Role of the EASL, RECIST, and WHO response guidelines alone or in combination for hepatocellular carcinoma: radiologic-pathologic correlation

The Evolving Scenario in the Assessment of Radiological Response for Hepatocellular Carcinoma in the Era of Immunotherapy: Strengths and Weaknesses of Surrogate Endpoints

Hepatocellular carcinoma (HCC) is a challenging malignancy characterised by clinical and biological heterogeneity, independent of the stage. Despite the application of surveillance programs, a substantial proportion of patients are diagnosed at advanced stages when curative treatments are no longer available. The landscape of systemic therapies has been rapidly growing over the last decade, and the advent of immune-checkpoint inhibitors (ICIs) has changed the paradigm of systemic treatments. The coexistence of the tumour with underlying cirrhosis exposes patients with HCC to competing events related to tumour progression and/or hepatic decompensation. Therefore, it is relevant to adopt proper clinical endpoints to assess the extent of treatment benefit. While overall survival (OS) is the most accepted endpoint for phase III randomised controlled trials (RCTs) and drug approval, it is affected by many limitations. To overcome these limits, several clinical and radiological outcomes have been used. For instance, progression-free survival (PFS) is a useful endpoint to evaluate the benefit of sequential treatments, since it is not influenced by post-progression treatments, unlike OS. Moreover, radiological endpoints such as time to progression (TTP) and objective response rate (ORR) are frequently adopted. Nevertheless, the surrogacy between these endpoints and OS in the setting of unresectable HCC (uHCC) remains uncertain. Since most of the surrogate endpoints are radiology-based (e.g., PFS, TTP, ORR), the use of standardised tools is crucial for the evaluation of radiological response. The optimal way to assess the radiological response has been widely debated, and many criteria have been proposed over the years. Furthermore, none of the criteria have been validated for immunotherapy in advanced HCC. The coexistence of the underlying chronic liver disease and the access to several lines of treatments highlight the urgent need to capture early clinical benefit and the need for standardised radiological criteria to assess cancer response when using ICIs in mono- or combination therapies. Here, we review the most commonly used clinical and radiological endpoints for trial design, as well as their surrogacy with OS. We also review the criteria for radiological response to treatments for HCC, analysing the major issues and the potential future perspectives.

Optimal time point of response assessment for predicting survival is associated with tumor burden in hepatocellular carcinoma receiving repeated transarterial chemoembolization

OBJECTIVES

Objective response rate (ORR) under mRECIST criteria after transarterial chemoembolization (TACE) is a well-perceived surrogate endpoint of overall survival (OS). However, its optimal time point remains controversial and may be influenced by tumor burden. We aim to investigate the surrogacy of initial/best ORR in relation to tumor burden.

METHODS

A total of 1549 eligible treatment-naïve patients with unresectable hepatocellular carcinoma (HCC), Child-Pugh score ≤ 7, and performance status score ≤ 1 undergoing TACE between January 2010 and May 2016 from 17 academic hospitals were retrospectively analyzed. Based on "six-and-twelve" criteria, tumor burden was graded as low, intermediate, and high if the sum of the maximum tumor diameter and tumor number was ≤ 6, > 6 but ≤ 12, and > 12, respectively.

RESULTS

Both initial and best ORRs interacted with tumor burden. Initial and best ORRs could equivalently predict and correlate with OS in low (adjusted HR, 2.55 and 2.95, respectively, both p < 0.001; R = 0.84, p = 0.035, and R = 0.97, p = 0.002, respectively) and intermediate strata (adjusted HR, 1.81 and 2.22, respectively, both p < 0.001; R = 0.74, p = 0.023, and R = 0.9, p = 0.002, respectively). For high strata, only best ORR exhibited qualified surrogacy (adjusted HR, 2.61, p < 0.001; R = 0.70, p = 0.035), whereas initial ORR was not significant (adjusted HR, 1.08, p = 0.357; R = 0.22, p = 0.54).

CONCLUSIONS

ORR as surrogacy of OS is associated with tumor burden. For patients with low/intermediate tumor burden, initial ORR should be preferred in its early availability upon similar sensitivity, whereas for patients with high tumor burden, best ORR has optimal sensitivity. Timing of OR assessment should be tailored according to tumor burden.

KEY POINTS

• This is the first study utilizing individual patient data to comprehensively analyze the surrogacy of ORR with a long follow-up period. • Optimal timing of ORR assessment for predicting survival should be tailored according to tumor burden. • For patients with low and intermediate tumor burden, initial ORR is optimal for its timeliness upon similar sensitivity with best ORR. For patients with high tumor burden, best ORR has optimal sensitivity.

Comparison of Chemoembolization, Radioembolization, and Transarterial Ethanol Ablation for Huge Hepatocellular Carcinoma (≥ 10 cm) in Tumour Response and Long-Term Survival Outcome

PURPOSE

To compare transarterial chemoembolization (TACE), transarterial radioembolization using Yttrium-90 (TARE), and transarterial ethanol ablation (TEA) for huge hepatocellular carcinoma (HCC) in treatment responses and long-term survival outcomes.

MATERIALS AND METHODS

In this retrospective study approved by institutional committee, inclusion criteria were tumour ≥ 10 cm, newly diagnosed, treatment naïve, Child A, Performance Score 0 or 1, no venous invasion or extrahepatic disease on contrast-enhanced CT or MRI. There were 107 patients (Supportive Care [SC] 17, TACE 54, TARE 17, TEA 19). Survival outcomes of SC and TACE were compared (TACE selected as benchmark for transarterial treatments). Tumour response and overall survival (OS) of the three groups were compared.

RESULTS

OS of TACE (vs. SC) was significantly longer (9.9 [5.9, 24.1] months versus 2.8 [1.5, 10.2], p = 0.001). Complete response of TEA was significantly better (TEA 10/19 [52.6%] versus TARE 2/17 [12.5%], p = 0.013, versus TACE 9/54 [16.7%], p = 0.002). OS of TEA (vs. TACE) was significantly longer (21.6 [12, 41] months versus 9.9 [5.9, 24.1], p = 0.014, hazard ratio 0.6 (0.3, 1). OS of TEA (vs. TARE) was longer (21.6 [12, 41] months versus 11.9 [7, 28.7], p = 0.082, hazard ratio 0.6 (0.3, 1.3) in favour of TEA).

CONCLUSION

In patients with huge HCC, transarterial treatment as represented by TACE had a survival benefit over supportive care. In this retrospective analysis, TEA was associated with better tumour response and survival outcome as compared to TACE or TARE; therefore, transarterial treatment could be useful for prolonging patient survival, and TEA could be a preferred option.

Treatment response assessment following transarterial radioembolization for hepatocellular carcinoma

Transarterial radioembolization with yttrium-90 microspheres is an established therapy for hepatocellular carcinoma. Post-procedural imaging is important for the assessment of both treatment response and procedural complications. A variety of challenging treatment-specific imaging phenomena complicate imaging assessment, such as changes in tumoral size, tumoral and peritumoral enhancement, and extrahepatic complications. A review of the procedural steps, emerging variations, and timelines for post-treatment tumoral and extra-tumoral imaging changes are presented, which may aid the reporting radiologist in the interpretation of post-procedural imaging. Furthermore, a description of post-procedural complications and their significance is provided.

Yttrium-90 Radioembolization and Tumor Hypoxia: Gas-challenge BOLD Imaging in the VX2 Rabbit Model of Hepatocellular Carcinoma

RATIONALE AND OBJECTIVES

To use a rapid gas-challenge blood oxygen-level dependent magnetic resonance imaging exam to evaluate changes in tumor hypoxia after ⁹⁰Y radioembolization (Y90) in the VX2 rabbit model.

MATERIALS AND METHODS

White New Zealand rabbits (n = 11) provided a Y90 group (n = 6 rabbits) and untreated control group (n = 5 rabbits). R2* maps were generated with gas-challenges (O₂/room air) at baseline, 1 week, and 2 weeks post-Y90. Laboratory toxicity was evaluated at baseline, 24 hours, 72 hours, 1 hours, and 2 weeks. Histology was used to evaluate tumor necrosis on hematoxylin and eosin and immunofluorescence imaging was used to assess microvessel density (CD31) and proliferative index (Ki67).

RESULTS

At baseline, median tumor volumes and time to imaging were similar between groups (p = 1.000 and p = 0.4512, respectively). The median administered dose was 50.4 Gy (95% confidence interval:44.8-55.9). At week 2, mean tumor volumes were 5769.8 versus 643.7 mm³ for control versus Y90 rabbits, respectively (p = 0.0246). At two weeks, ΔR2* increased for control tumors to 12.37 ± 12.36sec^-1 and decreased to 4.48 ± 9.00sec^-1 after Y90. The Pearson correlation coefficient for ΔR2* at baseline and percent increase in tumor size by two weeks was 0.798 for the Y90 group (p = 0.002). There was no difference in mean microvessel density for control versus Y90 treated tumors (p = 0.6682). The mean proliferative index was reduced in Y90 treated tumors at 30.5% versus 47.5% for controls (p = 0.0071).

CONCLUSION

The baseline ΔR2* of tumors prior to Y90 may be a predictive imaging biomarker of tumor response and treatment of these tumors with Y90 may influence tumor oxygenation over time.

Diagnostic accuracy of Liver Imaging Reporting and Data System locoregional treatment response criteria: a systematic review and meta-analysis

OBJECTIVE

There is increasing adoption of Liver Imaging Reporting and Data System (LI-RADS) treatment response (LR-TR) criteria. However, there is still a relative lack of evidence evaluating the performance of these criteria. We performed this study to assess the diagnostic accuracy of LI-RADS LR-TR criteria.

METHODS

A thorough search of PubMed, Embase, Scopus, and Cochrane Central Register of Controlled Trials for studies reporting diagnostic accuracy of LI-RADS LR-TR criteria was conducted through 30 June 2020. The meta-analytic summary of sensitivity, specificity, and diagnostic odds ratio of LI-RADS LR-TR criteria was computed using explant histopathology as the reference standard. The quality of the studies was assessed using the Quality Assessment of Diagnostic Accuracy Studies-2 tool.

RESULTS

Four studies were found eligible for meta-analysis. The total number of LR-TR observations was 462 (240 patients, 82.5% males). Different locoregional therapies (LRTs), including bland embolization, chemoembolization, radiofrequency ablation, and microwave ablation, had been used. The mean time interval between LRT and liver transplantation ranged from 181 to 219 days. There was a moderate to good inter-reader agreement for LR-TR criteria. The pooled sensitivity and specificity of LR-TR criteria for viable disease were 62% (95% CI, 49-74%; I² = 69%) and 87% (95% CI, 76-93%; I² = 57%), respectively. The pooled diagnostic odds ratio and area under the curve were 9.83 (95% CI, 5.34-18.08; I² = 19%) and 0.80.

CONCLUSIONS

LI-RADS LR-TR criteria have acceptable diagnostic performance for the diagnosis of viable tumor after LRT. Well-designed prospective studies evaluating criteria of equivocal lesions and effect of different LRTs should be performed.

KEY POINTS

• The pooled sensitivity and specificity of LI-RADS LR-TR criteria for the diagnosis of viable tumor were 62% and 87%, respectively. • The pooled diagnostic odds ratio and area under the curve were 9.83 and 0.80. • LR-TR criteria had a moderate to good inter-reader agreement.

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

BACKGROUND

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Consensus report from the 9th International Forum for Liver Magnetic Resonance Imaging: applications of gadoxetic acid-enhanced imaging

Objectives

The 9th International Forum for Liver Magnetic Resonance Imaging (MRI) was held in Singapore in September 2019, bringing together radiologists and allied specialists to discuss the latest developments in and formulate consensus statements for liver MRI, including the applications of gadoxetic acid–enhanced imaging.

Methods

As at previous Liver Forums, the meeting was held over 2 days. Presentations by the faculty on days 1 and 2 and breakout group discussions on day 1 were followed by delegate voting on consensus statements presented on day 2. Presentations and discussions centered on two main meeting themes relating to the use of gadoxetic acid–enhanced MRI in primary liver cancer and metastatic liver disease.

Results and conclusions

Gadoxetic acid–enhanced MRI offers the ability to monitor response to systemic therapy and to assist in pre-surgical/pre-interventional planning in liver metastases. In hepatocellular carcinoma, gadoxetic acid–enhanced MRI provides precise staging information for accurate treatment decision-making and follow-up post therapy. Gadoxetic acid–enhanced MRI also has potential, currently investigational, indications for the functional assessment of the liver and the biliary system. Additional voting sessions at the Liver Forum debated the role of multidisciplinary care in the management of patients with liver disease, evidence to support the use of abbreviated imaging protocols, and the importance of standardizing nomenclature in international guidelines in order to increase the sharing of scientific data and improve the communication between centers.

Key Points

• Gadoxetic acid–enhanced MRI is the preferred imaging method for pre-surgical or pre-interventional planning for liver metastases after systemic therapy.

• Gadoxetic acid–enhanced MRI provides accurate staging of HCC before and after treatment with locoregional/biologic therapies.

• Abbreviated protocols for gadoxetic acid–enhanced MRI offer potential time and cost savings, but more evidence is necessary. The use of gadoxetic acid–enhanced MRI for the assessment of liver and biliary function is under active investigation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00330-020-07637-4.

Radiopaque beads loaded with doxorubicin in the treatment of patients with hepatocellular carcinoma: A retrospective, multi-center study

BACKGROUND AND AIMS

Radiopaque drug-eluting beads are an emerging treatment option for patients with hepatocellular carcinoma (HCC). The primary objective of this study was to evaluate overall disease and target tumor response of non-resectable HCC after TACE with a doxorubicin-loaded radiopaque microsphere.

METHODS

Data were abstracted from records of patients with unresectable HCC who received TACE with doxorubicin-loaded radiopaque LC Bead LUMI^TM microspheres at one of five United States centers between February 2016 - November 2017. Response was measured using modified response criteria in solid tumors. Primary efficacy endpoints included objective response rate (ORR) and disease control rate (DCR) at first assessment post-treatment, both overall and for targeted tumors. ORR was the sum of complete and partial response. DCR was ORR plus stable disease. Toxicity was calculated using common terminology criteria for adverse events.

RESULTS

Eighty-two patients were included. Overall ORR and DCR were 47.6% (39/82) and 76.8% (63/82), respectively. ORR and DCR of target tumors were 56% and 98%, respectively. Five patients experienced adverse events (5/82, 6.1%). No grade 4-5 toxicities occurred.

CONCLUSIONS

TACE with drug-loaded radiopaque beads is a promising treatment for unresectable HCC. Prospective studies should evaluate whether radiopaque beads reduce off-target distribution of microspheres.

Evaluation of liver tumour response by imaging

The goal of assessing tumour response on imaging is to identify patients who are likely to benefit - or not - from anticancer treatment, especially in relation to survival. The World Health Organization was the first to develop assessment criteria. This early score, which assessed tumour burden by standardising lesion size measurements, laid the groundwork for many of the criteria that followed. This was then improved by the Response Evaluation Criteria in Solid Tumours (RECIST) which was quickly adopted by the oncology community. At the same time, many interventional oncology treatments were developed to target specific features of liver tumours that result in significant changes in tumours but have little effect on tumour size. New criteria focusing on the viable part of tumours were therefore designed to provide more appropriate feedback to guide patient management. Targeted therapy has resulted in a breakthrough that challenges conventional response criteria due to the non-linear relationship between response and tumour size, requiring the development of methods that emphasize the appearance of tumours. More recently, research into functional and quantitative imaging has created new opportunities in liver imaging. These results have suggested that certain parameters could serve as early predictors of response or could predict later tumour response at baseline. These approaches have now been extended by machine learning and deep learning. This clinical review focuses on the progress made in the evaluation of liver tumours on imaging, discussing the rationale for this approach, addressing challenges and controversies in the field, and suggesting possible future developments.

Transarterial Ethanol Ablation for Small Hepatocellular Carcinoma (≤ 3 cm): A Comparative Study Versus Radiofrequency Ablation

PURPOSE

The objective was to evaluate the local treatment efficacy of transarterial ethanol ablation (TEA) as compared to radiofrequency ablation (RFA) for small hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

This was a retrospective study between January 2005 and April 2017, in which the treatment outcomes of all patients who received either percutaneous TEA or RFA for HCC tumors of size ≤ 3 cm, of Child-Pugh grade A or B, received no prior treatment other than surgical resection, were compared. For TEA, a mixture of absolute ethanol and ethiodized oil at a proportion of 1:2 by volume was administered superselectively into the tumor via a microcatheter placed at the feeding arteries. The TEA group and the RFA group consisted of 68 consecutive patients (88 treated target tumors) and 129 consecutive patients (129 tumors), respectively.

RESULTS

Technical success was achieved in all the target tumors in both groups. Grade 3 complication (CIRSE Classification) of prolonged fever occurred in 3 cases with multi-focal and large tumors in the TEA group. There was no statistically significant difference in complete response rate between the TEA group (84/88 or 95.5%) and the RFA group (188/195 or 96.4%) (p = 0.7). Time to progression in the TEA group [median 11.9 months, interquartile range (IQR) 5.6-18 months] was not statistically different from that in the RFA group (median 9.5 months, IQR 3.5-18.7 months) (p = 0.773).

CONCLUSION

TEA could be an effective alternative of RFA for the local treatment of small HCC; it is especially valuable for tumors of unfavorable location.

Contralateral Liver Hypertrophy and Oncological Outcome Following Radioembolization with 90Y-Microspheres: A Systematic Review

Radioembolization with ⁹⁰Y-microspheres has been reported to induce contralateral liver hypertrophy with simultaneous ipsilateral control of tumor growth. The aim of the present systematic review was to summarize the evidence of contralateral liver hypertrophy and oncological outcome following unilateral treatment with radioembolization. A systematic literature search using the MEDLINE, EMBASE, and Cochrane libraries for studies published between 2008 and 2020 was performed. A total of 16 studies, comprising 602 patients, were included. The median kinetic growth rate per week of the contralateral liver lobe was 0.7% and declined slightly over time. The local tumor control was 84%. Surgical resection after radioembolization was carried out in 109 out of 362 patients (30%). Although the available data suggest that radioembolization prior to major hepatectomy is safe with a promising oncological outcome, the definitive role of radioembolization requires assessment within controlled clinical trials.

Yttrium-90 microsphere radioembolisation for unresectable hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the most common liver neoplasm and the sixth most common cancer worldwide. Its incidence has increased dramatically since the mid-2000s. Although surgical resection and liver transplantation are the main curative treatments, only about 20% of people with early hepatocellular carcinoma may benefit from these interventions. Treatment options for unresectable hepatocellular carcinoma include ablative and transarterial interventions - selective yttrium-90 microsphere transarterial radioembolisation - in addition to the drug sorafenib.

OBJECTIVES

To determine the benefits and harms of yttrium-90 (Y-90) microsphere transarterial radioembolisation given as monotherapy or in combination with other systemic or locoregional interventions versus placebo, no treatment, or other similar systemic or locoregional interventions for people with unresectable hepatocellular carcinoma.

SEARCH METHODS

We performed electronic searches in the Cochrane Hepato-Biliary Group (CHBG) Controlled Trials Register, CENTRAL, MEDLINE, Embase, Latin American Caribbean Health Sciences Literature (LILACS), Science Citation Index - Expanded, and Conference Proceedings Citation Index - Science until September 2019. We manually checked the reference lists of primary studies and review articles.

SELECTION CRITERIA

We searched for randomised clinical trials.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. We extracted information on participants, interventions, outcomes, trial design, and trial methods. We assessed risk of bias of the included trials using pre-defined domains and the certainty of evidence using GRADE. Our primary review outcomes were all-cause mortality, quality of life, and serious adverse events; our secondary outcomes were cancer-related mortality, time to progression of the tumour, tumour response, non-serious adverse events, and liver transplantation. For dichotomous variables, we calculated risk ratio (RR), and for continuous variables, we planned to calculate mean difference (MD) or standardised mean difference (SMD), with 95% confidence intervals (CIs). We based time-to-event data analyses on hazard ratios (HRs).

MAIN RESULTS

Six randomised trials with 1340 participants in total fulfilled the review inclusion criteria and provided data for one or more of our analysed outcomes. All trials were at high risk of bias. We assessed the certainty of evidence as low to very low. One trial compared radioembolisation plus sorafenib versus sorafenib alone in people with advanced hepatocellular carcinoma. All-cause mortality, health-related quality of life, cancer-related mortality, time to progression, and tumour response rates were not reported. Serious adverse events were reported in 63 trial participants (39.6%) in the radioembolisation plus sorafenib group versus 70 trial participants (38.5%) in the sorafenib group (very low-certainty evidence). Hyperbilirubinaemia was approximately three times more common in the radioembolisation plus sorafenib group versus the sorafenib group (14.5% versus 4.4%; very low-certainty evidence). Fatigue was more common in the radioembolisation plus sorafenib group than in the sorafenib group, at 35.2% versus 24.2% of trial participants. Two trials compared radioembolisation versus sorafenib for unresectable hepatocellular carcinoma in people with locally advanced hepatocellular carcinoma. From the data we could extract, one-year all-cause mortality was 62.7% in the radioembolisation group versus 53.0% in the sorafenib group (1 trial; n = 360; very low-certainty evidence). There were no differences in the quality of life between radioembolisation and sorafenib groups (1 trial). Global health status subscore was better in the radioembolisation group than in the sorafenib group (P = 0.0048; 1 trial). Fewer participants had serious adverse events in the radioembolisation group than in the sorafenib group (27 (20.8%) in the radioembolisation group versus 57 (35.2%) in the sorafenib group; 1 trial). Median time to progression of the tumour in the radioembolisation group was 6.1 months versus 5.4 months in the sorafenib group (1 trial). The RR for disease control rate was 0.94 (95% CI 0.84 to 1.05; n = 748; 2 trials; very low-certainty evidence), favouring neither radioembolisation nor sorafenib. In two trials with 734 participants, radioembolisation seemed to be less likely to be associated with hand-foot skin reaction (RR 0.02, 95% CI 0.00 to 0.06; P < 0.001; low-certainty evidence), skin rash (RR 0.11, 95% CI 0.04 to 0.34; low-certainty evidence), diarrhoea (RR 0.11, 95% CI 0.04 to 0.34; low-certainty evidence), and hypertension (RR 0.10, 95% CI 0.01 to 0.88; low-certainty evidence). No trial reported cancer-related mortality. Three trials compared radioembolisation versus chemoembolisation in people with intermediate-stage hepatocellular carcinoma. From the data we could extract, none of these trials reported all-cause mortality and cancer-related mortality. The RR for serious adverse events was 1.41 (95% CI 0.63 to 3.14; n = 97; very low-certainty evidence), favouring neither radioembolisation nor chemoembolisation. One trial reported quality of life and noted no differences between intervention groups with regard to this outcome at week 12 (very low-certainty evidence). Median time to progression was not reached in the radioembolisation group and was 6.8 months in the chemoembolisation group (HR 0.122, 95% CI 0.027 to 0.557; 1 trial). Median time to progression of the tumour in the radioembolisation group was 371 days versus 336 days in the chemoembolisation group (P = 0.5764; 1 trial). Disease control rates (complete response + partial response + stable disease) were 73.3% with radioembolisation versus 76.9% with chemoembolisation (1 trial). According to World Health Organization (WHO) criteria, tumour response was reported in 52% of participants who received radioembolisation versus 63% of those who received chemoembolisation (1 trial). Patients in the chemoembolisation group experienced diarrhoea (P = 0.031; 1 trial) and hypoalbuminaemia (P < 0.001; 1 trial) more frequently. Four trials were sponsored by industry, and two by University. We found two ongoing trials.

AUTHORS' CONCLUSIONS

Evidence showing effects of radioembolisation with or without sorafenib compared with sorafenib alone in people with unresectable hepatocellular carcinoma is highly insufficient. We cannot determine if radioembolisation plus sorafenib compared with sorafenib alone affects all-cause mortality or the occurrence of adverse events. Radioembolisation compared with sorafenib seemed to achieve equivalent survival and to cause fewer adverse effects, but our certainty was very low. Evidence showing effects of radioembolisation versus chemoembolisation in people with unresectable hepatocellular carcinoma is also highly insufficient. Radioembolisation did not seem to differ from chemoembolisation in terms of serious adverse events and quality of life, but the certainty of evidence was very low. Further high-quality placebo-controlled randomised clinical trials are needed to assess patient-centred outcomes.

A Pretreatment CT Model Predicts Survival Following Chemolipiodolization in Patients With Hepatocellular Carcinoma

Purpose:

To establish a computed tomography–based prognostic model for patients with hepatocellular carcinoma treated with transarterial chemoembolization.

Materials and Methods:

Using prospectively collected data from 195 consecutive patients with hepatocellular carcinoma who underwent chemolipiodolization at the Eastern Hepatobiliary Surgery Hospital between 2013 and 2016, we established a prognostic model based on hepatocellular carcinoma enhancement patterns on computed tomography scans to predict the outcome of transarterial chemoembolization. Furthermore, a histopathology analysis was performed on 108 different patients undergoing resection between 2014 and 2016 to identify whether there was a correlation between enhancement pattern and microvessel density.

Results:

The prognostic model classified hepatocellular carcinoma into 3 types: type I, which reached peak enhancement during the arterial phase and had a high mean microvessel density (101.5 vessels/0.74 mm²); type II, which reached peak enhancement during the portal venous or delayed phase and had an intermediate microvessel density (53.6 vessels/0.74 mm²); and type III, in which the tumor was insignificantly enhanced and had a low microvessel density (21.1 vessels/0.74 mm²). For type I, II, and III hepatocellular carcinoma, the post-transarterial chemoembolization 1-year tumor complete necrosis rates were 13.7%, 36.5%, and 0%, respectively (P < .001), and the 3-year overall survival rates were 14.1%, 38.6%, and 0%, respectively (P < .001).

Conclusion:

Our results indicate that hepatocellular carcinoma type is an independent predictor of complete necrosis and overall survival

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.

Dynamic Computed Tomography Perfusion Imaging: Complementary Diagnostic Tool in Hepatocellular Carcinoma Assessment From Diagnosis to Treatment Follow-up

Early diagnosis of HCC is of paramount importance in order to enable the application of curative treatments. Among these, radiofrequency ablation (RFA) is actually considered the most effective ablative therapy for early stage hepatocellular carcinoma (HCC) not suitable for surgery. On the other hand, transarterial chemoembolization (TACE) represents the standard of care for intermediate stage HCC and compensated liver function. Finally, sorafenib, an oral antiangiogenic targeted drug, is the only approved systemic therapy for advanced HCC with vascular invasion, extrahepatic spread, and well-preserved liver function. Beside traditional radiological techniques, new functional imaging tools have been introduced in order to provide not only morphological information but also quantitative functional data. In this review, we analyze perfusion-CT (pCT) from a technical point of view, describing the main different mathematical analytical models for the quantification of tissue perfusion from acquired CT raw data, the most commonly acquired perfusion parameters, and the technical parameters required to perform a standard pCT examination. Moreover, a systematic review of the literature was performed to assess the role of pCT as an emerging imaging biomarker for HCC diagnosis, response evaluation to RFA, TACE, and sorafenib, and we examine its challenges in HCC management.

Safety and efficacy of radioembolization with glass microspheres in hepatocellular carcinoma patients with elevated lung shunt fraction: analysis of a 103-patient cohort

BACKGROUND

Technetium-99m macroaggregated albumin is used to estimate lung shunt fraction (LSF) prior to yttrium-90 (Y90). Studies have debated the safety and efficacy of Y90 in patients with LSF > 15%. We aimed to assess the role of Y90 in hepatocellular carcinoma (HCC) with LSF > 15%.

METHODS

With IRB approval, we searched our prospectively acquired database of HCC patients with Y90 treated with LSF > 15%. Median LSF and liver and lung doses were calculated. The response was assessed using RECIST. Overall survival (OS) was calculated from date of first Y90.

RESULTS

A total of 103 HCC patients underwent Y90. The median baseline LSF was 24.4% (IQR 18.1-28.8). Patients exhibited multifocal disease (59/103, 60%) and median tumor size of 7.85 cm (IQR 5.2, 10.57). BCLC class was A, B, C, and D in 7 (7%), 5 (5%), 85 (83%), and 6 (6%) patients, respectively. The median liver dose was 84.6 Gy (IQR 57.4, 107.55). The median lung dose per session and cumulatively was 22.9 Gy (IQR 15-28) and 29.5 Gy (IQR 20.5-44.3). Thirty-three patients (32%) demonstrated partial response, 57 stable disease, and 13 (13%) had progressive disease. The median OS was 7.3 months (95% CI 5.3, 11.47). Twenty patients (19%) had non-specific pulmonary symptoms (cough, shortness of breath, wheezing) in the 1-year post-Y90. The median time to the appearance of non-specific pulmonary symptoms was 63 days (range 7-224). Thoracic imaging demonstrated no pulmonary fibrosis/injury following treatment in any patient.

CONCLUSION

Y90 can be performed in patients with LSF > 15%. The RECIST response was identified in 32% of the patients. In isolation, LSF > 15% should not deter from treatment with Y90.

Prediction of hepatocellular carcinoma response to 90Yttrium radioembolization using volumetric ADC histogram quantification: preliminary results

Purpose

To assess the predictive value of volumetric apparent diffusion coefficient (vADC) histogram quantification obtained before and 6 weeks (6w) post-treatment for assessment of hepatocellular carcinoma (HCC) response to ⁹⁰Yttrium radioembolization (RE).

Methods

In this retrospective study, 22 patients (M/F 15/7, mean age 65y) who underwent lobar RE were included between October 2013 and November 2014. All patients underwent routine liver MRI pre-treatment and 6w after RE. Two readers assessed index tumor response at 6 months after RE in consensus, using mRECIST criteria. vADC histogram parameters of index tumors at baseline and 6w, and changes in vADC (ΔvADC) histogram parameters were calculated. The predictive value of ADC metrics was assessed by logistic regression with stepwise parameter selection and ROC analyses.

Results

Twenty two HCC lesions (mean size 3.9 ± 2.9 cm, range 1.2–12.3 cm) were assessed. Response at 6 months was as follows: complete response (CR, n = 6), partial response (PR, n = 3), stable disease (SD, n = 12) and progression (PD, n = 1). vADC median/mode at 6w (1.81–1.82 vs. 1.29–1.35 × 10^− 3 mm²/s) and ΔvADC median/max (27–44% vs. 0–10%) were significantly higher in CR/PR vs. SD/PD (p = 0.011–0.036), while there was no significant difference at baseline. Logistic regression identified vADC median at 6w as an independent predictor of response (CR/PR) with odds ratio (OR) of 3.304 (95% CI: 1.099–9.928, p = 0.033) and AUC of 0.77. ΔvADC mean was identified as an independent predictor of CR with OR of 4.153 (95%CI: 1.229–14.031, p = 0.022) and AUC of 0.91.

Conclusion

Diffusion histogram parameters obtained at 6w and early changes in ADC from baseline are predictive of subsequent response of HCCs treated with RE, while pre-treatment vADC histogram parameters are not. These results need confirmation in a larger study.

Trial registration

This retrospective study was IRB-approved and the requirement for informed consent was waived.

From a Philosophical Framework to a Valid Prognostic Staging System of the New "Comprehensive Assessment" for Transplantable Hepatocellular Carcinoma

The comprehensive assessment of the transplantable tumor (TT) proposed and included in the last Italian consensus meeting still deserve validation. All consecutive patients with hepatocellular carcinoma (HCC) listed for liver transplant (LT) between January 2005 and December 2015 were post-hoc classified by the tumor/patient stage as assessed at the last re-staging-time (ReS-time) before LT as follow: high-risk-class (HRC) = stages TT_DR, TT_PR; intermediate-risk-class (IRC) = TT0_NT, TT_FR, TT_UT; low-risk-class (LRC) = TT1, TT0_L, TT0_C. Of 376 candidates, 330 received LT and 46 dropped-out. Transplanted patients were: HRC for 159 (48.2%); IRC for 63 (19.0%); LRC for 108 (32.7%). Cumulative incidence function (CIF) of tumor recurrence after LT was 21%, 12%, and 8% at 5-years and 27%, 15%, and 12% at 10-years respectively for HRC, IRC, and LRC (P = 0.011). IRC patients had significantly lower CIF of recurrence after LT if transplanted >2-months from ReS-time (28% vs. 3% for <2 and >2 months, P = 0.031). HRC patients had significantly lower CIF of recurrence after-LT if transplanted <2 months from the ReS-time (10% vs. 33% for <2 and >2 months, P = 0.006). The proposed TT staging system can adequately describe the post-LT recurrence, especially in the LRC and HRC patients. The intermediate-risk-class needs to be better defined and further studies on its ability in defining intention-to-treat survival (ITT) and drop-out are required.

The physics of radioembolization

Radioembolization is an established treatment for chemoresistant and unresectable liver cancers. Currently, treatment planning is often based on semi-empirical methods, which yield acceptable toxicity profiles and have enabled the large-scale application in a palliative setting. However, recently, five large randomized controlled trials using resin microspheres failed to demonstrate a significant improvement in either progression-free survival or overall survival in both hepatocellular carcinoma and metastatic colorectal cancer. One reason for this might be that the activity prescription methods used in these studies are suboptimal for many patients.In this review, the current dosimetric methods and their caveats are evaluated. Furthermore, the current state-of-the-art of image-guided dosimetry and advanced radiobiological modeling is reviewed from a physics' perspective. The current literature is explored for the observation of robust dose-response relationships followed by an overview of recent advancements in quantitative image reconstruction in relation to image-guided dosimetry.This review is concluded with a discussion on areas where further research is necessary in order to arrive at a personalized treatment method that provides optimal tumor control and is clinically feasible.

Reproducibility of European Association for the Study of the Liver criteria and modified Response Evaluation Criteria in Solid Tumors in patients treated with sorafenib

BACKGROUND & AIMS

The European Association for the Study of the Liver criteria and the modified Response Evaluation Criteria in Solid Tumors are used for assessing the treatment outcomes of hepatocellular carcinoma. We investigated the inter- and intra-observer reproducibility of the European Association for the Study of the Liver criteria and modified Response Evaluation Criteria in Solid Tumors in patients with advanced hepatocellular carcinoma treated with sorafenib.

METHODS

A total of 99 patients with treatment-naive advanced hepatocellular carcinoma receiving sorafenib were included. The κ-values for the inter- and intra-observer agreement of the treatment response were calculated.

RESULTS

Inter-observer agreement for baseline tumour number was excellent, as reflected by the high κ-value. The κ-statistics showed "excellent" concordance between the 2 sets of measurements by observer A regarding the overall responses using the European Association for the Study of the Liver criteria (κ = .948, agreement rate = 84.8%) and modified Response Evaluation Criteria in Solid Tumors (κ = .944, agreement rate = 83.8%; all P < .001). In addition, high κ-values indicated concordance between the first sets of measurements by observers A and B (κ = .991 by the European Association for the Study of the Liver criteria and .988 by modified Response Evaluation Criteria in Solid Tumors, all P < .001). When agreements in radiological overall responses between the 2 sets of measurements by observer B and between the second sets of measurements by observers A and B were calculated, similar results regarding high κ-values (>.8) were obtained.

CONCLUSIONS

The reproducibility of the European Association for the Study of the Liver criteria and modified Response Evaluation Criteria in Solid Tumors in assessing treatment outcomes was high in patients with advanced hepatocellular carcinoma treated with sorafenib.

Dynamic Three-Dimensional Contrast-Enhanced Ultrasound to Predict Therapeutic Response of Radiofrequency Ablation in Hepatocellular Carcinoma: Preliminary Findings

BACKGROUND & AIMS

To investigate the value of dynamic three-dimensional contrast-enhanced ultrasound (3D-CEUS) in the assessment of therapeutic response of hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA).

METHODS

Forty-two patients (31 men and 11 women; mean age (52.1 ± 13.1 years)) with 42 clinical diagnosed HCC lesions (size range 14-48 mm; mean size 28.4 ± 9.9 mm) treated by RFA were included. All patients underwent two-dimensional contrast-enhanced ultrasound (2D-CEUS) and 3D-CEUS 1 month after treatment. Two radiologists assessed the absence (complete response, CR) or presence (residual tumor, RT) of any arterially hyperenhancing nodules within or along the margin of the treated HCC lesions. Complete response on magnetic resonance (MR) imaging acted as standard of reference (SOR).

RESULTS

After RFA treatment, 3D-CEUS was successfully conducted in 34 HCC lesions. CR was observed on both 2D-CEUS and 3D-CEUS in 25/42 (59.5%) HCC and RT in 6/42 (14.3%) HCC lesions. In 3/42 (7.1%) HCC lesion, RT was documented by SOR and 3D-CEUS, but it was not appreciable at 2D-CEUS. In 3/42 (7.1%) HCC lesion, the presence of peripheral RT was suspected by both 2D-CEUS and 3D-CEUS, but it was not confirmed by SOR. No statistically significant difference between 2D-CEUS and 3D-CEUS in depicting either CR or RT was found (P = 0.25). Combined with dynamic 3D-CEUS, the diagnostic accuracy was improved from 85.7% to 92.9%.

CONCLUSIONS

3D-CEUS might be helpful in better diagnostic performance in the assessment of therapeutic response of HCC treated after RFA.

Angiosomal radiopathologic analysis of transarterial radioembolization for the treatment of hepatocellular carcinoma

PURPOSE

To assess the radiopathologic correlation following Yttrium-90 transarterial radioembolization (TARE) of hepatocellular carcinoma (HCC) using variable radiodosimetry to identify imaging surrogates of histologic response.

METHODS

Twelve patients with HCC underwent ablative (≥ 190 Gy) and/or non-ablative (< 190 Gy) TARE delivered in a segmental, lobar, or combined fashion as a surgical neoadjuvant or bridge to transplantation. Both targeted tumor and treatment angiosome were analyzed before and after TARE utilizing hepatocyte-specific contrast-enhanced MRI or contrast-enhanced CT. Responses were graded using EASL and mRECIST criteria. Histologic findings including percent tumor necrosis and adjacent hepatic substrate effects were correlated with imaging features.

RESULTS

Complete pathologic necrosis (CPN) was observed in 7/12 tumors post-TARE. Ablative and non-ablative dosing resulted in CPN in 5/6 and 2/6 tumors, respectively. Hyperintensity on T2-weighted imaging, the absence of hepatocyte-specific gadolinium contrast uptake, and plateau or persistent enhancement kinetics in the angiosome correlated with CPN and performed similarly to EASL and mRECIST criteria in predicting CPN.

CONCLUSIONS

The absence of hepatocyte-specific contrast uptake, increased signal on T2-weighted sequences, and plateau or persistent enhancement in the angiosome may represent MRI surrogates of CPN following TARE of HCC. These findings correlated with EASL and mRECIST response criteria. Further investigation is needed to determine the role of these findings as possible adjuncts to conventional imaging criteria.

Post Locoregional Therapy Treatment Imaging in Hepatocellular Carcinoma Patients: A Literature-based Review

Imaging plays a crucial role in the diagnosis of hepatocellular carcinoma (HCC) as well as in determining treatment efficacy, or complications, following therapy. Unlike other cancers, HCC is most commonly treated by locoregional therapies (LRTs) such as thermal ablation, transarterial chemoembolization, and transarterial radioembolization. These treatments can lead to changes on imaging that make determination of residual/recurrent disease difficult. This literature-based review discusses the expected postimaging findings following LRT.

Radioembolization for hepatocellular carcinoma: Statistical confirmation of improved survival in responders by landmark analyses

Does imaging response predict survival in hepatocellular carcinoma (HCC)? We studied the ability of posttherapeutic imaging response to predict overall survival. Over 14 years, 948 patients with HCC were treated with radioembolization. Patients with baseline metastases, vascular invasion, multifocal disease, Child-Pugh > B7, and transplanted/resected were excluded. This created our homogeneous study cohort of 134 patients with Child-Pugh ≤ B7 and solitary HCC. Response (using European Association for Study of the Liver [EASL] and Response Evaluation Criteria in Solid Tumors 1.1 [RECIST 1.1] criteria) was associated with survival using Landmark and risk-of-death methodologies after reviewing 960 scans. In a subanalysis, survival times of responders were compared to those of patients with stable disease (SD) and progressive disease (PD). Uni/multivariate survival analyses were performed at each Landmark. At the 3-month Landmark, responders survived longer than nonresponders by EASL (hazard ratio [HR], 0.46; confidence interval [CI], 0.26-0.82; P = 0.002) but not RECIST 1.1 criteria (HR, 0.70; CI, 0.37-1.32; P = 0.32). At the 6-month Landmark, responders survived longer than nonresponders by EASL (HR, 0.32; CI, 0.15-0.77; P < 0.001) and RECIST 1.1 criteria (HR, 0.50; CI, 0.29-0.87; P = 0.021). At the 12-month Landmark, responders survived longer than nonresponders by EASL (HR, 0.34; CI, 0.15-0.77; P <  0.001) and RECIST 1.1 criteria (HR, 0.52; CI 0.27-0.98; P = 0.049). At 6 months, risk of death was lower for responders by EASL (P <  0.001) and RECIST 1.1 (P = 0.0445). In subanalyses, responders lived longer than patients with SD or PD. EASL response was a significant predictor of survival at 3-, 6-, and 12-month Landmarks on uni/multivariate analyses.

CONCLUSION

Response to radioembolization in patients with solitary HCC can prognosticate improved survival. EASL necrosis criteria outperformed RECIST 1.1 size criteria in predicting survival. The therapeutic objective of radioembolization should be radiologic response and not solely to prevent progression. (Hepatology 2018;67:873-883).

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.

Which Criteria Applied in Multi-Phasic CT Can Predict Early Tumor Response in Patients with Hepatocellular Carcinoma Treated Using Conventional TACE: RECIST, mRECIST, EASL or qEASL?

PURPOSE

Our study aimed to evaluate quantitative tumor response assessment (quantitative EASL-[qEASL]) on computed tomography (CT) images in patients with hepatocellular carcinoma (HCC) treated using conventional transarterial chemoembolization (cTACE), compared to existing 1-dimensional and 2-dimensional methods (RECIST, mRECIST, EASL).

MATERIALS AND METHODS

In this IRB-approved, single-institution retrospective cohort study, 52 consecutive patients with intermediate-stage HCC were consecutively included. All patients underwent contrast-enhanced CT scan at baseline and 4 weeks after cTACE.

RESULTS

Median follow-up period was 13.5 months (range 1.2-54.1). RECIST, mRECIST and EASL identified progression in 2 (4%), 1 (2%) and 1 (2%) patients, respectively, whereas qEASL identified 10 (19%) patients. qEASL was the only tumor response method able to predict survival among different tumor response groups (P < 0.05), whereas RECIST, mRECIST and EASL did not (P > 0.05). Both EASL and qEASL were able to identify responders and non-responders and were predictive of survival (P < 0.05). Multivariate analysis showed that progression was an independent predictor of overall survival with hazard ratio of 1.9 (P = 0.025). Patients who demonstrated progression with qEASL had significantly shorter survival than those with non-progression (7.6 vs. 20.4 months, P = 0.012). Similar multivariate analysis using RECIST, mRECIST and EASL could not be performed because too few patients were categorized as progressive disease.

CONCLUSION

qEASL could be applied on CT images to assess tumor response following cTACE and is a more sensitive biomarker to predict survival and identify tumor progression than RECIST, mRECIST and EASL at an early time point.

LEVEL OF EVIDENCE

Level 2a, retrospective cohort study.

Radioembolisation of hepatocellular carcinoma: a primer

Transarterial radioembolisation (TARE) has gained increasing acceptance as an additional/alternative locoregional treatment option for hepatocellular carcinoma, and colorectal hepatic metastases that present beyond potentially curative options. This is a catheter-based transarterial selective internal brachytherapy that involves injection of radioactive microspheres (usually Y-90) that are delivered selectively to the liver tumours. Owing to the combined radioactive and microembolic effect, the findings at follow-up imaging are significantly different from that seen with other transarterial treatment options. Considering increasing confidence among clinicians, refinement in techniques and increasing number of ongoing trials, TARE is expected to gain further acceptance and become an important tool in the armamentarium for the treatment of liver malignancies. So it is imperative that all radiologists involved in the management of liver malignancies are well versed with TARE to facilitate appropriate discussion at multidisciplinary meetings to direct further management. In this article, we provide a comprehensive review on various aspects of radioembolisation with Y-90 for hepatocellular carcinoma including the patient selection, treatment planning, radiation dosimetry and treatment, side effects, follow-up imaging and future direction.

Interventional Oncology Service Development

Interventional oncology is rapidly expanding its suite of oncologic therapies, providing unique proven therapeutic benefits. To grow a practice alongside other oncology specialties, knowledge of cancer fundamentals is required. Areas of interest include methods to assess disease stage, treatment toxicity, and response. Additionally, techniques to leverage opportunities and resources available at one's institution toward practice development and efficiency will be reviewed.

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.

External beam radiotherapy for unresectable hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the most common liver neoplasm, the sixth most common cancer worldwide, and the third most common cause of cancer mortality. Moreover, its incidence has increased dramatically in the past decade. While surgical resection and liver transplantation are the main curative treatments, only around 20% of people with early hepatocellular carcinoma may benefit from these therapies. Current treatment options for unresectable hepatocellular carcinoma include various ablative and transarterial therapies in addition to the drug sorafenib.

OBJECTIVES

To assess the benefits and harms of external beam radiotherapy in the management of localised unresectable hepatocellular carcinoma.

SEARCH METHODS

We searched the Cochrane Hepato-Biliary Group Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, MEDLINE (OvidSP), Embase (OvidSP), Science Citation Index Expanded (Web of Science), and clinicaltrials.gov registry. We also checked reference lists of primary original studies and review articles manually for further related articles (cross-references) up to October 6, 2016.

SELECTION CRITERIA

Eligible studies included all randomised clinical trials comparing external beam radiotherapy either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other systemic or locoregional therapies for people with unresectable hepatocellular carcinoma.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We used a random-effects model as well as a fixed-effect model meta-analysis but in case of discrepancy between the two models (e.g. one giving a significant intervention effect, the other no significant intervention effect), we reported both results; otherwise, we reported only the results from the fixed-effect model meta-analysis. We assessed risk of bias of the included trials using predefined risk of bias domains; assessed risks of random errors with Trial Sequential Analysis; and presented the review results incorporating the methodological quality of the trials using GRADE.

MAIN RESULTS

Nine randomised clinical trials with 879 participants fulfilled our inclusion criteria. All trials were at high risk of bias, and we rated the evidence as low to very low quality. All of the included trials compared combined external beam radiotherapy plus chemoembolisation versus chemoembolisation alone in people with unresectable hepatocellular carcinoma; moreover, three of the trials compared external beam radiotherapy alone versus chemoembolisation alone. All trials were conducted in China. The median age in most of the included trials was around 52 years, and most trial participants were male. The median follow-up duration ranged from one to three years. None of the trials reported data on cancer-related mortality, quality of life, serious adverse events, or time to progression of the tumour. For the comparison of radiotherapy plus chemoembolisation versus chemoembolisation alone, the risk ratio for one-year all-cause mortality was 0.51 (95% confidence interval (CI) 0.41 to 0.62; P < 0.001; 9 trials; low-quality evidence); for complete response rate was 2.14 (95% CI 1.47 to 3.13; P < 0.001; 7 trials; low-quality evidence); and for overall response rate defined as complete response plus partial response was 1.58 (95% CI 1.40 to 1.78; P < 0.001; 7 trials; low-quality evidence), all in favour of combined treatment with external beam radiotherapy plus transarterial chemoembolisation and seemingly supported by our Trial Sequential Analysis. Additionally, the combined treatment was associated with a higher risk of elevated total bilirubin and elevated alanine aminotransferase. The risk ratio for the risk of elevated alanine aminotransferase was 1.41 (95% CI 1.08 to 1.84; P = 0.01; very low-quality evidence), while for elevated total bilirubin it was 2.69 (95% CI 1.34 to 5.40; P = 0.005; very low-quality evidence). For the comparison of radiotherapy versus chemoembolisation, the risk ratio for one-year all-cause mortality was 1.21 (95% CI 0.97 to 1.50; 3 trials; I² = 0%; very low-quality evidence) which was not supported by our Trial Sequential Analysis.In addition, we found seven ongoing randomised clinical trials evaluating different external beam radiotherapy techniques for people with unresectable hepatocellular carcinoma.

AUTHORS' CONCLUSIONS

We found very low- and low-quality evidence suggesting that combined external beam radiotherapy and chemoembolisation may be associated with lower mortality and increased complete and overall response rates, despite an increased toxicity as expressed by a higher rise of bilirubin and alanine aminotransferase. A high risk of systematic errors (bias) as well as imprecision and inconsistency suggest that these findings should be considered cautiously and that high-quality trials are needed to assess further the role of external beam radiotherapy for unresectable hepatocellular carcinoma.

Imaging of hepatocellular carcinoma and image guided therapies - how we do it

Treatment options for hepatocellular carcinoma have evolved over recent years. Interventional radiologists and surgeons can offer curative treatments for early stage tumours, and locoregional therapies can be provided resulting in longer survival times. Early diagnosis with screening ultrasound is the key. CT and MRI are used to characterize lesions and determine the extent of tumour burden. Imaging techniques are discussed in this article as the correct imaging protocols are essential to optimise successful detection and characterisation. After treatment it is important to establish regular imaging follow up with CT or MRI as local residual disease can be easily treated, and recurrence elsewhere in the liver is common.

Radiological biomarkers for assessing response to locoregional therapies in hepatocellular carcinoma: From morphological to functional imaging (Review)

Many hepatocellular carcinoma (HCC) patients do not qualify for curative surgical intervention and are instead treated with locoregional therapies (LRTs) including ablative and endovascular therapies. Assessment of imaging response is essential in the management of HCC for determining efficacy of therapy and as a surrogate marker for improved survival. The established morphological image biomarkers for tumor burden measurement continue to be applied, as size measurement can easily be used in clinical practice. However, in the setting of liver-directed LRTs for HCC, simple tumor morphological changes can be less informative and usually appear later than biologic changes. Functional imaging (such as perfusion and diffusion imaging, PET-CT/MR and MR spectroscopy) has the potential to be a promising technique for assessment of HCC response to LRTs. Although promising, none of these functional imaging biomarkers have gone through all the required steps of standardization and validation and established accepted criteria for clinical practice.

Intra-arterial therapies for liver cancer: assessing tumor response

INTRODUCTION

Intra-arterial therapies (IATs) play an integral role in the management of unresectable hepatocellular carcinoma and liver metastases. The ability to accurately assess tumor response to intra-arterial therapies is crucial for clinical management. Several one- and two-dimensional manual imaging-based response assessment techniques, based both on tumor size or enhancement, have shown to be highly subjective and merely surrogate for the actual tumor as a whole. Areas covered: Given the currently existing literature, we will discuss all available tumor assessment techniques and criteria for liver cancer with a strong emphasis on 3D quantitative imaging biomarkers of tumor response in this review. Expert commentary: The growing role of information technology in medicine has brought about the advent of software-assisted, segmentation-based assessment techniques that address the outstanding issues of a subjective reader and provide for more accurate assessment techniques for the locally treated lesions. Three-dimensional quantitative tumor assessment techniques are superior to one- and two-dimensional measurements. This allows for treatment alterations and more precise targeting, potentially resulting in improved patient outcome.

Correlation of tumor response on computed tomography with pathological necrosis in hepatocellular carcinoma treated by chemoembolization before liver transplantation

The purpose of this article was to compare the results of Response Evaluation Criteria in Solid Tumors (RECIST), modified Response Evaluation Criteria in Solid Tumors (mRECIST), and European Association for the Study of the Liver (EASL) criteria for the evaluation of tumor necrosis in patients treated with transarterial chemoembolization before liver transplantation (LT) for hepatocellular carcinoma. Response to treatment was evaluated on computed tomography scan by 2 independent readers based on RECIST, mRECIST, and EASL criteria, and compared with tumor necrosis assessed by explant pathology. Necrosis was defined as major when >90%. Factors associated with major necrosis were tested by multivariate analysis. Fifty-eight patients (53 males; mean age, 54 years; range, 31-64 years) were included with 88 nodules. Fifty-one (58%) nodules were shown to have major necrosis. Among them readers 1 and 2 identified a complete response (CR) according to RECIST, mRECIST, and EASL criteria in 2 (4%), 47 (92%), and 47 (92%), and 1 (2%), 45 (88%), and 45 (88%) nodules, respectively. However, 12-14 of 59 nodules classified as CR on mRECIST or EASL criteria were found to have intermediate or minor necrosis (overestimation in 20%-24% of the patients). Combining the classification of CR by mRECIST and EASL criteria and complete lipiodol deposition reduced the overestimation to 11%. Among 59 nodules classified with a CR according to mRECIST or EASL, those with complete lipiodol deposition (n = 36, 61%) had a higher rate of necrosis than those with incomplete lipiodol deposition (n = 23, 39%): 95% versus 68% and 95% versus 63% for reader 1 and 2, respectively. In conclusion, CR based on mRECIST/EASL combined with complete lipiodol deposition was better for identification of major tumor necrosis. Even in the presence of CR according to mRECIST/EASL, incomplete lipiodol deposition should be considered indicative of substantial viable tumor remnant. Liver Transplantation 22 1491-1500 2016 AASLD.

Renal Cell Carcinoma Metastatic to the Liver: Early Response Assessment after Intraarterial Therapy Using 3D Quantitative Tumor Enhancement Analysis

PURPOSE

Liver metastases from renal cell carcinoma (RCC) are not uncommon in the course of disease. However, data about tumor response to intraarterial therapy (IAT) are scarce. This study assessed whether changes of enhancing tumor volume using quantitative European Association for the Study of the Liver (qEASL) on magnetic resonance imaging (MRI) and computed tomography (CT) can evaluate tumor response and predict overall survival (OS) early after therapy.

METHODS AND MATERIALS

Fourteen patients with liver metastatic RCC treated with IAT (transarterial chemoembolization: n= 9 and yttrium-90: n= 5) were retrospectively included. All patients underwent contrast-enhanced imaging (MRI: n= 10 and CT: n= 4) 3 to 4 weeks pre- and posttreatment. Response to treatment was evaluated on the arterial phase using Response Evaluation Criteria in Solid Tumors (RECIST), World Health Organization, modified RECIST, EASL, tumor volume, and qEASL. Paired t test was used to compare measurements pre- and post-IAT. Patients were stratified into responders (≥65% decrease in qEASL) and nonresponders (<65% decrease in qEASL). OS was evaluated using Kaplan-Meier curves with log-rank test and the Cox proportional hazard model.

RESULTS

Mean qEASL (cm³) decreased from 93.5 to 67.2 cm³ (P= .004) and mean qEASL (%) from 63.1% to 35.6% (P= .001). No significant changes were observed using other response criteria. qEASL was the only significant predictor of OS when used to stratify patients into responders and nonresponders with median OS of 31.9 versus 11.1 months (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.97; P= .042) for qEASL (cm³) and 29.9 versus 10.2 months (HR, 0.09; 95% CI, 0.01-0.74; P= .025) for qEASL (%).

CONCLUSION

Three-dimensional (3D) quantitative tumor analysis is a reliable predictor of OS when assessing treatment response after IAT in patients with RCC metastatic to the liver. qEASL outperforms conventional non-3D methods and can be used as a surrogate marker for OS early after therapy.

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.

A nonrandomized cohort and a randomized study of local control of large hepatocarcinoma by targeting intratumoral lactic acidosis

Background:

Previous works suggested that neutralizing intratumoral lactic acidosis combined with glucose deprivation may deliver an effective approach to control tumor. We did a pilot clinical investigation, including a nonrandomized (57 patients with large HCC) and a randomized controlled (20 patients with large HCC) study.

Methods:

The patients were treated with transarterial chemoembolization (TACE) with or without bicarbonate local infusion into tumor.

Results:

In the nonrandomized controlled study, geometric mean of viable tumor residues (VTR) in TACE with bicarbonate was 6.4-fold lower than that in TACE without bicarbonate (7.1% [95% CI: 4.6%–10.9%] vs 45.6% [28.9%–72.0%]; p<0.0001). This difference was recapitulated by a subsequent randomized controlled study. TACE combined with bicarbonate yielded a 100% objective response rate (ORR), whereas the ORR treated with TACE alone was 44.4% (nonrandomized) and 63.6% (randomized). The survival data suggested that bicarbonate may bring survival benefit.

Conclusions:

Bicarbonate markedly enhances the anticancer activity of TACE.

Funding:

Funded by National Natural Science Foundation of China.

Clinical trial number:

ChiCTR-IOR-14005319.

Surgery is the main treatment for liver cancer, but the most common liver cancer – called hepatocellular carcinoma – can sometimes become too large to remove safely. An alternative option to kill the tumor is to block its blood supply via a process called embolization. This procedure deprives the tumor cells of oxygen and nutrients such as glucose. However, embolization also prevents a chemical called lactic acid – which is commonly found around tumors – from being removed. Lactic acid actually helps to protect cancer cells and also aids the growth of new blood vessels, and so the “trapped” lactic acid may reduce the anticancer activity of embolization.

Previous works suggested that neutralizing the acidic environment in a tumor while depriving it of glucose via embolization could become a new treatment option for cancer patients. Chao et al. now report a small clinical trial that tested this idea and involved patients with large hepatocellular carcinomas. First, a group of thirty patients received the embolization treatment together with an injection of bicarbonate – a basic compound used to neutralize the lactic acid – that was delivered directly to the tumor. The neutralization killed these large tumors more effectively than what is typically seen in patients who just undergo embolization

Chao et al. then recruited another twenty patients and randomly assigned them to receive either just the embolization or the embolization with bicarbonate treatment. This randomized trial showed that the tumors died more and patients survived for longer if they received the bicarbonate together with the embolization treatment compared to those patients that were only embolized. In fact, four patients initially assigned to, and treated in, the embolization-only group subsequently asked to cross over to, and indeed received, the bicarbonate treatment as well.

These data indicate that this bicarbonate therapy may indeed be effective for patients with large tumors that are not amenable to surgery. In future, larger clinical trials will need to be carried out to verify these initial findings.

Yttrium-90 Selective Internal Radiation Therapy with Glass Microspheres for Hepatocellular Carcinoma: Current and Updated Literature Review

Hepatocellular carcinoma is the most common primary liver cancer and it represents the majority of cancer-related deaths in the world. More than 70% of patients present at an advanced stage, beyond potentially curative options. Ytrrium-90 selective internal radiation therapy (Y90-SIRT) with glass microspheres is rapidly gaining acceptance as a potential therapy for intermediate and advanced stage primary hepatocellular carcinoma and liver metastases. The technique involves delivery of Y90 infused glass microspheres via the hepatic arterial blood flow to the appropriate tumor. The liver tumor receives a highly concentrated radiation dose while sparing the healthy liver parenchyma due to its preferential blood supply from portal venous blood. There are two commercially available devices: TheraSphere® and SIR-Spheres®. Although, Y90-SIRT with glass microspheres improves median survival in patients with intermediate and advanced hepatocellular carcinoma and has the potential to downstage hepatocellular carcinoma so that the selected candidates meet the transplantable criteria, it has not gained widespread acceptance due to the lack of large randomized controlled trials. Currently, there are various clinical trials investigating the use of Y90-SIRT with glass microspheres for treatment of hepatocellular carcinoma and the outcomes of these trials may result in the incorporation of Y90-SIRT with glass microspheres into the treatment guidelines as a standard therapy option for patients with intermediate and advanced stage hepatocellular carcinoma.

Hepatic imaging following intra-arterial embolotherapy

PURPOSE

To discuss guidelines and salient imaging findings of solid tumors treated with common intra-arterial procedures used in interventional oncology.

METHODS

A meticulous literature search of PubMed-indexed articles was conducted. Key words included "imaging + embolization," "imaging + TACE," "imaging + radioembolization," "imaging + Y90," "mRECIST," and "EASL." Representative post-treatment cross-sectional images were obtained from past cases in this institution.

RESULTS

Intra-arterial therapy (IAT) in interventional oncology includes bland embolization, chemoembolization, and radioembolization. Solid tumors of the liver are the primary focus of these procedures. Cross-sectional CT and/or MR are the main modalities used to image tumors after treatment. Traditional size-based response criteria (WHO and RECIST) alone are of limited utility in determining response to IAT; tumoral necrosis and enhancement must be considered. Specifically for HCC, the EASL and mRECIST guidelines are becoming widely adopted response criteria to assess these factors. DWI, FDG-PET, and CEUS are modalities that play an adjunctive but controversial role.

CONCLUSIONS

Radiologists must be aware that the different forms of intra-arterial therapy yield characteristic findings on cross-sectional imaging. Knowledge of these findings is integral to accurate assessment of tumor response and progression.

Yttrium-90 microsphere radioembolisation for unresectable hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma is the most common liver neoplasm and the fifth most common cancer worldwide. Moreover, its incidence has increased dramatically since the mid-2000s. While surgical resection and liver transplantation are the main curative treatments, only around 20% of people with early hepatocellular carcinoma may benefit from these therapies. Current treatment options for unresectable hepatocellular carcinoma include various ablative and trans-arterial therapies in addition to the drug sorafenib.

OBJECTIVES

To determine the benefits and harms of yttrium-90 microsphere trans-arterial radioembolisation either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other similar systemic or locoregional therapies for people with unresectable hepatocellular carcinoma.

SEARCH METHODS

We reviewed data from the Cochrane Hepato-Biliary Controlled Trials Register, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and Science Citation Index Expanded. We also checked reference lists of primary original studies and review articles manually for further related articles (cross-references) up to December 2015.

SELECTION CRITERIA

Eligible studies included all randomised clinical trials comparing yttrium-90-90 microsphere radioembolisation either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other systemic or locoregional therapies for unresectable hepatocellular carcinoma.

DATA COLLECTION AND ANALYSIS

The two review authors independently extracted the relevant information on participant characteristics, interventions, study outcomes, and data on the outcomes for this review, as well as information on the design and methodology of the studies. The two review authors assessed risk of bias of the included trials using pre-defined risk of bias domains. We used Trial Sequential Analysis to control the risk of random errors. We assessed the methodological quality with GRADE.

MAIN RESULTS

Two randomised clinical trials with 68 participants fulfilled our inclusion criteria. Both trials were at high risk of bias, and we rated the evidence as very low quality. One of the included trials compared radioembolisation versus chemoembolization for intermediate stage hepatocellular carcinoma as classified by the Barcelona Clinic Liver Cancer (BCLC) staging system, while the other included trial was an interim analysis of a randomised trial assessing radioembolisation combined with sorafenib versus sorafenib monotherapy in participants with BCLC-advanced stage hepatocellular carcinoma. The available data were insufficient to perform the planned analyses. Neither of the two trials reported data on all-cause mortality, cancer-related mortality, or time to progression of the tumour. The trial comparing radioembolisation with chemoembolization reported quality of life and serious adverse events, and there were no statistically significant differences between the trial groups with regard to these outcomes at week 12. On the basis of the two included randomised clinical trials, single-session radioembolisation appeared to be as safe as multiple sessions of chemoembolization for intermediate stage hepatocellular carcinoma and had a similar impact on quality of life, but data were too sparse to exclude even major differences. Radioembolisation followed by sorafenib appeared to be as well tolerated as sorafenib alone for advanced stage hepatocellular carcinoma, but data were too sparse to exclude even major differences. We also identified five ongoing studies evaluating the topic of our review.

AUTHORS' CONCLUSIONS

There was insufficient evidence to assess the beneficial and harmful effects of yttrium-90 microsphere radioembolisation for people with unresectable hepatocellular carcinoma. Further randomised clinical trials are mandatory to better assess the potential beneficial and harmful outcomes of yttrium-90 microsphere trans-arterial radioembolisation either as a monotherapy or in combination with other systemic or locoregional therapies versus placebo, no treatment, or other systemic or locoregional therapies for people with unresectable hepatocellular carcinoma.