Radioembolization for hepatocellular carcinoma: what clinicians need to know

Advances and Emerging Techniques in Y-90 Radioembolization for Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer deaths worldwide. Despite the high incidence of HCC, mortality remains high, with an estimated 5-year survival rate of less than 20%. Surgical resection represents a potential curative treatment for HCC; however, less than 20% of patients with HCC are candidates for surgical resection. In patients with unresectable HCC, Yttrium-90 (Y90) transarterial radioembolization (TARE) has emerged as an innovative treatment option. This locoregional therapy delivers high doses of radiation directly to liver tumors via intra-arterial injection, allowing for the targeted destruction of malignant cells while sparing surrounding healthy tissue. In this review, we will explore the latest advances in Y90 TARE for the treatment of HCC, focusing on key developments such as the following: (1) improvements in radiation lobectomy and segmentectomy techniques, (2) the introduction of personalized dosimetry, (3) the integration of combination therapies, (4) the use of imageable microspheres, (5) pressure-enabled Y90 delivery systems, and (6) the application of Y90 surrogates.

Depth and Duration of Response Are Associated with Survival in Patients with Unresectable Hepatocellular Carcinoma: Exploratory Analyses of IMbrave150

Introduction

IMbrave150 established first-line atezolizumab plus bevacizumab as a global standard of care for unresectable hepatocellular carcinoma (HCC). We report exploratory analyses of associations between overall survival (OS) and depth of response (DpR) or duration of response (DoR).

Methods

IMbrave150 was a phase III randomized study of atezolizumab plus bevacizumab versus sorafenib in patients with unresectable HCC. DpR was defined as maximum tumor shrinkage from baseline based on the sum of longest diameters per independent review facility (IRF)-assessed RECIST 1.1. DoR was defined as time from first complete/partial response by IRF-assessed RECIST 1.1 until progression or death. Associations between OS and DpR or DoR were evaluated by scatterplot in both arms; OS and PFS were evaluated by DpR in atezolizumab plus bevacizumab-treated patients. To minimize immortal time bias, the DpR analysis included patients who survived ≥6 months.

Results

Of 312 and 140 patients with baseline measurable disease in the atezolizumab plus bevacizumab and sorafenib arms, respectively, 264 and 99 surviving ≥6 months were included in the DpR analysis, and 97 and 18 in the DoR analysis. Tumor shrinkage occurred in 230/312 (74%) patients in the atezolizumab plus bevacizumab arm and 76/140 (54%) in the sorafenib arm; their mean (SD) DpR was -42.5% (32.4%) and -25.0% (21.9%), respectively. Atezolizumab plus bevacizumab-treated ≥6-month survivors with DpR <0% had improved OS versus those with DpR ≥0% (HR: 0.29; 95% CI: 0.19-0.44). Those with deeper responses (DpR -100% to -60%) had longer OS than those with DpR ≥20% (unstratified HR: 0.08; 95% CI: 0.03-0.21). In scatterplots, DpR and DoR were generally associated with OS in both arms; interpretation was limited by censored patients.

Conclusions

DpR and DoR to atezolizumab plus bevacizumab and sorafenib were associated with OS in patients with unresectable HCC. More longer, deeper responses occurred with atezolizumab plus bevacizumab.

[Hepatocellular carcinoma (HCC)]

Primary liver cancers are tumors that develop from different liver cells. Hepatocellular carcinoma (HCC), which develops from hepatocytes, accounts for approximately 75-85% of primary liver cancers.HCC is the 6th leading cause of cancer worldwide and the 3rd leading cause of cancer-related death. Its incidence is low in northern Europe, but high in sub-Saharan Africa and the Far East, where both hepatotropic viruses and exposure to mycotoxins are. It complicates cirrhosis in over 90% of cases and is predominantly male.The prevalence of HCC is increasing due to improved diagnostic techniques and criteria, but also to the persistence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections in adults. A worldwide increase in the incidence of steatopathy makes it the leading cause of liver disease worldwide, associated with alcohol abuse and/or steatohepatitis associated with metabolic dysfunction (MASH), including type 2 diabetes.Chronic hepatotropic viral infections, cirrhosis and chemical carcinogens combine to produce an annual incidence of 2-5% of hepatocellular carcinoma arising from cirrhosis. This justifies biannual surveillance of known cirrhosis, without which late diagnosis limits therapeutic options.Major advances have been made in curative treatment (liver transplantation, surgery, radiodestruction) and palliative treatment (chemo- or radioembolization, sorafenib chemotherapy or immunotherapy), depending on how early HCC is diagnosed (size, number of hepatic or extrahepatic lesions) and the severity of underlying liver disease and associated comorbidities.

Transarterial radioembolization vs transarterial chemoembolization with drug-eluting beads for treating hepatocellular carcinoma: a cost-effectiveness analysis in Japanese healthcare system

PURPOSE

Transarterial radioembolization (TARE) is effective for unresectable hepatocellular carcinoma; however, it awaits approval in Japan. This study aimed to simulate the cost-effectiveness of TARE over chemoembolization when TARE is approved in Japan and identify the requirements for cost-effectiveness.

MATERIALS AND METHODS

A Markov model was constructed to analyze the costs and effectiveness associated with TARE and transarterial chemoembolization with drug-eluting beads (DEB-TACE) for 2-month cycles over 5 years. In the primary analysis, the intention-to-treat survival data were used to calculate transition probabilities, whereas the ancillary analysis assessed the per-protocol survival data. DEB-TACE costs were calculated using the Japanese nationwide claims Diagnosis Procedure Combination database between April 2018 and March 2022, whereas TARE costs were estimated using database and international sources. The incremental cost-effectiveness ratio (ICER) was determined based on the payer's perspective and compared with the Japanese willingness-to-pay threshold of 5 million Japanese yen (JPY) (31,250 USD) per quality-adjusted life years (QALY).

RESULTS

From the claims database, 6,986 patients with hepatocellular carcinoma who received DEB-TACE were identified. In the primary analysis, the ICER was 5,173,591 JPY (32,334 USD)/QALY, surpassing the Japanese willingness-to-pay threshold. However, the ancillary analysis showed a lower ICER of 4,156,533 JPY (25,978 USD)/QALY, falling below the threshold. The one-way deterministic sensitivity analysis identified progression-free survival associated with TARE and DEB-TACE, DEB-TACE costs, and radioactive microsphere reimbursement price as key ICER influencers. The primary analysis suggested that setting the reimbursement price of radioactive microspheres below 1.399 million JPY (8,744 USD), approximately 2.8% lower than the price in the United Kingdom, would place the ICER below the Japanese willingness-to-pay threshold.

CONCLUSIONS

Under specific conditions, TARE can be a more cost-effective treatment than DEB-TACE. If the reimbursement price of radioactive microspheres is set approximately 2.8% lower than that in the United Kingdom, TARE could be cost-effective compared with DEB-TACE.

Yttrium-90 radioembolization treatment strategies for management of hepatocellular carcinoma

As the third leading cause of cancer-related deaths worldwide, hepatocellular carcinoma (HCC) represents a significant global health challenge. This paper provides an introduction and comprehensive review of transarterial radioembolization (TARE) with Yttrium-90 (Y90), a widely performed transcatheter procedure for HCC patients who are not suitable candidates for surgery. TARE involves the targeted delivery of radioactive microspheres to liver tumors, offering a promising treatment option for managing HCC across various stages of the disease. By evaluating Y90 TARE outcomes across early, intermediate, and advanced stages of HCC, the review aims to present a thorough understanding of its efficacy and safety. Additionally, this paper highlights future research directions focusing on the potential of combination therapies with systemic and immunotherapies, as well as personalized treatments. The exploration of these innovative approaches aims to improve treatment outcomes, reduce adverse events, and provide new therapeutic opportunities for HCC patients. The review underscores the importance of ongoing research and clinical trials to optimize TARE further and integrate it into comprehensive HCC treatment paradigms.

Advances in Understanding Hepatocellular Carcinoma Vasculature: Implications for Diagnosis, Prognostication, and Treatment

Hepatocellular carcinoma (HCC) progresses through multiple stages of hepatocarcinogenesis, with each stage characterized by specific changes in vascular supply, drainage, and microvascular structure. These vascular changes significantly influence the imaging findings of HCC, enabling non-invasive diagnosis. Vascular changes in HCC are closely related to aggressive histological characteristics and treatment responses. Venous drainage from the tumor toward the portal vein in the surrounding liver facilitates vascular invasion, and the unique microvascular pattern of vessels that encapsulate the tumor cluster (known as a VETC pattern) promotes vascular invasion and metastasis. Systemic treatments for HCC, which are increasingly being used, primarily target angiogenesis and immune checkpoint pathways, which are closely intertwined. By understanding the complex relationship between histopathological vascular changes in hepatocarcinogenesis and their implications for imaging findings, radiologists can enhance the accuracy of imaging diagnosis and improve the prediction of prognosis and treatment response. This, in turn, will ultimately lead to better patient care.

Feasibility of Liver Transplantation after 90 Y Radioembolization: Lessons from a Radiation Protection Incident

ABSTRACT

Radioembolization using 90 Y is a growing procedure in nuclear medicine for treating hepatocellular carcinoma. Current guidelines suggest postponing liver transplantation or surgical resection for a period of 14 to 30 d after radioembolization to minimize surgeons' exposure to ionizing radiation. In light of a radiation protection incident, we reevaluated the minimum delay required between radioembolization and subsequent liver transplantation. A patient with a hepatocellular carcinoma underwent a liver transplantation 44 h after undergoing radioembolization using 90 Y (860 MBq SIR-Spheres). No specific radioprotection measures were followed during surgery and pathological analysis. We subsequently (1) evaluated the healthcare professionals' exposure to ionizing radiation by conducting dose rate measurements from removed liver tissue and (2) extrapolated the recommended interval to be observed between radioembolization and surgery/transplantation to ensure compliance with the radiation dose limits for worker safety. The surgeons involved in the transplantation procedure experienced the highest radiation exposure, with whole-body doses of 2.4 mSv and extremity doses of 24 mSv. The recommended delay between radioembolization and liver transplantation was 8 d when using SIR-Spheres and 15 d when injecting TheraSphere. This delay can be reduced further when considering the specific 90 Y activity administered during radioembolization. This dosimetric study suggests the feasibility of shortening the delay for liver transplantation/surgery after radioembolization from the 8th or 15th day after using SIR-Spheres or TheraSphere, respectively. This delay can be decreased further when adjusted to the administrated activity while upholding radiation protection standards for healthcare professionals.

Radiation Safety Assessment of 177Lu-DOTATATE Intra-arterial Peptide Receptor Therapy (PRRT)

Objective

177Lu-DOTATATE peptide receptor therapy (PRRT) is an established treatment for patients suffering from neuroendocrine tumors. In the last few years, intra-arterial PRRT is being considered for patients having liver metastatic disease predominantly. The aim of our study is to measure the radiation doses received by the treating intervention radiologists involved in intra-arterial PRRT treatment using 177Lu-DOTATATE.

Materials and Methods

Radiation safety-related data of 31 patients who underwent 177Lu-DOTATATE intra-arterial PRRT treatment were used for this study. The exposure rate was measured at the hand and eye and chest level of treating intervention radiologists continuously from the beginning to the end of the administration. Exposure from the patient at the body surface (at the level of liver, thigh, and extremities) and 1 m from the body surface was measured just after the administration. The mean radiation exposure from the patient at the body surface and 1 m from the body was also calculated.

Results

The mean administered activity was found to be 194 (±17) mCi. The mean radiation exposure at the surface at the level of the liver, thigh, and feet and at 1 m from the surface was found to be 100 (±25.11), 9 (±1.27), 5.6 (±0.52), and 5.3± (0.50) μSv/hr, respectively. The mean administration time was found to be 23 ± 5.6 min. The mean radiation dose to the hands, and eyes, of the treating intervention radiologist per procedure, was found to be 6.425 ± 2.75 μSv, 5.43 ± 1.76 μSv and 1-m exposure from the patient was found to be 5.3 ± 0.246 μSv, respectively.

Conclusion

Our result shows that the radiation exposure from the patient postadministration is below the permissible limit of discharge. The radiation exposure to the intervention radiologist is also suggestive of a safe procedure to be performed by maintaining the radiation dose well within the permissible limit for radiation professionals.

Selective internal radiation therapy segmentectomy: A new minimally invasive curative option for primary liver malignancies?

Transarterial radioembolization or selective internal radiation therapy (SIRT) has emerged as a minimally invasive approach for the treatment of tumors. This percutaneous technique involves the local, intra-arterial delivery of radioactive microspheres directly into the tumor. Historically employed as a palliative measure for liver malignancies, SIRT has gained traction over the past decade as a potential curative option, mirroring the increasing role of radiation segmentectomy. The latest update of the BCLC hepatocellular carcinoma guidelines recognizes SIRT as an effective treatment modality comparable to other local ablative methods, particularly well-suited for patients where surgical resection or ablation is not feasible. Radiation segmentectomy is a more selective approach, aiming to deliver high-dose radiation to one to three specific hepatic segments, while minimizing damage to surrounding healthy tissue. Future research efforts in radiation segmentectomy should prioritize optimizing radiation dosimetry and refining the technique for super-selective administration of radiospheres within the designated hepatic segments.

Liver-Directed Locoregional Therapies for Neuroendocrine Liver Metastases: Recent Advances and Management

Neuroendocrine tumors (NETs) are a heterogeneous class of cancers, predominately occurring in the gastroenteropancreatic system, which pose a growing health concern with a significant rise in incidence over the past four decades. Emerging from neuroendocrine cells, these tumors often elicit paraneoplastic syndromes such as carcinoid syndrome, which can manifest as a constellation of symptoms significantly impacting patients' quality of life. The prognosis of NETs is influenced by their tendency for metastasis, especially in cases involving the liver, where the estimated 5-year survival is between 20 and 40%. Although surgical resection remains the preferred curative option, challenges emerge in cases of neuroendocrine tumors with liver metastasis (NELM) with multifocal lobar involvement, and many patients may not meet the criteria for surgery. Thus, minimally invasive and non-surgical treatments, such as locoregional therapies, have surfaced. Overall, these approaches aim to prioritize symptom relief and aid in overall tumor control. This review examines locoregional therapies, encompassing catheter-driven procedures, ablative techniques, and radioembolization therapies. These interventions play a pivotal role in enhancing progression-free survival and managing hormonal symptoms, contributing to the dynamic landscape of evolving NELM treatment. This review meticulously explores each modality, presenting the current state of the literature on their utilization and efficacy in addressing NELM.

Impact of Low Skeletal Muscle Mass on Long-Term Outcomes in Hepatocellular Carcinoma Treated with Trans-Arterial Radioembolization: A Retrospective Multi-Center Study

Trans-arterial radioembolization (TARE) is a form of radiation therapy performed for hepatocellular carcinoma (HCC) via selective intra-arterial injection of Yttrium-90-loaded microspheres. This was a multi-center retrospective study of consecutive patients with HCC who underwent TARE between July 2009 and May 2019. Using pre-treatment computed tomography imaging, the total cross-sectional area (cm2) of the abdominal skeletal muscle at the third lumbar vertebra was measured. The skeletal muscle index (SMI) was calculated by normalizing the muscle area to patient height. In total, 347 patients (median age, 65 years; 284 male) were included in the study. A total of 108 (31.1%) patients had portal vein tumor thrombus (PVTT), and 126 (36.3%) were classified as LSMM. The median overall survival (OS) was 28.1 months (95% CI, 24.8-35.7), and median progression-free survival was 8.0 months (95% CI, 6.4-9.4). Multivariate Cox regression analysis revealed that LSMM (hazard ratio [HR], 1.36; 95% CI, 1.00-1.85, p = 0.05), PVTT (HR, 1.82; 95% CI, 1.33-2.49, p < 0.01), alpha-fetoprotein (AFP) (≥200 ng/mL) (HR 1.41; 95% CI, 1.04-1.92, p = 0.03), and albumin-bilirubin grade (2-3) (HR 1.74; 95% CI, 1.24-2.43, p < 0.01) were independently associated with poor OS. TARE provided favorable long-term outcomes for patients with advanced HCC. Pre-treatment LSMM independently associated with survival, suggesting its utility as a surrogate biomarker for identifying TARE candidates.

Multidisciplinary consensus recommendations for management of hepatocellular carcinoma in Middle East and North Africa region

Hepatocellular carcinoma (HCC) is a growing health concern projected to cross over a million cases worldwide by 2025. HCC presents a significant burden of disease in Middle East and North African (MENA) countries due to a high prevalence of risk factors such as hepatitis C and B infections and rising incidence of non-alcoholic steatohepatitis and non-alcoholic fatty liver disease. In August 2022, an advisory meeting consisting of experts from 5 MENA countries was convened in an attempt to provide consensus recommendations on HCC screening, early diagnosis, current treatment modalities and unmet medical needs in the region. Data were collected from a pre-meeting survey questionnaire and responses analysed and presented during the advisory meeting. This review summarizes the evidence discussed at the meeting and provides expert recommendations on the management of HCC. The 2022 update of Barcelona clinic liver cancer (BCLC) staging and treatment strategy and its implementation in the MENA region was extensively discussed. A key consensus of the expert panel was that multidisciplinary care is crucial to effective patient management that results in better clinical outcomes and overall survival of the patient. The panel recommended the use of predictive and early response biomarkers to guide clinicians in arriving at more effective therapeutic decisions. The experts also emphasized the role of robust screening/surveillance systems, population-based registries, effective referral pathways and standardization of guidelines to ensure the successful management of HCC in the region.

Recent Advances in Image-Guided Locoregional Therapies for Primary Liver Tumors

Primary liver cancer is the leading cause of cancer-related deaths worldwide. with incidences predicted to rise over the next several decades. Locoregional therapies, such as radiofrequency or microwave ablation, are described as image-guided percutaneous procedures, which offer either a curative intent for early-stage hepatocellular carcinoma or bridging/downstaging for surgical resection or transplantation. Catheter-driven locoregional therapies, such as transarterial chemoembolization and radioembolization, induce tumor hypoxia, can be palliative, and improve survival for early-to-intermediate hepatocellular carcinoma and unresectable intrahepatic cholangiocarcinoma. Herein, we provide a comprehensive overview of the antineoplastic mechanisms underpinning locoregional therapies, different treatment approaches, and the current state of the literature for the efficacy of locoregional therapies for primary liver cancer. We also discuss emerging advancements, such as the adjuvant use of immunotherapies and molecular targeting agents with locoregional therapy, for the treatment of primary liver cancer.

The evolution of immune checkpoint inhibitor combinations in advanced hepatocellular carcinoma - A systematic review

BACKGROUND AND OBJECTIVE

Since approval of sorafenib in 2008, systemic therapy has been established as the main treatment option for advanced hepatocellular carcinoma (HCC). Recently, immune checkpoints inhibitors (ICIs) have been extensively tested in this setting. Multiple ICI combination regimens have recently received regulatory approval and new data continues to emerge. The purpose of this review is to provide a comprehensive summary of the most up-to-date evidence on ICI combinations in advanced HCC.

METHODS

A search of published and presented literature was conducted to identify phase III trials of ICI combinations in advanced HCC patients. Supplemental bibliographic search of review articles and meta-analyses was also conducted. Efficacy and safety data was summarized in text, tables, and plots.

FINDINGS AND DISCUSSION

The literature search identified a total of six phase III trials assessing ICI combinations in advanced HCC. Two trials compared ICI plus anti-VEGF monoclonal antibody combinations to sorafenib, three trials compared ICI plus tyrosine kinase inhibitor (TKI) combinations to TKIs alone, and one trial compared a dual ICI regimen to sorafenib. Statistically significant survival benefits were seen with atezolizumab-bevacizumab and sintilimab-bevacizumab biosimilar as well as durvalumab-tremelimumab and camrelizumab-rivoceranib combinations. ICI combination regimens have also shown improvements in response rates and progression-free survival relative to the previous standard of care, sorafenib, and generally presented predictable and manageable safety profiles.

CONCLUSION

ICI combinations represent the new standard of care for advanced HCC. Ongoing randomized trials and real-world evidence will further clarify the role of these combinations in this rapidly evolving field.

Transarterial chemoembolization as an alternative to radioembolization is associated with earlier tumor recurrence than in radioembolization-eligible patients

Introduction

Although transarterial radioembolization (TARE) using yttrium-90 (90Y) is a treatment option for large hepatocellular carcinoma (HCC), a fraction of patients are ineligible for TARE due to high lung shunt fraction (LSF).

Methods

We evaluated if treatment with transarterial chemoembolization (TACE), owing to TARE ineligibility was associated with early HCC progression. Consecutive patients with HCC who were initially TARE candidates were included. Patients with vascular invasion or metastasis were excluded. Primary endpoints were time-to-progression (TTP) and overall survival (OS). The secondary endpoint was objective response rate.

Results

In total, 175 patients were included: 144 underwent TARE (TARE-eligible group) and 31 underwent TACE due to high LSF (TARE-ineligible group). This latter group had larger tumors (13.8 cm vs. 7.8 cm, P<0.001) and higher MoRAL scores (1,385.8 vs. 413.3, P=0.002) than the TARE-eligible group. After balancing baseline characteristics with an inverse probability of treatment weighting (IPTW), the TARE-ineligible group showed shorter TTP [adjusted hazard ratio (aHR)=2.16, 95% confidence interval (CI)=1.14-4.07, P=0.02] and OS (aHR=1.80, 95% CI=0.85-3.80, P=0.12), although the latter was not statistically significant. The TARE-ineligible group had a significantly lower objective response rate than the TARE-eligible group (9.7% vs. 56.9%, P<0.001).

Conclusion

TARE-ineligible patients had larger tumors and higher MoRAL scores than TARE-eligible patients. Treatment with TACE, owing to high LSF, was associated with a shorter TTP even after balancing tumor size and MoRAL scores.