Hepatobiliary and Pancreatic Neoplasms: Essential Predictive Imaging Features for Personalized Therapy

Tumor biologic characteristics encompassing histopathologic, immune microenvironmental, genetic, and molecular aspects are becoming indispensable factors to be considered in treatment strategies for patients with cancer. Innovations in oncologic treatment have broadened the range of therapeutic approaches and now hold promise for treatments personalized according to tumor biologic characteristics. Particularly for hepatobiliary and pancreatic neoplasms, the advent of cytostatic agents such as molecularly targeted agents and immune checkpoint inhibitors, which differ markedly from conventional cytotoxic agents, has contributed to advances in clinical practice. These cytostatic agents increase the potential for curative-intent treatment of unresectable cancers by reducing tumor volume. Radiologic examinations are of more interest than ever to noninvasively obtain information about tumor biologic features. Radiomics represents an invaluable research method for elucidating associations between tumor biologic characteristics and radiologic imaging findings, but their applicability in daily clinical practice remains challenging. Various radiologic predictive findings for tumor biologic characteristics have already been proposed for hepatobiliary and pancreatic neoplasms. Radiologists must gain familiarity with these findings and the roles they have in predicting the clinical prognosis and treatment efficacy. In addition, radiologists should explore the potential applications of these imaging findings to current treatment strategies for the coming era of personalized medicine. The authors describe predictive findings using CT and MRI for diagnosis of hepatocellular carcinoma, colorectal liver metastases, intrahepatic cholangiocarcinoma, and pancreatic adenocarcinoma, with correlations to pathologic, immunologic, molecular, and genetic background factors. ©RSNA, 2025 Supplemental material is available for this article. See the invited commentary by Ronot in this issue.

The Relationship Between Rim-like Enhancement on Pre-ablation Contrast-enhanced Ultrasound of Colorectal Liver Metastasis and Early Intrahepatic Progression After Thermal Ablation: A Preliminary Study

OBJECTIVE

To investigate the relationship between the rim-like enhancement pattern on pre-ablation contrast-enhanced ultrasound (CEUS) of colorectal liver metastasis (CRLM) and the therapeutic efficacy of percutaneous microwave ablation (MWA).

METHODS

Patients with CRLM underwent MWA and were evaluated using CEUS before ablation in our hospital between February 2020 and February 2023 were enrolled in this retrospective study. The enhancement patterns of CRLM were assessed by two radiologists and classified as rim-like enhancement and non-rim-like enhancement patterns. The therapeutic outcomes, including cumulative intrahepatic progression rate and early intrahepatic progression rate, were followed up and analyzed.

RESULTS

Overall, 50 patients with 121 nodules were enrolled. Rim-like enhancement pattern was observed in 18 patients (18/50, 36.0%). The cumulative intrahepatic progression rate was significantly higher in the rim-like enhancement group than the rate in the non-rim-like enhancement group (p = 0.022). The early intrahepatic progression rate in the rim-like enhancement group was also significantly higher than the rate in the non-rim-like enhancement group (12/17, 70.6% vs. 6/24, 25.0%, p = 0.005). The multivariable analysis demonstrated that the rim-like enhancement pattern of CRLM was a significant risk factor associated with early intrahepatic progression after MWA (p = 0.013).

CONCLUSION

Rim-like enhancement pattern on pre-ablation CEUS of CRLM was associated with a higher risk of intrahepatic progression after MWA.

Benign and malignant focal liver lesions displaying rim arterial phase hyperenhancement on CT and MRI

Rim arterial phase hyperenhancement is an imaging feature commonly encountered on contrast-enhanced CT and MRI in focal liver lesions. Rim arterial phase hyperenhancement is a subtype of arterial phase hyperenhancement mainly present at the periphery of lesions on the arterial phase. It is caused by a relative arterialization of the periphery compared with the center of the lesion and needs to be differentiated from other patterns of peripheral enhancement, including the peripheral discontinuous nodular enhancement and the corona enhancement. Rim arterial phase hyperenhancement may be a typical or an atypical imaging presentation of many benign and malignant focal liver lesions, challenging the radiologists during imaging interpretation. Benign focal liver lesions that may show rim arterial phase hyperenhancement may have a vascular, infectious, or inflammatory origin. Malignant focal liver lesions displaying rim arterial phase hyperenhancement may have a vascular, hepatocellular, biliary, lymphoid, or secondary origin. The differences in imaging characteristics on contrast-enhanced CT may be subtle, and a multiparametric approach on MRI may be helpful to narrow the list of differentials. This article aims to review the broad spectrum of focal liver lesions that may show rim arterial phase hyperenhancement, using an approach based on the benign and malignant nature of lesions and their histologic origin. CRITICAL RELEVANCE STATEMENT: Rim arterial phase hyperenhancement may be an imaging feature encountered in benign and malignant focal liver lesions and the diagnostic algorithm approach provided in this educational review may guide toward the final diagnosis. KEY POINTS: Several focal liver lesions may demonstrate rim arterial phase hyperenhancement. Rim arterial phase hyperenhancement may occur in vascular, inflammatory, and neoplastic lesions. Rim arterial phase hyperenhancement may challenge radiologists during image interpretation.

Prediction of macrotrabecular-massive hepatocellular carcinoma by using MR-based models and their prognostic implications

PURPOSE

To evaluate the efficacy of MRI-based radiomics and clinical models in predicting MTM-HCC. Additionally, to investigate the ability of the radiomics model designed for MTM-HCC identification in predicting disease-free survival (DFS) in patients with HCC.

METHODS

A total of 336 patients who underwent oncological resection for HCC between June 2007 and March 2021 were included. 127 patients in Cohort1 were used for MTM-HCC identification, and 209 patients in Cohort2 for prognostic analyses. Radiomics analysis was performed using volumes of interest of HCC delineated on pre-operative MRI images. Radiomics and clinical models were developed using Random Forest algorithm in Cohort1 and a radiomics probability (RP) of MTM-HCC was obtained from the radiomics model. Based on the RP, patients in Cohort2 were divided into a RAD-MTM-HCC (RAD-M) group and a RAD-non-MTM-HCC (RAD-nM) group. Univariate and multivariate Cox regression analyses were employed to identify the independent predictors for DFS of patients in Cohort2. Kaplan-Meier curves were used to compare the DFS between different groups pf patients based on the predictors.

RESULTS

The radiomics model for identifying MTM-HCC showed AUCs of 0.916 (95% CI: 0.858-0.960) and 0.833 (95% CI: 0.675-0.935), and the clinical model showed AUCs of 0.760 (95% CI: 0.669-0.836) and 0.704 (95% CI: 0.532-0.843) in the respective training and validation sets. Furthermore, the radiomics biomarker RP, portal or hepatic vein tumor thrombus, irregular rim-like arterial phase hyperenhancement (IRE) and AFP were independent predictors of DFS in patients with HCC. The DFS of RAD-nM group was significantly higher than that of the RAD-M group (p < .001).

CONCLUSION

MR-based clinical and radiomic models have the potential to accurately diagnose MTM-HCC. Moreover, the radiomics signature designed to identify MTM-HCC also can be used to predict prognosis in patients with HCC, realizing the diagnostic and prognostic aims at the same time.

Predicting Outcome after Percutaneous Ablation for Early-Stage Hepatocellular Carcinoma Using Various Imaging Modalities

Percutaneous ablation is a low-invasive, repeatable, and curative local treatment that is now recommended for early-stage hepatocellular carcinoma (HCC) that is not suitable for surgical resection. Poorly differentiated HCC has high-grade malignancy potential. Microvascular invasion is frequently seen, even in tumors smaller than 3 cm in diameter, and prognosis is poor after percutaneous ablation. Biopsy has a high risk of complications such as bleeding and dissemination; therefore, it has limitations in determining HCC tumor malignancy prior to treatment. Advances in diagnostic imaging have enabled non-invasive diagnosis of tumor malignancy. We describe the usefulness of ultrasonography, computed tomography, magnetic resonance imaging, and 18F-fluorodeoxyglucose positron emission tomography for predicting outcome after percutaneous ablation for HCC.

Deep learning nomogram based on Gd-EOB-DTPA MRI for predicting early recurrence in hepatocellular carcinoma after hepatectomy

OBJECTIVES

The accurate prediction of post-hepatectomy early recurrence in patients with hepatocellular carcinoma (HCC) is crucial for decision-making regarding postoperative adjuvant treatment and monitoring. We aimed to explore the feasibility of deep learning (DL) features derived from gadoxetate disodium (Gd-EOB-DTPA) MRI, qualitative features, and clinical variables for predicting early recurrence.

METHODS

In this bicentric study, 285 patients with HCC who underwent Gd-EOB-DTPA MRI before resection were divided into training (n = 195) and validation (n = 90) sets. DL features were extracted from contrast-enhanced MRI images using VGGNet-19. Three feature selection methods and five classification methods were combined for DL signature construction. Subsequently, an mp-MR DL signature fused with multiphase DL signatures of contrast-enhanced images was constructed. Univariate and multivariate logistic regression analyses were used to identify early recurrence risk factors including mp-MR DL signature, microvascular invasion (MVI), and tumor number. A DL nomogram was built by incorporating deep features and significant clinical variables to achieve early recurrence prediction.

RESULTS

MVI (p = 0.039), tumor number (p = 0.001), and mp-MR DL signature (p < 0.001) were independent risk factors for early recurrence. The DL nomogram outperformed the clinical nomogram in the training set (AUC: 0.949 vs. 0.751; p < 0.001) and validation set (AUC: 0.909 vs. 0.715; p = 0.002). Excellent DL nomogram calibration was achieved in both training and validation sets. Decision curve analysis confirmed the clinical usefulness of DL nomogram.

CONCLUSION

The proposed DL nomogram was superior to the clinical nomogram in predicting early recurrence for HCC patients after hepatectomy.

KEY POINTS

• Deep learning signature based on Gd-EOB-DTPA MRI was the predominant independent predictor of early recurrence for hepatocellular carcinoma (HCC) after hepatectomy. • Deep learning nomogram based on clinical factors and Gd-EOB-DTPA MRI features is promising for predicting early recurrence of HCC. • Deep learning nomogram outperformed the conventional clinical nomogram in predicting early recurrence.

Radiologic features of hepatocellular carcinoma related to prognosis

The cross-sectional imaging findings play a crucial role in the diagnosis of hepatocellular carcinoma (HCC). Recent studies have shown that imaging findings of HCC are not only relevant for the diagnosis of HCC, but also for identifying genetic and pathologic characteristics and determining prognosis. Imaging findings such as rim arterial phase hyperenhancement, arterial phase peritumoral hyperenhancement, hepatobiliary phase peritumoral hypointensity, non-smooth tumor margin, low apparent diffusion coefficient, and the LR-M category of the Liver Imaging-Reporting and Data System have been reported to be associated with poor prognosis. In contrast, imaging findings such as enhancing capsule appearance, hepatobiliary phase hyperintensity, and fat in mass have been reported to be associated with a favorable prognosis. Most of these imaging findings were examined in retrospective, single-center studies that were not adequately validated. However, the imaging findings can be applied for deciding the treatment strategy for HCC, if their significance can be confirmed by a large multicenter study. In this literature, we would like to review imaging findings related to the prognosis of HCC as well as their associated clinicopathological characteristics.

Well-preserved liver function enhances the clinical impact of curative-intent subsequent treatment during lenvatinib treatment for unresectable hepatocellular carcinoma

BACKGROUND

The aims of this study were to evaluate the clinical impact of curative-intent subsequent treatment on overall prognosis in lenvatinib-treated hepatocellular carcinoma (HCC) patients.

METHODS

Eighty-three consecutive patients with intrahepatic target nodules who received lenvatinib were reviewed. The clinical impact of curative-intent subsequent treatments was investigated through analysis of overall survival (OS) according to pathological deterioration stratified by mALBI grade.

RESULTS

In patients with mALBI grade 1 and 2a liver function, R0 resection and lenvatinib-transarterial chemoembolization (lenvatinib-TACE) sequential therapy resulted in significantly better OS compared with other, non-curative-intent subsequent therapy and lack of additional treatment (median OS, 37.6 vs 29.0 months and 17.1 vs 8.9 months, respectively; P < 0.001). Multivariate analysis confirmed that use of R0 resection and lenvatinib-TACE sequential therapy were associated with better OS (hazard ratio [HR], 0.021; P < 0.001 and 0.108; P < 0.001) compared with other, non-curative-intent subsequent treatment (HR 0.256; P = 0.010). In contrast, in patients with mALBI grade 2b liver function, multivariate analysis confirmed higher treatment efficacy for non-curative-intent subsequent treatment with respect to OS (HR 0.041; P < 0.001) compared with R0 resection and lenvatinib-TACE sequential therapy (HR 0.057; P = 0.027 and 0.063; P = 0.001).

CONCLUSION

Curative-intent subsequent treatment is more useful for HCC patients with better liver function (mALBI grade 1 and 2a) and intrahepatic target nodules who have received lenvatini b-based treatment.

Predictive Value of Ablative Margin Assessment After Microwave Ablation for Local Tumor Progression in Medium and Large Hepatocellular Carcinoma: Computed Tomography-Computed Tomography Image Fusion Method Versus Side-by-Side Method

OBJECTIVE

This study aimed to explore the feasibility and predictive value for local tumor progression (LTP) of the computed tomography (CT)-CT image fusion method versus side-by-side method to assess ablative margin (AM) in hepatocellular carcinoma ≥3 cm in diameter.

MATERIALS AND METHODS

We selected patients with hepatocellular carcinoma ≥3 cm in diameter who underwent microwave ablation and had complete tumor ablation. We used the CT-CT image fusion method and side-by-side method to assess AM separately and divided the lesions into 3 groups: group I, minimum ablative margin (min-AM) <0 mm (the ablation zone did not fully cover the tumor); group II, 0 mm ≤ min-AM <5 mm; and group III, min-AM ≥5 mm.

RESULTS

A total of 71 patients involving 71 lesions were included. The κ coefficient for the agreement between the CT-CT image fusion method and the side-by-side method in assessing min-AM was 0.14 (P = 0.028). Cumulative LTP rate was significantly different between groups by min-AM from the CT-CT image fusion method (P < 0.05) but not by min-AM from the side-by-side method (P = 0.807). Seventeen of the 20 LTP lesions were located at min-AM on fused CT images, with consistency rate of 85%.

CONCLUSIONS

Compared with the side-by-side method, the CT-CT image fusion method is more accurate in assessing the AM of eccentrically ablated lesions and shows better predictive value for LTP. The min-AM based on CT-CT image fusion assessment is an important influencing factor for LTP.

Prognostic implications of CT/MRI LI-RADS in hepatocellular carcinoma: State of the art and future directions

Hepatocellular carcinoma (HCC) is the fourth most lethal malignancy with an increasing incidence worldwide. Management of HCC has followed several clinical staging systems that rely on tumour morphologic characteristics and clinical variables. However, these algorithms are unlikely to profile the full landscape of tumour aggressiveness and allow accurate prognosis stratification. Noninvasive imaging biomarkers on computed tomography (CT) or magnetic resonance imaging (MRI) exhibit a promising prospect to refine the prognostication of HCC. The Liver Imaging Reporting and Data System (LI-RADS) is a comprehensive system for standardizing the terminology, techniques, interpretation, reporting and data collection of liver imaging. At present, it has been widely accepted as an effective diagnostic system for HCC in at-risk patients. Emerging data have provided new insights into the potential of CT/MRI LI-RADS in HCC prognostication, which may help refine the prognostic paradigm of HCC that promises to direct individualized management and improve patient outcomes. Therefore, this review aims to summarize several prognostic imaging features at CT/MRI for patients with HCC; the available evidence regarding the use of LI-RDAS for evaluation of tumour biology and clinical outcomes, pitfalls of current literature, and future directions for LI-RADS in the management of HCC.

A Predictive Nomogram of Early Recurrence for Patients with AFP-Negative Hepatocellular Carcinoma Underwent Curative Resection

Background: Alpha-fetoprotein-negative (<20 ng/mL) hepatocellular carcinoma (AFP-NHCC) cannot be easily diagnosed in clinical practice, which may affect early treatment and prognosis. Furthermore, there are no reliable tools for the prediction of AFP-NHCC early recurrence that have been developed currently. The objective of this study was to identify the independent risk factors for AFP-NHCC and construct an individual prediction nomogram of early recurrence of these patients who underwent curative resection. Methods: A retrospective study of 199 patients with AFP-NHCC who had undergone curative resection and another 231 patients with AFP-positive HCC were included in case-controlled analyses. All AFP-NHCC patients were randomly divided into training and validation datasets at a ratio of 7:3. The univariate and multivariate Cox proportional hazards regression analyses were applied to identify the risk factors, based on which the predictive nomogram of early recurrence was constructed in the training dataset. The area under the curve (AUC), calibration curve, and decision curve was used to evaluate the predictive performance and discriminative ability of the nomogram, and the results were validated in the validation dataset. Results: Compared to AFP-positive patients, the AFP-negative group with lower values of laboratory parameters, lower tumor aggressiveness, and less malignant magnetic resonance (MR) imaging features. AST (HR = 2.200, p = 0.009), tumor capsule (HR = 0.392, p = 0.017), rim enhancement (HR = 2.825, p = 0.002) and TTPVI (HR = 5.511, p < 0.001) were independent predictors for early recurrence of AFP-NHCC patients. The nomogram integrated these independent predictors and achieved better predictive performance with AUCs of 0.89 and 0.85 in the training and validation datasets, respectively. The calibration curve and decision curve analysis both demonstrated better predictive efficacy and discriminative ability of the nomogram. Conclusions: The nomogram based on the multivariable Cox proportional hazards regression analysis presented accurate individual prediction for early recurrence of AFP-NHCC patients after surgery. This nomogram could assist physicians in personalized treatment decision-making for patients with AFP-NHCC.

Changes in the Mean Intrahepatic Target Computed Tomography Attenuation Value During Treatment May Be a Useful New Predictor of the Post-progression Survival Associated with Lenvatinib Treatment

Objective The relationship between the prognosis and magnitude of a decrease in tumor blood flow according to estimated tumor differentiation remains unclear. This study investigated the relationship between reductions in the rate of mean computed tomography (CT) attenuation values and the clinical prognosis. Methods We evaluated 63 consecutive patients who received lenvatinib treatment for unresectable hepatocellular carcinoma (HCC). The oncological aggressiveness of the tumors was estimated using classification by dynamic CT enhancement patterns. The utility of changes in mean CT attenuation values of intra-hepatic targets during treatment to estimate the prognosis was investigated by calculating the progression-free survival (PFS) and post-progression survival (PPS). A multivariate analysis was used to identify potential confounders for the survival after progression during lenvatinib therapy. Results The rate of decrease in the mean CT attenuation value gradually increased according to the degree of deterioration in estimated tumor differentiation, and the rate of a decrease in attenuation ≥40% showed a tendency to increase (p=0.064). This trend was reflected by a better objective response in oncological aggressiveness heterogeneous enhancement patterns (Type-3 and Type-4) than a homogeneous enhancement pattern (Type-2) (83% vs. 56% of modified Response Evaluation Criteria in Solid Tumors). This resulted in a similar PFS between the groups (p=0.773), whereas the PPS was significantly worse when the rate of decrease in the attenuation value was ≥40% (p=0.012). A multivariate analysis confirmed that a rate of decease in attenuation value ≥40% was a poor prognostic factor for the PPS (hazard ratio, 2.993; 95% confidence interval, 1.196-7.490; p=0.019). Conclusion A rate of decrease in attenuation ≥40% may reflect a good response of a highly malignant tumor to lenvatinib. Therefore, this value may have utility as a surrogate marker for estimating the oncological aggressiveness of tumors and their associated prognosis.

Gadoxetic Acid-Enhanced MRI Features for Predicting Treatment Outcomes of Early Hepatocellular Carcinoma (< 3 cm) After Transarterial Chemoembolization

RATIONALE AND OBJECTIVES

Magnetic resonance imaging (MRI) is the most useful imaging tool for small hepatocellular carcinoma (HCC) evaluation. Patients undergoing transarterial chemoembolization (TACE) might have predictive imaging prognostic factors. This study aimed to find predictive gadoxetic acid (GA)-enhanced MRI features that affect tumor response and outcomes in patients with early HCC who underwent conventional TACE.

MATERIALS AND METHODS

Among patients who underwent conventional TACE as a first-line treatment for Barcelona clinic liver cancer stage 0 or A (<3 cm), 135 patients who underwent GA-enhanced MRI before treatment were included in this retrospective study. The patients' pretreatment clinical characteristics and MRI features were evaluated. Post-treatment tumor response, progression-free survival (PFS), and overall survival (OS) were also investigated.

RESULTS

The median follow-up period was 47 (range: 7-133) months, with 90 (67%) patients showing complete remission (CR) at the 1-month follow-up after TACE. Tumor number (odds ratio [OR] 0.602, 95% confidence interval [CI]: 0.375-0.967), central location (OR: 0.349, 95% CI: 0.145-0.837) were inversely associated with CR achievement. Median PFS and OS time were 22 (range: 1-133) and 67 (range: 7-133) months, respectively. The MRI features affecting poor survival outcomes were tumor number (PFS: hazard ratio [HR]=1.444, 95% CI=1.124-1.854; OS: HR=1.459, 95% CI=1.018-2.090), central location (PFS: HR=1.664, 95% CI=1.038-2.667; OS: HR=1.890, 95% CI=1.021-3.497), and marginal irregularity (PFS: HR=3.099, 95% CI=1.953-4.979; OS: HR=1.985, 95% CI=1.084-3.634).

CONCLUSION

Multiplicity, central location, and marginal irregularity of HCC on GA-enhanced MRI were significant factors associated with poor prognosis of patients with early HCC after conventional TACE.

Efficacy and Prognostic Factors of Trans-Arterial Chemoembolization Combined With Stereotactic Body Radiation Therapy for BCLC Stage B Hepatocellular Carcinoma

Purpose

This study aimed to evaluate the efficacy and safety of trans-arterial chemoembolization (TACE) followed by stereotactic body radiation therapy (SBRT) in treating Barcelona Clinic Liver Cancer (BCLC) stage B hepatocellular carcinoma (HCC) not amenable to resection and radiofrequency ablation (RFA).

Methods

From February 2012 to January 2017, a total of 57 BCLC stage B HCC patients who were unsuitable candidates for resection and RFA treated with TACE combined with CyberKnife SBRT were included in this retrospective study. Patients underwent TACE for a median of two times (1-5 times) before SBRT. SBRT prescription doses ranged from 30 Gy to 50 Gy in 3-5 fractions.

Results

The median follow-up time was 42 months. The objective response rate (CR + PR) was 85.9%, and the disease control rate (CR + PR + SD) was 96.5%. The local control (LC) rates were 91.1% and 84.3% at 1 and 2 years, respectively. The 1-, 2-, 3-year overall survival (OS) and the median survival time were 73.2%, 51.4%, 32.4% and 26.6 months, respectively. The 1-, 2-, and 3-year progression-free survival (PFS) were 34.2%, 21.6%, and 9%, respectively, with a median PFS time of 9.7 months. A subgroup analysis was conducted in 32 patients with AFP ≥ 200 ng/ml before TACE. OS was significantly prolonged in those with AFP that decreased by more than 75% than those with AFP that decreased by less than 75% (P = 0.018) after SBRT. The treatment was well tolerated with only one patient (1.8%) developed grade 3 gastrointestinal toxicity, and another patient developed non-classical RILD. In multivariate analysis, tumor length ≥ 10 cm and AFP ≥ 200 ng/ml were independent poor prognostic factors for OS.

Conclusion

The combination of TACE and Cyberknife SBRT showed optimal efficacy with acceptable toxicity for BCLC stage B HCC.

Gadoxetate-enhanced MRI Features of Proliferative Hepatocellular Carcinoma Are Prognostic after Surgery

Background Hepatocellular carcinomas (HCCs) are heterogeneous neoplasms, and the prognosis varies based on the subtype. Two broad molecular classes of HCC have been proposed: a proliferative and a nonproliferative class. Purpose To evaluate the gadoxetate-enhanced MRI findings of the proliferative class HCC and its prognostic significance after surgery. Materials and Methods This retrospective cohort study evaluated patients with surgically resected treatment-naive single HCC (≤5 cm) who underwent hepatic resection from January 2010 through February 2013 and preoperative gadoxetate-enhanced MRI. A Cox proportional hazards model was used to determine the predictive factors for overall survival (OS), intrahepatic distant recurrence, and extrahepatic metastasis (EM). The mean follow-up period was 75.5 months ± 30.2 (standard deviation). Multivariable logistic regression was performed to determine factors associated with proliferative class HCC. Results A total of 158 patients (mean age, 57 years ± 11; 128 men and 30 women) were evaluated. Forty-two of the 158 HCCs (26.6%) were proliferative class HCCs (17 macrotrabecular-massive HCCs, 14 keratin 19-positive HCCs, 10 scirrhous HCCs, and one sarcomatoid HCC). The proliferative class was associated with worse OS (hazard ratio [HR], 3.1; 95% CI: 1.5, 6.0; P = .01) and higher rates of intrahepatic distant recurrence (HR, 1.83; 95% CI: 1.1, 2.9; P = .01) and EM (HR, 9.97; 95% CI: 3.2, 31.4; P < .001). Rim arterial phase hyperenhancement (APHE) at gadoxetate-enhanced MRI (odds ratio [OR], 6.35; 95% CI: 1.9, 21.7; P = .01) and high serum α-fetoprotein (>100 ng/mL) (OR, 4.18; 95% CI: 1.64, 10.7; P = .01) were independent predictors for proliferative HCC. The presence of rim APHE was associated with poor OS (HR, 2.4; 95% CI: 1.2, 4.9; P = .02) and higher rates of EM (HR, 7.4; 95% CI: 2.5, 21.7; P < .01). Conclusion The proliferative class of hepatocellular carcinoma (HCC) is an independent factor for poor overall survival with increased rates of intrahepatic and extrahepatic metastasis. Rim arterial phase hyperenhancement at gadoxetate-enhanced MRI may help to identify proliferative class HCC and predict poor overall survival and an increased incidence of extrahepatic metastasis. © RSNA, 2021 Online supplemental material is available for this article. See also the editorial by Krinsky and Shanbhogue in this issue.

A radiomics nomogram based on contrast-enhanced MRI for preoperative prediction of macrotrabecular-massive hepatocellular carcinoma

BACKGROUND

Macrotrabecular-massive hepatocellular carcinoma (MTM-HCC) represents an aggressive form of hepatocellular carcinoma and is associated with poor survival outcomes.

AIMS

This study aimed to develop a radiomics nomogram based on contrast-enhanced MRI for preoperative prediction of MTM-HCC.

METHODS

This study enrolled 88 patients with histologically confirmed HCC, including 32 MTM-HCCs and 56 Non-MTM-HCCs. The clinical and gadobenate dimeglumine (Gd)-enhanced MRI features were retrospectively reviewed by two abdominal radiologists. The regions of interest (ROIs) on the largest cross-sectional image and two adjacent images of the tumor, from which radiomics features were extracted via MaZda software and a radiomics score (Rad-score) was calculated via Python software. Combined with the Rad-score and independent imaging factors, a radiomics nomogram was constructed using R software. Nomogram performance was estimated with calibration curve.

RESULTS

A total of eleven top weighted radiomics features were selected among five sequences of MR images. There was a significant difference in Rad-score between MTM-HCC and non-MTM-HCC patients (P < 0.001), where patients with MTM-HCC generally had higher Rad-scores (absolute value). After multivariate analysis, radiomics score (OR = 7.794, P < 0.001) and intratumor fat (OR = 9.963, P = 0.014) were determined as independent predictors associated with MTM-HCC. The area under the receiver operating characteristic (ROC) curve of the selected model was 0.813 (95% CI 0.714-0.912) and the optimal cutoff value was 0.60. The nomogram showed overall satisfactory prediction performance (AUC = 0.785 [95% CI 0.684-0.886]).

CONCLUSIONS

A contrast-enhanced MRI-based radiomics nomogram may be useful for preoperative prediction of MTM-HCC in primary HCC patients, allowing opportunity to improve the treatment course and patient outcomes.

Liver Imaging Reporting and Data System Category on Magnetic Resonance Imaging Predicts Recurrence of Hepatocellular Carcinoma After Liver Transplantation Within the Milan Criteria: A Multicenter Study

BACKGROUND

This study was designed to investigate the association between Liver Imaging Reporting and Data System (LI-RADS) category and recurrence of hepatocellular carcinoma (HCC) after primary liver transplantation (LT) within the Milan criteria.

METHODS

This multicenter, retrospective study included 140 recipients who underwent living donor LT (LDLT) for treatment-naïve HCC and pretransplant contrast-enhanced magnetic resonance imaging (MRI) between 2009 and 2013. LI-RADS categories were assigned using LI-RADS version 2018. Recurrence-free survival (RFS) and associated factors were evaluated using Cox proportional hazards regression analysis, Kaplan-Meier analysis, and log-rank test. Histological grading and microvascular invasion (MVI) were analyzed on the pathologic examinations of explanted livers.

RESULTS

The overall 1-, 3-, 5-, and 7-year RFS rates were 95.6%, 92.6%, 90.2%, and 89.3%, respectively. In the multivariable analysis, independent predictors of recurrence included HCCs categorized as LR-M (hazard ratio [HR], 18.68; 95% confidence interval [CI], 5.79-60.23; P < 0.001) and the largest tumor size of ≥ 3 cm on MRI (HR, 4.18; 95% CI, 1.42-12.37; P = 0.010). The 5-year RFS rate was significantly lower in patients with HCCs categorized as LR-M than in those with HCCs categorized as LR-5 or 4 (LR-5/4) (36.9% vs. 95.8%, respectively; P < 0.001). HCCs categorized as LR-M exhibited significantly more MVI than HCCs categorized as LR-5/4 (57.1% vs. 17.5%, respectively; P = 0.002).

CONCLUSIONS

Patients with HCCs categorized as LR-M using LI-RADS version 2018 may have a worse prognosis after primary LT within the Milan criteria than those with HCCs categorized as LR-5/4.

Lenvatinib-Transarterial Chemoembolization Sequential Therapy as an Effective Treatment at Progression during Lenvatinib Therapy for Advanced Hepatocellular Carcinoma

BACKGROUND

The aims of this study were to evaluate the efficacy of additional treatment, especially lenvatinib-transarterial chemoembolization (TACE) sequential therapy, for unresectable hepatocellular carcinoma (HCC).

METHODS

Consecutive 56 patients who underwent lenvatinib treatment were reviewed. Oncological aggressiveness of tumor was estimated using a dynamic CT enhancement pattern classification, and clinical impact of subsequent treatment was investigated through analysis of progression-free survival (PFS), post-progression survival (PPS), and multivariate analysis of potential confounders for survival after progression during lenvatinib therapy.

RESULTS

Heterogeneous enhancement patterns (Type-3 and -4), which are reportedly associated with higher oncological aggressiveness of HCC, were associated with better objective response to lenvatinib compared to homogeneous enhancement pattern (Type-2) (86 and 85% vs. 53% in modified Response Evaluation Criteria in Solid Tumors), resulting in similar PFS (p = 0.313). Because of significantly worse PPS, overall survival of Type-4 tumor was poor compared to Type-2 or -3 tumors (p = 0.009). However, subgroup of patients who achieved subsequent treatment showed significantly better PPS, regardless of CT enhancement pattern. Multivariate analysis confirmed that use of lenvatinib-TACE sequential treatment after progression during lenvatinib therapy was associated with better PPS (hazard ratio [HR], 0.08; 95% CI, 0.01-0.71; p = 0.023), while Type-4 enhancement pattern was correlated with worse PPS (HR, 2.92; 95% CI, 1.06-8.05; p = 0.039).

CONCLUSION

Oncological aggressiveness of HCC estimated by CT enhancement pattern was predictive of PPS after progression during lenvatinib. Successful subsequent treatment with lenvatinib-TACE sequential therapy may offer survival benefit regardless of CT enhancement pattern of HCC.

Pretreatment Heterogeneous Enhancement Pattern of Hepatocellular Carcinoma May Be a Useful New Predictor of Early Response to Lenvatinib and Overall Prognosis

OBJECTIVE

The aim of this study was to evaluate the performance of pretreatment computed tomography (CT) enhancement of hepatocellular carcinoma (HCC) as a potential predictor of response to lenvatinib and its relevance to survival outcomes.

METHODS

We evaluated 51 consecutive patients who received lenvatinib treatment for unresectable HCC. On imaging analysis, pretreatment arterial/portal phase dynamic CT images were classified as follows: type 2, homogeneous enhancement pattern with increased arterial blood flow; type 3, heterogeneous enhancement pattern with a septum-like structure; and type 4, heterogeneous enhancement pattern with irregularly shaped ring structures. Treatment response was evaluated using modified Response Evaluation Criteria in Solid Tumors at 2-12 weeks after initiation of lenvatinib, and the correlations between the CT enhancement patterns and response to lenvatinib or survival outcomes were investigated.

RESULTS

Of the 51 patients, 38 (75%) experienced an objective response (OR). ORs were significantly more common in heterogeneously enhanced HCC (types 3 and 4) than in homogeneous HCC (type 2) (83 vs. 53%, respectively; p = 0.037). Multivariate analysis revealed that pretreatment heterogeneous enhancement pattern is an independent predictor for response to lenvatinib (odds ratio, 4.75; p = 0.042). Presence of OR was associated with longer progression-free survival (PFS) (hazard ratio, 0.36; p = 0.017), and patients with oncologically aggressive type 3 and 4 tumors showed similar PFS to those harboring type 2 tumors (p = 0.455), reflecting that OR was more common in type 3 or 4 tumors compared with type 2 tumors. Although postprogression survival was extremely poor in patients with type 4 tumors (p = 0.064), overall survival after introduction of lenvatinib was not statistically different among the three groups of patients (p = 0.053).

CONCLUSION

The CT enhancement pattern of HCC may predict response to lenvatinib. OR seems to occur more frequently in HCC with oncologically aggressive features and may contribute to prolonged survival through a prolonged progression-free interval, even in an oncologically poor-risk group of patients.

A Novel Pre-treatment Model Predicting Risk of Developing Refractoriness to Transarterial Chemoembolization in Unresectable Hepatocellular Carcinoma

Background and aim: Refractoriness to transarterial chemoembolization is common during the therapeutic process of hepatocellular carcinoma, which is an intractable issue and may compromise the prognosis. We aim to establish a pre-treatment model to identify patients with high risks of refractoriness.

Methods: From 2010 to 2016, 824 treatment-naive patients who had initially underwent at least two sessions of transarterial chemoembolization in Zhongshan Hospital, Fudan University were retrospectively enrolled. These patients were randomly allocated into a training cohort and a validation cohort. The pre-treatment scoring model was established based on the clinical and radiological variables using logistic regression and nomogram. The discrimination and calibration of the model were also evaluated.

Results: Logistic regression identified vascularization pattern, ALBI grade, serum alpha-fetoprotein level, serum γ-glutamyl transpeptidase level and major tumor size as the key parameters related to refractoriness. The p-TACE model was established using these variables (risk score range: 0-19.5). Patients were divided into six risk subgroups based on their scores (<4, ≥4, ≥7, ≥10, ≥13, ≥16). The discriminative ability, as determined by the area under receiver operating characteristic curve was 0.784 (95% confidence interval: 0.741-0.827) in the training cohort and 0.743 (95% confidence interval: 0.696-0.789) in the validation cohort. Moreover, satisfactory calibration was confirmed by Hosmer-Lemeshow test with P values of 0.767 and 0.913 in the training cohort and validation cohort.

Conclusions: This study presents a pre-treatment model to identify patients with high risks of refractoriness after transarterial chemoembolization and shed light on clinical decision making.

Predictive imaging for tumor response to drug-eluting microsphere transarterial chemoembolization in patients with BCLC-C advanced hepatocellular carcinoma

Drug-eluting microsphere transarterial chemoembolization (DEM-TACE) has been introduced to ensure more sustained and tumor-selective drug delivery for permanent embolization of HCC. The aim of this study was to determine the imaging characteristics that related to favourable treatment response in BCLC-C HCC patients treated with DEM-TACE. In total, 64 patients with BCLC-C HCC that treated with DEM-TACE using doxorubicin-eluted microspheres were retrospectively included. The images were assessed at baseline and at 4-12 weeks follow-up after receiving DEM-TACE. Pre- and post-procedural imaging characteristics were analysed by two independent radiologists and treatment response was evaluated using the modified Response Evaluation Criteria in Solid Tumors criteria. Multivariate analysis showed that vascular lake phenomenon (OR = 5.94, p = 0.03*), and homogeneous tumor enhancement (HTE) on cone-beam computed tomography (CBCT) during angiography (OR = 11.66, p < 0.001*) are associated with better radiological response. In contrast, residual tumor blush (OR = 0.11, p < 0.001*) is associated with worse radiological response. In conclusion, the initial tumor burden <50% (p = 0.012*) and HTE on CBCT (p = 0.040*) are good predictors for locoregional tumor control in patients with advanced HCCs, which can potentially improve patients' outcome.

Value of Imaging Findings in the Prediction of Microvascular Invasion in Hepatocellular Carcinoma

BACKGROUND

The purpose of this study was to determine the utility of some imaging findings in predicting microvascular invasion (MVI) and hepatocellular carcinoma (HCC) recurrence risk after liver transplantation.

METHOD

This retrospective study included 123 patients with histopathologically proven HCC at explant. All HCCs were classified as MVI positive (group I) or negative (group II) based on histopathological findings. In each group, multifocality, largest tumor size, bulging (tumor causing liver capsule expansion), beak sign (the acute angle between the tumor and liver parenchyma), and diffusion restriction on diffusion weighted images (DWI) were evaluated. These findings were compared between the groups by Student's t test. The relation between the parameters and MVI was analyzed by using the Spearman's correlation test.

RESULTS

Of the total patients, 30.1% had MVI (group I) and 69.9% (group II) did not have MVI. Presence of beak sign (P ≤ .005), bulging sign (P = .002), and diffusion restriction (P = .045) were significantly more frequent in group I than group II. The beak sign, bulging sign, and diffusion restriction were correlated with presence of MVI. Largest tumor size and multifocality were higher in group I than group II, but the differences were not statistically significant.

CONCLUSION

Radiologists and transplant surgeons should be aware of some clue imaging findings, especially beak and bulging signs because these findings may predict the presence of MVI in HCC. These patients might benefit from histologic confirmation of the tumor characteristics through biopsy and subsequent bridging treatment options before liver transplantation to reduce the risk of recurrence.

No-touch ablation in hepatocellular carcinoma has the potential to prevent intrasubsegmental recurrence to the same degree as surgical resection

AIM

The aim of this study was to clarify the utility of a no-touch pincer ablation procedure that uses bipolar electrodes to prevent intrasubsegmental tumor recurrence after radiofrequency ablation (RFA) for patients with hepatocellular carcinoma (HCC) compared to surgical resection.

METHODS

We evaluated 175 consecutive patients with HCC (single nodule, tumor diameter ≤ 30 mm) who underwent surgical resection (146 received partial resection) and 313 patients who received RFA; 277 patients received touch ablation using a monopolar or bipolar RFA device, and 36 received no-touch ablation using a bipolar RFA device. Pretreatment arterial and portal phase dynamic computed tomography (CT) or magnetic resonance imaging (MRI) images were classified into four enhancement patterns: Type 1 and Type 2 are homogeneous enhancement patterns without or with increased arterial blood flow, respectively; Type 3 is a heterogeneous enhancement pattern with a septum-like structure; and Type 4 is an irregularly shaped ring structure enhancement pattern.

RESULTS

Cumulative recurrence rates significantly differed between procedures (surgical resection, 7.5%; no-touch ablation, 2.9%; and touch ablation, 17.7% at the third year; P = 0.005). Multivariate Cox proportional hazards analysis revealed that enhancement pattern type (Type 3: hazard ratio [HR], 2.95; P = 0.002; and Type 4: HR, 3.88, P = 0.002), treatment procedure (touch ablation: HR, 3.36; P < 0.001), and serum α-fetoprotein level (≥30 μg/L: HR, 1.87; P = 0.009) were significant predictors of intrasubsegmental recurrence. No significant differences between no-touch ablation and surgical resection were observed.

CONCLUSION

The no-touch pincer ablation procedure has the potential to prevent intrasubsegmental recurrence after RFA for patients with HCC to the same degree as partial resection.

Hepatocellular Carcinoma with Irregular Rim-Like Arterial Phase Hyperenhancement: More Aggressive Pathologic Features

BACKGROUND AND AIMS

The purpose of our study was to examine the histopathologic characteristics of hepatocellular carcinoma (HCC) with irregular rim-like arterial phase enhancement (IRE), which has been reported to be associated with more aggressive tumor behavior.

METHODS

We investigated 84 pathologically confirmed HCCs in 84 patients who underwent curative hepatic resection after gadoxetate-enhanced magnetic resonance imaging between January 2008 and February 2013. Two abdominal radiologists independently reviewed these images and classified HCCs into two categories: HCC showing IRE (IRE-HCC) and HCC showing hypoenhancement or diffuse arterial enhancement (non-IRE-HCC). Twenty-two HCCs were classified as IRE-HCCs, and 51 were classified as non-IRE-HCCs concordantly by both reviewers. The remaining 11 HCCs, on whose radiologic classifications the reviewers disagreed, were classified as HCCs with intermediate enhancement patterns. The HCC clinicopathologic characteristics and patient outcomes were then compared.

RESULTS

IRE-HCCs showed more frequent microvascular invasion (91 vs. 35%), lower microvascular density (246.5 vs. 426.5/mm²), higher proportions of sinusoid-like microvascular pattern (55 vs. 0%) and macrotrabecular pattern (45 vs. 0%), and larger areas of tumor necrosis (15 vs. 0%) and fibrous stroma (8.3 vs. 2.1%) than non-IRE-HCCs. IRE-HCCs also expressed higher levels of immunomarkers of hypoxia (carbonic anhydrase IX, 64 vs. 8%) and stemness (EpCAM, 50 vs. 20%). p values were < 0.001 for all comparisons except for EpCAM (p = 0.026). HCCs with intermediate enhancement patterns showed mixed/intermediate pathologic features from both IRE- and non-IRE-HCCs. IRE-HCC patients showed poorer 5-year disease-free survival after curative resection than non-IRE-HCC patients (p = 0.005).

CONCLUSIONS

IRE-HCCs demonstrate aggressive histopathologic features, including more hypoxic and fibrotic tumor microenvironments and increased stemness, compared to non-IRE-HCCs. IRE might therefore serve as a noninvasive imaging biomarker for aggressive HCC.

Imaging features related with prognosis of hepatocellular carcinoma

We discuss various imaging features that have been reported to be associated with the prognosis of hepatocellular carcinoma (HCC) but not included in the current staging systems: findings related with microvascular invasion, tumor encapsulation, intratumoral fat, presence of satellite nodules, peritumoral hypointensity on hepatobiliary phase images of gadoxetic-acid enhanced MRI, restricted diffusion, and irregular rim-like hyperenhancement. Current evidence suggests that larger (> 2 cm) tumor size, presence of satellite nodules, presence of irregular rim-like hyperenhancement of a tumor, peritumoral parenchymal enhancement in the arterial phase, and peritumoral hypointensity observed on hepatobiliary phase images are independent imaging features to portend a worse prognosis in patients with hepatocellular carcinoma.

Safety margin after radiofrequency ablation of hepatocellular carcinoma: precise assessment with a three-dimensional reconstruction technique using CT imaging

PURPOSE

To analyse the precise ablative margin (AM) after radiofrequency ablation (RFA) for hepatocellular carcinoma (HCC) and the correlation between AM and local tumour progression (LTP) with a three-dimension (3D) reconstruction technique.

METHODS

From March 2011 to May 2013, 134 patients who underwent RFA for 159 primary or recurrent HCCs within Milan criteria were enrolled. Contrast-enhanced computed tomography (CECT) scans were performed 1 week before and 1 month after treatment. The AM was measured in various directions using a 3D reconstruction technique that shows the index tumour and ablated zone on the same image. The average of all obtained AMs (average AM) and the smallest AM (min-AM) were calculated.

RESULTS

The min-AM after RFA ranged from 1 to 9.3 mm (median ± standard deviation, 4.8 ± 1.8 mm). LTP was observed in 19 tumours from 19 patients. The median min-AM was 3.1 ± 1.6 mm for patients with LTP, while the median min-AM of patients without LTP was 5.1 ± 1.8 mm (p = 0.023). After RFA, the 1-, 2- and 3-year LTP rates were 10.9, 25.9 and 35.1%, respectively, for patients with min-AM <5 mm, and 4.1, 4.1 and 4.1%, respectively, for patients with min-AM ≥5 mm (p = 0.016). Multivariate analysis showed that only min-AM <5 mm was an independent risk factor for LTP after RFA (p = 0.044, hazard ratio =4.587, 95% confidence interval, 1.045-22.296).

CONCLUSIONS

The 3D reconstruction technique is a precise method for evaluating the post-ablation margin. Patients with min-AM less than 5 mm had a higher probability of developing LTP.

A radiogenomic analysis of hepatocellular carcinoma: association between fractional allelic imbalance rate index and the liver imaging reporting and data system (LI-RADS) categories and features

OBJECTIVE

To evaluate the association between the liver imaging reporting and data system (LI-RADS) categories and features and the fractional allelic imbalance (FAI) rate index of hepatocellular carcinoma (HCC).

METHODS

The institutional review board approved this retrospective study. Medical records collected between January 2008 and December 2013 were reviewed to find patients with histologically confirmed HCC, FAI analysis, and CT or MR imaging of the liver. The final population included 71 patients (54 males, 17 females). Three radiologists reviewed the images using the LI-RADS v. 2014. The association between FAI and LI-RADS categories and features was tested using the Spearman's rank correlation coefficient (rho) and the Wilcoxon rank-sum test [low FAI (<40%) vs high FAI (≥40%)]. A p value < 0.007 was used as the threshold for statistical significance after application of the Bonferroni correction for multiple comparisons.

RESULTS

HCCs were classified as LR-3 (n = 4), LR-4 (n = 22), and LR-5 (n = 45). There was a positive correlation (rho = 0.264) between FAI rate index and LI-RADS category, although not statistically significant after Bonferroni correction (p = 0.024). 14 of the 20 (70%) HCCs with high FAI (≥40%) were categorized as LR-5, 6/20 (30%) as LR-4 and none as LR-3 (p = 0.377). Among the evaluated LI-RADS imaging features, only lesion size showed a statistically significant different distribution in tumors with high FAI compared to those with low FAI. HCCs with FAI ≥40% were larger (56 ± 42 mm) compared to those with FAI <40% (36 ± 30 mm; p = 0.005).

CONCLUSION

There was a positive correlation, although not statistically significant, between the LI-RADS diagnostic categories and the FAI rate of HCC. Tumors with high FAI were larger compared to those with low FAI. Advances in knowledge: HCCs with high (≥40%) FAI are larger compared to those with low (<40%) FAI.

Efficacy of Stereotactic Body Radiotherapy for Recurrent or Residual Hepatocellular Carcinoma after Transcatheter Arterial Chemoembolization

Aim

To evaluate the efficacy and toxicity of hypofractionated stereotactic body radiotherapy (SBRT) for patients with recurrent or residual hepatocellular carcinoma (HCC) after transcatheter arterial chemoembolization (TACE).

Methods

Between June 2008 and July 2015, thirty-three patients with HCC were treated by SBRT. There were 63 lesions in 33 patients. A total dose of 39-45 Gy/3-5 fractions was delivered to the 70-80% isodose line.

Results

Objective response rate (CR + PR) was 84.8% at 6 months. The overall survival rate was 87.9%, 75.8%, 57.6%, and 45.5% at 6, 12, 18, and 24 months, respectively. Median overall survival was 19 months. At 3 months, AFP decreased by more than 75% in 51.5% of patients (17/33). Overall survival was significantly different (P < 0.001) between the group of patients for whom AFP decreased more than 75% and the group for whom AFP decreased by less than 75%. The AFP-negative rate was 48.5% (16/33) after 6 months. Eight patients (24.2%) had grade 1-2 transient fatigue, and 11 patients (33.3%) had grade 1-2 gastrointestinal reactions within 1 month.

Conclusion

SBRT is a promising noninvasive and palliative treatment with acceptable toxicity for recurrent or residual HCC after TACE.

Evaluation of CT vascularization patterns for survival prognosis in patients with hepatocellular carcinoma treated by conventional TACE

PURPOSE

Transarterial chemoembolization (TACE) is an established treatment for intermediate stage hepatocellular carcinoma (HCC). The aim of this retrospective study was to evaluate the power of lesion vascularization criteria based on computed tomography for prognosis of overall survival before initiation of treatment.

METHODS

A total of 59 patients with intermediate stage HCC treated with TACE as first-line treatment were retrospectively evaluated. TACE procedures were performed using doxorubicin, cisplatin, and lipiodol. Response evaluation criteria in solid tumors version 1.1 (RECIST 1.1) were used to determine the initial tumor response. Four vascularization patterns (VP) of the largest target lesion (homogeneous vascularization [VP1], homogeneous vascularization with additional arterial hypervascularization [VP2], heterogeneous vascularization with [VP3] and without zones of hypervascularization [VP4]) were assessed prior to the first TACE and correlated to survival.

RESULTS

Kaplan-Meier analysis yielded a median overall survival of 608 days (standard error [SE], 120.5 days). Survival analysis showed significant differences depending on the vascularization patterns (P = 0.012; hazard ratio, 0.327): patients with homogeneously vascularized lesions (VP1, VP2) had a median overall survival of 1091 days (SE, 235.5 days). Patients with heterogeneous vascularization of the lesion (VP3 and VP4) showed a median overall survival of 508 days (SE, 113.9 days).

CONCLUSION

The vascularization pattern of the largest HCC lesion is helpful for survival prognosis under TACE treatment and therefore has the potential to be used as an additional parameter for treatment stratification.

Preoperative gadoxetic acid-enhanced MRI for predicting microvascular invasion in patients with single hepatocellular carcinoma

BACKGROUND & AIMS

This study aimed to identify preoperative magnetic resonance (MR) imaging biomarkers for predicting microvascular invasion (MVI), to determine their diagnostic performance and to evaluate whether they are associated with early recurrence after surgery for single hepatocellular carcinoma (HCC).

METHODS

The study included 197 patients with surgically resected HCC (≤5cm) who underwent preoperative gadoxetic acid-enhanced MR imaging. Significant MR imaging findings for predicting MVI were identified by univariate and multivariate analyses. Early recurrence rates (<2years) were analyzed with respect to significant imaging findings for predicting MVI.

RESULTS

Three MR imaging features were independently associated with MVI: arterial peritumoral enhancement (odds ratio [OR]=5.184; 95% confidence interval [CI]: 2.228, 12.063; p<0.001), non-smooth tumor margin (OR=3.555; 95% CI: 1.627, 7.769; p=0.001), and peritumoral hypointensity on hepatobiliary phase (HBP) (OR=4.705; 95% CI: 1.671, 13.246; p=0.003). When two of three findings were combined, the specificity was 92.5% (124/134). When all three findings were satisfied, the specificity was 99.3% (133/134). Early recurrence rates were significantly higher in patients with single HCC, with two or three significant MR imaging findings, compared to those with none (27.9% vs. 12.6%, respectively, p=0.030).

CONCLUSIONS

A combination of two or more of the following; arterial peritumoral enhancement, non-smooth tumor margin, and peritumoral hypointensity on HBP, can be used as a preoperative imaging biomarker for predicting MVI, with specificity >90%, and is associated with early recurrence after surgery of single HCC. Lay summary: A combination of two or more of the following; arterial peritumoral enhancement, non-smooth tumor margin, and peritumoral hypointensity on hepatobiliary phase, can be used as a preoperative imaging biomarker for predicting microvascular invasion, with specificity >90%, and is associated with early recurrence after curative resection of single HCC.

Potential of a no-touch pincer ablation procedure that uses a multipolar radiofrequency ablation system to prevent intrasubsegmental recurrence of small and single hepatocellular carcinomas

OBJECTIVE

The aim of this study was to clarify the usefulness of a no-touch pincer ablation procedure that uses bipolar electrodes to prevent intrasubsegmental tumor recurrence after radiofrequency ablation (RFA) for patients with hepatocellular carcinoma (HCC).

METHODS

We studied 303 consecutive patients with HCC (single nodule and tumor diameter ≤30 mm) who received RFA between January 2005 and April 2015; 268 patients received touch ablation using a monopolar or bipolar RFA device, and 35 received no-touch ablation using a bipolar RFA device. The pretreatment arterial and portal phase dynamic computed tomography or magnetic resonance images were classified into four enhancement patterns. Type 1 and Type 2 are homogeneous enhancement patterns without or with increased arterial blood flow, respectively. Type 3 is a heterogeneous enhancement pattern with a septum-like structure, and Type 4 is an irregularly shaped ring structure enhancement pattern.

RESULTS

With regard to intrasubsegmental tumor recurrence, among the 268 patients who underwent the touch ablation procedure, tumors recurred in 52 (19.4%) patients, and among the 35 patients who underwent the no-touch ablation procedure, tumors recurred in one (2.9%) patient. Cumulative intrasubsegmental tumor recurrence rates tended to be higher with touch ablation (P = 0.083). Multivariate Cox proportional hazards analysis revealed that ablation procedure (touch ablation, hazard ratio [HR] 10.32, P = 0.032), type of enhancement pattern (Type 3, HR 3.05, P = 0.006; and Type 4, HR 8.87, P < 0.001) and serum des-γ-carboxyprothrombin level (≥100 AU/L; HR 2.73, P = 0.035) were significant predictors for intrasubsegmental recurrence.

CONCLUSION

The no-touch pincer ablation procedure has the potential to prevent intrasubsegmental recurrence after RFA for patients with HCC.

Small hepatocellular carcinomas displayed as a ring enhancing mass on arterial phase MRI in the chronically diseased liver

AIM

To assess the prevalence of arterial phase (AP) ring-enhancing small hepatocellular carcinomas (HCC) on magnetic resonance imaging (MRI); detail additional MRI features that enable HCC diagnosis; and examine arterial timing as one possible cause of this appearance.

MATERIALS AND METHODS

Patients undergoing HCC screening with both computed tomography (CT) and MRI within 40 days were examined at a single institution over a 7- year time period ending in 2013. From this initial group, small (1-3 cm), (AP) ring-enhancing HCC on MRI were studied.

RESULTS

From the initial group of 64 patients with 129 HCC, 20 patients with 78 HCCs had a small diameter with 32 (41%) having an AP ring at MRI. The mean age of this latter group was 63-years old, with the average tumour diameter of 1.9 cm. Histopathology and secondary imaging supported a diagnosis of HCC in 20 (100%) patients and 31 (97%) lesions. Most of the ringed lesions had early AP timing.

CONCLUSION

This study revealed a high prevalence (41%) of small, AP ring HCC with MRI. The use of other MRI sequences adds support in making the proper diagnosis with this appearance. Early AP timing may help create this pattern.

NIACE score for hepatocellular carcinoma patients treated by surgery or transarterial chemoembolization

BACKGROUND AND AIMS

Hepatocellular carcinoma (HCC) prognostic scores could be useful in addition to the Barcelona Clinic Liver Cancer (BCLC) system to clarify patient prognosis and guide treatment decision. The NIACE (tumor Nodularity, Infiltrative nature of the tumor, serum Alpha-fetoprotein level, Child-Pugh stage, ECOG performance status) score distinguishes different prognosis groups among BCLC A, B, and C HCC patients. Our aims are to evaluate the NIACE score and its additive value in two HCC cohorts treated either by surgery or by chemoembolization, and then according to the BCLC recommendations.

PATIENTS AND METHODS

This was a retrospective multicenter study with two BCLC A, B, and C HCC cohorts treated either by surgery (n=207) or by chemoembolization (n=168) carried out between 2008 and 2013. We studied survival time according to the baseline NIACE score and compared it with the Cancer of the Liver Italian Program score and the BCLC system.

RESULTS

The NIACE score differentiates between subgroups of patients with different prognosis within each BCLC class. Among BCLC A patients treated by surgery and BCLC B patients treated by chemoembolization, the NIACE score differentiates between two subgroups with a significant difference in survival time: 68 (55-81) months versus 35 (21-56) months (P=0.0004) and 20 (17-24) months versus 13 (7-17) months (P=0.0008), respectively. Among those subgroups, the NIACE score has a significantly better prognostic value than the BCLC system or the Cancer of the Liver Italian Program score.

CONCLUSION

In this study, among HCC patients treated according to the BCLC recommendations, the NIACE score predicts more accurately than any other system the survival time.

Rate of local tumor progression following radiofrequency ablation of pathologically early hepatocellular carcinoma

AIM

To evaluate whether pathologically early hepatocellular carcinoma (HCC) exhibited local tumor progression after radiofrequency ablation (RFA) less often than typical HCC.

METHODS

Fifty pathologically early HCCs [tumor diameter (mm): mean, 15.8; range, 10-23; follow-up days after RFA: median, 1213; range, 216-2137] and 187 typical HCCs [tumor diameter (mm): mean, 15.6; range, 6-30; follow-up days after RFA: median, 1116; range, 190-2328] were enrolled in this retrospective study. The presence of stromal invasion (namely, tumor cell invasion into the intratumoral portal tracts) was considered to be the most important pathologic finding for the diagnosis of early HCCs. Typical HCC was defined as the presence of a hyper-vascular lesion accompanied by delayed washout using contrast-enhanced computed tomography or contrast-enhanced magnetic resonance imaging. Follow-up examinations were performed at 3-mo intervals to monitor for signs of local tumor progression. The local tumor progression rates of pathologically early HCCs and typical HCCs were then determined using the Kaplan-Meier method.

RESULTS

During the follow-up period for the 50 pathologically early HCCs, 49 (98%) of the nodules did not exhibit local tumor progression. However, 1 nodule (2%) was associated with a local tumor progression found 636 d after RFA. For the 187 typical HCCs, 46 (24.6%) of the nodules exhibited local recurrence after RFA. The follow-up period until the local tumor progression of typical HCC was a median of 605 d, ranging from 181 to 1741 d. Among the cases with typical HCCs, local tumor progression had occurred in 7.0% (7/187), 16.0% (30/187), 21.9% (41/187) and 24.6% (46/187) of the cases at 1, 2, 3 and 4 years, respectively. Pathologically early HCC was statistically associated with a lower rate of local tumor progression, compared with typical HCC, when evaluated using a log-rank test (P = 0.002).

CONCLUSION

The rate of local tumor progression for pathologically early HCCs after RFA was significantly lower than that for typical HCCs.

Single Hepatocellular Carcinoma: Preoperative MR Imaging to Predict Early Recurrence after Curative Resection

PURPOSE

To identify magnetic resonance (MR) imaging features that enable prediction of early recurrence (<2 years) after curative resection of hepatocellular carcinoma (HCC) and to derive a preoperative prediction model.

MATERIALS AND METHODS

This retrospective study was approved by the institutional review board. The requirement to obtain written informed consent was waived. A total of 268 patients who underwent hepatic resection for a single HCC from January 2008 to August 2011 were divided into two cohorts: a training cohort, which was used to derive a prediction model (n = 187), and a validation cohort (n = 81). All MR images from the training cohort were reviewed by two radiologists. A prediction model was constructed by using MR imaging features that were independently associated with early recurrence with use of multiple logistic regression analysis. The performance of the prediction model in the validation cohort was evaluated with respect to discrimination (ie, whether the relative ranking of individual predictions of subsequent early recurrence is in the correct order).

RESULTS

In the training cohort, four MR imaging features were independently associated with early recurrence: rim enhancement (odds ratio [OR] = 3.83; 95% confidence interval [CI]: 1.39, 10.52), peritumoral parenchymal enhancement in the arterial phase (OR = 2.64; 95% CI: 1.27, 5.46), satellite nodule (OR = 4.07; 95% CI: 1.09, 15.21), and tumor size (OR = 1.66; 95% CI: 1.31, 2.09). A prediction model derived from these variables showed an area under the receiver operating characteristic curve (AUC) of 0.788 in the prediction of the risk of early recurrence in the training cohort. When applied to the validation cohort, this model showed good discrimination (AUC, 0.783).

CONCLUSION

The prediction model derived from rim enhancement, peritumoral parenchymal enhancement, satellite nodule, and tumor size can be used preoperatively to estimate the risk of early recurrence after resection of a single HCC.

Post-transplantation hepatocellular carcinoma recurrence: Patterns and relation between vascularity and differentiation degree

AIM: To evaluate the relationship between hepatocellular carcinoma (HCC) vascularity and grade; to describe patterns and vascular/histopathological variations of post-transplantation recurrence.

METHODS: This retrospective study included 165 patients (143 men, 22 women; median age 56.8 years, range 28-70.4 years) transplanted for HCC who had a follow-up period longer than 2 mo. Pre-transplantation dynamic computed tomography or magnetic resonance examinations were retrospectively reviewed, classifying HCC imaging enhancement pattern into hypervascular and hypovascular based on presence of wash-in during arterial phase. All pathologic reports of the explanted livers were reviewed, collecting data about HCC differentiation degree. The association between imaging vascular pattern and pathological grade was estimated using the Fisher exact test. All follow-up clinical and imaging data were reviewed for evidence of recurrence. Recurrence rate was calculated and imaging features of recurrent tumor were collected, classifying early and late recurrences based on timing (< or ≥ 2 years after transplantation) and intrahepatic, extrahepatic and both intrahepatic and extrahepatic recurrences based on location. All intrahepatic recurrences were classified as hypervascular or hypovascular and the differentiation degree was collected where available. The presence of variations in imaging enhancement pattern and pathological grade between the primary tumor and the intrahepatic recurrence was evaluated and the association between imaging and histopatholgical variations was estimated by using the χ² test.

RESULTS: Of the 163 patients with imaging evidence of viable tumor, 156 (95.7%) had hypervascular and 7 (4.3%) hypovascular HCC. Among the 125 patients with evidence of viable tumor in the explanted liver, 19 (15.2%) had grade 1, 56 (44.8%) grade 2, 40 (32%) grade 3 and 4 (3.2%) grade 4 HCC, while the differentiation degree was not assessable for 6 patients (4.8%). A significant association was found between imaging vascularity and pathological grade (P = 0.035). Post-transplantation recurrence rate was 14.55% (24/165). All recurrences occurred in patients who had a hypervascular primary tumor. Three patients (12.5%) experienced late recurrence; the location of the first recurrence was extrahepatic in 14 patients (58.3%), intrahepatic in 7 patients (29.2%) and both intrahepatic and extrahepatic in 3 patients (12.5%). Two patients had a variation in imaging characteristics between the primary HCC (hypervascular) and the intrahepatic recurrent HCC (hypovascular), while 1 patient had a variation of histopathological characteristics (from moderate to poor differentiation), however no association was found between imaging and histopathological variations.

CONCLUSION: A correlation was found between HCC grade and vascularity; some degree of variability may exist between the primary and the recurrence imaging/histopathological characteristics, apparently not correlated.

CT and MR imaging diagnosis and staging of hepatocellular carcinoma: part II. Extracellular agents, hepatobiliary agents, and ancillary imaging features

Computed tomography (CT) and magnetic resonance (MR) imaging play critical roles in the diagnosis and staging of hepatocellular carcinoma (HCC). The second article of this two-part review discusses basic concepts of diagnosis and staging, reviews the diagnostic performance of CT and MR imaging with extracellular contrast agents and of MR imaging with hepatobiliary contrast agents, and examines in depth the major and ancillary imaging features used in the diagnosis and characterization of HCC.

In hepatocellular carcinomas, any proportion of poorly differentiated components is associated with poor prognosis after hepatectomy

BACKGROUND

Hepatocellular carcinoma (HCC) often consists of various differentiation components in a single tumor. However, the categorization of histologic grade in hepatectomy for those tumors has not been standardized. Some studies have determined the differentiation grade of the tumor according to its worst component, whereas others have determined it according to its predominant component. The present study aimed to resolve the controversy about whether the worst component or the dominant component determines the nature of the tumor, especially focusing on the presence of a poorly differentiated component (PDC).

METHODS

In total, 427 hepatectomized patients with solitary HCC were divided into three groups, tumors without a PDC (NP), tumors with a PDC but dominantly consisting of non-PDC as poorly contained (PC), and tumors predominantly consisted of a PDC as poorly dominant (PD). PC was compared with PD and NP.

RESULTS

Statistical analysis revealed that large tumors and high alpha-fetoprotein level were significantly more frequent in PC than in NP (P < 0.01 and P = 0.04, respectively), although no remarkable difference was observed between PC and PD. Both recurrence-free and overall survival rates were significantly worse in the PC and PD groups than in the NP group (PC vs. NP: P = 0.01 and P < 0.01, PD vs. NP: P < 0.01 and P < 0.01, respectively), but there was no significant difference in these parameters between PC and PD.

CONCLUSIONS

All HCC, including PDC, should be categorized as poorly differentiated HCC regardless of the predominant differentiation component.

Computed tomography during hepatic arteriography pattern may predict hepatocellular carcinoma recurrence following transarterial chemoembolization

AIM

This study aimed to determine the role of morphological patterns seen on imaging in predicting hepatocellular carcinoma recurrence following transarterial chemoembolization therapy.

METHODS

Forty-seven patients from a single center who underwent transarterial chemoembolization to treat unresectable hepatocellular carcinomas between January 2011 and June 2012 were included in this study. We investigated whether the two pretreatment findings on computed tomography during hepatic arteriography (pattern 1, the single nodule pattern; pattern 2, at least one nodule showing the contiguous multinodular pattern) and other factors (age, sex, etiology, serum total bilirubin, serum albumin, prothrombin time, platelet count, serum level of protein induced by vitamin K absence/antagonist-II, serum α-fetoprotein, number of previous treatments for hepatocellular carcinoma, tumor number and maximum tumor size, presence of hypovascular lesions) could predict post-treatment recurrence.

RESULTS

In a univariate analysis using Cox's proportional hazards model, serum total bilirubin, the serum level of protein induced by vitamin K absence/antagonist-II (≤100 vs ≥101 mAU/mL), tumor morphology (pattern 1 vs 2) and tumor number (≤3 vs ≥4) showed statistical significance (≤0.05). In a multivariate analysis of these factors, morphology and tumor number showed significance. According to Kaplan-Meier estimation, the cumulative disease-free survival rates were significantly lower in patients with four or more lesions than in those with three or less lesions and in patients showing pattern 2 than in those showing pattern 1.

CONCLUSION

Patients with pattern 2 hepatocellular carcinoma and/or four or more lesions may have a relatively high recurrence rate after transarterial chemoembolization.

Potential of a no-touch pincer ablation procedure for small hepatocellular carcinoma that uses a multipolar radiofrequency ablation system: An experimental animal study

AIM

Treatment of hepatocellular carcinoma located on the liver surface is frequently difficult because direct puncture of the tumor must be avoided during needle insertion. The aim of this study was to investigate the utility of a no-touch pincer ablation procedure that uses a multipolar radiofrequency ablation (RFA) system for a tumor located on the liver surface.

METHODS

The experimental animals were three pigs, and RFA was performed with two internally cooled bipolar electrodes. Three ablative procedures were compared: linear insertion at regular 13-mm intervals (pattern 1; virtual target tumor size, <10 mm); fan-shape insertion, maximum interval 20 mm (pattern 2; virtual target tumor size, <15 mm); and 25 mm (pattern 3; virtual target tumor size, <20 mm). All electrodes were inserted at a 30-mm depth. For patterns 1 and 2, ablation was performed on three other parts of the liver, and for pattern 3, ablation was performed on two other parts.

RESULTS

For the median transverse and longitudinal diameter to the shaft, with the pattern 1 procedure, the ablative areas were 32 mm × 30 mm, and with the pattern 2 procedure, the ablative areas were 27 mm × 30 mm with carbonization of the liver surface. In contrast, with the pattern 3 procedure, the ablative areas were 45 mm × 26 mm; however, the ablative margin did not reach the surface, and carbonization was not apparent.

CONCLUSION

The no-touch pincer ablation procedure (with an electrode interval of ≤20 mm) may be useful when performed with two internally cooled bipolar electrodes for small nodules that protrude from the liver surface.

Clinicopathology of recurrent hepatocellular carcinomas after radiofrequency ablation treated with salvage surgery

AIM

Radiofrequency ablation (RFA) is an effective standard local therapy for small hepatocellular carcinoma (HCC). However, local recurrence and/or tumor seeding after RFA remain major problems. For better understanding of underlying factors, we clarified clinicopathological features of recurrent HCC treated with RFA.

METHODS

This retrospective study included 21 patients who underwent surgical resection for HCC disease recurrence after RFA. Clinicopathological findings, including patterns of recurrence, immunohistochemical expression of proliferation markers (Ki-67 and p27(Kip1) ) and survival outcome were assessed.

RESULTS

The median time interval after RFA until the diagnosis of intrahepatic and/or extrahepatic tumor progression was 12 months (range, 3-84). Radical surgical resection was attempted for intrahepatic local recurrence in 16 patients (18 lesions), for peritoneal dissemination in four, for lymph node metastases in three and for adrenal metastasis in two. In 14 of the 21 (67%) patients, the recurrent HCC were histologically diagnosed as of poorly differentiated type. Their average Ki-67 and p27(Kip1) labeling indices were significantly higher (P = 0.020) and lower (P < 0.001), respectively, compared with values for the 108 HCC surgically resected at the initial treatment. Portal involvement was significantly higher (P = 0.01) in recurrent tumors after RFA (72%) than in HCC surgically resected at the initial treatment (43%). The mortality rate of salvage surgery was 0%, with cumulative survival rates at 1 and 3 years of 58.9% and 35.7%, respectively.

CONCLUSION

The recurrent tumors after RFA have characteristics of poor differentiation degree and abnormalities in cell-cycle regulators and are associated with aggressive vascular invasiveness.

Ablation of hepatocellular carcinoma

Radiofrequency ablation (RFA) has gained a wide acceptance as a first-line therapeutic option for small hepatocellular carcinoma (HCC). For very early-stage HCC, despite a higher rate of local tumour progression, RFA is considered as a viable alternative to surgical resection owing to its comparable long-term survival, reduced morbidity, and greater preservation of hepatic parenchyma. For HCCs larger than 2 cm, RFA can contribute to near-curative therapy when combined with chemoembolization. RFA can be used as part of a multimodal treatment strategy for more advanced or recurrent cases, and could be a useful bridging therapy for patients who are waiting for liver transplantation. However, the use of RFA is still limited in treating large tumours and some tumours in high-risk locations. To overcome its current limitations, other ablation techniques are being developed and it is important to validate the role of other techniques for enhancing performance of ablation therapy for HCC.

Prognostic factors for hepatocellular carcinoma recurrence

The recurrence of hepatocellular carcinoma, the sixth most common neoplasm and the third leading cause of cancer-related mortality worldwide, represents an important clinical problem, since it may occur after both surgical and medical treatment. The recurrence rate involves 2 phases: an early phase and a late phase. The early phase usually occurs within 2 years after resection; it is mainly related to local invasion and intrahepatic metastases and, therefore, to the intrinsic biology of the tumor. On the other hand, the late phase occurs more than 2 years after surgery and is mainly related to de novo tumor formation as a consequence of the carcinogenic cirrhotic environment. Since recent studies have reported that early and late recurrences may have different risk factors, it is clinically important to recognize these factors in the individual patient as soon as possible. The aim of this review was, therefore, to identify predicting factors for the recurrence of hepatocellular carcinoma, by means of invasive and non-invasive methods, according to the different therapeutic strategies available. In particular the role of emerging techniques (e.g., transient elastography) and biological features of hepatocellular carcinoma in predicting recurrence have been discussed. In particular, invasive methods were differentiated from non-invasive ones for research purposes, taking into consideration the emerging role of the genetic signature of hepatocellular carcinoma in order to better allocate treatment strategies and surveillance follow-up in patients with this type of tumor.

Prediction of poorly differentiated hepatocellular carcinoma using contrast computed tomography

BACKGROUND

Percutaneous radiofrequency ablation (RFA) is a well-established local treatment for small hepatocellular carcinoma (HCC). However, poor differentiation is a risk factor for tumor seeding or intrahepatic dissemination after RFA for HCC. The present study aimed to develop a method for predicting poorly differentiated HCC using contrast computed tomography (CT) for safe and effective RFA.

METHODS

Of HCCs diagnosed histologically, 223 patients with 226 HCCs showing tumor enhancement on contrast CT were analyzed. The tumor enhancement pattern was classified into two categories, with and without non-enhanced areas, and tumor stain that disappeared during the venous or equilibrium phase with the tumor becoming hypodense was categorized as positive for washout.

RESULTS

The 226 HCCs were evaluated as well differentiated (w-) in 56, moderately differentiated (m-) in 137, and poorly differentiated (p-) in 33. The proportions of small HCCs (3 cm or less) in w-HCCs, m-HCCs, and p-HCCs were 86% (48/56), 59% (81/137), and 48% (16/33), respectively. The percentage with heterogeneous enhancement in all HCCs was 13% in w-HCCs, 29% in m-HCCs, and 85% in p-HCCs. The percentage with tumor stain washout in the venous phase was 29% in w-HCCs, 63% in m-HCCs, and 94% in p-HCCs. The percentage with heterogeneous enhancement in small HCCs was 10% in w-HCCs, 10% in m-HCCs, and 75% in p-HCCs. The percentage with tumor stain washout in the venous phase in small HCCs was 23% in w-HCCs, 58% in m-HCCs, and 100% in p-HCCs. Significant correlations were seen for each factor (p < 0.001 each). Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for prediction of poor differentiation in small HCCs by tumor enhancement with non-enhanced areas were 75%, 90%, 48%, 97%, and 88%, respectively; for tumor stain washout in the venous phase, these were 100%, 55%, 22%, 100%, and 60%, respectively.

CONCLUSIONS

Tumor enhancement patterns were associated with poor histological differentiation even in small HCCs. Tumor enhancement with non-enhanced areas was valuable for predicting poorly differentiated HCC.