Radiation lobectomy: preliminary findings of hepatic volumetric response to lobar yttrium-90 radioembolization

Comprehensive Review of Future Liver Remnant (FLR) Assessment and Hypertrophy Techniques Before Major Hepatectomy: How to Assess and Manage the FLR

BACKGROUND

The regenerative capacities of the liver and improvements in surgical techniques have expanded the possibilities of resectability. Liver resection is often the only curative treatment for primary and secondary malignancies, despite the risk of post-hepatectomy liver failure (PHLF). This serious complication (with a 50% mortality rate) can be avoided by better assessment of liver volume and function of the future liver remnant (FLR).

OBJECTIVE

The aim of this review was to understand and assess clinical, biological, and imaging predictors of PHLF risk, as well as the various hypertrophy techniques, to achieve an adequate FLR before hepatectomy.

METHOD

We reviewed the state of the art in liver regeneration and FLR hypertrophy techniques.

RESULTS

The use of new biological scores (such as the aspartate aminotransferase/platelet ratio index + albumin-bilirubin [APRI+ALBI] score), concurrent utilization of 99mTc-mebrofenin scintigraphy (HBS), or dynamic hepatocyte contrast-enhanced MRI (DHCE-MRI) for liver volumetry helps predict the risk of PHLF. Besides portal vein embolization, there are other FLR optimization techniques that have their indications in case of risk of failure (e.g., associating liver partition and portal vein ligation for staged hepatectomy, liver venous deprivation) or in specific situations (transarterial radioembolization).

CONCLUSION

There is a need to standardize volumetry and function measurement techniques, as well as FLR hypertrophy techniques, to limit the risk of PHLF.

Prognostic factors influencing outcomes in hepatocellular carcinoma patients undergoing selective internal radiation therapy

Selective internal radiation therapy (SIRT) has emerged as a viable endovascular treatment strategy for hepatocellular carcinoma (HCC). According to the Barcelona Clinic Liver Cancer (BCLC) classification, SIRT is currently recommended for early- and intermediate-stage HCC that is unsuitable for alternative locoregional therapies. Additionally, SIRT remains a recommended treatment for patients with advanced-stage HCC and portal vein thrombosis (PVT) without extrahepatic metastasis. Several studies have shown that SIRT is a versatile and promising treatment with a wide range of applications. Consequently, given its favourable characteristics in various scenarios, SIRT could be an encouraging treatment option for patients with HCC across different BCLC stages. Over the past decade, an increasing number of studies have focused on better understanding the prognostic factors associated with SIRT to identify patients who derive the most benefit from this treatment or to refine the optimal technical procedures of SIRT. Several variables can influence treatment decisions, with a growing emphasis on a personalised approach. This review, based on the literature, will focus on the prognostic factors associated with the effectiveness of radioembolization and related complications. By comprehensively analysing these factors, we aimed to provide a clearer understanding of how to optimise the use of SIRT in managing HCC patients, thereby enhancing outcomes across various clinical scenarios.

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.

Modified Radiation Lobectomy Strategy of Radioembolization for Right-Sided Unresectable Primary Liver Tumors

PURPOSE

To assess the safety and effectiveness of using modified radiation lobectomy (mRL) to treat primary hepatic tumors located in the right hepatic lobe (Segments V-VIII) and to determine future liver remnant (FLR) hypertrophy.

MATERIALS AND METHODS

A retrospective review was performed at a single institution to include 19 consecutive patients (7 females, 12 males) who underwent single-session mRL for right-sided primary hepatic tumors: 15 received segmentectomy plus lobectomy (segmental dose of >190 Gy and lobar dose of >80 Gy); 4 were treated with the double-segmental approach (dominant segments of >190 Gy and nondominant segments of >80 Gy). Treated tumors included 13 hepatocellular carcinoma (HCC), 4 cholangiocarcinoma (CCA), and 2 mixed-type HCC-CCA with a median dominant tumor size of 5.3 cm (interquartile range [IQR], 3.7-7.3 cm). FLR of the left hepatic lobe was measured at baseline, T1 (4-8 weeks), T2 (2-4 months), T3 (4-6 months), and T4 (9-12 months).

RESULTS

Objective tumor response and tumor control were achieved in 17 of the 19 (89.5%) and 18 of the 19 (94.7%) patients, respectively. FLR hypertrophy was observed at T1 (median, 47.8%; P = .025), T2 (median, 48.4%; P = .012), T3 (median, 50.4%; P = .015), and T4 (median, 59.1%; P < .001). Patients without cirrhosis demonstrated greater hypertrophy by 6 months (median, 55.8% vs 47.2%; P = .031). One patient developed a Grade 3 adverse event (ascites requiring paracentesis) at 1-month follow-up. Grade ≥2 serum toxicities were associated with worse baseline Child-Pugh Score, serum albumin, and total bilirubin (P < .05). Among 7 patients who underwent neoadjuvant mRL, 2 underwent resection and 1 received liver transplant.

CONCLUSIONS

mRL appears safe and effective for treatment of right-sided primary hepatic tumors with the benefit of promoting FLR hypertrophy.

Molecular Pathways Governing the Termination of Liver Regeneration

The liver has the unique capacity to regenerate, and up to 70% of the liver can be removed without detrimental consequences to the organism. Liver regeneration is a complex process involving multiple signaling networks and organs. Liver regeneration proceeds through three phases: the initiation phase, the growth phase, and the termination phase. Termination of liver regeneration occurs when the liver reaches a liver-to-body weight that is required for homeostasis, the so-called "hepatostat." The initiation and growth phases have been the subject of many studies. The molecular pathways that govern the termination phase, however, remain to be fully elucidated. This review summarizes the pathways and molecules that signal the cessation of liver regrowth after partial hepatectomy and answers the question, "What factors drive the hepatostat?" SIGNIFICANCE STATEMENT: Unraveling the pathways underlying the cessation of liver regeneration enables the identification of druggable targets that will allow us to gain pharmacological control over liver regeneration. For these purposes, it would be useful to understand why the regenerative capacity of the liver is hampered under certain pathological circumstances so as to artificially modulate the regenerative processes (e.g., by blocking the cessation pathways) to improve clinical outcomes and safeguard the patient's life.

Contralateral Hypertrophy Post Yttrium-90 Transarterial Radioembolization in Patients With Hepatocellular Carcinoma and Portal Vein Tumor Thrombus

Objectives Contralateral hypertrophy of non-irradiated liver following Yttrium-90 (90Y) transarterial radioembolization (TARE) is increasingly recognized as an option to facilitate curative surgical resection in patients that would otherwise not be surgical candidates due to a small future liver remnant (FLR). This study aimed to investigate the correlation between patient features and liver hypertrophy and identify potential predictors for liver growth in patients with hepatocellular carcinoma (HCC) and portal vein tumor thrombus (PVTT) undergoing TARE. Methodology Twenty-three patients with HCC and PVTT were included. Contralateral liver hypertrophy was assessed at six months posttreatment based on CT or MRI imaging. Thirteen patient features were selected for statistical and prediction analysis. Univariate Spearman correlation and analysis of variance (ANOVA) tests were performed. Subsequently, four feature-selection methods based on multivariate analysis were used to improve model generalization performance. The selected features were applied to train linear regression models, with fivefold cross-validation to assess the performance of the predicted models. Results The ratio of disease-free target liver volume to spared liver volume and total liver volume showed the highest correlations with contralateral hypertrophy (P-values = 0.03 and 0.05, respectively). In three out of four feature-selection methods, the feature of disease-free target liver volume to total liver volume ratio was selected, having positive correlations with the outcome and suggesting that more hypertrophy may be expected when more volume of disease-free liver is irradiated. Conclusions Contralateral hypertrophy post-90Y TARE can be an option for facilitating surgical resection in patients with otherwise small FLR.

Long-Term Overall Survival After Selective Internal Radiation Therapy for Locally Advanced Hepatocellular Carcinomas: Updated Analysis of DOSISPHERE-01 Trial

Interim analysis of the DOSISPHERE-01 study demonstrated a strong improvement in response and overall survival (OS) on using 90Y-loaded glass microspheres with personalized dosimetry compared with standard dosimetry in patients with nonoperable locally advanced hepatocellular carcinoma. This report sought to provide a long-term analysis of OS. Methods: In this phase II study (ClinicalTrials.gov identifier NCT02582034), treatment was randomly assigned (1:1) with the goal to deliver either at least 205 Gy (if possible >250-300 Gy) to the index lesion in the personalized dosimetry approach (PDA) or 120 ± 20 Gy to the treated volume in the standard dosimetry approach (SDA). The 3-mo response of the index lesion was the primary endpoint, with OS being one of the secondary endpoints. This report is a post hoc long-term analysis of OS. Results: Overall, 60 hepatocellular carcinoma patients with at least 1 lesion larger than 7 cm and more than 30% of hepatic reserve were randomized (intent-to-treat population: PDA, n = 31; SDA, n = 29), with 56 actually treated (modified intent-to-treat population: n = 28 in each arm). The median follow-up for long-term analysis was 65.8 mo (range, 2.1-73.1 mo). Median OS was 24.8 mo and 10.7 mo (hazard ratio [HR], 0.51; 95% CI, 0.29-0.9; P = 0.02) for PDA and SDA, respectively, in the modified intent-to-treat population. Median OS was 22.9 mo for patients with a tumor dose of at least 205 Gy, versus 10.3 mo for those with a tumor dose of less than 205 Gy (HR, 0.42; 95% CI, 0.22-0.81; P = 0.0095), and was 22.9 mo for patients with a perfused liver dose of 150 Gy or higher, versus 10.3 mo for those with a perfused liver dose of less than 150 Gy (HR, 0.42; 95% CI, 0.23-0.75; P = 0.0033). Lastly, median OS was not reached in patients who were secondarily resected (n = 11, 10 in the PDA group and 1 in the SDA group), versus 10.8 mo in those without secondary resection (n = 45) (HR, 0.17; 95% CI, 0.065-0.43; P = 0.0002). Only resected patients displayed favorable long-term OS rates, meaning an OS of more than 50% at 5 y. Conclusion: After longer follow-up, personalized dosimetry sustained a meaningful improvement in OS, which was dramatically improved for patients who were accurately downstaged toward resection, including most portal vein thrombosis patients.

90Y-/166Ho- 'Radiation lobectomy' for liver tumors induces abnormal morphology and impaired drainage of peritumor lymphatics

Background & Aims

High-dose unilobar radioembolization, or 'radiation lobectomy' (RL), is an induction therapy that achieves contralateral future liver remnant hypertrophy while simultaneously irradiating the tumor. As such, it may prevent further growth, but it is unknown whether RL affects intrahepatic lymphatics, a major route via which liver tumors disseminate.

Methods

This was a case-control study conducted at University Medical Center Utrecht. The study compared lymph vessels in livers that had undergone RL (cases) with those in livers that had not undergone RL (controls). Histological samples were acquired from patients diagnosed with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLM) between 2017 and 2022. Lymph vessel morphology was analyzed by two researchers using podoplanin, a protein that is expressed in lymphatic endothelium. In vivo liver lymph drainage of radioembolized livers was assessed using intraoperative liver lymphangiography (ILL): during liver surgery, patent blue dye was injected into the liver parenchyma, followed by inspection for staining of perihepatic lymph structures. ILL results were compared to a previously published cohort.

Results

Immunohistochemical analysis on post-RL tumor tissues from ten patients with CRLM and nine patients with HCC revealed aberrant morphology of irradiated liver lymphatics when compared to controls (n = 3 per group). Irradiated lymphatics were tortuous (p <0.05), thickened (p <0.05) and discontinuous (p <0.05). Moreover, post-RL lymphatics had larger lumens (1.5-1.7x, p <0.0001), indicating lymph stasis. ILL revealed diminished lymphatic drainage to perihepatic lymph nodes and vessels in irradiated livers when compared to non-radioembolized controls (p = 1.0x10-4).

Conclusions

Radioembolization impairs peritumoral lymph vessel function. Further research is needed to evaluate if radioembolization impairs tumor dissemination via this route.

Impact and implications

Unilobar radioembolization can serve as an alternative to portal venous embolization for patients who are considered unresectable due to an insufficient future liver remnant. This research suggests that radioembolization impairs the function of peritumoral liver lymph vessels, potentially hindering dissemination via this route. These findings provide support for considering unilobar radioembolization over standard portal venous embolization.

Anatomical Quantitative Volumetric Evaluation of Liver Segments in Hepatocellular Carcinoma Patients Treated with Selective Internal Radiation Therapy: Key Parameters Influencing Untreated Liver Hypertrophy

Background: Factors affecting morphological changes in the liver following selective internal radiation therapy (SIRT) are unclear, and the available literature focuses on non-anatomical volumetric assessment techniques in a lobar treatment setting. This study aimed to investigate quantitative changes in the liver post-SIRT using an anatomical volumetric approach in hepatocellular carcinoma (HCC) patients with different levels of treatment selectivity and evaluate the parameters affecting those changes. This retrospective, single-institution, IRB-approved study included 88 HCC patients. Whole liver, liver segments, tumor burden, and spleen volumes were quantified on MRI at baseline and 3/6/12 months post-SIRT using a segmentation-based 3D software relying on liver vascular anatomy. Treatment characteristics, longitudinal clinical/laboratory, and imaging data were analyzed. The Student's t-test and Wilcoxon test evaluated volumetric parameters evolution. Spearman correlation was used to assess the association between variables. Uni/multivariate analyses investigated factors influencing untreated liver volume (uLV) increase. Results: Most patients were cirrhotic (92%) men (86%) with Child-Pugh A (84%). Absolute and relative uLV kept increasing at 3/6/12 months post-SIRT vs. baseline (all, p ≤ 0.005) and was maximal during the first 6 months. Absolute uLV increase was greater in Child-Pugh A5/A6 vs. ≥B7 at 3 months (A5, p = 0.004; A6, p = 0.007) and 6 months (A5, p = 0.072; A6, p = 0.031) vs. baseline. When the Child-Pugh class worsened at 3 or 6 months post-SIRT, uLV did not change significantly, whereas it increased at 3/6/12 months vs. baseline (all p ≤ 0.015) when liver function remained stable. The Child-Pugh score was inversely correlated with absolute and relative uLV increase at 3 months (rho = -0.21, p = 0.047; rho = -0.229, p = 0.048). In multivariate analysis, uLV increase was influenced at 3 months by younger age (p = 0.013), administered 90Y activity (p = 0.003), and baseline spleen volume (p = 0.023). At 6 months, uLV increase was impacted by younger age (p = 0.006), whereas treatment with glass microspheres (vs. resin) demonstrated a clear trend towards better hypertrophy (f = 3.833, p = 0.058). The amount (percentage) of treated liver strongly impacted the relative uLV increase at 3/6/12 months (all f ≥ 8.407, p ≤ 0.01). Conclusion: Liver function (preserved baseline and stable post-SIRT) favored uLV hypertrophy. Younger patients, smaller baseline spleen volume, higher administered 90Y activity, and a larger amount of treated liver were associated with a higher degree of untreated liver hypertrophy. These factors should be considered in surgical candidates undergoing neoadjuvant SIRT.

A Review of Resection and Surgical Ablation for Primary and Secondary Liver Cancers

The surgical management of primary and secondary liver tumors is constantly evolving. Patient selection, particularly with regard to determining resectability, is vital to the success of programs directed toward invasive treatments of liver tumors. Particular attention should be paid toward determining whether patients are best served with surgical resection or ablative therapies. A multidisciplinary approach is necessary to provide optimal care to patients with liver malignancy.

Current status of yttrium-90 microspheres radioembolization in primary and metastatic liver cancer

Liver malignancy, including primary liver cancer and metastatic liver cancer, has become one of the most common causes of cancer-related death worldwide due to the high malignant degree and limited systematic treatment strategy. Radioembolization with yttrium-90 (90Y)-loaded microspheres is a relatively novel technology that has made significant progress in the local treatment of liver malignancy. The different steps in the extensive work-up of radioembolization for patients with an indication for treatment with 90Y microspheres, from patient selection to follow up, both technically and clinically, are discussed in this paper. It describes the application and development of 90Y microspheres in the treatment of liver cancer.

Colorectal liver metastases that survive radioembolization display features of aggressive tumor behavior

BACKGROUND

Radiation lobectomy is a therapeutic approach that involves targeted radiation delivery to induce future liver remnant hypertrophy and tumor control. In patients with colorectal liver metastases, only 30-40% have complete tumor regression. The importance of tumor biology in treatment response remains elusive.

METHODS

Patients with colorectal liver metastases who received radiation lobectomy were selected from surgical pathology files. Using a machine learning scoring protocol, pathological response was correlated to tumor absorbed dose and expression of markers of radioresistance Ki-67 (proliferation), CAIX (hypoxia), Olfm4 (cancer stem cells) and CD45 (leukocytes).

RESULTS

No linear association was found between tumor dose and response (ρ < 0.1, P = 0.73 (90Y), P = 0.92 (166Ho)). Response did correlate with proliferation (ρ = 0.56, P = 0.012), and non-responsive lesions had large pools (>15%) of Olfm4 positive cancer stem cells (Fisher's exact test, P = 0.0037). Responding lesions (regression grade ≤2) were highly hypoxic compared to moderate and non-responding lesions (P = 0.011). Non-responsive lesions had more tumor-infiltrating leukocytes (3240 cells/mm2 versus 650 cells/mm2), although this difference was not significant (P = 0.08).

CONCLUSION

The aggressive phenotype of a subset of surviving cancer cells emphasizes the importance of prompt resection after radiation lobectomy.

Management of early-stage hepatocellular carcinoma: challenges and strategies for optimal outcomes

Although hepatocellular carcinoma (HCC) is associated with a poor prognosis, management of early-stage HCC is often successful with highly efficacious treatment modalities such as liver transplantation, surgical resection, and radiofrequency ablation. However, unfavorable clinical outcomes have been observed under certain circumstances, even after efficient treatment. Factors that predict unsuitable results after treatment include tumor markers, inflammatory markers, imaging findings reflecting tumor biology, specific outcome indicators for each treatment modality, liver functional reserve, and the technical feasibility of the treatment modalities. Various strategies may overcome these challenges, including the application of reinforced treatment indication criteria with predictive markers reflecting tumor biology, compensation for technical issues with up-to-date technologies, modification of treatment modalities, downstaging with locoregional therapies (such as transarterial chemotherapy or radiotherapy), and recently introduced combination immunotherapies. In this review, we discuss the challenges to achieving optimal outcomes in the management of early-stage HCC and suggest strategies to overcome these obstacles.

Dose finding study for unilobar radioembolization using holmium-166 microspheres to improve resectability in patients with HCC: the RALLY protocol

BACKGROUND

High dose unilobar radioembolization (also termed 'radiation lobectomy')-the transarterial unilobar infusion of radioactive microspheres as a means of controlling tumour growth while concomitantly inducing future liver remnant hypertrophy-has recently gained interest as induction strategy for surgical resection. Prospective studies on the safety and efficacy of the unilobar radioembolization-surgery treatment algorithm are lacking. The RALLY study aims to assess the safety and toxicity profile of holmium-166 unilobar radioembolization in patients with hepatocellular carcinoma ineligible for surgery due to insufficiency of the future liver remnant.

METHODS

The RALLY study is a multicenter, interventional, non-randomized, open-label, non-comparative safety study. Patients with hepatocellular carcinoma who are considered ineligible for surgery due to insufficiency of the future liver remnant (< 2.7%/min/m2 on hepatobiliary iminodiacetic acid scan will be included. A classical 3 + 3 dose escalation model will be used, enrolling three to six patients in each cohort. The primary objective is to determine the maximum tolerated treated non-tumourous liver-absorbed dose (cohorts of 50, 60, 70 and 80 Gy). Secondary objectives are to evaluate dose-response relationships, to establish the safety and feasibility of surgical resection following unilobar radioembolization, to assess quality of life, and to generate a biobank.

DISCUSSION

This will be the first clinical study to assess the unilobar radioembolization-surgery treatment algorithm and may serve as a stepping stone towards its implementation in routine clinical practice.

TRIAL REGISTRATION

Netherlands Trial Register NL8902 , registered on 2020-09-15.

Surgery and radioembolization of liver tumors

Surgical resection is considered the curative treatment par excellence for patients with primary or metastatic liver tumors. However, less than 40% of them are candidates for surgery, either due to non-modifiable factors (comorbidities, age, liver dysfunction…), or to the invasion or proximity of the tumor to the main vascular requirements, the lack of a future liver remnant (FLR) adequate to maintain postoperative liver function, or criteria of tumor size and number. In these last factors, hepatic radioembolization has been shown to play a role as a presurgical tool, either by hypertrophy of the FLR or by reducing tumor size that manages to reduce tumor staging (term known as "downstaging"). To these is added a third factor, which is its ability to apply the test of time, which makes it possible to identify those patients who present progression of the disease in a short period of time (both locally and at distance), avoiding a unnecessary surgery. This paper aims to review RE as a tool to facilitate liver surgery, both through the experience of our center and the available scientific evidence.

A bibliometric and visualized analysis of preoperative future liver remnant augmentation techniques from 1997 to 2022

Background

The size and function of the future liver remnant (FLR) is an essential consideration for both eligibility for treatment and postoperative prognosis when planning surgical hepatectomy. Over time, a variety of preoperative FLR augmentation techniques have been investigated, from the earliest portal vein embolization (PVE) to the more recent Associating liver partition and portal vein ligation for staged hepatectomy (ALPPS) and liver venous deprivation (LVD) procedures. Despite numerous publications on this topic, no bibliometric analysis has yet been conducted.

Methods

Web of Science Core Collection (WoSCC) database was searched to identify studies related to preoperative FLR augmentation techniques published from 1997 to 2022. The analysis was performed using the CiteSpace [version 6.1.R6 (64-bit)] and VOSviewer [version 1.6.19].

Results

A total of 973 academic studies were published by 4431 authors from 920 institutions in 51 countries/regions. The University of Zurich was the most published institution while Japan was the most productive country. Eduardo de Santibanes had the most published articles, and Masato Nagino was the most frequently co-cited author. The most frequently published journal was HPB, and the most cited journal was Ann Surg, with 8088 citations. The main aspects of preoperative FLR augmentation technique is to enhance surgical technology, expand clinical indications, prevent and treat postoperative complications, ensure long-term survival, and evaluate the growth rate of FLR. Recently, hot keywords in this field include ALPPS, LVD, and Hepatobiliary Scintigraphy.

Conclusion

This bibliometric analysis provides a comprehensive overview of preoperative FLR augmentation techniques, offering valuable insights and ideas for scholars in this field.

Emerging treatment strategies in hepatobiliary cancer

INTRODUCTION

There have been significant advances in the treatment of hepatobiliary cancers, especially for advanced-stage disease. However, data is limited for optimal therapy selection in the first line and sequencing of available options.

AREAS COVERED

This review covers the systemic treatment of hepatobiliary cancers with an emphasis on the advanced stage. The previously published and ongoing trials will be discussed to create an algorithm for the current practice and to give future perspectives on how the field could go forward.

EXPERT OPINION

While there is no standard-of-care option in the adjuvant treatment of hepatocellular cancer, capecitabine is the standard of care for biliary tract cancer. The efficacy of adjuvant gemcitabine and cisplatin and the added benefit of radiotherapy to chemotherapy are yet to be defined. For the advanced stage, immunotherapy-based combinations became the standard of care for both hepatocellular and biliary tract cancers. The molecularly targeted therapy has profoundly changed the second-line and later treatment for biliary tract cancers, while the optimal second-line treatment for advanced hepatocellular cancer is yet to be defined due to rapid advances in the first-line setting.

Liver Resection and Transplantation Following Yttrium-90 Radioembolization for Primary Malignant Liver Tumors: A 15-Year Single-Center Experience

Radioembolization (RE) may help local control and achieve tumor reduction while hypertrophies healthy liver and provides a test of time. For liver transplant (LT) candidates, it may attain downstaging for initially non-candidates and bridging during the waitlist.

METHODS

Patients diagnosed with HCC and ICC treated by RE with further liver resection (LR) or LT between 2005-2020 were included. All patients selected were discarded for the upfront surgical approach for not accomplishing oncological or surgical safety criteria after a multidisciplinary team assessment. Data for clinicopathological details, postoperative, and survival outcomes were retrospectively reviewed from a prospectively maintained database.

RESULTS

A total of 34 patients underwent surgery following RE (21 LR and 13 LT). Clavien-Dindo grade III-IV complications and mortality rates were 19.0% and 9.5% for LR and 7.7% and 0% for LT, respectively. After RE, for HCC and ICC patients in the LR group, 10-year OS rates were 57% and 60%, and 10-year DFS rates were 43.1% and 60%, respectively. For HCC patients in the LT group, 10-year OS and DFS rates from RE were 51.3% and 43.3%, respectively.

CONCLUSION

Liver resection after RE is safe and feasible with optimal short-term outcomes. Patients diagnosed with unresectable or high biological risk HCC or ICC, treated with RE, and rescued by LR may achieve optimal global and DFS rates. On the other hand, bridging or downstaging strategies to LT with RE in HCC patients show adequate recurrence rates as well as long-term survival.

Yttrium-90 Radioembolization: Current Indications and Outcomes

BACKGROUND

Radioembolization (RE) with 90Yttrium (Y90) has generally been used to treat patients with advanced disease. Recent data suggest, however, that RE is also safe and feasible to treat patients with early or intermediate stage disease. We herein review the current evidence regarding the use of RE with Y90 for patients with HCC.

METHODS

A comprehensive review of the literature was performed using MEDLINE/PubMed and Web of Science databases with a search end date of August 1, 2022.

RESULTS

Patients with HCC are often treated according to the BCLC staging system. Among patients with early-stage HCC (BCLC A), intermediate-stage HCC (BCLC B), and advanced-stage HCC (BCLC C), RE with Y90 has demonstrated promising results with comparable overall survival, time to disease progression, and radiological response compared with other standard of care treatment modalities. Moreover, Y90 RE can be used as a downstaging treatment modality for patients with advanced HCC who have a disease burden that is initially outside LT criteria. Radiation lobectomy (RL) has been described as a treatment modality with the intent of treating the ipsilateral liver that harbors the HCC, while also causing compensatory hypertrophy of the future liver remnant (FLR).

CONCLUSION

While initially considered as a palliative option for HCC patients, Y90 RE has emerged as an important part of the multi-modality care of patients with HCC across a wide spectrum of clinical indications.

Predictors of Liver Failure in Non-Cirrhotic Patients Undergoing Hepatectomy

BACKGROUND

Post-hepatectomy liver failure (PHLF) is associated with high mortality following liver resection. There have been limited studies evaluating predictors of PHLF and clinically significant PHLF in non-cirrhotic patients.

METHODS

This was a retrospective cohort study using the National Surgical Quality Improvement Program database (NSQIP) to evaluate 8,093 non-cirrhotic patients undergoing hepatectomy from 2014 to 2018. Primary endpoints were PHLF and clinically significant PHLF (PHLF grade B or C).

RESULTS

Among all patients, 4.74% (n = 383) developed PHLF and 2.5% clinically significant PHLF (n = 203). The overall 30-day mortality was 1.35% (n = 109), 11.5% (n = 44) in patients with PHLF, and 19.2% in those with clinically significant PHLF. Factors associated with PHLF were: metastatic liver disease (OR = 1.84, CI = 1.14-2.98), trisectionectomy (OR = 3.71, CI = 2.59-5.32), right total lobectomy (OR = 4.17, CI = 3.06-5.68), transfusions (OR = 1.99, CI = 1.52-2.62), organ/space SSI (OR = 2.84, CI = 2.02-3.98), post-operative pneumonia (OR = 2.43, CI = 1.57-3.76), sepsis (OR = 2.27, CI = 1.47-3.51), and septic shock (OR = 5.67, CI = 3.43-9.36). Patients who developed PHLF or clinically significant PHLF had 2-threefold increased risk of perioperative mortality. Post-hepatectomy renal failure (OR = 8.47, CI = 3.96-18.1), older age (OR = 1.04, CI = 1.014-1.063), male sex (OR = 1.83, CI = 1.07-3.14), sepsis (OR = 2.96, CI = 1.22-7.2), and septic shock (OR = 3.92, CI = 1.61-9.58) were independently associated with 30-mortality in patients with clinically significant PHLF.

CONCLUSION

PHLF in non-cirrhotic patients increased the risk of perioperative mortality and is associated with the extent of hepatectomy and infectious complications. Careful evaluation of the liver remnant, antibiotic prophylaxis, nutritional assessment, and timely management of post-operative infections could decrease major morbidity and mortality following hepatectomy.

The Radiation Dose Absorbed by Healthy Parenchyma Is a Predictor for the Rate of Contralateral Hypertrophy After Unilobar Radioembolization of the Right Liver

Purpose

To investigate the predictors of contralateral hypertrophy in patients treated with unilobar transarterial radioembolization (TARE) with yttrium-90-loaded resin microspheres due to unresectable right-liver tumors.

Methods

Patients who underwent right unilobar TARE with resin microspheres between May 2019 and September 2021 were screened retrospectively. Contralateral hypertrophy was evaluated by calculating the kinetic growth rate (KGR) in 8-10 weeks after TARE. The predictors of increased KGR were determined with linear regression analysis.

Results

A total of 24 patients (16 with primary and 8 with metastatic liver tumors) were included in the study. After right unilobar TARE, mean volume of the left lobe increased from 368.26 to 436.16 mL, while the mean volume of the right lobe decreased from 1576.22 to 1477.89 mL. The median KGR of the left lobe was 0.28% per week. The radiation dose absorbed by the healthy parenchyma of the right lobe was significantly higher in patients with increased KGR (31.62 vs. 18.78 Gy, p = 0.037). Linear regression analysis showed that the dose absorbed by healthy parenchyma was significantly associated with increased KGR (b = 0.014, p = 0.043).

Conclusion

Patients who received right unilobar TARE for liver malignancies could develop a substantial contralateral hypertrophy, and the radiation dose absorbed by the healthy parenchyma of the right lobe was significantly associated with increased KGR in the left lobe. TARE could have a role for inducing contralateral hypertrophy as it offers the advantage of concurrent local tumor control along with its hypertrophic effect.

Unresectable Intrahepatic Cholangiocarcinoma Treated with Radiation Segmentectomy/Lobectomy Using Yttrium 90-labeled Glass Microspheres

Background

There is no curative treatment option for patients with unresectable intrahepatic, cholangiocarcinoma (IHC). The aim of this study was to evaluate the efficacy of; radiation segmentectomy/lobectomy using Y90-labeled glass microspheres in patients with; unresectable IHC.

Methods

This IRB-approved, single-center study included, 16 patients (age: 67 ± 7.7 years) with IHC who received radiation segmentectomy or lobectomy, treatment using Y90-labeled glass microspheres between May 2009 and October 2019. Radiation, segmentectomy/lobectomy was defined as at least 190 Gy dose delivered into treated liver; volume.

Results

The median OS from IHC diagnosis was 22.7 months (95% CI: 13.9-66.1) and from, radioembolization it was 7 months (95% CI: 4.33-54.17). Patients who did not receive, chemotherapy before the radioembolization had significantly longer median OS (26.8 vs. 5.9, months, P = 0.03). Four patients had >20 months survival after radioembolization, including 2, patients with survival of 42 and 54 months. There was no 30-day mortality and no severe, complications.

Conclusion

Radiation segmentectomy/lobectomy is safe with minimal side effects. The median, OS of the study group is modest; however, 4 patients (25%) showed excellent survival. These results suggest a need for a larger study to define the IHC patient group who could, most benefit from this procedure.

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.

Yttrium-90 Radioembolization of Unresectable Intrahepatic Cholangiocarcinoma: Long-Term Follow-up for a 136-Patient Cohort

PURPOSE

Unresectable intrahepatic cholangiocarcinoma (ICC) signifies a poor prognosis with limited treatment options beyond systemic chemotherapy. This study's purpose was to evaluate the safety, efficacy, and potential for downstaging to resection of yttrium-90 (Y90) radioembolization for treatment of unresectable ICC.

MATERIALS AND METHODS

From 2004 to 2020, 136 patients with unresectable ICC were treated with radioembolization at a single institution. Retrospective review was performed of a prospectively collected database. Outcomes were (1) biochemical and clinical toxicities, (2) local tumor response, (3) time to progression, and (4) overall survival (OS) after Y90. Univariate/multivariate survival analyses were performed. A subgroup analysis was performed to calculate post-resection recurrence and OS in patients downstaged to resection after Y90.

RESULTS

Grade 3+ clinical and biochemical toxicities were 7.6% (n = 10) and 4.9% (n = 6), respectively. Best index lesion response was complete response in 2 (1.5%), partial response in 42 (32.1%), stable disease in 82 (62.6%), and progressive disease in 5 (3.8%) patients. Median OS was 14.2 months. Solitary tumor (P < 0.001), absence of vascular involvement (P = 0.009), and higher serum albumin (P < 0.001) were independently associated with improved OS. Eleven patients (8.1%) were downstaged to resection and 2 patients (1.5%) were bridged to transplant. R0-resection was achieved in 8/11 (72.7%). Post-resection median recurrence and OS were 26.3 months and 39.9 months, respectively.

CONCLUSION

Y90 has an acceptable safety profile and high local disease control rates for the treatment of unresectable ICC. Downstaging to resection with > 3 years survival supports the therapeutic role of Y90 for unresectable ICC.

LEVEL OF EVIDENCE

Level 3, single-arm single-center cohort study.

Radioembolization, Principles and indications

Radioembolization is the selective application of radionuclide-loaded microspheres into liver arteries for the therapy of liver tumours and metastases. In this review, we focused on therapy planning and dosimetry, as well as the main indications of 90Y-glass and resin microspheres and 166Ho-microspheres.

Pure laparoscopic major liver resection after yttrium90 radioembolization: a case-matched series analysis of feasibility and outcomes

Background

Liver surgery after radioembolization (RE) entails highly demanding and challenging procedures due to the frequent combination of large tumors, severe RE-related adhesions, and the necessity of conducting major hepatectomies. Laparoscopic liver resection (LLR) and its associated advantages could provide benefits, as yet unreported, to these patients. The current study evaluated feasibility, morbidity, mortality, and survival outcomes for major laparoscopic liver resection after radioembolization.

Material and methods

In this retrospective, single-center study patients diagnosed with hepatocellular carcinoma, intrahepatic cholangiocarcinoma or metastases from colorectal cancer undergoing major laparoscopic hepatectomy after RE were identified from institutional databases. They were matched (1:2) on several pre-operative characteristics to a group of patients that underwent major LLR for the same malignancies during the same period but without previous RE.

Results

From March 2011 to November 2020, 9 patients underwent a major LLR after RE. No differences were observed in intraoperative blood loss (50 vs. 150 ml; p = 0.621), operative time (478 vs. 407 min; p = 0.135) or pedicle clamping time (90.5 vs 74 min; p = 0.133) between the post-RE LLR and the matched group. Similarly, no differences were observed on hospital stay (median 3 vs. 4 days; p = 0.300), Clavien–Dindo ≥ III complications (2 vs. 1 cases; p = 0.250), specific liver morbidity (1 vs. 1 case p = 1.000), or 90 day mortality (0 vs. 0; p = 1.000).

Conclusion

The laparoscopic approach for post radioembolization patients may be a feasible and safe procedure with excellent surgical and oncological outcomes and meets the current standards for laparoscopic liver resections. Further studies with larger series are needed to confirm the results herein presented.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00423-022-02474-z.

TARE in Hepatocellular Carcinoma: From the Right to the Left of BCLC

The Barcelona Clinic Liver Cancer (BCLC) system is the most commonly used staging system for hepatocellular carcinoma (HCC) in Western countries. BCLC aims to categorize patients into five stages with different prognoses and to allocate treatment according to these stages based on the best possible contemporary evidence. Transarterial radioembolization (TARE) has recently entered at the left of the BCLC algorithm (i.e., BCLC 0-A), mainly because of negative phase III trials in BCLC C stage. TARE has shown a steady increase in nationwide studies over the past 20 years and has even been adopted in some tertiary centers as the primary HCC treatment across all BCLC stages. We aimed to review the history of TARE in HCC, starting from advanced HCC and gradually expanding to earlier stages at the left of the BCLC system.

A new animal model of atrophy-hypertrophy complex and liver damage following Yttrium-90 lobar selective internal radiation therapy in rabbits

Lobar selective internal radiation therapy (SIRT) is widely used to treat liver tumors inducing atrophy of the treated lobe and contralateral hypertrophy. The lack of animal model has precluded further investigations to improve this treatment. We developed an animal model of liver damage and atrophy–hypertrophy complex after SIRT. Three groups of 5–8 rabbits received transportal SIRT with Yttrium 90 resin microspheres of the cranial lobes with different activities (0.3, 0.6 and 1.2 GBq), corresponding to predicted absorbed radiation dose of 200, 400 and 800 Gy, respectively. Another group received non-loaded microspheres (sham group). Cranial and caudal lobes volumes were assessed using CT volumetry before, 15 and 30 days after SIRT. Liver biochemistry, histopathology and gene expression were evaluated. Four untreated rabbits were used as controls for gene expression studies. All animals receiving 1.2 GBq were euthanized due to clinical deterioration. Cranial SIRT with 0.6 GBq induced caudal lobe hypertrophy after 15 days (median increase 34% -ns-) but produced significant toxicity. Cranial SIRT with 0.3 GBq induced caudal lobe hypertrophy after 30 days (median increase 82%, p = 0.04). No volumetric changes were detected in sham group. Transient increase in serum transaminases was detected in all treated groups returning to normal values at 15 days. There was dose-dependent liver dysfunction with bilirubin elevation and albumin decrease. Histologically, 1.2 GBq group developed permanent severe liver damage with massive necrosis, 0.6 and 0.3 GBq groups developed moderate damage with inflammation and portal fibrosis at 15 days, partially recovering at 30 days. There was no difference in the expression of hepatocyte function and differentiation genes between 0.3 GBq and control groups. Cranial SIRT with 0.3 GBq of ⁹⁰Y resin microspheres in rabbits is a reliable animal model to analyse the atrophy–hypertrophy complex and liver damage without toxicity.

SIRT in 2025

Selective internal radiation therapy represents an endovascular treatment option for patients with primary liver malignancies, in different clinical stages. Potential applications of this treatment are in early-stage hepatocellular carcinoma, as a curative option, or in combination with systemic treatments in intermediate and advanced-stages. This review, based on existing literature and ongoing trials, will focus on the future of this treatment in patients with hepatocellular carcinoma, in combination with systemic treatments, or with the use of new devices and technological developments; it will also describe new potential future indications and structural and organizational perspectives.

Clinical application of advances and innovation in radiation treatment of hepatocellular carcinoma

Background

Hepatocellular carcinoma (HCC) management has evolved over the past two decades, with the development of newer treatment modalities. While various options are available, unmet needs are reflected through the mixed treatment outcome for intermediate-stage HCC. As HCC is radiosensitive, radiation therapies have a significant role in management. Radiation therapies offer local control for unresectable lesions and for patients who are not surgical candidates. Radiotherapy also provides palliation in metastatic disease, and acts as a bridge to resection and transplantation in selected patients. Advancements in radiotherapy modalities offer improved dose planning and targeted delivery, allowing for better tumor response and safer dose escalations while minimizing the risks of radiation-induced liver damage. Radiotherapy modalities are broadly classified into external beam radiation therapy and selective internal radiation therapy. With emerging modalities, radiotherapy plays a complementary role in the multidisciplinary care of HCC patients.

Aim

We aim to provide an overview of the role and clinical application of radiation therapies in HCC management.

Relevance for Patients

The continuous evolution of radiotherapy techniques allows for improved therapeutic outcomes while mitigating unwanted adverse effects, making it an attractive modality in HCC management. Rigorous clinical studies, quality research and comprehensive datasets will further its application in the present era of evidence-based practice in Medicine.

Neoadjuvant treatment strategies for hepatocellular carcinoma

The incidence of hepatocellular carcinoma (HCC) remains high globally. Surgical treatment is the best treatment for improving the prognosis of patients with HCC. Neoadjuvant therapy plays a key role in preventing tumor progression and even downstaging HCC. The liver transplantation rate and resectability rate have increased for neoadjuvant therapy. Neoadjuvant therapy is effective in different stages of HCC. In this review, we summarized the definition, methods, effects, indications and contraindications of neoadjuvant therapy in HCC, which have significance for guiding treatment.

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.

Downstaging Conversion Therapy in Patients With Initially Unresectable Advanced Hepatocellular Carcinoma: An Overview

The high mortality rate associated with hepatocellular carcinoma (HCC) is partly due to the high proportion of patients who present with advanced stage disease at diagnosis, for whom there are limited treatment options. For selected patients with initially unresectable HCC, locoregional and/or systemic treatments can result in tumor downstaging and consequently provide opportunities for surgical intervention and the potential for long-term survival. Therefore, the key aim of 'conversion therapy' is to reduce tumor burden so that patients become amenable to surgical resection. Various therapies have been investigated as candidates for downstaging patients with potentially resectable HCC including transarterial chemoembolization, transarterial radioembolization with yttrium-90 microspheres, radiotherapy, systemic therapies and combination or multimodality treatment approaches. However, downstaging conversion therapy remains controversial and there are several challenges such as defining the criteria used to identify the population of patients who are 'potentially resectable', the criteria used to define successful downstaging, and the optimum treatment approach to maximize the success of downstaging therapy. In this review article, we summarize clinical experience and evidence of downstaging conversion treatment in patients identified as having 'potentially resectable' HCC.

Radioembolization for the Treatment of Hepatocellular Carcinoma: The Road to Personalized Dosimetry and Ablative Practice

Radioembolization dosimetry for the treatment of hepatocellular carcinoma has evolved alongside our understanding of best practice for this therapy. At the core of advances in dosimetry are personalized and ablative applications of radioembolization, which have generated paradigm shifts in both safety and efficacy. This review provides a summary of fundamental radioembolization dosimetry concepts and narrates how our approach to treating patients has shifted from conventional to tailored and definitive therapy.

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.

Extrahepatic Applications of Yttrium-90 Radioembolization

While initially described and now accepted as treatment for primary and secondary malignancies in the liver, radioembolization therapy has expanded to include treatment for other disease pathologies and other organ systems. Advantages and limitations for these treatments exist and must be compared against more traditional treatments for these processes. This article provides an overview of the current applications for radioembolization outside of the liver, for both malignant and nonmalignant disease.

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.

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.

Optimization of the future remnant liver: review of the current strategies in Europe

Liver resection still represent the treatment of choice for liver malignancies, but in some cases inadequate future remnant liver (FRL) can lead to post hepatectomy liver failure (PHLF) that still represents the most common cause of death after hepatectomy. Several strategies in recent era have been developed in order to generate a compensatory hypertrophy of the FRL, reducing the risk of post hepatectomy liver failure. Portal vein embolization, portal vein ligation, and ALLPS are the most popular techniques historically adopted up to now. The liver venous deprivation and the radio-embolization are the most recent promising techniques. Despite even more precise tools to calculate the relationship among volume and function, such as scintigraphy with ^99mTc-mebrofenin (HBS), no consensus is still available to define which of the above mentioned augmentation strategy is more adequate in terms of kind of surgery, complexity of the pathology and quality of liver parenchyma. The aim of this article is to analyse these different strategies to achieve sufficient FRL.

Why Adjuvant and Neoadjuvant Therapy Failed in HCC. Can the New Immunotherapy Be Expected to Be Better?

INTRODUCTION

HCC remains a challenging disease with its unique characteristics and aggressive behavior. Although there are some curative-intent treatments such as liver transplantation and surgical resection, they themselves did not cure the patients with relatively high recurrence rates. Several modalities including local ablation methods like TACE or TARE, systemic treatments such as chemotherapy, tyrosine kinase inhibitors or antiviral therapies are tested in adjuvant or neoadjuvant setting, but none of them offered a survival benefit (except antiviral therapy in HBV-related HCC).

CONCLUSION

After a decade of plateau in drug development, ICPIs came into podium with their different mechanism of action consistent with immunogenic nature of the disease and with high expectations, and ongoing trials will show if these agents can satisfy unmet demand in this area.

The use of neoadjuvant lobar radioembolization prior to major hepatic resection for malignancy results in a low rate of post hepatectomy liver failure

Background

Neoadjuvant yttrium-90 transarterial radioembolization (TARE) is increasingly being used as a strategy to facilitate resection of otherwise unresectable tumors due to its ability to generate both tumor response and remnant liver hypertrophy. Perioperative outcomes after the use of neoadjuvant lobar TARE remain underinvestigated.

Methods

A single center retrospective review of patients who underwent lobar TARE prior to major hepatectomy for primary or metastatic liver cancer between 2007 and 2018 was conducted. Baseline demographics, radioembolization parameters, pre- and post-radioembolization volumetrics, intra-operative surgical data, adverse events, and post-operative outcomes were analyzed.

Results

Twenty-six patients underwent major hepatectomy after neoadjuvant lobar TARE. The mean age was 58.3 years (17-88 years). 62% of patients (n=16) had primary liver malignancies while the remainder had metastatic disease. Liver resection included right hepatectomy or trisegmentectomy, left or extended left hepatectomy, and sectorectomy/segmentectomy in 77% (n=20), 8% (n=2), and 15% (n=4) of patients, respectively. The mean length of stay was 8.3 days (range, 3-33 days) and there were no grade IV morbidities or 90-day mortalities. The incidence of post hepatectomy liver failure (PHLF) was 3.8% (n=1). The median time to progression after resection was 4.5 months (range, 3.3-10 months). Twenty-three percent (n=6) of patients had no recurrence. The median survival was 28.9 months (range, 16.9-46.8 months) from major hepatectomy and 37.6 months (range, 25.2-53.1 months) from TARE.

Conclusions

Major hepatectomy after neoadjuvant lobar radioembolization is safe with a low incidence of PHLF.

3D voxel-based dosimetry to predict contralateral hypertrophy and an adequate future liver remnant after lobar radioembolization

INTRODUCTION

Volume changes induced by selective internal radiation therapy (SIRT) may increase the possibility of tumor resection in patients with insufficient future liver remnant (FLR). The aim was to identify dosimetric and clinical parameters associated with contralateral hepatic hypertrophy after lobar/extended lobar SIRT with ⁹⁰Y-resin microspheres.

MATERIALS AND METHODS

Patients underwent ⁹⁰Y PET/CT after lobar or extended lobar (right + segment IV) SIRT. ⁹⁰Y voxel dosimetry was retrospectively performed (PLANET Dose; DOSIsoft SA). Mean absorbed doses to tumoral/non-tumoral-treated volumes (NTL) and dose-volume histograms were extracted. Clinical variables were collected. Patients were stratified by FLR at baseline (T0-FLR): < 30% (would require hypertrophy) and ≥ 30%. Changes in volume of the treated, non-treated liver, and FLR were calculated at < 2 (T1), 2-5 (T2), and 6-12 months (T3) post-SIRT. Univariable and multivariable regression analyses were performed to identify predictors of atrophy, hypertrophy, and increase in FLR. The best cut-off value to predict an increase of FLR to ≥ 40% was defined using ROC analysis.

RESULTS

Fifty-six patients were studied; most had primary liver tumors (71.4%), 40.4% had cirrhosis, and 39.3% had been previously treated with chemotherapy. FLR in patients with T0-FLR < 30% increased progressively (T0: 25.2%; T1: 32.7%; T2: 38.1%; T3: 44.7%). No dosimetric parameter predicted atrophy. Both NTL-Dmean and NTL-V30 (fraction of NTL exposed to ≥ 30 Gy) were predictive of increase in FLR in patients with T0 FLR < 30%, the latter also in the total cohort of patients. Hypertrophy was not significantly associated with tumor dose or tumor size. When ≥ 49% of NTL received ≥ 30 Gy, FLR increased to ≥ 40% (accuracy: 76.4% in all patients and 80.95% in T0-FLR < 30% patients).

CONCLUSION

NTL-Dmean and NTL exposed to ≥ 30 Gy (NTL-V30) were most significantly associated with increase in FLR (particularly among patients with T0-FLR < 30%). When half of NTL received ≥ 30 Gy, FLR increased to ≥ 40%, with higher accuracy among patients with T0-FLR < 30%.

Prognostic Significance of Neutrophil to Lymphocyte Ratio Dynamics in Patients with Hepatocellular Carcinoma Treated with Radioembolization Using Glass Microspheres

PURPOSE

To study the prognostic significance of neutrophil and lymphocyte dynamics in patients with hepatocellular carcinoma (HCC) treated with radioembolization.

METHODS

A retrospective, single-center review of clinical records and treatment parameters (liver volume treated, administered activity, and radiation dose) in consecutive patients who received radioembolization for HCC was performed between August 20, 2015, and May 24, 2019. Neutrophil and lymphocyte variables associated with overall survival (OS) were determined by Barcelona Clinic Liver Cancer (BCLC) stage and were correlated with radioembolization treatment parameters. Statistical methods included Wilcoxon signed-rank test, univariate, and multivariate Cox regression analysis; receiver operating characteristic analysis; and the Kaplan-Meier method.

RESULTS

One hundred sixty-three patients with a median 67.0 years of age were included for analysis. Eighty-one percent of patients received segmental radioembolization with a median treatment dose of 358 Gray (interquartile range 256-497). The post-treatment lymphocyte count decreased significantly in 94.5 % (p < 0.001) of patients but was not predictive of OS (p = 0.248). The pre-procedure neutrophil to lymphocyte ratio (NLR_pre) was not predictive of OS (p = 0.891), and the 1-month post-procedure NLR was a borderline independent predictor of OS (p = 0.05). The NLR ratio (NLRR = NLR_{post-procedure}/NLR_pre) (Hazard ratio [HR], 1.31; 95% Cl, 1.04-1.66) and change in NLR (ΔNLR= NLR_{post-procedure} - NLR_pre) (HR, 1.09; 95% CI, 1.02-1.15) were associated with worse OS in BCLC C patients. NLRR (> 3.17) and ΔNLR (> 3.74) were independent predictors when adjusted for tumor presentation, treatment parameters, and liver function. Volume of liver treated and administered activity positively correlated with NLRR and ΔNLR (p < 0.001).

CONCLUSION

A decrease in lymphocyte count is common after radioembolization, but of little clinical impact. Neither pre-treatment or post-treatment NLR was a predictor of survival in our study population. NLRR and ΔNLR were independent predictors of survival in BCLC stage C disease and had positive correlations with volume of liver tissue treated and administered activity.

Correlation and Agreement of Yttrium-90 Positron Emission Tomography/Computed Tomography with Ex Vivo Radioembolization Microsphere Deposition in the Rabbit VX2 Liver Tumor Model

PURPOSE

To demonstrate a stronger correlation and agreement of yttrium-90 (⁹⁰Y) positron emission tomography (PET)/computed tomography (CT) measurements with explant liver tumor dosing compared with the standard model (SM) for radioembolization.

MATERIALS AND METHODS

Hepatic VX2 tumors were implanted into New Zealand white rabbits, with growth confirmed by 7 T magnetic resonance imaging. Seventeen VX2 rabbits provided 33 analyzed tumors. Treatment volumes were calculated from manually drawn volumes of interest (VOI) with three-dimensional surface renderings. Radioembolization was performed with glass ⁹⁰Y microspheres. PET/CT imaging was completed with scatter and attenuation correction. Three-dimensional ellipsoid VOI were drawn to encompass tumors on fused images. Tumors and livers were then explanted for inductively coupled plasma (ICP)-optical emission spectroscopy (OES) analysis of microsphere content. ⁹⁰Y PET/CT and SM measurements were compared with reference standard ICP-OES measurements of tumor dosing with Pearson correlation and Bland-Altman analyses for agreement testing with and without adjustment for tumor necrosis.

RESULTS

The median infused activity was 33.3 MBq (range, 5.9-152.9). Tumor dose was significantly correlated with ⁹⁰Y PET/CT measurements (r = 0.903, P < .001) and SM estimates (r = 0.607, P < .001). Bland-Altman analyses showed that the SM tended to underestimate the tumor dosing by a mean of -8.5 Gy (CI, -26.3-9.3), and the degree of underestimation increased to a mean of -18.3 Gy (CI, -38.5-1.9) after the adjustment for tumor necrosis.

CONCLUSIONS

⁹⁰Y PET/CT estimates were strongly correlated and had better agreement with reference measurements of tumor dosing than SM estimates.

Current locoregional therapies and treatment strategies in hepatocellular carcinoma

Locoregional therapies (lrts) play an important role in the treatment of hepatocellular carcinoma (hcc), with the aim of increasing overall survival while preserving liver function. Various forms of lrt are available, and choosing the best one depends on technical aspects, liver morphology, tumour biology, and the patient's symptoms. The purpose of the present review article is to provide an overview of the current evidence relating to the use of percutaneous ablation, transarterial chemoembolization, and transarterial radioembolization for the curative or palliative treatment of hcc. Special situations are also reviewed, including the combined use of systemic therapy and lrt, indications and techniques for bridging to transplant and downstaging, and the use of lrt to treat patients with hcc and macrovascular invasion.