Neoadjuvant Radiation Lobectomy As an Alternative to Portal Vein Embolization in Hepatocellular Carcinoma

Image-guided percutaneous strategies to improve the resectability of HCC: Portal vein embolization, liver venous deprivation, or radiation lobectomy?

Despite considerable advances in surgical technique, many patients with hepatic malignancies are not operative candidates due to projected inadequate hepatic function following resection. Consequently, the size of the future liver remnant (FLR) is an essential consideration when predicting a patient's likelihood of liver insufficiency following hepatectomy. Since its initial description 30 years ago, portal vein embolization has become the standard of care for augmenting the size and function of the FLR preoperatively. However, new minimally invasive techniques have been developed to improve surgical candidacy, chief among them liver venous deprivation and radiation lobectomy. The purpose of this review is to discuss the status of preoperative liver augmentation prior to resection of hepatocellular carcinoma with a focus on these three techniques, highlighting the distinctions between them and suggesting directions for future investigation.

Clinical, dosimetric, and reporting considerations for Y-90 glass microspheres in hepatocellular carcinoma: updated 2022 recommendations from an international multidisciplinary working group

PURPOSE

In light of recently published clinical reports and trials, the TheraSphere Global Dosimetry Steering Committee (DSC) reconvened to review new data and to update previously published clinical and dosimetric recommendations for the treatment of hepatocellular carcinoma (HCC).

METHODS

The TheraSphere Global DSC is comprised of health care providers across multiple disciplines involved in the treatment of HCC with yttrium-90 (Y-90) glass microsphere-based transarterial radioembolization (TARE). Literature published between January 2019 and September 2021 was reviewed, discussed, and adjudicated by the Delphi method. Recommendations included in this updated document incorporate both the results of the literature review and the expert opinion and experience of members of the committee.

RESULTS

Committee discussion and consensus led to the expansion of recommendations to apply to five common clinical scenarios in patients with HCC to support more individualized efficacious treatment with Y-90 glass microspheres. Existing clinical scenarios were updated to reflect recent developments in dosimetry approaches and broader treatment paradigms evolving for patients presenting with HCC.

CONCLUSION

Updated consensus recommendations are provided to guide clinical and dosimetric approaches for the use of Y-90 glass microsphere TARE in HCC, accounting for disease presentation, tumor biology, and treatment intent.

Promoting Surgical Resection through Future Liver Remnant Hypertrophy

An inadequate future liver remnant (FLR) can preclude curative-intent surgical resection for patients with primary or secondary hepatic malignancies. For patients with normal baseline liver function and without risk factors, an FLR of 20% is needed to maintain postsurgical hepatic function. However, the FLR requirement is higher for patients who are exposed to systemic chemotherapy (FLR, >30%) or have cirrhosis (FLR, >40%). Interventional radiologic and surgical methods to achieve FLR hypertrophy are evolving, including portal vein ligation, portal vein embolization, radiation lobectomy, hepatic venous deprivation, and associating liver partition and portal vein ligation for staged hepatectomy. Each technique offers particular advantages and disadvantages. Knowledge of these procedures can help clinicians to choose the suitable technique for each patient. The authors review the techniques used to develop FLR hypertrophy, focusing on technical considerations, outcomes, and the advantages and disadvantages of each approach. Online supplemental material is available for this article. ^©RSNA, 2022.

The American Brachytherapy Society consensus statement for permanent implant brachytherapy using Yttrium-90 microsphere radioembolization for liver tumors

PURPOSE

To develop a multidisciplinary consensus for high quality multidisciplinary implementation of brachytherapy using Yttrium-90 (90Y) microspheres transarterial radioembolization (90Y TARE) for primary and metastatic cancers in the liver.

METHODS AND MATERIALS

Members of the American Brachytherapy Society (ABS) and colleagues with multidisciplinary expertise in liver tumor therapy formulated guidelines for 90Y TARE for unresectable primary liver malignancies and unresectable metastatic cancer to the liver. The consensus is provided on the most recent literature and clinical experience.

RESULTS

The ABS strongly recommends the use of 90Y microsphere brachytherapy for the definitive/palliative treatment of unresectable liver cancer when recommended by the multidisciplinary team. A quality management program must be implemented at the start of 90Y TARE program development and follow-up data should be tracked for efficacy and toxicity. Patient-specific dosimetry optimized for treatment intent is recommended when conducting 90Y TARE. Implementation in patients on systemic therapy should account for factors that may enhance treatment related toxicity without delaying treatment inappropriately. Further management and salvage therapy options including retreatment with 90Y TARE should be carefully considered.

CONCLUSIONS

ABS consensus for implementing a safe 90Y TARE program for liver cancer in the multidisciplinary setting is presented. It builds on previous guidelines to include recommendations for appropriate implementation based on current literature and practices in experienced centers. Practitioners and cooperative groups are encouraged to use this document as a guide to formulate their clinical practices and to adopt the most recent dose reporting policies that are critical for a unified outcome analysis of future effectiveness studies.

Conversion to resection post radioembolization in patients with HCC: recommendations from a multidisciplinary working group

BACKGROUND

Transarterial radioembolization (TARE) with yttrium-90 (⁹⁰Y) glass microspheres is an efficacious option for converting appropriately selected patients with borderline-resectable hepatocellular carcinoma (HCC) to surgical candidacy.

METHODS

In 2018 and 2019, a diverse multidisciplinary group of surgical and interventional experts with experience using ⁹⁰Y for downstaging and bridging to liver transplant convened to review peer-reviewed literature and personal experience in the use of ⁹⁰Y to convert borderline resectable liver cancer patients to surgical candidacy. The working group included surgical oncologists specializing in liver cancer, liver transplant surgeons with experience in complex hepatobiliary surgery, and interventional radiologists with experience using ⁹⁰Y.

RESULTS

This document presents expert recommendations based upon the group's experience and consensus.

CONCLUSIONS

By combining related evidence from the literature with expert experiences with TARE in surgical candidates, these recommendations aim to demonstrate the safety, efficacy, and feasibility of TARE in converting borderline-resectable patients to surgical options. The document also addresses the concerns about potential complications associated with TARE during the surgical intervention.

Neoadjuvant approaches in hepatocellular carcinoma: There's no time like the present

Hepatocellular carcinoma remains a lethal malignancy and is an increasingly common cause of cancer death worldwide. Curative-intent surgical resection remains the standard of care for eligible patients, yet outcomes remain poor for many patients, with most patients experiencing recurrence in the five years after resection. There is currently significant interest in utilizing locoregional and systemic therapies - in both the neoadjuvant and adjuvant settings - to increase the chance of cure. This review article appraises the existing literature and current clinical trial landscape of neoadjuvant therapies in hepatocellular carcinoma.

Hepatocellular carcinoma locoregional therapies: Outcomes and future horizons

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver and has an overall five-year survival rate of less than twenty percent. For patients with unresectable disease, evolving liver-directed locoregional therapies provide efficacious treatment across the spectrum of disease stages and via a variety of catheter-directed and percutaneous techniques. Goals of locoregional therapies in HCC may include curative intent in early-stage disease, bridging or downstaging to surgical resection or transplantation for early or intermediate-stage disease, and local disease control and palliation in advanced-stage disease. This review explores the outcomes of chemoembolization, bland embolization, radioembolization, and percutaneous ablative therapies. Attention is also given to prognostic factors related to each of the respective techniques, as well as future directions of locoregional therapies for HCC.

Yttrium-90 Radioembolization for the Treatment of Solitary, Unresectable HCC: The LEGACY Study

BACKGROUND AND AIMS

Locoregional therapies, including yttrium-90 radioembolization, play an important role in the treatment of unresectable HCC. The aim of the LEGACY (Local radioEmbolization using Glass Microspheres for the Assessment of Tumor Control with Y-90) study was to evaluate objective response rate (ORR) and duration of response (DoR) in patients with solitary unresectable HCC treated with yttrium-90 glass microspheres.

APPROACH AND RESULTS

LEGACY is a multicenter, single-arm, retrospective study conducted at three sites that included all eligible, consecutive patients with HCC treated with radioembolization between 2014 and 2017. Eligibility criteria included solitary HCC ≤ 8 cm, Child-Pugh A cirrhosis, and Eastern Cooperative Oncology Group performance status 0-1. Primary endpoints were ORR and DoR based on modified Response Evaluation Criteria in Solid Tumors in the treated area (localized), as evaluated by blinded, independent, central review. Radioembolization was performed with intent of ablative-level dosimetry in a selective fashion when possible. Overall survival was evaluated using Kaplan-Meier and multivariate Cox proportional hazards. Among the 162 patients included, 60.5% were Eastern Cooperative Oncology Group 0, and the median tumor size was 2.7 cm (range: 1-8) according to blinded, independent, central review. Radioembolization served as neoadjuvant therapy for transplantation or resection in 21.0% (34 of 162) and 6.8% (11 of 162) of patients, respectively, and as primary treatment for all others. Median follow-up time was 29.9 months by reverse Kaplan-Meier. ORR (best response) was 88.3% (CI: 82.4-92.4), with 62.2% (CI: 54.1-69.8) exhibiting a DoR ≥ 6 months. Three-year overall survival was 86.6% for all patients and 92.8% for those neoadjuvant patients with resected or transplanted liver.

CONCLUSIONS

In this multicenter study of radioembolization, clinical meaningful response rates and prolonged DoR were observed in the treatment of unresectable, solitary HCC ≤ 8 cm.

Contemporary Algorithm for the Management of Hepatocellular Carcinoma in 2021: The Northwestern Approach

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and a major cause of cancer-related morbidity and mortality around the world. Frequently, concurrent liver dysfunction and variations in tumor burden make it difficult to design effective and standardized treatment pathways. Contemporary treatment guidelines designed for an era of personalized medicine should consider these features in a more clinically meaningful way to improve outcomes for patients across the HCC spectrum. Given the heterogeneity of HCC, we propose a detailed clinical algorithm for selecting optimal treatment using an evidence-based and practical approach, incorporating liver function, tumor burden, the extent of disease, and ultimate treatment intent, with the goal of individualizing clinical decision making.

Radiation Lobectomy: An Overview of Concept and Applications, Technical Considerations, Outcomes

Surgical resection has long been considered curative for patients with early-stage hepatocellular carcinoma (HCC). However, inadequate future liver remnant (FLR) renders many patients not amenable to surgery. Recently, lobar administration of yttrium-90 (Y90) radioembolization has been utilized to induce FLR hypertrophy while providing disease control, eventually facilitating resection in patients with hepatic malignancy. This has been termed "radiation lobectomy (RL)." The concept is evolving, with modified approaches combining RL and high-dose curative-intent radioembolization (radiation segmentectomy) to achieve tumor ablation. This article provides an overview of the concept and applications of RL, including technical considerations and outcomes in patients with hepatic malignancies.

Review of Use of Y90 as a Bridge to Liver Resection and Transplantation in Hepatocellular Carcinoma

BACKGROUND

The incidence of hepatocellular carcinoma (HCC) has been rising, and 80% of HCCs are unresectable at the time of presentation. In recent years, Yttrium-90 (Y90) radioembolization has arisen as a potential tool to treat the primary HCC tumor while also inducing contralateral liver hypertrophy to increase future liver remnant volumes. The goal of this multidisciplinary review is to summarize the contemporary evidence on the safety, efficacy, and utility of Y90 as a bridge to liver resection and transplant in patients with HCC.

METHODS

A narrative review was conducted of the recent literature regarding the utilization of Y90 as a therapy prior to liver resection or transplant in patients with HCC. A specific emphasis was placed on articles published in the last 10 years.

RESULTS

Y90 radioembolization has demonstrated a high safety profile and increasing utility in bridging and downstaging patients with HCC who subsequently undergo liver resection or transplant. The continuous advancements in treatment strategies and radiation dosimetry have paved the way for the incorporation of Y90 in all stages of HCC with different intents, including downstaging and bridging.

CONCLUSIONS

Y90 radioembolization can be safely used in the HCC population to bridge patients to resection or transplantation, induce future liver remnant growth, and select for less aggressive tumor biology prior to surgery.

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

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

Frontiers of therapy for hepatocellular carcinoma

The incidence of hepatocellular carcinoma continues to increase worldwide. Fortunately, there have been notable recent advances in locoregional and systemic therapy. In this current review, we will highlight these new developments and future directions of hepatocellular carcinoma treatment and address the importance of a multidisciplinary approach to treatment.

Radioembolization for Hepatocellular Carcinoma in Downstaging and Bridging for Liver Transplantation

PURPOSE

Hepatocellular carcinoma (HCC) is the most common primary liver tumor. Only about one third of them are eligible for curative treatments like liver transplantation. Various interventional oncologic treatment options could be employed for some of the HCC patients outside the acceptable liver transplantation criteria to make them suitable for transplantation by downstaging and keeping them inside the criteria by bridging to transplantation.

METHODS

We reviewed the literature by the terms of downstaging and bridging therapy for liver transplantation.

RESULTS

About only 30% of the patients are suitable for curative procedures like transplantation at the time of diagnosis of HCC. Even the Milan Criteria is expanded or new criteria are defined, still there are many patients who need downstaging to be eligible for transplantation. There are different procedures in interventional oncology for primary and metastatic liver lesions. Radioembolization (RE) is one of the locoregional therapies which is more effective than others for downstaging and bridging for liver transplantation.

CONCLUSION

Downstaging by RE is an effective and reasonable method for unresectable HCC cases initially beyond established criteria for liver transplantation by selecting suitable and favorable tumor biology.

Induction of Contralateral Hepatic Hypertrophy by Unilobar Yttrium-90 Transarterial Radioembolization versus Portal Vein Embolization: An Animal Study

PURPOSE

To compare hepatic hypertrophy in the contralateral lobe achieved by unilobar transarterial radioembolization (TARE) versus portal vein embolization (PVE) in a swine model.

METHODS

After an escalation study to determine the optimum dose to achieve hypertrophy after unilobar TARE in 4 animals, 16 pigs were treated by TARE (yttrium-90 resin microspheres) or PVE (lipiodol/n-butyl cyanoacrylate). Liver volume was calculated based on CT before treatment and during 6 months of follow-up. Independent t-test (P < .05) was used to compare hypertrophy. The relationship between hypertrophy after TARE and absorbed dose was calculated using the Pearson correlation.

RESULTS

At 2 and 4 weeks after treatment, a significantly higher degree of future liver remnant hypertrophy was observed in the PVE group versus the TARE group, with a median volume gain of 31% (interquartile range [IQR]: 16%-66%) for PVE versus 23% (IQR: 6%-36%) for TARE after 2 weeks and 51% (IQR: 47%-69%) for PVE versus 29% (IQR: 20%-50%) for TARE after 4 weeks. After 3 and 6 months, hypertrophy converged without a statistically significant difference, with a volume gain of 103% (IQR: 86%-119%) for PVE versus 82% (IQR: 70%-96%) for TARE after 3 months and 115% (IQR: 70%-46%) for PVE versus 86% (IQR: 58%-111%) for TARE after 6 months. A strong correlation was observed between radiation dose (median 162 Gy, IQR: 139-175) and hypertrophy.

CONCLUSIONS

PVE resulted in rapid hypertrophy within 1 month of the procedure, followed by a plateau, whereas TARE resulted in comparable hypertrophy by 3-6 months. TARE-induced hypertrophy correlated with radiation absorbed dose.

Role of Multidisciplinary Care in the Management of Hepatocellular Carcinoma

Despite advances in treatment options for hepatocellular carcinoma (HCC), 5-year survival for HCC remains below 20%. This poor survival is multifactorial but is partly related to underuse of curative treatment in clinical practice. In light of growing treatment options, delivered by different types of providers, optimal management requires input from multiple specialties. A multidisciplinary approach has been evolving over the past couple of decades, bringing different specialists together to develop a therapeutic plan to treat and manage HCC, which significantly increases timely guideline-concordant treatment and improves overall survival. The present review attempts to highlight the need for such a multimodal approach by providing insights on its potential structure and impact on the various aspects of HCC management.

Interventional Oncology Approach to Hepatic Metastases

Metastatic liver disease is one of the major causes of cancer-related morbidity and mortality. Locoregional therapies offered by interventional oncologists alleviate cancer-related morbidity and in some cases improve survival. Locoregional therapies are often palliative in nature but occasionally can be used with curative intent. This review will discuss important factors to consider prior to palliative and curative intent treatment of metastatic liver disease with locoregional therapy. These factors include those specific to the tumor, liver function, liver reserve, differences between treatment modalities, and patient-specific considerations.

Locoregional Therapy Approaches for Hepatocellular Carcinoma: Recent Advances and Management Strategies

Hepatocellular carcinoma (HCC) is the most common primary liver malignancy and third leading cause of cancer-related mortality worldwide. While surgical resection and transplantation are the standard first-line treatments for early-stage HCC, most patients do not fulfill criteria for surgery. Fortunately, catheter-directed and percutaneous locoregional approaches have evolved as major treatment modalities for unresectable HCC. Improved outcomes have been achieved with novel techniques which can be employed for diverse applications ranging from curative-intent for small localized tumors, to downstaging or bridging to resection and transplantation for early and intermediate disease, and locoregional control and palliation for advanced disease. This review explores recent advances in liver-directed techniques for HCC including bland transarterial embolization, chemoembolization, radioembolization, and ablative therapies, with a focus on patient selection, procedural technique, periprocedural management, and outcomes.

The safety of hepatectomy after transarterial radioembolization: Single institution experience and review of the literature

BACKGROUND AND OBJECTIVES

The liver is a frequent site of malignancy, both primary and metastatic. The treatment goal of patients with liver cancer may include transarterial radioembolization (TARE). There are limited reports on the safety of hepatectomy following TARE. Our study's purpose is to review patients who have received TARE followed by hepatectomy.

METHODS

A retrospective study was performed on patients diagnosed with any liver cancer from 2013 to 2019 who underwent TARE followed by hepatectomy. Postoperative complications were prospectively collected. Descriptive statistics and the Kaplan-Meier test were used to assess survival outcomes.

RESULTS

Twelve patients were treated with a TARE followed by a hepatectomy (nine with ≥4 segments resected). Diagnoses included: six HCC, four cholangiocarcinoma, one metastatic neuroendocrine tumor, and one metastatic colorectal cancer. There were no 90-day post-hepatectomy mortalities and the overall morbidity was 66% (16% severe ≥MAGS 3). Hepatectomy-specific complications after hepatectomy included two (16%) bile leaks and no post-hepatectomy liver failures. The median recurrence free survival was 26 months. Overall survival at 1-year was 78% and at 3 years was 47%.

CONCLUSIONS

Our results support the safety of hepatectomy in select patients after TARE. Additional comparison to patients who receive hepatectomy as a first-line treatment for liver cancers should be investigated.

Improving the Safety of Major Resection for Hepatobiliary Malignancy: Portal Vein Embolization and Recent Innovations in Liver Regeneration Strategies

PURPOSE OF REVIEW

For three decades, portal vein embolization (PVE) has been the "gold-standard" strategy to hypertrophy the anticipated future liver remnant (FLR) in advance of major hepatectomy. During this time, CT volumetry was the most common method to preoperatively assess FLR quality and function and used to determine which patients are appropriate surgical candidates. This review provides the most up-to-date methods for preoperatively assessing the anticipated FLR and summarizes data from the currently available strategies used to induce FLR hypertrophy before surgery for hepatobiliary malignancy.

RECENT FINDINGS

Functional and physiological imaging is increasingly replacing standard CT volumetry as the method of choice for preoperative FLR assessment. PVE, associating liver partition and portal vein ligation, radiation lobectomy, and liver venous deprivation are all currently available techniques to hypertrophy the FLR. Each strategy has pros and cons based on tumor type, extent of resection, presence or absence of underlying liver disease, age, performance status, complication rates, and other factors. Numerous strategies can lead to FLR hypertrophy and improve the safety of major hepatectomy. Which is best has yet to be determined.

Curative-Intent Therapies in Localized Hepatocellular Carcinoma

PURPOSE OF REVIEW

The high mortality rate for hepatocellular carcinoma (HCC) relative to its prevalence underscores the need for curative-intent therapies. Image-guided therapies such as ablation and embolization have an established role as primary or neoadjuvants preparing patients for curative treatment.

RECENT FINDINGS

For HCC < 3 cm, percutaneous thermal ablation provides oncologic outcomes similar to surgical resection and is now a recommended first-line therapy in the EASL guidelines. Both ablation and embolization are recommended as bridging therapies for HCC patients awaiting liver transplantation. T3 HCC can be downstaged by embolization to T2, allowing liver transplantation with similar outcomes to patients transplanted within Milan criteria. New and evolving techniques such as SBRT, radiation segmentectomy and lobectomy, and combination therapies show promise but require further prospective data before they can be integrated into treatment algorithms. Combinations of embolic, ablative, and extirpative therapies can increase access to curative-intent treatment of HCC. Multidisciplinary treatment decisions are required to craft optimal treatment strategies considering tumor size, location, and underlying liver cirrhosis.