Radiologic-pathologic correlation of hepatocellular carcinoma treated with chemoembolization

Comparative Radiologic Response Assessment after Transarterial Chemoembolization, Percutaneous Ablation, and Multimodal Treatment: Radiologic-Pathologic Correlation in 81 Tumors

PURPOSE

To compare concordance of radiologic and pathologic response of hepatocellular carcinoma (HCC) to transarterial chemoembolization (TACE), percutaneous ablation, and multimodal treatment using radiologic-pathologic correlation.

MATERIALS AND METHODS

This single-center retrospective study analyzed 56 treatment-naive patients (male, 75%; Barcelona Clinic Liver Cancer Stage A, 63%) with 81 HCC tumors (mean diameter, 2.1 cm [SD ± 0.9]) who underwent locoregional therapy (LRT) (TACE, n = 44; ablation, n = 10; TACE + ablation, n = 27) prior to liver transplantation (LT) between 2010 and 2019. Immediate pre-LT cross-sectional imaging was used to assess modified Response Evaluation Criteria in Solid Tumours (mRECIST) response. Explant liver pathology was reviewed for percent pathologic necrosis (PN). Associations between imaging and pathologic observations were statistically characterized using the chi-square and Kruskal-Wallis tests.

RESULTS

Median time from imaging to LT was 37 days (range, 2-191 days). Across all LRT types, 68% (55/81), 19% (15/81), and 13% (11/83) of tumors displayed mRECIST complete response (CR), partial response (PR), and stable disease. The mean percent PN (%PN) in CR tumors (89% [SD ± 21]) was significantly higher than those in PR (68% [SD ± 34], P = .005) and stable disease (67% [SD ± 36], P = .009) tumors. Sixty percent (33/55) of CR tumors showed 100% complete PN (CPN), whereas only 20% (3/15) of PR tumors and 18% (2/11) of stable disease tumors showed CPN (P = .002). There was no association between %PN and CPN across different LRT modalities and radiologic response categories, indicating consistent performance between treatments. Sensitivity and specificity for radiologic CR to predict 100% PN were 87% and 49%, respectively.

CONCLUSIONS

Herein, radiologic-pathologic outcomes suggest that radiologic response criteria are associated with PN, with no differences across treatment modalities. However, the imperfect predictive capacity of imaging for PN supports surveillance of treated tumors before LT.

CT/MRI LI-RADS 2024 Update: Treatment Response Assessment

With the rising incidence of hepatocellular carcinoma, there has been increasing use of local-regional therapy (LRT) to downstage or bridge to transplant, for definitive treatment, and for palliation. The CT/MRI Liver Imaging Reporting and Data System (LI-RADS) Treatment Response Assessment (TRA) algorithm provides guidance for step-by-step tumor assessment after LRT and standardized reporting. Current evidence suggests that the algorithm performs well in the assessment of tumor response to arterial embolic and loco-ablative therapies and fair when assessing response to radiation-based therapies, with limited data to validate the latter. Both evidence-based and expert-based refinements of the algorithm are needed to improve its diagnostic accuracy after varying types of LRT. This review provides an overview of the challenges and limitations of the LI-RADS TRA algorithm version 2017 and discusses the refinements introduced in the updated 2024 LI-RADS algorithm for CT/MRI.

Influence of the Radiological Response on Histological Necrosis and on the Survival of Patients Treated With Transarterial Chemoembolization for Hepatocellular Carcinoma Secondary to Cirrhosis on the Liver Transplantation Waiting List

BACKGROUND AND AIMS

Transarterial chemoembolization is the most common treatment used for HCC patients on liver transplant waiting list. The aims of this study are to evaluate the radio-histological correlation of the post-chemoembolization HCC response and its influence on overall survival (OS) and recurrence-free survival (RFS).

METHODS

Monocentric, retrospective study, including liver transplant patients with HCC who received chemoembolization from 2007 to 2018. The response of the hypervascular nodules was evaluated according to mRECIST, EASL.

RESULTS

A total of 70 patients with 122 hypervascular and 28 hypovascular HCCs were included. A complete radiological response concerned 34.3% patients. Concordance rates of hypervascular nodules (mRECIST, EASL and lipiodol uptake) with tumor necrosis ranged from 49% to 57%, with a specificity of 35% and a positive predictive value of 54%. Bilobar involvement was a predictive factor for incomplete radiological response. Major tumor necrosis was significantly correlated with the decrease in αFP level between the first CEL and liver transplantation. OS and RFS at 5 years were 64% and 60%, respectively, and 69% and 66% at complete radiological response.

CONCLUSION

Radiological response is significantly related to histological tumor necrosis, but with poor prediction. In case of complete radiological response, OS and RFS seem to be improved.

Ethiodized oil as an imaging biomarker after conventional transarterial chemoembolization

Conventional transarterial chemoembolization (cTACE) utilizing ethiodized oil as a chemotherapy carrier has become a standard treatment for intermediate-stage hepatocellular carcinoma (HCC) and has been adopted as a bridging and downstaging therapy for liver transplantation. Water-in-oil emulsion made up of ethiodized oil and chemotherapy solution is retained in tumor vasculature resulting in high tissue drug concentration and low systemic chemotherapy doses. The density and distribution pattern of ethiodized oil within the tumor on post-treatment imaging are predictive of the extent of tumor necrosis and duration of response to treatment. This review describes the multiple roles of ethiodized oil, particularly in its role as a biomarker of tumor response to cTACE. CLINICAL RELEVANCE: With the increasing complexity of locoregional therapy options, including the use of combination therapies, treatment response assessment has become challenging; Ethiodized oil deposition patterns can serve as an imaging biomarker for the prediction of treatment response, and perhaps predict post-treatment prognosis. KEY POINTS: • Treatment response assessment after locoregional therapy to hepatocellular carcinoma is fraught with multiple challenges given the varied post-treatment imaging appearance. • Ethiodized oil is unique in that its' radiopacity can serve as an imaging biomarker to help predict treatment response. • The pattern of deposition of ethiodozed oil has served as a mechanism to detect portions of tumor that are undertreated and can serve as an adjunct to enhancement in order to improve management in patients treated with intraarterial embolization with ethiodized oil.

Prognostic value of systemic immune-inflammation index/ albumin for transcatheter arterial chemoembolization treatment

Background and objective

In the process of tumor occurrence, evolution and development, immune, inflammation and nutrition are principal elements. The purpose of this study was to assess the prognostic value of systemic immune-inflammation index/albumin (SII/ALB) for patients with HBV-related hepatocellular carcinoma (HCC) who underwent transcatheter arterial chemoembolization (TACE).

Methods

A total of 125 HBV-related HCC patients met inclusion criteria and were all enrolled in this research. The survminer R package. was used to calculate the best SII/ALB cutoff values. Chi-square test was used to analyze the relationship between SII/ALB and clinicopathological parameters. Kaplan-Meier curves and Cox proportional hazards models were used to investigate the effect of SII/ALB on overall survival (OS).

Results

The cutoff value of SII/ALB was 2.992. In the derivation cohort, the patients were divided into SII/ALB-low (SII/ALB≤2.992) and SII/ALB-high (SII/ALB >2.992) groups. SII/ALB-high was found in patients with tumor size ≥3 (cm), white blood cell ≥3.5 (10⁹/L), platelet ≥100 (10⁹/L), neutrophils ≥1.8 (10⁹/L), PT ≥ 14(s), SII ≥100, NLR ≥1.50 and PLR ≥60, (P < 0.05). The Kaplan-Meier curves showed that elevated SII/ALB were associated with decreased OS. OS rate of SII/ALB-low and SII/ALB-high groups at 1 and 2 years were 96.6% vs. 70.3% and 87.8% vs. 48.5%, respectively (C² = 9.804, P = 0.002). The BCLC stage, tumor number, tumor size, vascular invasion, AST, SII/ALB, SII, NLR and PNI were all significant prognostic indicators of OS. The SII/ALB (HR: 17.98; 95%CI: 1.82-177.32) and tumor size (HR: 3.26; 95%CI: 1.27-8.35) were all independent prognostic factors for OS, (p < 0.05).Conclusion: we found that SII/ALB could be an important prognostic parameter for HBV-related HCC patients after TACE treatment.

Evolution of Radioembolization in Treatment of Hepatocellular Carcinoma: A Pictorial Review

Transarterial radioembolization (TARE) with yttrium 90 has increasingly been performed to treat hepatocellular carcinoma (HCC). TARE was historically used as a palliative lobar therapy for patients with advanced HCC beyond surgical options, ablation, or transarterial chemoembolization, but recent advancements have led to its application across the Barcelona Clinic Liver Cancer staging paradigm. Newer techniques, termed radiation lobectomy and radiation segmentectomy, are being performed before liver resection to facilitate hypertrophy of the future liver remnant, before liver transplant to bridge or downstage to transplant, or as a definite curative treatment. Imaging assessment of therapeutic response to TARE is challenging as the intent of TARE is to deliver local high-dose radiation to tumors through microembolic microspheres, preserving blood flow to promote radiation injury to the tumor. Because of the microembolic nature, early imaging assessment after TARE cannot rely solely on changes in size. Knowledge of the evolving methods of TARE along with the tools to assess posttreatment imaging and response is essential to optimize TARE as a therapeutic option for patients with HCC. ^©RSNA, 2021.

Predicting Long-Term Hepatocellular Carcinoma Response to Transarterial Radioembolization Using Contrast-Enhanced Ultrasound: Initial Experiences

Conventional cross-sectional imaging done shortly after radioembolization of hepatocellular carcinoma (HCC) does not reliably predict long-term response to treatment. This study evaluated whether quantitative contrast-enhanced ultrasound (CEUS) can predict the long-term response of HCC to yttrium-90 (Y-90) treatment. Fifteen patients underwent CEUS at three time points: immediately following treatment and 1 and 2 wk post-treatment. Response 3-6 mo after treatment was categorized on contrast-enhanced magnetic resonance imaging by two experienced radiologists using the Modified Response Evaluation Criteria in Solid Tumors. CEUS data were analyzed by quantifying tumor perfusion and residual fractional vascularity using time-intensity curves. Patients with stable disease on magnetic resonance imaging had significantly greater fractional vascularity 2 wk post-treatment (65.15%) than those with partial or complete response (13.8 ± 9.9%, p = 0.007, and 14.9 ± 15.4%, p = 0.009, respectively). Complete responders had lower tumor vascularity at 2 wk than at post-operative examination (-38.3 ± 15.4%, p = 0.045). Thus, this pilot study suggests CEUS may provide an earlier indication of Y-90 treatment response than cross-sectional imaging.

Automated feature quantification of Lipiodol as imaging biomarker to predict therapeutic efficacy of conventional transarterial chemoembolization of liver cancer

Conventional transarterial chemoembolization (cTACE) is a guideline-approved image-guided therapy option for liver cancer using the radiopaque drug-carrier and micro-embolic agent Lipiodol, which has been previously established as an imaging biomarker for tumor response. To establish automated quantitative and pattern-based image analysis techniques of Lipiodol deposition on 24 h post-cTACE CT as biomarker for treatment response. The density of Lipiodol deposits in 65 liver lesions was automatically quantified using Hounsfield Unit thresholds. Lipiodol deposition within the tumor was automatically assessed for patterns including homogeneity, sparsity, rim, and peripheral deposition. Lipiodol deposition was correlated with enhancing tumor volume (ETV) on baseline and follow-up MRI. ETV on baseline MRI strongly correlated with Lipiodol deposition on 24 h CT (p < 0.0001), with 8.22% ± 14.59 more Lipiodol in viable than necrotic tumor areas. On follow-up, tumor regions with Lipiodol showed higher rates of ETV reduction than areas without Lipiodol (p = 0.0475) and increasing densities of Lipiodol enhanced this effect. Also, homogeneous (p = 0.0006), non-sparse (p < 0.0001), rim deposition within sparse tumors (p = 0.045), and peripheral deposition (p < 0.0001) of Lipiodol showed improved response. This technical innovation study showed that an automated threshold-based volumetric feature characterization of Lipiodol deposits is feasible and enables practical use of Lipiodol as imaging biomarker for therapeutic efficacy after cTACE.

Influence of pretreatment tumor growth rate on objective response of hepatocellular carcinoma treated with transarterial chemoembolization

BACKGROUND AND AIM

The study aims to assess the influence of pretreatment tumor growth rate (TGR) on modified response evaluation criteria in solid tumors (mRECIST) objective response (OR) after a first session of selective transarterial chemoembolization (TACE) for the treatment of hepatocellular carcinoma (HCC).

METHODS

One hundred fifteen patients (101 men [88%], mean 65.1 ± 10.5 years [range 26-87]) with 169 tumors (mean 34.2 ± 29.3 mm [10-160]), undergoing a first session of selective TACE for the treatment of HCC between 2011 and 2016, were included. TGR was calculated as the percentage change in tumor volume per month (%/month) on imaging before treatment. TGR cut-off for prediction of OR was identified by receiver operating characteristic curve analysis.

RESULTS

Overall 88/189 (52%) and 46/189 (27%) tumors showed complete response (CR) and partial response (PR) (OR rate 79%), while 32/189 (19%) showed stable disease (SD), and 3/189 (2%) were progressive disease (PD) on computed tomography at 1-month post-TACE. The mean pretreatment TGR was 12.0 ± 15.4 (-3.2-90.4) %/month. TGR of tumors showing CR, PR, SD, and PD was a mean 13.2 ± 16.4%, 12.1 ± 15.1%, 5.3 ± 4.5%, and 44.8 ± 20.4%, respectively (P < 0.001). The three tumors showing PD had TGR values > 20%/month. TGR was significantly higher in tumors with OR (12.8 ± 15.9% vs 5.3 ± 4.5% in SD, P = 0.009). A cut-off value of 6.5%/month had the highest predictive value of OR (AUROC 0.65 ± 0.05, P = 0.009).

CONCLUSION

Pretreatment TGR is highly variable in HCC before TACE with a U-shaped distribution for the prediction of tumor response. It provides insight into tumor biology that may be used during pretreatment workup to help stratify patients.

Pathologic complete response to chemoembolization improves survival outcomes after curative surgery for hepatocellular carcinoma: predictive factors of response

BACKGROUND

We identified the predictive factors and prognostic significance of transarterial chemoembolization (TACE) for achieving pathologic complete response (pCR) before curative surgery for hepatocellular carcinoma (HCC) in hepatitis B-endemic areas.

METHODS

Among 753 HCC patients treated with surgery, 124 patients underwent preoperative TACE before liver resection (LR), and 166 before liver transplantation (LT) between 2005 and 2016. Overall survival (OS) and recurrence-free survival (RFS) were analyzed. Pathologic response (PR) was defined as the mean percentage of necrotic area, and pCR was defined as the absence of viable tumor.

RESULTS

A total of 34 (27%) and 38 (23%) patients had pCR before LR and LT, respectively. Alpha-fetoprotein (AFP) < 100 ng/mL and single tumor were significant preoperative predictors of pCR. OS and RFS were significantly improved in patients with pCR or a PR ≥ 90%, but not in patients with PR ≥ 50% after LR and LT. On multivariate analyses, PR ≥ 90% remained an independent predictor of better OS and RFS in LR and LT groups.

CONCLUSION

Overall, our data clearly demonstrate that pCR predicts favorable prognosis after curative surgery for HCC, and predictors of pCR are AFP <100 ng/mL and single tumor.

Radiological appearance of hepatocellular carcinoma predicts the response to trans-arterial chemoembolization in patients undergoing liver transplantation

Background

The ultimate goal of locoregional therapy (LRT) to the liver is to induce total tumor necrosis. Trans-arterial chemoembolization (TACE) is the mainstay bridging therapy for patients with hepatocellular carcinoma (HCC) waiting for liver transplantation (LT). However, tumor response rate is variable. The purpose of this study was to correlate HCC radiological appearance with level of tumor necrosis during explant analysis from patients undergoing LT who received pre-LT TACE.

Methods

From January 2000 to December 2018, a total of 66 patients with HCC who had been treated prior to LT by means of TACE were analyzed. Diagnosis of HCC was made based on AASLD guidelines and confirmed via histopathology explant analysis. Radiologic tumor response after TACE was based on modified Response Evaluation Criteria in Solid Tumors (mRECIST). Degree of tumor necrosis was determined by histopathology analysis of liver explants. HCC radiological appearances on CT before TACE were assessed and correlated with histological findings after LT.

Results

Eighty nine TACE procedures (1.35 ± 0.67; 1–4) were performed, of which 18 were repeated TACE (27.3%) procedures. In 56.1% of the patients, ≥90% (near-complete) tumor necrosis was achieved. Concordance between mRECIST criteria and pathology was observed in 63% of the patients, with an underestimation of tumor response in 18 (27%) patients and an overestimation in 6 (9.1%). Near-complete tumor necrosis upon pathological analysis was associated with tumor hyper-enhancement in the arterial phase (P = 0.002), “typical tumor enhancement” (P = 0.010) and smooth tumor margins (p = 0.011). The multivariate analysis showed that well circumscribed HCCs with smooth margins and arterial hyper-enhancement independently correlated with post-TACE near-complete histological tumor necrosis.

Conclusions

The well circumscribed HCC lesions with arterial hyper-enhancement are more susceptible to TACE than lesions with arterial phase iso or hypo-enhancement and lesions with infiltrative appearance. Pre-TACE CT imaging may ease the selection of an optimal treatment strategy for bridging patients with HCC to liver transplantation.

Radiologic Modalities and Response Assessment Schemes for Clinical and Preclinical Oncology Imaging

Clinical drug trials for oncology have resulted in universal protocols for medical imaging in order to standardize protocols for image procurement, radiologic interpretation, and therapeutic response assessment. In recent years, there has been increasing interest in using large animal models to study oncologic disease, though few standards currently exist for imaging of large animal models. This article briefly reviews medical imaging modalities, the current state-of-the-art in radiologic diagnostic criteria and response assessment schemes for evaluating therapeutic response and disease progression, and translation of radiologic imaging protocols and standards to large animal models of malignant disease.

Theranostics in Interventional Oncology: Versatile Carriers for Diagnosis and Targeted Image-Guided Minimally Invasive Procedures

We are continuously progressing in our understanding of cancer and other diseases and learned how they can be heterogeneous among patients. Therefore, there is an increasing need for accurate characterization of diseases at the molecular level. In parallel, medical imaging and image-guided therapies are rapidly developing fields with new interventions and procedures entering constantly in clinical practice. Theranostics, a relatively new branch of medicine, refers to procedures combining diagnosis and treatment, often based on patient and disease-specific features or molecular markers. Interventional oncology which is at the convergence point of diagnosis and treatment employs several methods related to theranostics to provide minimally invasive procedures tailored to the patient characteristics. The aim is to develop more personalized procedures able to identify cancer cells, selectively reach and treat them, and to assess drug delivery and uptake in real-time in order to perform adjustments in the treatment being delivered based on obtained procedure feedback and ultimately predict response. Here, we review several interventional oncology procedures referring to the field of theranostics, and describe innovative methods that are under development as well as future directions in the field.

Diagnostic accuracy of MRI with extracellular vs. hepatobiliary contrast material for detection of residual hepatocellular carcinoma after locoregional treatment

PURPOSE

To compare the diagnostic accuracy of extracellular gadolinium-based contrast-enhanced MRI (Gd-MRI) and gadoxetic acid-enhanced MRI (EOB-MRI) for the assessment of hepatocellular carcinoma (HCC) response to locoregional therapy (LRT) using explant correlation as the reference standard.

METHODS

Forty-nine subjects with cirrhosis and HCC treated with LRT who underwent liver MRI using either Gd-MRI (n = 26) or EOB-MRI (n = 23) within 90 days of liver transplantation were included. Four radiologists reviewed the MR images blinded to histology to determine the size and percentage of viable residual HCC using a per-lesion explant reference standard. Sensitivities, specificities, accuracies, and agreement with histology for the detection residual HCC were calculated.

RESULTS

Gd-MRI had greater agreement with histology (ICC: 0.98 [0.95-0.99] vs. 0.80 [0.63-0.90]) and greater sensitivity for viable HCC (76% [13/17 50-93%] vs. 58% [7/12; 28-85%]) than EOB-MRI; specificities were similar (84% [16/19; 60-97%] vs. 85% [23/27; 66-96%]). Areas under ROC curves for detecting residual viable tumor were 0.80 (0.64-0.92) for Gd-MRI and 0.72 (0.55-0.85) for EOB-MRI. Gd-MRI had greater inter-rater agreement than EOB-MRI for determining the size of residual viable HCC (ICC: 0.96 [0.92-0.98] vs. 0.85 [0.72-0.92]).

CONCLUSION

Gd-MRI may be more accurate and precise than EOB-MRI for the assessment of viable HCC following LRT.

Mapping Drug Dose Distribution on CT Images Following Transarterial Chemoembolization with Radiopaque Drug-Eluting Beads in a Rabbit Tumor Model

Purpose To correlate bead location and attenuation on CT images with the quantity and distribution of drug delivered to the liver following transarterial chemoembolization (TACE) with radiopaque drug-eluting beads (DEB) in a rabbit tumor model. Materials and Methods All procedures were performed with a protocol approved by the Institutional Animal Care and Use Committee. TACE was performed in rabbits (n = 4) bearing VX2 liver tumors by using radiopaque DEB (70-150 µm) loaded with doxorubicin (DOX). Livers were resected 1 hour after embolization, immediately frozen, and cut by using liver-specific three-dimensional-printed molds for colocalization of liver specimens and CT imaging. DOX penetration into tissue surrounding beads was evaluated with fluorescence microscopy. DOX levels in liver specimens were predicted by using statistical models correlating DOX content measured in tissue with bead volume and attenuation measured on CT images. Model predictions were then compared with actual measured DOX concentrations to assess the models' predictive power. Results Eluted DOX remained in close proximity (<600 µm) to beads in the liver 1 hour after TACE. Bead volume and attenuation measured on CT images demonstrated positive linear correlations (0.950 and 0.965, respectively) with DOX content in liver specimens. DOX content model predictions based on CT images were accurate compared with actual liver DOX levels at 1 hour. Conclusion CT may be used to estimate drug dose delivery and distribution in the liver following transarterial chemoembolization (TACE) with doxorubicin-loaded radiopaque drug-eluting beads (DEB). Although speculative, this informational map might be helpful in planning and understanding the spatial effects of TACE with DEB. © RSNA, 2018.

Evaluation of the Heat Sink Effect After Transarterial Embolization When Performed in Combination with Thermal Ablation of the Liver in a Rabbit Model

PURPOSE

To assess the contribution of the heat sink effect when combining thermal ablation with transarterial embolization (TAE).

MATERIALS AND METHODS

Radiofrequency ablation (RFA) or microwave ablation (MWA) were performed in the liver of non-tumor bearing rabbits. Three perfusion groups were used: rabbits that were killed then immediately ablated (non-perfused liver group to simulate embolized tumor with no heat sink), rabbits that underwent hepatic TAE followed by ablation (embolized liver group), and rabbits that underwent ablation while alive (normally perfused liver control group). For each perfusion group, 8 RFAs and 8 MWAs were performed. Probes were inserted using ultrasound guidance to avoid areas with major blood vessels. During ablation, temperatures were obtained from a thermocouple located 1 cm away from the ablation probe to assess heat conduction. With MWA, temperatures were also measured from the antennae tip.

RESULTS

For RFA, embolization of normal liver did not increase temperature conduction when compared to the control group. However, temperature conduction was significantly increased in the non-perfused group (simulating embolized tumor) compared to controls (p = 0.007). For MWA, neither embolization nor non-perfusion increased temperature conduction compared to controls. With MWA, the probe tip temperature was significantly higher in the non-perfused group compared to the control and embolized group.

CONCLUSIONS

In non-perfused tissue simulating tumor, RFA demonstrated modest enhancement of temperature conduction, whereas MWA did not. Embolization of normal liver did not affect RFA or MWA. Findings suggest that heat sink mitigation plays a limited role with combination embolization-ablation therapies, albeit more with RFA than MWA.

Prediction of post-TACE necrosis of hepatocellular carcinoma usingvolumetric enhancement on MRI and volumetric oil deposition on CT, with pathological correlation

OBJECTIVE

To investigate whether volumetric enhancement on baseline MRI and volumetric oil deposition on unenhanced CT would predict HCC necrosis and response post-TACE.

METHOD

Of 115 retrospective HCC patients (173 lesions) who underwent cTACE, a subset of 53 HCC patients underwent liver transplant (LT). Semiautomatic volumetric segmentation of target lesions was performed on dual imaging to assess the accuracy of predicting tumour necrosis after TACE in the whole cohort and at pathology in the LT group. Predicted percentage tumour necrosis is defined as 100 % - (%baseline MRI enhancement - %CT oil deposition).

RESULTS

Mean predicted tumour necrosis by dual imaging modalities was 61.5 % ± 31.6%; mean percentage tumour necrosis on follow-up MRI was 63.8 % ± 31.5 %. In the LT group, mean predicted tumour necrosis by dual imaging modalities was 77.6 % ± 27.2 %; mean percentage necrosis at pathology was 78.7 % ± 31.5 %. There was a strong significant correlation between predicted tumour necrosis and volumetric necrosis on MRI follow-up (r = 0.889, p<0.001) and between predicted tumour necrosis and pathological necrosis (r = 0.871, p<0.001).

CONCLUSION

Volumetric pre-TACE enhancement on MRI and post-TACE oil deposition in CT may accurately predict necrosis in treated HCC lesions.

KEY POINTS

• Imaging-based tumour response can assist in therapeutic decisions. • Lipiodol retention as carrier agent in cTACE is a tumour necrosis biomarker. • Predicting tumour necrosis with dual imaging potentially obviates immediate post-treatment MRI. • Predicting tumour necrosis would facilitate further therapeutic decisions in HCC post-cTACE. • Pre-TACE MRI and post-TACE CT predict necrosis in treated HCC.

Evaluation of HCC response to locoregional therapy: Validation of MRI-based response criteria versus explant pathology

BACKGROUND AND AIMS

This study evaluates the performance of various magnetic resonance imaging (MRI) response criteria for the prediction of complete pathologic necrosis (CPN) of hepatocellular carcinoma (HCC) post locoregional therapy (LRT) using explant pathology as a reference.

METHODS

We included 61 patients (male/female 46/15; mean age 60years) who underwent liver transplantation after LRT with transarterial chemoembolization plus radiofrequency or microwave ablation (n=56), or ⁹⁰Yttrium radioembolization (n=5). MRI was performed <90days before liver transplantation. Three independent readers assessed the following criteria: RECIST, EASL, modified RECIST (mRECIST), percentage of necrosis on subtraction images, and diffusion-weighted imaging (DWI), both qualitative (signal intensity) and quantitative (apparent diffusion coefficient [ADC]). The degree of necrosis was retrospectively assessed at histopathology. Intraclass correlation coefficient (ICC) and Cohen's kappa were used to assess inter-reader agreement. Logistic regression and receiver operating characteristic analyses were used to determine imaging predictors of CPN. Pearson correlation was performed between imaging criteria and pathologic degree of tumor necrosis.

RESULTS

A total of 97HCCs (mean size 2.3±1.3cm) including 28 with CPN were evaluated. There was excellent inter-reader agreement (ICC 0.77-0.86, all methods). EASL, mRECIST, percentage of necrosis and qualitative DWI were all significant (p<0.001) predictors of CPN, while RECIST and ADC were not. EASL, mRECIST and percentage of necrosis performed similarly (area under the curves [AUCs] 0.810-0.815) while the performance of qualitative DWI was lower (AUC 0.622). Image subtraction demonstrated the strongest correlation (r=0.71-0.72, p<0.0001) with pathologic degree of tumor necrosis.

CONCLUSIONS

EASL/mRECIST criteria and image subtraction have excellent diagnostic performance for predicting CPN in HCC treated with LRT, with image subtraction correlating best with pathologic degree of tumor necrosis. Thus, MR image subtraction is recommended for assessing HCC response to LRT.

LAY SUMMARY

The assessment of hepatocellular carcinoma (HCC) tumor necrosis after locoregional therapy is essential for additional treatment planning and estimation of outcome. In this study, we assessed the performance of various magnetic resonance imaging (MRI) response criteria (RECIST, mRECIST, EASL, percentage of necrosis on subtraction images, and diffusion-weighted imaging) for the prediction of complete pathologic necrosis of HCC post locoregional therapy on liver explant. Patients who underwent liver transplantation after locoregional therapy were included in this retrospective study. All patients underwent routine liver MRI within 90days of liver transplantation. EASL/mRECIST criteria and image subtraction had excellent diagnostic performance for predicting complete pathologic necrosis in treated HCC, with image subtraction correlating best with pathologic degree of tumor necrosis.

Value of the portal venous phase in evaluation of treated hepatocellular carcinoma following transcatheter arterial chemoembolisation

AIM

To evaluate the utility of the portal venous phase on multiphasic computed tomography (CT) after treatment of hepatocellular carcinoma (HCC) with trans-arterial chemoembolisation (TACE).

MATERIALS AND METHODS

This was a retrospective review of patients who underwent TACE for HCC between 1 April 2012 and 21 December 2014, with appropriate multiphasic, pre- and post-procedural CT examinations. The maximum non-contrast, arterial phase, and portal venous phase attenuation values of the tumour and tumour bed were evaluated within a region of interest (ROI), with values adjusted against background hepatic parenchyma. Linear regression analyses were performed for both the arterial and venous phases, to assess the level of enhancement and to determine if the venous phase had additional value in this setting.

RESULTS

A total of 86 cases from 51 patients were reviewed. All pre-procedural CT examinations of lesions demonstrated arterial phase enhancement with portal venous and delayed phase washout compatible with HCC. The post-procedural CT examinations following TACE revealed expected decreased arterial enhancement. Sixty-five cases (76%) showed persistent non-enhancement on the portal venous phase following embolisation therapy. A total of 21 cases (24%), however, demonstrated progressive portal venous hyper enhancement. Linear regression analysis demonstrated a statistical significance between the difference in maximal arterial and portal venous enhancement in these cases.

CONCLUSION

Following TACE, the treated lesion may demonstrate portal venous phase hyper-enhancement within the tumour bed. As such, full attention should be given to these images for comprehensive evaluation of tumour response following treatment.

Radiological response and inflammation scores predict tumour recurrence in patients treated with transarterial chemoembolization before liver transplantation

AIM

To investigate the prognostic value of the radiological response after transarterial chemoembolization (TACE) and inflammatory markers in patients affected by hepatocellular carcinoma (HCC) awaiting liver transplantation (LT).

METHODS

We retrospectively evaluated the preoperative predictors of HCC recurrence in 70 patients treated with conventional (n = 16) or doxorubicin-eluting bead TACE (n = 54) before LT. The patient and tumour characteristics, including the static and dynamic alpha-fetoprotein, neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio (PLR) measurements, were recorded. Treatment response was classified according to the modified Response Evaluation Criteria in Solid Tumours (mRECIST) and the European Association for the Study of the Liver (EASL) criteria as complete response (CR), partial response (PR), stable disease or progressive disease. After examination of the explanted livers, histological necrosis was classified as complete (100% of the cumulative tumour area), partial (50%-99%) or minimal (< 50%) and was correlated with the preoperative radiological findings.

RESULTS

According to the pre-TACE radiological evaluation, 22/70 (31.4%) and 12/70 (17.1%) patients were beyond Milan and University of San Francisco (UCSF) criteria, respectively. After TACE procedures, the objective response (CR + PR) rates were 71.4% and 70.0% according to mRECIST and EASL criteria, respectively. The agreement between the two guidelines in defining the radiological response was rated as very good both for the overall and target lesion response (weighted k-value: 0.98 and 0.93, respectively). Complete and partial histological necrosis were achieved in 14/70 (20.0%) and 28/70 (40.0%) patients, respectively. Using histopathology as the reference standard, mRECIST criteria correctly classified necrosis in 72.9% (51/70) of patients and EASL criteria in 68.6% (48/70) of cases. The mRECIST non-response to TACE [Exp(b) = 9.2, p = 0.012], exceeding UCSF criteria before TACE [Exp(b) = 4.7, p = 0.033] and a preoperative PLR > 150 [Exp(b) = 5.9, p = 0.046] were independent predictors of tumour recurrence.

CONCLUSION

The radiological response and inflammatory markers are predictive of tumour recurrence and allow the proper selection of TACE-treated candidates for LT.

Treatment Options in Patients Awaiting Liver Transplantation with Hepatocellular Carcinoma and Cholangiocarcinoma

Liver transplantation (LT) provides a good chance of cure for selected patients with hepatocellular carcinoma (HCC) and perihilar cholangiocarcinoma (pCCA). Patients with HCC on a waiting list for LT are at risk for tumor progression and dropout. Treatment of HCC with locoregional therapies may lessen dropout due to tumor progression. Strict selection and adherence to the LT criteria for patients with pCCA before and after neoadjuvant chemotherapy are critical for optimal outcome with LT. This article reviews the existing data for the various treatment strategies used for patients with HCC and pCCA awaiting LT.

New concepts in embolotherapy of HCC

Hepatocellular carcinoma (HCC) is the second most common cause of cancer-related deaths worldwide with rapidly growing incidence rates in the USA and Europe. Despite improving surveillance programs, most patients are diagnosed at intermediate to advanced stages and are no longer amenable to curative therapies, such as ablation, surgical resection and liver transplantation. For such patients, catheter-based image-guided embolotherapies such as transarterial chemoembolization (TACE) represent the standard of care and mainstay therapy, as recommended and endorsed by a variety of national guidelines and staging systems. The main benefit of these therapies is explained by the preferentially arterial blood supply of liver tumors, which allows to deliver the anticancer therapy directly to the tumor-feeding artery while sparing the healthy hepatic tissue mainly supplied by the portal vein. The tool box of an interventional oncologist contains several different variants of transarterial treatment modalities. Ever since the first TACE more than 30 years ago, these techniques have been progressively refined, both with respect to drug delivery materials and with respect to angiographic micro-catheter and image-guidance technology, thus substantially improving therapeutic outcomes of HCC. This review will summarize the fundamental principles, technical and clinical data on the application of different embolotherapies, such as bland transarterial embolization, Lipiodol-based conventional transarterial chemoembolization as well as TACE with drug-eluting beads (DEB-TACE). Clinical data on ⁹⁰Yttrium radioembolization as an emerging alternative, mostly applied for niche indications such as HCC with portal vein invasion, will be discussed. Furthermore, we will summarize the principle of HCC staging, patient allocation and response assessment in the setting of HCC embolotherapy. In addition, we will evaluate the role of cone-beam computed tomography as a novel intra-procedural image-guidance technology. Finally, this review will touch on new technical developments such as radiopaque, imageable DEBs and the rationale and role of combined systemic and locoregional therapies, mostly in combination with Sorafenib.

Radiofrequency Ablation in Treating Colorectal Cancer Patients with Liver Metastases

PURPOSE

To evaluate efficacy of radiofrequency ablation (RFA) in treating colorectal cancer patients with liver metastases.

METHODS

During January 2010 to April 2012, 56 colorectal cancer patients with liver metastases underwent RFA. CT scans were obtained one month after RFA for all patients to evaluate tumor response. (CR+PR+SD)/n was used to count the disease control rates (DCR). Survival data of 1, 2 and 3 years were obtained from follow up.

RESULTS

Patients were followed for 10 to 40 months after RFA (mean time, 25±10 months). Median survival time was 27 months. The 1, 2, 3 year survival rate were 80.4%, 71.4%, 41%, 1 % respectively. 3-year survival time for patients with CR or PR after RFA was 68.8% and 4.3% respectively, the difference was statistically significant. The number of CR, PR, SD and PD in our study was 13, 23, 11 and 9 respectively.

CONCLUSIONS

RFA could be an effective method for treating colorectal cancer patients with liver metastases, and prolong survival time, especially for metastatic lesions less than or equal to 3 cm. But this result should be confirmed by randomized controlled studies.

Radiological-pathological correlation study of hepatocellular carcinoma undergoing local chemoradiotherapy and surgery

BACKGROUND AND AIMS

Optimal response criteria and assessment timing were investigated through radiologic-pathologic correlation in hepatocellular carcinoma (HCC) treated with localized chemoradiotherapy (CRT).

METHODS

We reviewed 19 consecutive HCC patients who underwent surgical resection after radiotherapy and concurrent hepatic arterial infusion chemotherapy. Patients who received transarterial chemoembolization before RT or surgery were excluded from evaluation. Tumor diameters and total and enhancing tumor volumes were measured from CT images obtained 1, 3, 6, and 9 months after CRT. Percent changes calculated using size (RECIST and WHO) and enhancement criteria (mRECIST and EASL) were correlated with percent changes in total and enhancing tumor volumes, and with percent viable tumor in surgical specimens.

RESULTS

Median time between CRT and resection was 4.1 months (range, 1.5-15.4 months). CR and PR rates were 0 and 68% by RECIST, 0 and 63% by WHO, 53% and 37% by mRECIST, and 53% and 42% by EASL. Pathologic CR (pCR) rate was 52.6%. Radiologic criteria showed strong correlation with tumor volumes at 1 and 3 months after CRT; at 6 months, however, size and enhancement criteria showed strong correlation only with total and enhancing tumor volumes, respectively. Enhancement criteria were better predictors of pathologic response at all times including preoperative evaluation (RECIST: R(2)  = 0.303, P = 0.015 and WHO: R(2)  = 0.366, P = 0.006 vs. mRECIST: R(2)  = 0.760, P < 0.0001 and EASL: R(2)  = 0.768, P < 0.0001). Time interval >6 months before resection showed significant correlation with pCR (P = 0.013).

CONCLUSIONS

We recommend using enhancement criteria in assessing tumor viability, especially if the tumor was to be resected <6 months after CRT.

Prognostic Significance of the Histologic Response of Perihilar Cholangiocarcinoma to Preoperative Neoadjuvant Chemoradiation in Liver Explants

Perihilar cholangiocarcinoma (pCCA) has a dismal prognosis. Protocols incorporating chemotherapy, radiotherapy, and liver transplantation (LT) have emerged as curative options for unresectable tumors with 70% 5-year survival rates. We aimed to assess the value of extent of residual tumor (ERT) and other pathologic factors following chemoradiation in predicting outcome; 152 liver explants with pCCA treated with neoadjuvant chemoradiation and LT between 1993 and 2013 were reviewed for ERT, pathologic stage, histologic grade, and perineural and lymphovascular invasion. ERT was quantified as the percentage of viable carcinoma in the tumor bed. Tumors were classified into 4 ERT categories: (1) complete/near-complete response (≤1% ERT); (2) marked response (>1 to <10% ERT); (3) moderate response (10 to <30% ERT); and (4) minimal response (≥30% ERT). Overall 5-year survival rate was 69%. 5-year disease-free estimate was 74%. 57%, 16%, 18%, and 9% of explants were placed in ERT categories 1, 2, 3, and 4, respectively. ERT correlated significantly with the overall 5-year survival rate and 5-year, disease-free estimate by univariate (P<0.0001) and multivariate analysis (P=0.004 and 0.009, respectively). By multivariate analysis, pathologic stage was also an independent predictor of recurrence (P=0.003). Other variables that correlated with risk of death and recurrence by univariate analysis included perineural (P<0.0001) and lymphovascular invasion (P<0.0001), absence of primary sclerosing cholangitis (P=0.006 and P<0.0001, respectively), and pretreatment CA19-9 level (P=0.001 and 0.02, respectively). Histologic grade did not predict outcome. In summary, ERT independently predicts outcome in pCCA patients following neoadjuvant chemoradiation and LT and can stratify patient prognosis.

Efficacy of Transarterial Chemoembolization Combined with Radiofrequency Ablation in Treatment of Hepatocellular Carcinoma

PURPOSE

To evaluate efficacy of transarterial chemoembolization (TACE) combined with radiofrequency ablation (RFA) in treatment of patients with hepatocellular carcinoma.

MATERIALS AND METHODS

During January 2009 to March 2012, 80 patients with hepatocellular carcinoma underwent TACE, with or without RFA. Alfa- fetoprotein (AFP) was checked before and after procedure. CT scans were obtained one month after TACE or RFA for all patients to evaluate tumor changes. Complete response+partial response+stable disease (CR+PR+SD)/n were used to assess the disease control rate (DCR). Survival at 3, 6 and 12 months was compared in both groups.

RESULTS

AFP levels in TACE + RFA group dropped rapidly, becoming obviously lower than that of the TACE group. In the TACE + RFA group DCR was 93.8%, while only 76.8% in the TACE group. The treatment effect between the two groups was statistically significant (P<0.05) by Ridit analysis. 1 year survival rate in the TACE + RFA group was 92.5%, significantly higher than that of the TACE group at 77.5% (P<0.05).

CONCLUSIONS

TACE and RFA as combined therapy method for patients with middle and terminal stage HCC gives full play to synergy between the two and improves the therapeutic effect.

Correlation of Doxorubicin Delivery and Tumor Necrosis after Drug-eluting Bead Transarterial Chemoembolization of Rabbit VX2 Liver Tumors

Purpose To quantify the correlation between doxorubicin (DOX) delivery and tumor necrosis after drug-eluting bead (DEB) transarterial chemoembolization (TACE). Materials and Methods In this animal care committee-approved study, New Zealand white rabbit VX2 liver tumors were treated transarterially with DOX-loaded 70-150-μm DEBs in five treatment groups with varying drug doses: sham (saline), 0 mg, 12.5 mg, 25 mg, and 37.5 mg. DEB TACE was followed by 3- and 7-day sacrifice, tumor harvest, and sectioning. Drug delivery was assessed by using fluorescence imaging, and tumor necrosis was quantified by means of histologic analysis. Statistical correlation of DOX delivery and tumor necrosis was performed by using the Spearman rank correlation coefficient (ρ). Results Thirty-six VX2 tumors (median diameter, 1.3 cm) in 20 rabbits (median weight, 2.8 kg) underwent successful DEB TACE. Treatment groups included eight, seven, eight, five, and eight tumors of similar size (P > .05). Tumors showed progressively greater DOX extent (sham, 0%; 0 mg, 0%; 12.5 mg, 3%; 25 mg, 20%; and 37.5 mg, 27%) and intensity (sham, 0.4; 0 mg, 1.9; 12.5 mg, 8.5; 25 mg, 9.6; and 37.5 mg, 18.3) and higher median percentage necrosis (sham, 68%; 0 mg, 64%; 12.5 mg, 76%; 25 mg, 78%; and 37.5 mg, 83%) across DOX treatment groups. Correlation of DOX extent (ρ = 0.975, P = .005) and intensity (ρ = 0.900, P = .037) with percentage tumor necrosis was statistically significant. Conclusion Incremental increases in DOX correlate with greater necrosis in rabbit VX2 liver tumors after DEB TACE. This result indicates an essential role for chemotherapy-induced cytotoxicity in TACE effectiveness and supports the use of chemotherapeutic drugs in transarterial therapy. (©) RSNA, 2016 Online supplemental material is available for this article.

The Prognostic Value of Alpha-Fetoprotein Response for Advanced-Stage Hepatocellular Carcinoma Treated with Sorafenib Combined with Transarterial Chemoembolization

This retrospective cohort study aimed to evaluate the prognostic value of the alpha-fetoprotein (AFP) response in advanced-stage hepatocellular carcinoma (HCC) patients treated with sorafenib combined with transarterial chemoembolization. From May 2008 to July 2012, 118 HCC patients with baseline AFP levels >20 ng/ml treated with combination therapy were enrolled. A receiver operating characteristic curve was used to generate a cutoff point for AFP changes for predicting survival. The AFP response was defined as an AFP decrease rate [ΔAFP(%)] greater than the cutoff point. The ΔAFP(%) was defined as the percentage of changes between the baseline and the nadir values within 2 months after therapy. The median follow-up time was 8.8 months (range 1.2-66.9). A level of 46% was chosen as the threshold value for ΔAFP (sensitivity = 53.7%, specificity = 83.3%). The median overall survival was significantly longer in the AFP response group than in the AFP non-response group (12.8 vs. 6.4 months, P = 0.001). Multivariate analysis showed that ECOG ≥ 1 (HR = 1.95; 95% CI 1.24-3.1, P = 0.004) and AFP nonresponse (HR = 1.71; 95% CI 1.15-2.55, P = 0.009) were associated with increased risk of death. In conclusion, AFP response could predict the survival of patients with advanced-stage HCC at an early time point after combination therapy.

TRIP: a pathological score for transarterial chemoembolization resistance individualized prediction in hepatocellular carcinoma

BACKGROUND & AIMS

Although potentially very useful in optimizing patient selection and follow-up, the individual response to transarterial chemoembolization (TACE) in hepatocellular carcinoma (HCC) is generally unpredictable. The aim of this study was to identify tissue predictors of tumour resistance to TACE for use in clinical practice on pretreatment biopsies.

METHODS

We investigated the association of residual tumour in post-TACE-resected HCC with pathological and immunophenotypical features, mainly related to hypoxia and angiogenesis. Comparison of tumour phenotype between post-TACE HCC and both paired pre-TACE biopsies and control TACE-untreated HCC was performed. Cases showing >50% residual tumour (RT) were defined as TACE-resistant.

RESULTS

A consecutive series of 108 HCC from 41 patients was studied. Overall, 45/108 (44%) HCC were classified as TACE-resistant. Among these, 32 (71%) and 40 (89%) showed diffuse CD34 vascular staining and negative VEGF staining respectively (p<0.05). The association of these two parameters in a weighted score (TRIP) was able to predict TACE resistance with 81% accuracy, 89% sensitivity and 59% specificity. The effectiveness of TRIP was validated in an independent series of 28 HCC biopsies from patients subsequently treated with TACE and for whom radiological follow-up was available.

CONCLUSIONS

This study demonstrates the potential value of pretreatment tumour biopsy as predictors of TACE resistance in HCC.

Predictive factors for complete response of chemoembolization with drug-eluting beads (DEB-TACE) for hepatocellular carcinoma

OBJECTIVES

To identify clinical and imaging features associated with complete response (CR) to first session of transarterial chemoembolization (TACE) with drug-eluting beads (DEB) in patients with hepatocellular carcinoma.

METHODS

In this prospective historical cohort, 172 patients with 315 tumours who received at least one DEB-TACE from 2007 to 2013 were studied. Imaging response was evaluated according to the modified Response Evaluation Criteria in Solid Tumours (mRECIST). Age, gender, aetiology of cirrhosis, Child and BCLC scores, particles size, location in the liver, size of the tumour, presence of a capsule, hypervascularisation on DSA and CT/MRI scans, and blush extinction were analysed.

RESULTS

After one session of treatment, CR was observed in 36 % of the 315 tumours treated. Nodule size, location in the liver, and complete blush extinction on DSA was statistically correlated to complete response, whereas capsule aspect on imaging and demographic criteria were not. In multivariate analysis only, location in the liver and nodule size were significant features.

CONCLUSIONS

Tumour location in the segments 1 and 4 is a pejorative factor for CR, whereas tumour size <5 cm is a positive predictive factor. These criteria could, therefore, be taken into consideration to improve the selection of patients for DEB-TACE.

KEY POINTS

• Literature on predictive factors of complete response after DEB-TACE is under-studied. • Tumour size <5 cm is associated with complete response. • Location in segments 1 or 4 is a pejorative factor for response. • No demographic parameter influences complete response.

Inter-observer variability of response evaluation criteria for hepatocellular carcinoma treated with chemoembolization

BACKGROUND

Data comparing EASL and mRECIST criteria for response evaluation in treatment of hepatocellular carcinoma are rare. We evaluated inter-observer variability by these two response evaluation criteria in treatment-naïve patients undergoing chemoembolization.

METHODS

For 133 patients undergoing chemoembolization, two radiologists independently measured sum of bi-dimensional and uni-dimensional diameters at baseline using both EASL criteria and mRECIST, and their changes on first follow-up for up to 5 target lesions.

RESULTS

Concordance correlation coefficients for sum of bi-dimensional and uni-dimensional diameters at baseline between two observers were 0.992 and 0.988, respectively. However, those for their changes on follow-up were 0.865 and 0.877, respectively. Similarly, mean differences in sum of bi-dimensional and uni-dimensional diameters at baseline between two observers were small; -0.455 and 0.079 cm, respectively. However, mean differences in changes (%) in sum of bi-dimensional and uni-dimensional diameters on first follow-up between observers increased by -9.715% and -9.320%, respectively. Regarding tumour numbers, kappa-value between observers was 0.942. For treatment response (complete or partial response, stable disease and progression), kappa-value was 0.941 by both criteria. When only up to two target lesions were assessed, kappa-value was 1.000 by both criteria.

CONCLUSIONS

Inter-observer agreements using both response evaluation criteria were excellent, especially when up to two targets were assessed.

Identifying Staging Markers for Hepatocellular Carcinoma before Transarterial Chemoembolization: Comparison of Three-dimensional Quantitative versus Non-three-dimensional Imaging Markers

Purpose To test and compare the association between radiologic measurements of lesion diameter, volume, and enhancement on baseline magnetic resonance (MR) images with overall survival and tumor response in patients with unresectable hepatocellular carcinoma (HCC) treated with transarterial chemoembolization (TACE). Materials and Methods This HIPAA-compliant retrospective, single-institution analysis was approved by the institutional review board, with waiver of informed consent. It included 79 patients with unresectable HCC who were treated with TACE. Baseline arterial phase contrast material-enhanced (CE) MR imaging was used to measure the overall and enhancing tumor diameters. A segmentation-based three-dimensional quantification of the overall and enhancing tumor volumes was performed in each patient. Numeric cutoff values (5 cm for diameters and 65 cm(3) for volumes) were used to stratify the patient cohort in two groups. Tumor response rates according to Response Evaluation Criteria in Solid Tumors (RECIST), modified RECIST (mRECIST), and European Association for the Study of the Liver (EASL) guidelines were recorded for all groups. Survival was evaluated by using Kaplan-Meier analysis and was compared by using Cox proportional hazard ratios (HRs) after univariate and multivariate analysis. Results Stratification according to overall and enhancing tumor diameters did not result in a significant separation of survival curves (HR, 1.4; 95% confidence interval [CI]: 0.7, 2.5; P = .234; and HR, 1.6; 95% CI: 0.9, 2.8; P = .08, respectively). The stratification according to overall and enhancing tumor volume achieved significance (HR, 1.8; 95% CI: 0.9, 3.4; P = .022; and HR, 1.8; 95% CI: 1.1, 3.1; P = .017, respectively). As for tumor response, higher response rates were observed in smaller lesions compared with larger lesions, when the 5-cm threshold (27% vs 15% for mRECIST and 45% vs 24% for EASL) was used. Conclusion As opposed to anatomic tumor diameter as the most commonly used staging marker, volumetric assessment of lesion size and enhancement on baseline CE MR images is strongly associated with survival of patients with HCC who were treated with TACE.

Radioembolization with Yttrium-90 microspheres in hepatocellular carcinoma: Role and perspectives

Transarterial radioembolization (TARE) is a form of brachytherapy in which intra-arterially injected yttrium-90-loaded microspheres serve as a source for internal radiation purposes. On the average, it produces disease control rates exceeding 80% and it is a consolidated therapy for hepatocellular carcinoma (HCC); however, current data are all based on retrospective series or non-controlled prospective studies since randomized controlled trials comparing it with the other liver-directed therapies for intermediate and locally advanced stage HCC are still underway. The data available show that TARE provides similar or even better survival rates when compared to transarterial chemoembolization (TACE). First-line TARE is best indicated for both intermediate-stage patients (staged according to the barcelona clinic liver cancer staging classification) who have lesions which respond poorly to TACE due to multiple tumors or a large tumor burden, and for locally advanced-stage patients with solitary tumors, and segmental or lobar portal vein tumor thrombosis. In addition, emerging data have suggested the use of TARE in patients who are classified slightly beyond the Milan criteria regarding radical treatment for downstaging purposes. As a second-line treatment, TARE can also be applied in patients progressing to TACE or sorafenib; a large number of phase II/III trials are ongoing with the purpose of evaluating the best association with systemic therapies. Transarterial radioembolization is very well tolerated and has a low rate of complications which are mainly related to unintended non-target tissue irradiation, including the surrounding liver parenchyma. The complications can be additionally reduced by accurate patient selection and a strict pre-treatment evaluation including dosimetry and assessment of the vascular anatomy. Since a correct treatment algorithm for potential TARE candidates is not clear and standardized, this comprehensive review analyzes the best selection criteria for patients who really benefit from TARE and also the new advances of this therapy, which can be a very important weapon against HCC.

Radioembolization with Yttrium-90 microspheres in hepatocellular carcinoma: Role and perspectives

Transarterial radioembolization (TARE) is a form of brachytherapy in which intra-arterially injected yttrium-90-loaded microspheres serve as a source for internal radiation purposes. On the average, it produces disease control rates exceeding 80% and it is a consolidated therapy for hepatocellular carcinoma (HCC); however, current data are all based on retrospective series or non-controlled prospective studies since randomized controlled trials comparing it with the other liver-directed therapies for intermediate and locally advanced stage HCC are still underway. The data available show that TARE provides similar or even better survival rates when compared to transarterial chemoembolization (TACE). First-line TARE is best indicated for both intermediate-stage patients (staged according to the barcelona clinic liver cancer staging classification) who have lesions which respond poorly to TACE due to multiple tumors or a large tumor burden, and for locally advanced-stage patients with solitary tumors, and segmental or lobar portal vein tumor thrombosis. In addition, emerging data have suggested the use of TARE in patients who are classified slightly beyond the Milan criteria regarding radical treatment for downstaging purposes. As a second-line treatment, TARE can also be applied in patients progressing to TACE or sorafenib; a large number of phase II/III trials are ongoing with the purpose of evaluating the best association with systemic therapies. Transarterial radioembolization is very well tolerated and has a low rate of complications which are mainly related to unintended non-target tissue irradiation, including the surrounding liver parenchyma. The complications can be additionally reduced by accurate patient selection and a strict pre-treatment evaluation including dosimetry and assessment of the vascular anatomy. Since a correct treatment algorithm for potential TARE candidates is not clear and standardized, this comprehensive review analyzes the best selection criteria for patients who really benefit from TARE and also the new advances of this therapy, which can be a very important weapon against HCC.

Radioembolization with Yttrium-90 microspheres in hepatocellular carcinoma: Role and perspectives

Transarterial radioembolization (TARE) is a form of brachytherapy in which intra-arterially injected yttrium-90-loaded microspheres serve as a source for internal radiation purposes. On the average, it produces disease control rates exceeding 80% and it is a consolidated therapy for hepatocellular carcinoma (HCC); however, current data are all based on retrospective series or non-controlled prospective studies since randomized controlled trials comparing it with the other liver-directed therapies for intermediate and locally advanced stage HCC are still underway. The data available show that TARE provides similar or even better survival rates when compared to transarterial chemoembolization (TACE). First-line TARE is best indicated for both intermediate-stage patients (staged according to the barcelona clinic liver cancer staging classification) who have lesions which respond poorly to TACE due to multiple tumors or a large tumor burden, and for locally advanced-stage patients with solitary tumors, and segmental or lobar portal vein tumor thrombosis. In addition, emerging data have suggested the use of TARE in patients who are classified slightly beyond the Milan criteria regarding radical treatment for downstaging purposes. As a second-line treatment, TARE can also be applied in patients progressing to TACE or sorafenib; a large number of phase II/III trials are ongoing with the purpose of evaluating the best association with systemic therapies. Transarterial radioembolization is very well tolerated and has a low rate of complications which are mainly related to unintended non-target tissue irradiation, including the surrounding liver parenchyma. The complications can be additionally reduced by accurate patient selection and a strict pre-treatment evaluation including dosimetry and assessment of the vascular anatomy. Since a correct treatment algorithm for potential TARE candidates is not clear and standardized, this comprehensive review analyzes the best selection criteria for patients who really benefit from TARE and also the new advances of this therapy, which can be a very important weapon against HCC.

Gene expression in hepatocellular carcinoma: pilot study of potential transarterial chemoembolization response biomarkers

PURPOSE

To perform a feasibility study to explore the relationship between hepatocellular carcinoma genetics and transarterial chemoembolization treatment response to identify potential biomarkers associated with enhanced treatment efficacy.

MATERIALS AND METHODS

In this single-institution study, pretreatment hepatocellular carcinoma biopsy specimens for tumors in 19 patients (14 men, five women; mean age, 59 y) treated with chemoembolization between 2007 and 2013 were analyzed for a panel of 60 chemotherapy-sensitivity, hypoxia, mitosis, and inflammatory genes with the QuantiGene Plex 2.0 mRNA detection assay. Demographic, disease, and procedure data and tumor response outcomes were collected. Quantitative mRNA levels were compared based on radiologic response between tumors exhibiting complete response (CR) versus partial response (PR).

RESULTS

The study sample included 19 biopsy specimens from tumors (mean size, 3.0 cm; grade 1, n = 6; grade 2, n = 9; grade 3, n = 4) in patients treated with a mean of two conventional chemoembolization sessions. Thirteen and six tumors exhibited CR and PR, respectively, at a mean of 116 days after treatment. Tumors with CR showed a significant increase in (P < .05) or trend toward (P < .1) greater (range, 1.49-3.50 fold) pretreatment chemotherapy-sensitivity and mitosis (ATF4, BAX, CCNE1, KIF11, NFX1, PPP3CA, SNX1, TOP2A, and TOP2B) gene mRNA expression compared with tumors with PR, in addition to lower CXCL10 levels (0.48-fold), and had significantly (P < .05) higher (1.65-fold) baseline VEGFA levels.

CONCLUSIONS

Genetic signatures may allow prechemoembolization stratification of tumor response probability, and gene analysis may therefore offer an opportunity to personalize locoregional therapy by enhancing treatment modality allocation. Further corroboration of identified markers and exploration of their respective predictive capacity thresholds is necessary.

Radiologic-pathologic analysis of contrast-enhanced and diffusion-weighted MR imaging in patients with HCC after TACE: diagnostic accuracy of 3D quantitative image analysis

PURPOSE

To evaluate the diagnostic performance of three-dimensional ( 3D three-dimensional ) quantitative enhancement-based and diffusion-weighted volumetric magnetic resonance (MR) imaging assessment of hepatocellular carcinoma ( HCC hepatocellular carcinoma ) lesions in determining the extent of pathologic tumor necrosis after transarterial chemoembolization ( TACE transarterial chemoembolization ).

MATERIALS AND METHODS

This institutional review board-approved retrospective study included 17 patients with HCC hepatocellular carcinoma who underwent TACE transarterial chemoembolization before surgery. Semiautomatic 3D three-dimensional volumetric segmentation of target lesions was performed at the last MR examination before orthotopic liver transplantation or surgical resection. The amount of necrotic tumor tissue on contrast material-enhanced arterial phase MR images and the amount of diffusion-restricted tumor tissue on apparent diffusion coefficient ( ADC apparent diffusion coefficient ) maps were expressed as a percentage of the total tumor volume. Visual assessment of the extent of tumor necrosis and tumor response according to European Association for the Study of the Liver ( EASL European Association for the Study of the Liver ) criteria was performed. Pathologic tumor necrosis was quantified by using slide-by-slide segmentation. Correlation analysis was performed to evaluate the predictive values of the radiologic techniques.

RESULTS

At histopathologic examination, the mean percentage of tumor necrosis was 70% (range, 10%-100%). Both 3D three-dimensional quantitative techniques demonstrated a strong correlation with tumor necrosis at pathologic examination (R(2) = 0.9657 and R(2) = 0.9662 for quantitative EASL European Association for the Study of the Liver and quantitative ADC apparent diffusion coefficient , respectively) and a strong intermethod agreement (R(2) = 0.9585). Both methods showed a significantly lower discrepancy with pathologically measured necrosis (residual standard error [ RSE residual standard error ] = 6.38 and 6.33 for quantitative EASL European Association for the Study of the Liver and quantitative ADC apparent diffusion coefficient , respectively), when compared with non- 3D three-dimensional techniques ( RSE residual standard error = 12.18 for visual assessment).

CONCLUSION

This radiologic-pathologic correlation study demonstrates the diagnostic accuracy of 3D three-dimensional quantitative MR imaging techniques in identifying pathologically measured tumor necrosis in HCC hepatocellular carcinoma lesions treated with TACE transarterial chemoembolization .

Transarterial radioembolization using yttrium-90 microspheres in the treatment of hepatocellular carcinoma: a review on clinical utility and developments

A selective intra-arterial liver injection using yttrium-90-loaded microspheres as sources for internal radiation therapy is a form of transarterial radioembolization (TARE). Current data from the literature suggest that TARE is effective in hepatocellular carcinoma (HCC) and is associated with a low rate of adverse events; however, they are all based on retrospective series or non-controlled prospective studies, since randomized controlled trials comparing the other liver-directed therapies for intermediate and locally advanced stages HCC are still ongoing. The available data show that TARE provides similar or even better survival rates. TARE is very well tolerated and has a low rate of complications; these complications do not result from the embolic effects but mainly from the unintended irradiation to non-target tissue, including the liver parenchyma. The complications can be further reduced by accurate patient selection and a strict pre-treatment evaluation, including dosimetry and assessment of the vascular anatomy. First-line TARE is best indicated for intermediate-stage patients (according to the Barcelona Clinic Liver Cancer [BCLC] staging classification) who are poor candidates for transarterial chemoembolization or patients having locally advanced disease with segmental or lobar branch portal vein thrombosis. Moreover, data are emerging regarding the use of TARE in patients classified slightly above the criteria for liver transplantation with the purpose of downstaging them. TARE can also be applied as a second-line treatment in patients progressing to transarterial chemoembolization or sorafenib; a large number of Phase II/III trials are in progress in order to evaluate the best association with systemic therapies. Given the complexity of a correct treatment algorithm for potential TARE candidates and the need for clinical guidance, a comprehensive review was carried out analyzing both the best selection criteria of patients who really benefit from TARE and the new advances of this therapy which add significant value to the therapeutic weaponry against HCC.

Chemoembolization and radioembolization

Chemoembolization and radioembolization are at the core of the treatment of patients with hepatocellular carcinoma who cannot receive potentially curative therapies such as transplantation, resection or percutaneous ablation. They differ in the mechanism of action (ischaemia and increase cytotoxic drug exposure for chemoembolization, internal irradiation for radioembolization) and may target different patient populations. Chemoembolization with cytotoxic drug-eluting beads is a more standardized although not necessarily more effective way of performing chemoembolization. Cytoreduction is achieved in most patients but complete tumor ablation may be achieved and lead to extended survival. Grade 1 level of evidence support the use of chemoembolization for the treatment of patients in the early and intermediate stages while grade 2 evidence supports the use of radioembolization for the treatment of patients in intermediate to advanced stages. Selecting the best candidates for both techniques is still a work in progress that ongoing clinical trials are trying to address.

Hepatocellular carcinomas within the Milan criteria: predictors of histologic necrosis after drug-eluting beads transarterial chemoembolization

PURPOSE

To evaluate pathologic, imaging, and technical predictors of therapy response in patients with hepatocellular carcinoma (HCC) within the Milan criteria undergoing doxorubicin drug-eluting beads transarterial chemoembolization (DEB-TACE) before orthotopic liver transplantation (OLT).

METHODS

This prospective study included consecutive patients with HCC who underwent DEB-TACE before OLT. Tumor histologic necrosis on liver explants was utilized as the standard of reference to categorize treated HCCs as group 1 (>50 % necrosis) or group 2 (≤50 % necrosis). DEB-TACE technique, histological factors, and imaging evaluation utilizing the modified Response Evaluation Criteria in Solid Tumors (mRECIST) were compared between groups 1 and 2.

RESULTS

Twenty-seven HCCs were identified in 23 patients. Group 1 comprised 18 HCCs (mean necrosis 86.2 %). Group 2 comprised 9 HCCs (mean necrosis 31.1 %). The mean time between the last DEB-TACE session and the OLT was 112 days. Lesion size was significantly larger in group 1 (mean 3.2 cm; 95 % confidence interval 2.55-3.85) than in group 2 (mean 2.1 cm; 95 % confidence interval 1.79-2.48) (p = 0.030). Group 1 also demonstrated a higher frequency of encapsulated lesions when compared to group 2 (78 % vs. 22 %; p = 0.0027). A significant linear correlation was found between the quantification of necrosis by imaging and pathology (p = 0.0011) using the mRECIST, with a poorer correlation index in group 2.

CONCLUSION

Larger and encapsulated HCCS are associated with a higher percentage of necrosis. A significant linear correlation between the amount of necrosis by imaging and pathology was encountered when mRECIST was utilized.

Efficacy and nontarget effects of transarterial chemoembolization in bridging of hepatocellular carcinoma patients to liver transplantation: a histopathologic study

PURPOSE

To histologically evaluate the efficacy and nontarget effects induced by transarterial chemoembolization as a "bridge" treatment of hepatocellular carcinoma (HCC) before liver transplantation (LT) and its relation to patient survival.

MATERIALS AND METHODS

Between October 2003 and January 2011, 51 patients with HCC underwent LT after chemoembolization with iodized oil, small spherical particles, and carboplatin. The decision for LT was made according to national guidelines. The efficacy and nontarget effects of chemoembolization were determined histologically in explanted livers, and their impact on patients' survival after LT was analyzed.

RESULTS

A total of 126 chemoembolization procedures were performed in 51 patients; the median number of procedures per patient was three (range, one to six). The extent of HCC necrosis was less than or equal to 50% in 32% of treated HCCs, more than 50% and less than or equal to 90% in 17%, and more than 90%-99% in 14%; 38% showed complete necrosis of the lesion. The most common nontarget effects were focal necrosis of the liver parenchyma adjacent to the embolized HCC nodule (28%), intralesional (micro)abscess (26%), intralesional hemorrhage (22%), and peritumoral bile duct necrosis (12%). Based on histopathologic examination, 35% of patients had HCC that did not meet Milan criteria. None of these findings was significantly associated with patient survival after LT.

CONCLUSIONS

Transarterial chemoembolization induces histopathologically confirmed HCC necrosis with a high degree of efficacy, but histologically proven complete HCC necrosis was not predictive of survival in this cohort of patients. Although histopathologic examination revealed (clinically relevant) nontarget effects in a subset of patients, they did not impair survival.