis, as well as the evaluation of treatment response and post-treatment follow-up. From liver ultrasonography with or without contrast to dynamic multiple phased CT and dynamic MRI with diffusion protocols, great progress has been achieved in the last decade. Throughout the last few years, pathological, biological, genetic, and immune-chemical analyses have revealed several tumoral subtypes with diverse biological behavior, highlighting the need for the re-evaluation of established radiological methods. Considering these changes, novel methods that provide functional and quantitative parameters in addition to morphological information are increasingly incorporated into modern diagnostic protocols for HCC. In this way, differential diagnosis became even more challenging throughout the last few years. Use of liver specific contrast agents, as well as CT/MRI perfusion techniques, seem to not only allow earlier detection and more accurate characterization of HCC lesions, but also make it possible to predict response to treatment and survival. Nevertheless, several limitations and technical considerations still exist. This review will describe and discuss all these imaging modalities and their advances in the imaging of HCC lesions in cirrhotic and non-cirrhotic livers. Sensitivity and specificity rates, method limitations, and technical considerations will be discussed.

Application of intravoxel incoherent motion diffusion-weighted imaging in hepatocellular carcinoma

The morbidity and mortality of hepatocellular carcinoma (HCC) rank 6^th and 4^th, respectively, among malignant tumors worldwide. Traditional diffusion-weighted imaging (DWI) uses the apparent diffusion coefficient (ADC) obtained by applying the monoexponential model to reflect water molecule diffusion in active tissue; however, the value of ADC is affected by microcirculation perfusion. Using a biexponential model, intravoxel incoherent motion (IVIM)-DWI quantitatively measures information related to pure water molecule diffusion and microcirculation perfusion, thus compensating for the shortcomings of DWI. The number of studies examining the application of IVIM-DWI in patients with HCC has gradually increased over the last few years, and many results show that IVIM-DWI has vital value for HCC differentiation, pathological grading, and predicting and evaluating the treatment response. The present study principally reviews the principle of IVIM-DWI and its research progress in HCC differentiation, pathological grading, predicting and evaluating the treatment response, predicting postoperative recurrence and predicting gene expression prediction.

Additive role of dynamic subtraction MRI in assessment of unresolved HCC post-radiofrequency ablation

Background

Malignant Hepatocellular carcinoma (HCC) is one amongst the foremost widespread cancers within the world. Radiofrequency ablation (RFA) is that the most generally used substitute tool for hepatic carcinoma treatment. Monitoring tumoral response to loco-regional therapy is a vital mission in oncological imaging. Dynamic contrast enhanced MR and recently added subtraction imaging technique improve assessment of the ablated hepatic focal lesions. The aim of this study is that the evaluation of the role of Subtraction MRI within the detection of recurrent or residual tumoral viability after RF ablation.

Results

Fifty patients were conducted during this retrospective study, all underwent RFA for 76 hepatic focal lesions and underwent Dynamic MRI study 1 month after ablation. Subtraction imaging was then performed. MRI images were interpreted by two readers who are experienced in hepatic imaging. The primary reader interpreted the standard Dynamic MRI and was blinded to the subtraction sequences; the second reader interpreted both Dynamic and Subtraction MRI images. the primary reader detected 49 resolved cases by dynamic MRI, while the second reader detected residual activity in 6 cases out of 49 via subtraction dynamic MRI (added value). The second reader agreed with first reader in 43 cases (agreement).The first reader detected 27 residual cases by dynamic MRI. The second reader disagreed with first reader in 11 cases appeared resolved out of 27 via subtraction dynamic MRI (added value). The second reader agreed with first reader in residual activity in 16 cases (agreement).The statistical analysis of those results revealed a big additive value of the subtraction imaging to the dynamic MRI (P < 0.001) with moderate degree of agreement between the 2 diagnostic tools (Kappa value = 0.491). This implies that Subtraction MRI significantly improves the reader confidence level within the assessment of treatment response following loco-regional therapies for HCC.

Conclusion

Dynamic Subtraction MRI is a powerful detector for real enhancement in treated HCC lesions after radiofrequency ablation and hence increasing the degree of readers’ confidence and accuracy of treated lesions in follow-up studies. So it's recommended to feature this powerful tool as a routine to any or all Dynamic MRI studies of the Liver.

The role of dynamic and diffusion MR imaging in therapeutic response assessment after microwave ablation of hepatocellular carcinoma using LI-RADS v2018 treatment response algorithm

Background

Hepatocellular carcinoma (HCC) is considered as one of the major causes of morbidity and mortality worldwide. Microwave ablation (MWA) is a widely used treatment option having less morbidity and complications as compared with surgery and liver transplantation. MRI is the most widely used modality in the assessment of treatment response after MWA. Currently, LI-RADS v2018 algorithm is considered the cornerstone in daily clinical practice for assessment of the treatment response after locoregional therapy. The aim of the study was to assess the role of dynamic MRI and diffusion imaging in the assessment of treatment response and detection of tumor viability following microwave ablation therapy of HCC according to LI-RADS v2018 treatment response algorithm.

Results

This retrospective study was performed over 45 HCC lesions underwent MWA as the only therapeutic procedure and followed up by dynamic MRI with diffusion images and then classified according to the LI-RADS treatment response criteria into LR-TR viable and LR-TR nonviable groups. All the malignant lesions found in this study showed arterial phase hyperenhancment (APHE), whether in the early or late arterial phases. Delayed washout was found in all malignant lesions as well. In the diffusion analysis, the mean ADC value for the malignant lesions was 0.900 ± 0.126 × 10-3 mm2/s, while the mean ADC of the treatment-related specific benign parenchymal enhancement was 1.284 ± 0.129 × 10-3 mm2/s with a significant statistical difference in between (P = 0.0001) and a cutoff value of 1.11 × 10-3 mm2/s. Our findings showed that the dynamic MRI has 100% sensitivity, 93.5% specificity, 87.5% PPV, and 100% NPV in the detection of tumoral activity compared with 71.43% sensitivity, 93.55% specificity, 83.33% PPV, and 87.88% NPV for diffusion images.

Conclusion

LI-RADS 2018 provides a treatment response algorithm superior to the previously used assessment criteria. MRI with dynamic contrast-enhanced technique and diffusion imaging provide a powerful tool in the evaluation of treatment response after microwave ablation of hepatocellular carcinoma using the LI-RADS treatment response criteria and is considered a reliable method in differentiating between the recurrent or residual malignant lesions and the posttreatment benign liver changes.

Hepatocellular Carcinoma in 2021: An Exhaustive Update

Primary liver cancer is a challenging global health concern with an estimated more than a million persons to be affected annually by the year 2025. The commonest type is hepatocellular carcinoma (HCC), which has been increasing in incidence the world over, mostly due to chronic viral hepatitis B infection. In the last decade, paradigm changes in the etiology, understanding of molecular biology, and pathogenesis, including the role of gut microbiota; medical and surgical treatments, and outcome trends are notable. The application of omics-based technology has helped us unlock the molecular and immune landscape of HCC, through which novel targets for drug treatment such as immune-checkpoint inhibitors have been identified. Novel tools for the surveillance and diagnosis of HCC include protein-, genomics-, and composite algorithm-based clinical/biomarker panels. Magnetic resonance imaging-based novel techniques have improved HCC diagnosis through ancillary features that enhance classical criteria while positron emission tomography has shown value in prognostication. Identification of the role of gut microbiota in the causation and progression of HCC has opened areas for novel therapeutic research. A select group of patients still benefit from modified surgical and early interventional radiology treatments. Improvements in radiotherapy protocols, identification of parameters of futility among radiological interventions, and the emergence of novel first-line systemic therapies that include a combination of antiangiogenic and immune-checkpoint inhibitors have seen a paradigm change in progression-free and overall survival. The current review is aimed at providing exhaustive updates on the etiology, molecular biology, biomarker diagnosis, imaging, and recommended treatment options in patients with HCC.

Monitoring the therapeutic efficacy of CA4P in the rabbit VX2 liver tumor using dynamic contrast-enhanced MRI

PURPOSE

The present work aims to evaluate whether dynamic contrast-enhanced magnetic resonance Imaging (DCE-MRI) can monitor non-invasively the blocking effect on microvessels of the Combretastatin-A4-phosphate (CA4P) and assess the therapeutic efficacy.

METHODS

Forty rabbits were implanted the VX2 tumors specimens. Two weeks later, serial MRI (T1 weighted image, T2 weighted image and DCE) were performed at 0 h, 4 h, 24 h, 3 d and 7 d after CA4P (10 mg/kg) or saline treatment. The parameters of DCE (Ktrans, Kep, Ve and iAUC60) of enhancement tumor portions were measured. Then all the tumor samples were stained to count microvessel density (MVD). At last, two-way repeated measures ANOVA was used to analyze the difference between and within groups. The correlation between the Ktrans, Kep, Ve, iAUC60 and MVD was analyzed by using the Pearson correlation analysis and Spearman's rank correlation.

RESULTS

The Ktrans and iAUC60 in the CA4P group were lower than the values of the control group at 4 h after treatment, which have significant differences (D-value: -0.133 min-1, 95%CI: -0.169~-0.097 min-1，F = 59.109, p < 0.001 for Ktrans; D-value: -10.533 mmol/sec, 95%CI: -17.147~-3.919 mmol/sec，F = 11.110, and p = 0.003 for iAUC60). In the CA4P group, the Ktrans and iAUC60 reached the minimum values at 4 h. There were significant differences between 4 h and other different time points of the Ktrans and iAUC60 in the treatment group (all p < 0.01). The parameters Ktrans (r = 0.532, P = 0.016 and r = 0.681, P = 0.001, respectively) and iAUC60 (r = 0.580, P = 0.007 and r = 0.568, P = 0.009, respectively) of 7 days showed correlation with MVD in both groups, while Kep and Ve did not show correlation with MVD (P > 0.05).

CONCLUSION

The blocking effect of microvessels after CA4P treatment can be evaluated by DCE-MRI, and the parameters of quantitative Ktrans and semi- quantitative iAUC60 can assess the change of the tumor angiogenesis noninvasively.

SBRT for HCC: Overview of technique and treatment response assessment

Stereotactic body radiation therapy (SBRT) is an emerging locoregional treatment (LRT) modality used in the management of patients with hepatocellular carcinoma (HCC). The decision to treat HCC with LRT is evaluated in a multidisciplinary setting, and the specific LRT chosen depends on the treatment intent, such as bridge-to-transplant, down-staging to transplant, definitive/curative treatment, and/or palliation, as well as underlying patient clinical factors. Accurate assessment of treatment response is necessary in order to guide clinical management in these patients. Patients who undergo LRT need continuous imaging evaluation to assess treatment response and to evaluate for recurrence. Thus, an accurate understanding of expected post-SBRT imaging findings is critical to avoid misinterpreting normal post-treatment changes as local progression or viable tumor. SBRT-treated HCC demonstrates unique imaging findings that differ from HCC treated with other forms of LRT. In particular, SBRT-treated HCC can demonstrate persistent APHE and washout on short-term follow-up imaging. This brief review summarizes current evidence for the use of SBRT for HCC, including patient population, SBRT technique and procedure, tumor response assessment on contrast-enhanced cross-sectional imaging with expected findings, and pitfalls in treatment response evaluation.

Evaluation of Hepatocellular Carcinoma Treatment Response After Locoregional Therapy

Locoregional therapy (LRT) for hepatocellular carcinoma can be used alone or with other treatment modalities to reduce rates of progression, improve survival, or act as a bridge to cure. As the use of LRT expands, so too has the need for systems to evaluate treatment response, such as the World Health Organization and modified Response Evaluation Criteria In Solid Tumors systems and more recently, the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA). Early validation results for LI-RADS TRA have been promising, and as research accrues, the TRA is expected to evolve in the near future.

The diagnostic efficiency of the perfusion-related parameters in assessing the vascular disrupting agent (CA4P) response in a rabbit VX2 liver tumor model

BACKGROUND

There are inconsistencies when concomitantly using dynamic contrast enhancement (DCE) and intravoxel incoherent motion (IVIM) to evaluate diagnostic efficiency.

PURPOSE

To evaluate the diagnostic efficiency of perfusion-related parameters in assessing the effect of Combretastatin-A4-phosphate (CA4P) in a rabbit VX2 liver tumor model using DCE and IVIM.

MATERIAL AND METHODS

Twenty rabbits implanted with VX2 tumors were included in the study. The perfusion-parameters of DCE (K^trans and iAUC60) and IVIM (f and D*) were measured at baseline and 4 h after administration of CA4P. Subsequently, the rabbits were euthanized. Pre- and post-treatment perfusion parameters were analyzed using paired t-test. Correlation between the various perfusion parameters and correlation of perfusion parameters with microvascular density (MVD) were assessed using Pearson correlation analysis. The diagnostic efficiency was evaluated using receiver operating characteristic (ROC) curve analysis.

RESULTS

All perfusion parameters (K^trans, iAUC60, f and D*) showed significant decrease after 4 h of CA4P administration (all P < 0.001). Post-treatment perfusion parameters showed a moderate correlation with MVD (r = 0.663, r = 0.567, r = 0.685, r = 0.618, respectively; all P < 0.05). At baseline and after treatment, K^trans values and iAUC60 showed correlation with f and D* (all P < 0.05). Concomitant use of perfusion parameters of DCE and IVIM showed the best diagnostic performance, which was slightly greater than that observed with individual application of DCE or IVIM (AUC = 0.915, 0.880, and 0.895, respectively).

CONCLUSION

Although concomitant application of DCE and IVIM can slightly improve the diagnostic value in assessing the effect of CA4P, the values were relatively small.

Atypical magnetic resonance imaging features and differential diagnosis of hepatocellular carcinoma

Objective

Hepatocellular carcinoma (HCC) is the most common primary malignant tumor of the liver. We aimed to summarize and analyze the atypical magnetic resonance imaging (MRI) features of HCC to improve its diagnostic accuracy.

Methods

We retrospectively analyzed MRI data for 66 patients with HCC with atypical MRI features confirmed by operation and pathology.

Results

Twelve patients had high signals and 18 patients had significant decreases in opposed phase signals in T1WI plain scans. Nine patients had high signals and six patients had large cystic lesions in apparent diffusion coefficient images. Dynamic enhancement showed progressive enhancement in 15 patients, ring enhancement in three, irregular patchy enhancement in three, ‘nodule-in-nodule’ enhancement in six, delayed central patchy enhancement in six, delayed central ‘star-like aristate scars’ (T2WI revealed high signal intensity) in 21, and poor blood supply in three patients.

Conclusions

MRI can make a clear diagnosis of typical HCC, and atypical cases can also be distinguished from other tumors or tumor-like lesions by MRI. The analysis of atypical signs may improve the diagnostic accuracy of MRI for HCC.

A preliminary study of hepatocellular carcinoma post proton beam therapy using MRI as an early prediction of treatment effectiveness

Purpose

To demonstrate the feasibility of magnetic resonance imaging (MRI) for early prediction of proton beam therapy (PBT) effectiveness in hepatocellular carcinoma (HCC).

Methods

Clinical data of the HCC patients without regional lymph node involvement or distant metastasis who received PBT at this institution between 2014 and 2017 were reviewed. A total of 43 patients were included. Tumor regression pattern after PBT were examined on the basis of follow-up duration. The variables were compared between patients with and without early tumor regression (ETR).

Results

The median follow-up duration was 40 months (range, 9–62 months). The cumulative overall survival rate at 6 months, 1 years and 5 years was 100%, 88.4%, 63.4%, respectively. Child-Pugh class A, local tumor control (LTC), complete response (CR), and ETR were significantly associated with overall survival (p < 0.05 each). Of 43 patients, 25 patients (58.1%) reached CR in the PBT-irradiated region. Twelve patients (27.9%) had a partial response and 3 patients (7.0%) had a stationary disease. Three patients (7.0%) developed in-field progression. The LTC rate at 5 years was 93.0%. Of the 25 patients who achieved a CR in the PBT-irradiated region, the median time to CR was 5 months (range, 1–19 months). Twenty-two patients (51.2%) showed ETR of the HCC, while 21 patients (48.8%) showed non-ETR. A significant association was observed between ETR and CR of the HCC after PBT (p < 0.001).

Conclusion

The post-PBT MRI follow-up at 3 months is helpful for monitoring therapeutic response. ETR of the HCC predicted a higher rate of CR and was associated with overall survival, which provides more accurate clinical management.

Identifying the Prognostic Risk Factors of Synaptojanin 2 and Its Underlying Perturbations Pathways in Hepatocellular Carcinoma

Synaptojanin 2 (SYNJ2) regulates cell proliferation and apoptosis via dephosphorylating plasma membrane phosphoinositides. Aim of this study is to first seek the full-scale expression levels and potential emerging roles of SYNJ2 in hepatocellular carcinoma (HCC). We systematically analyzed SYNJ2 mRNA expression and protein levels in HCC tissues based on large-scale data and in-house immunohistochemistry (IHC). The clinical significance and risk factors for SYNJ2-related HCC cases were identified. A nomogram of prognosis was created and its performance was validated by concordance index (C-index) and shown in calibration plots. Based on the identified differentially coexpressed genes (DCGs) of SYNJ2, enriched annotations and potential pathways were predicted, and the protein interacting networks were mapped. Upregulated SYNJ2 in 3,728 HCC and 3,203 non-HCC tissues were verified and in-house IHC showed higher protein levels of SYNJ2 in HCC tissues. Pathologic T stage was identified as a risk factor. Upregulated mRNA levels and mutated SYNJ2 might cause a poorer outcome. The C-index of the nomogram model constructed by SYNJ2 level, age, gender, TNM classification, grade, and stage was evaluated as 0.643 (95%CI = 0.619–0.668) with well-calibrated plots. A total of 2,533 DCGs were extracted and mainly functioned together with SYNJ2 in metabolic pathways. Possible transcriptional axis of CTCF/POLR2A-SYNJ2/INPP5B (transcription factor-target) in metabolic pathways was discovered based on ChIP-seq datasets. In summary, transcriptional regulatory axis CTCF/POLR2A-SYNJ2 might influence SYNJ2 expression levels. Increased SYNJ2 expression level could be utilized for predicting HCC prognosis and potentially accelerates the occurrence and development of HCC via metabolic perturbations pathways.

Critical review of HCC imaging in the multidisciplinary setting: treatment allocation and evaluation of response

Imaging has not only an established role in screening and diagnosis of hepatocellular carcinoma (HCC) in patients with chronic liver inflammatory diseases, but also a crucial importance for patient stratification and treatment allocation, as well as for assessing treatment response. In the setting of increasing therapeutic options for HCC, the Barcelona Clinic Liver Cancer (BCLC) system still remains the most appropriate way to select candidate cohorts for best treatments. This classification takes into account the imaging information on tumor burden and extension, liver function, and cancer-related symptoms, stratifying patients in five risk categories (Stages 0, A, B, C and D) associated with different treatment options. Still now, there are no clear roles for biomarkers use in treatment allocation. The increasing use of locoregional non-surgical therapies in the different stages is highly dependent on reliable evaluation of treatment response, in particular when they are used with curative intention or for downstaging at liver transplantation re-assessment. Moreover, objective response (OR) has emerged as an important imaging biomarker, providing information on tumor biology, which can contribute for further prognostic assessment. Current guidelines for OR assessment recommend only the measurement of viable tumor according to mRECIST criteria, with further classification into complete response, partial response, stable disease or progressive disease. Either computed tomography (CT) or magnetic resonance (MR) imaging can be used for this purpose, and the Liver Imaging Reporting and Data System (LI-RADS) committee has recently provided some guidance for reporting after locoregional therapies. Nevertheless, imaging pitfalls resulting from treatment-related changes can impact with the correct evaluation of treatment response, especially after transarterial radioembolization (TARE). Volume criteria and emerging imaging techniques might also contribute for a better refinement in the assessment of treatment response and monitoring. As the role of imaging deeply expands in the multidisciplinary assessment of HCC, our main objective in this review is to discuss state-of-the-art decision-making aspects for treatment allocation and provide guidance for treatment response evaluation.

Predicting the Outcome of Transcatheter Arterial Embolization Therapy for Unresectable Hepatocellular Carcinoma Based on Radiomics of Preoperative Multiparameter MRI

BACKGROUND

In unresectable hepatocellular carcinoma (HCC), methods to predict patients at increased risk of progression are required.

PURPOSE

To investigate the feasibility of radiomics model in predicting early progression of unresectable HCC after transcatheter arterial chemoembolization (TACE) therapy using preoperative multiparametric magnetic resonance imaging (MP-MRI).

STUDY TYPE

Retrospective.

POPULATION

A total of 84 patients with BCLC B stage HCC from one medical center. According to the modified response evaluation criteria in solid tumors, patients who progressed at 6 months after TACE therapy were assigned as the progressive disease (PD) group (n = 32). Patients whose MRI was performed on four devices were divided into a training cohort (n = 67). Patients whose MRI was performed on other than the previous four devices were used as the testing set (n = 17).

FIELD STRENGTH/SEQUENCE

3.0T, 1.5T axial T₂ -weighted imaging (T₂ WI), diffusion-weighted imaging (DWI, b = 0, 500 s/mm² ), and apparent diffusion coefficient (ADC) ASSESSMENT: PD was confirmed via imaging studies with MRI. Risk factors, including age, alpha fetoprotein (AFP), size, and radiomic-related features of PD were assessed. In addition, the discrimination ability of each radiomics signature was tested on an independent testing set.

STATISTICAL TESTS

The area under the receiver-operator characteristic (ROC) curve (AUC) was used to evaluate the predictive accuracy of the radiomic signature in both the training and testing sets. The results indicated that the MP-MRI model achieved the greatest benefit.

RESULTS

In the testing set, the model based on DWI features presented an AUC of (b = 0, 0.786; b = 500, 0.729), followed by T₂ WI features (0.729) and ADC (0.714). The AUC of the MP-MRI signature was increased to 0.800 compared to any single MRI signature. The multivariate logistic analysis identified the radiomics signature as independent parameters of PD, while clinical information such as age, AFP, size, etc., had no significance in the PD group.

DATA CONCLUSION

Preoperative MP-MRI has the potential to predict the outcome of TACE therapy for unresectable HCC. In addition, these image features may be complementary to the current staging systems of HCC patients.

LEVEL OF EVIDENCE

2.

TECHNICAL EFFICACY STAGE

3. J. Magn. Reson. Imaging 2020;52:1083-1090.

CEUS LI-RADS: a pictorial review

Contrast-enhanced ultrasound (CEUS) greatly improved the diagnostic accuracy of US in the detection and characterization of focal liver lesions (FLLs), and it is suggested and often included in many international guidelines as an important diagnostic tool in the imaging work-up of cirrhotic patients at risk for developing hepatocellular carcinoma (HCC). In particular, CEUS Liver Imaging Reporting and Data System (LI-RADS) provides standardized terminology, interpretation, and reporting for the diagnosis of HCC. The aim of this pictorial essay is to illustrate CEUS features of nodules discovered at US in cirrhotic liver according to LI-RADS categorization.