Left-liver hypertrophy after therapeutic right-liver radioembolization is substantial but less than after portal vein embolization

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.

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.

Assessing regional hepatic function changes after hypertrophy induction by radioembolisation: comparison of gadoxetic acid-enhanced MRI and 99mTc-mebrofenin hepatobiliary scintigraphy

BACKGROUND

To compare Gd-ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance imaging (MRI) and 99mTc-labelled mebrofenin hepatobiliary scintigraphy (HBS) as imaging-based liver function tests after unilateral radioembolisation (RE) in patients with primary or secondary liver malignancies.

METHODS

Twenty-three patients with primary or secondary liver malignancies who underwent Gd-EOB-DTPA-enhanced MRI within a prospective study (REVoluTion) were evaluated. REVoluTion was a prospective open-label, non-randomised, therapy-optimising study of patients undergoing right-sided or sequential RE for contralateral liver hypertrophy at a single centre in Germany. MRI and hepatobiliary scintigraphy were performed before RE (baseline) and 6 weeks after (follow-up). This exploratory subanalysis compared liver enhancement on hepatobiliary phase MRI normalised to the spleen (liver-to-spleen ratio (LSR)) and the muscle (liver-to-muscle ratio (LMR)) with mebrofenin uptake on HBS for the total liver (TL) and separately for the right (RLL) and left liver lobe (LLL).

RESULTS

Mebrofenin uptake at baseline and follow-up each correlated significantly with LSR and LMR on MRI for TL (≤ 0.013) and RLL (≤ 0.049). Regarding the LLL, mebrofenin uptake correlated significantly with LMR (baseline, p = 0.013; follow-up, p = 0.004), whereas with LSR, a borderline significant correlation was only seen at follow-up (p = 0.051; p = 0.046).

CONCLUSION

LSRs and LMR correlate with mebrofenin uptake in HBS. This study indicates that Gd-EOB-DTPA-enhanced MRI and 99mTc-labelled mebrofenin HBS may equally be used to assess an increase in contralateral liver lobe function after right-sided RE.

RELEVANCE STATEMENT

MRI may be a convenient and reliable method for assessing the future liver remnant facilitating treatment planning and monitoring of patients after RE-induced hypertrophy induction.

KEY POINTS

• Both MRI and HBS can assess liver function after RE. • Liver enhancement on MRI correlates with mebrofenin uptake on HBS. • MRI might be a convenient alternative for estimating future liver remnants after hypertrophy induction.

Management of Intermediate-Stage Hepatocellular Carcinoma: Systemic Versus Locoregional Therapy

Intermediate-stage hepatocellular carcinoma (HCC) comprises a heterogeneous group of patients with varying levels of tumor burden. Transarterial chemoembolization was traditionally the mainstay of treatment for intermediate-stage HCC for almost 2 decades. New and emerging treatment options have revolutionized HCC therapy, allowing for broader application to patients with intermediate- and advanced-stage disease. Accordingly, new guidelines acknowledge these options, and intermediate stage HCC can now be treated with surgical, locoregional or systemic therapies, or a combination thereof. Patients will continue to benefit from the development of complex treatment strategies in a multidisciplinary setting to optimize individual outcomes.

Portal hypertension increases the risk of hepatic decompensation after 90Yttrium radioembolization in patients with hepatocellular carcinoma: a cohort study

Background

Transarterial radioembolization (TARE) is increasingly used in patients with hepatocellular carcinoma (HCC). This treatment can induce or impair portal hypertension, leading to hepatic decompensation. TARE also promotes changes in liver and spleen volumes that may modify therapeutic decisions and outcomes after therapy.

Objectives

We aimed to investigate the impact of TARE on the incidence of decompensation events and its predictive factors.

Design

In all, 63 consecutive patients treated with TARE between February 2012 and December 2018 were retrospectively included.

Methods

We assessed clinical (including Barcelona Clinic Liver Cancer stage, portal hypertension assessment, and liver decompensation), laboratory parameters, and liver and spleen volumes before and 6 and 12 weeks after treatment. A multivariate analysis was performed.

Results

In total, 18 out of 63 (28.6%) patients had liver decompensation (ascites, variceal bleeding, jaundice, or encephalopathy) within the first 3 months after therapy, not associated with tumor progression. Clinically significant portal hypertension (CSPH) and bilobar treatment independently predicted the development of liver decompensation after TARE. A significant volume increase in the non-treated hemi-liver was observed only in patients with unilobar treatment (median volume increase of 20.2% in patients with right lobe TARE; p = 0.007), especially in those without CSPH. Spleen volume also increased after TARE (median volume increase of 16.1%; p = 0.0001) and was associated with worsening liver function scores and decreased platelet count.

Conclusion

Bilobar TARE and CSPH may be associated with an increased risk of liver decompensation in patients with intermediate or advanced HCC. A careful assessment considering these variables before therapy may optimize candidate selection and improve treatment planning.

Contemporary applications of Y90 for the treatment of hepatocellular carcinoma

Transarterial radioembolization (TARE) with yttrium-90 (90Y) microspheres has been widely adopted for the treatment of HCC. Recent advances in yttrium-90 (90Y) dosimetry have led to durable local responses. Radiation segmentectomy has become a viable alternative to thermal ablation for early-stage HCC (Barcelona Clinic Liver Cancer 0 and A) and has been commonly used as a bridge to transplant. TARE is also commonly used for downstaging to transplant using traditional lobar dosimetry and radiation segmentectomy techniques. Radiation lobectomy has a dual role in local tumor control and induction of contralateral liver lobe hypertrophy as a bridge to resection for patients with an inadequate future liver remnant. TARE continues to provide disease control for patients with limited vascular invasion and may be an alternative to systemic therapy for patients with localized advanced disease. The potential synergy between TARE and immunotherapy has been recognized, and prospective studies evaluating this combination are needed for patients with Barcelona Clinic Liver Cancer B and C HCC.

Sequential Y90 liver radioembolization and portal vein embolization: an additional strategy to downstage liver tumors and to enhance liver hypertrophy before major hepatectomies

BACKGROUND

Yttrium (Y)90 liver radioembolization (TARE) induces both tumor downsizing and contralateral liver hypertrophy. In this study, we report the preliminary results of a sequential strategy combining Y90 radioembolization and portal vein embolization (PVE) before major right liver resections.

METHODS

We retrospectively reviewed clinical, radiological, and biological data of 5 consecutive patients undergoing Y90 TARE-PVE before major right liver resections. Comparison was made with patients undergoing PVE alone or liver venous deprivation (LVD) during the same period.

RESULTS

Between January 2019 and September 2022, five patients underwent sequential TARE-PVE. Type of resection included the following: right hepatectomy (n = 1), right hepatectomy + 1 (n = 2), and right hepatectomy + 1 + 4 (n = 2) with no postoperative mortality. Volumetric data showed a mean hypertrophy ratio of 30.4% after TARE and an additional 37.4% after sequential PVE. Patients undergoing sequential TARE-PVE had higher hypertrophy ratio (p = 0.02; p = 0.004), hypertrophy degree (p = 0.02; p < 0.0001), shorter time to normalize bilirubin (p = 0.04), and prothrombin time (p = 0.003; p < 0.0001) compared with patients receiving LVD or PVE. Time from diagnosis to surgery was statistically significant longer in patients undergoing sequential TARE-PVE compared with LVD or PVE (293.4 ± 169.1 vs 54.18 ±18.26 vs 58.62±13.15; p = 0.0008; p = <0.0001).

CONCLUSIONS

This preliminary report suggests that sequential PVE and TARE can represent a safe and an alternative strategy to downstage liver tumors and to enhance liver hypertrophy before major hepatectomies. When compared with PVE and LVD, sequential TARE/PVE takes longer times but achieves some advantages which warrant further evaluation in a larger setting.

Interventional radiological therapies in colorectal hepatic metastases

Colorectal malignancy is the third most common cancer and one of the prevalent causes of death globally. Around 20-25% of patients present with metastases at the time of diagnosis, and 50-60% of patients develop metastases in due course of the disease. Liver, followed by lung and lymph nodes, are the most common sites of colorectal cancer metastases. In such patients, the 5-year survival rate is approximately 19.2%. Although surgical resection is the primary mode of managing colorectal cancer metastases, only 10-25% of patients are competent for curative therapy. Hepatic insufficiency may be the aftermath of extensive surgical hepatectomy. Hence formal assessment of future liver remnant volume (FLR) is imperative prior to surgery to prevent hepatic failure. The evolution of minimally invasive interventional radiological techniques has enhanced the treatment algorithm of patients with colorectal cancer metastases. Studies have demonstrated that these techniques may address the limitations of curative resection, such as insufficient FLR, bi-lobar disease, and patients at higher risk for surgery. This review focuses on curative and palliative role through procedures including portal vein embolization, radioembolization, and ablation. Alongside, we deliberate various studies on conventional chemoembolization and chemoembolization with irinotecan-loaded drug-eluting beads. The radioembolization with Yttrium-90 microspheres has evolved as salvage therapy in surgically unresectable and chemo-resistant metastases.

Influence of cholestasis on portal vein embolization-induced hypertrophy of the future liver remnant

PURPOSE

In the pre-clinical setting, hepatocellular bile salt accumulation impairs liver regeneration following partial hepatectomy. Here, we study the impact of cholestasis on portal vein embolization (PVE)-induced hypertrophy of the future liver remnant (FLR).

METHODS

Patients were enrolled with perihilar cholangiocarcinoma (pCCA) or colorectal liver metastases (CRLM) undergoing PVE before a (extended) right hemihepatectomy. Volume of segments II/III was considered FLR and assessed on pre-embolization and post-embolization CT scans. The degree of hypertrophy (DH, percentual increase) and kinetic growth rate (KGR, percentage/week) were used to assess PVE-induced hypertrophy.

RESULTS

A total of 50 patients (31 CRLM, 19 pCCA) were included. After PVE, the DH and KGR were similar in patients with CRLM and pCCA (5.2 [3.3-6.9] versus 5.7 [3.2-7.4] %, respectively, p = 0.960 for DH; 1.4 [0.9-2.5] versus 1.9 [1.0-2.4] %/week, respectively, p = 0.742 for KGR). Moreover, pCCA patients with or without hyperbilirubinemia had comparable DH (5.6 [3.0-7.5] versus 5.7 [2.4-7.0] %, respectively, p = 0.806) and KGR (1.7 [1.0-2.4] versus 1.9 [0.8-2.4] %/week, respectively, p = 1.000). For patients with pCCA, unilateral drainage in FLR induced a higher DH than bilateral drainage (6.7 [4.9-7.9] versus 2.7 [1.5-4.2] %, p = 0.012). C-reactive protein before PVE was negatively correlated with DH (ρ = - 0.539, p = 0.038) and KGR (ρ = - 0.532, p = 0.041) in patients with pCCA.

CONCLUSIONS

There was no influence of cholestasis on FLR hypertrophy in patients undergoing PVE. Bilateral drainage and inflammation appeared to be negatively associated with FLR hypertrophy. Further prospective studies with larger and more homogenous patient cohorts are desirable.

Prediction of left lobe hypertrophy after right lobe radioembolization of the liver using a clinical data model with external validation

In cirrhotic patients with hepatocellular carcinoma (HCC), right-sided radioembolization (RE) with Yttrium-90-loaded microspheres is an established palliative therapy and can be considered a "curative intention" treatment when aiming for sequential tumor resection. To become surgical candidate, hypertrophy of the left liver lobe to > 40% (future liver remnant, FLR) is mandatory, which can develop after RE. The amount of radiation-induced shrinkage of the right lobe and compensatory hypertrophy of the left lobe is difficult for clinicians to predict. This study aimed to utilize machine learning to predict left lobe liver hypertrophy in patients with HCC and cirrhosis scheduled for right lobe RE, with external validation. The results revealed that machine learning can accurately predict relative and absolute volume changes of the left liver lobe after right lobe RE. This prediction algorithm could help to estimate the chances of conversion from palliative RE to curative major hepatectomy following significant FLR hypertrophy.

Radiological and pathological assessment with EOB-MRI after Y90 radiation lobectomy prior to liver resection for hepatocellular carcinoma

BACKGROUND

Radiation lobectomy (RL) utilizes Yttrium-90 (Y90) radioembolization for achieving tumor control and inducing contralateral lobe hypertrophy. Our objective was to evaluate the chronological changes occurring radiologically and histopathologically after Y90 RL.

METHODS

We retrospectively reviewed 22 patients with chronic liver disease who underwent Y90 RL prior to planned liver resection for hepatocellular carcinoma. Gadolinium ethoxybenzyl diethylenetriamine penta-acetic acid (Gd-EOB-DTPA) enhanced magnetic resonance imaging (EOB-MRI) was performed every 3 months.

RESULTS

Future liver remnant volume (FLRV) significantly increased up to 9 months after Y90 RL. Gd-EOB-DTPA uptake in the treated lobe experienced a 40% reduction in enhancement ratio (ER) during ensuing first 3 months, and never recovered. The reduced ER in the non-tumoral parenchyma was significantly correlated with increased FLRV and FLR (r = 0.41 and r = 0.35, respectively; both p < 0.01). Histopathological evaluation of non-tumor liver tissue found features of sinusoidal obstruction syndrome as an early change after Y90 RL (median 5.7 months) and parenchymal collapse as a late change (mean 11 months).

DISCUSSION

The reduced uptake of Gd-EOB-DTPA at 3 months post Y90 RL correlates with a significant increase in FLRV prior to liver resection. EOB-MRI evaluation at 3 months can guide future plan of action after Y90 RL.

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.

Transarterial Radioembolization to Impact Liver Volumetry: When and How

Inadequate volume of the future liver remnant (FLR) renders many patients with liver malignancies not amenable to surgical resection. Depending on the health of the liver and the patient in general, an FLR of 25-40% is required to avoid acute post-hepatectomy liver failure. Transarterial radioembolization (TARE) of a diseased liver lobe leads to atrophy of the embolized lobe and compensatory hypertrophy of the contralateral lobe. Although the absolute degree of FLR hypertrophy seems to be comparable to portal vein embolization, the kinetic of hypertrophy is much slower after radioembolization. However, TARE has the unique advantages of simultaneously offering local tumor control, possibly downstaging disease, and providing biological test of time. Progressions in technique and personalized dosimetry allow for more predictable ablative treatment of liver malignancies and preparation for major liver surgery. This article provides an overview of the existing literature, discusses the evidence, and considers possible criteria for patient selection.

Economic evaluations of radioembolization with Itrium-90 microspheres in hepatocellular carcinoma: a systematic review

Background

Transarterial radioembolization (TARE) with yttrium-90 microspheres is a clinically effective therapy for hepatocellular carcinoma (HCC) treatment. This study aimed to perform a systematic review of the available economic evaluations of TARE for the treatment of HCC.

Methods

The Preferred Reported Items for Systematic reviews and Meta-Analyses guidelines was followed by applying a search strategy across six databases. All studies identified as economic evaluations with TARE for HCC treatment in English or Spanish language were considered. Costs were adjusted using the 2020 US dollars based on purchasing-power-parity ($US PPP).

Results

Among 423 records screened, 20 studies (6 cost-analyses, 3 budget-impact-analyses, 2 cost-effectiveness-analyses, 8 cost-utility-analyses, and 1 cost-minimization analysis) met the pre-defined criteria for inclusion. Thirteen studies were published from the European perspective, six from the United States, and one from the Canadian perspectives. The assessed populations included early- (n = 4), and intermediate-advanced-stages patients (n = 15). Included studies were evaluated from a payer perspective (n = 20) and included both payer and social perspective (n = 2). TARE was compared with transarterial chemoembolization (TACE) in nine studies or sorafenib (n = 11). The life-years gained (LYG) differed by comparator: TARE versus TACE (range: 1.3 to 3.1), and TARE versus sorafenib (range: 1.1 to 2.53). Of the 20 studies, TARE was associated with lower treatment costs in ten studies. The cost of TARE treatment varied widely according to Barcelona Clinic Liver Cancer (BCLC) staging system and ranged from 1311 $US PPP/month (BCLC-A) to 71,890 $US PPP/5-years time horizon (BCLC-C). The incremental cost-utility ratio for TARE versus TACE resulted in a 17,397 $US PPP/Quality-adjusted-Life-Years (QALY), and for TARE versus sorafenib ranged from dominant (more effectiveness and lower cost) to 3363 $US PPP/QALY.

Conclusions

Economic evaluations of TARE for HCC treatment are heterogeneous. Overall, TARE is a cost-effective short- and long-term therapy for the treatment of intermediate-advanced HCC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02396-6.

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.

Combining Laparoscopic Liver Partitioning and Simultaneous Portohepatic Venous Deprivation for Rapid Liver Hypertrophy

Future liver remnant (FLR) volume is an important indicator of the risk of posthepatectomy liver failure (PHLF) and limits the feasibility of major hepatectomies. A case series of 5 patients treated with a novel approach is presented. Laparoscopic liver partitioning was combined with subsequent liver venous deprivation (embolization of both the portal and the hepatic veins). Baseline average FLR was 28.8%. All procedures were successfully performed without major complications. Mean 1-, 2- and 4-week hypertrophy of the FLR were 35%, 40.3%, and 46.4%, respectively. Four patients underwent planned surgery after a mean interval of 28 days. Of these, 2 patients achieved sufficient FLR volume and function after 2 weeks and underwent surgery before the 4-week volumetric analysis. One patient did not undergo surgery because of intraoperative diagnosis of peritoneal metastases. No cases of PHLF were observed at 5-day follow-up.

Imaging-guided interventions modulating portal venous flow: evidence and controversies

Portal hypertension is defined by an increase in the portosystemic venous gradient. In most cases, increased resistance to portal blood flow is the initial cause of elevated portal pressure. More than 90% of cases of portal hypertension are estimated to be due to advanced chronic liver disease or cirrhosis. Transjugular intrahepatic portosystemic shunts, a non-pharmacological treatment for portal hypertension, involve the placement of a stent between the portal vein and the hepatic vein or inferior vena cava which helps bypass hepatic resistance. Portal hypertension may also be a result of extrahepatic portal vein thrombosis or compression. In these cases, percutaneous portal vein recanalisation restores portal trunk patency, thus preventing portal hypertension-related complications. Any portal blood flow impairment leads to progressive parenchymal atrophy and triggers hepatic regeneration in preserved areas. This provides the rationale for using portal vein embolisation to modulate hepatic volume in preparation for extended hepatic resection. The aim of this paper is to provide a comprehensive evidence-based review of the rationale for, and outcomes associated with, the main imaging-guided interventions targeting the portal vein, as well as to discuss the main controversies around such approaches.

A prospective, multicenter, open-label, single-arm clinical trial design to evaluate the safety and efficacy of 90Y resin microspheres for the treatment of unresectable HCC: the DOORwaY90 (Duration Of Objective Response with arterial Ytrrium-90) study

Background

Selective internal radiation therapy (SIRT) with yttrium-90 (⁹⁰Y) resin microspheres is an established locoregional treatment option for unresectable hepatocellular carcinoma (HCC), which delivers a lethal dose of radiation to hepatic tumors, while sparing surrounding healthy tissue. DOORwaY90 is a prospective, multicenter, open-label, single arm study, designed to evaluate the safety and effectiveness of ⁹⁰Y resin microspheres as first-line treatment in patients with unresectable/unablatable HCC. It is unique in that it is the first study with resin microspheres to utilize a personalized ⁹⁰Y dosimetry approach, and independent review for treatment planning and response assessment.

Methods

Eligibility criteria include unresectable/unablatable HCC, Barcelona Clinic Liver Cancer stage A, B1, B2, or C with a maximal single tumor diameter of ≤ 8 cm, and a sum of maximal tumor diameters of ≤ 12 cm, and at least one tumor ≥ 2 cm (long axis) per localized, modified Response Evaluation Criteria in Solid Tumors. Partition model dosimetry is used to determine the optimal dose; the target mean dose to tumor is ≥ 150 Gy. Patients are assessed at baseline and at regular intervals up until 12 months of treatment for response rates, safety, and quality of life (QoL). Post-treatment dosimetry is used to assess dose delivered to tumor and consider if retreatment is necessary. The co-primary endpoints are best objective response rate and duration of response. Secondary endpoints include grade ≥ 3 toxicity, QoL, and incidence of liver resection and transplantation post SIRT. Target recruitment is 100 patients.

Discussion

The results of this trial should provide further information on the potential use of SIRT with ⁹⁰Y resin microspheres as first-line therapy for unresectable HCC.

Trial registration

Clinicaltrials.gov; NCT04736121; date of 1st registration, January 27, 2021, https://clinicaltrials.gov/ct2/show/NCT04736121.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12876-022-02204-1.

Radioembolization for Hepatocellular Carcinoma: The Effects of Arterioportal Shunts on Nontargeted Liver Hypertrophy

PURPOSE

To determine whether arterioportal shunting to the contralateral lobe attenuates the liver function and the hypertrophy of the nontargeted liver after radioembolization in patients with hepatocellular carcinoma (HCC) MATERIALS AND METHODS: This retrospective study included 46 patients who received radioembolization for HCC contained within the right lobe between 2012 and 2020. The patients were divided into the following groups based on the presence and extent of arterioportal shunt : patients with retrograde arterioportal shunting to the left lobe (contralateral group) and patients with arterioportal shunt limited to the right lobe or no arterioportal shunt (control group). Safety profiles including adverse events, tumor response and overall survival were compared. With the volume of left lateral segment used as a surrogate marker for nontarget liver, degree of hypertrophy was compared between two groups at 3 and 6 months.

RESULTS

Liver function significantly deteriorated in contralateral group in a month (p=<0.05). Tumor response and overall survival did not significantly differ between two groups. Degree of hypertrophy was significantly higher in the control group compared with the contralateral group at 3 months [10.6% vs 3.5% (p = 0.008)] and at 6 months [20.7% vs 2.4% (p < 0.001)].

CONCLUSION

In patients with arterioportal shunting to the contralateral lobe, hypertrophy of the nontarget liver may not occur and the liver function may be worsened.

Long-Term Outcomes of Transarterial Radioembolization for Large Single Hepatocellular Carcinoma: A Comparison to Resection

The surgical treatment for large hepatocellular carcinoma (HCC) remains controversial due to a high risk of recurrence after resection. This study aimed to compare long-term outcomes of transarterial radioembolization (TARE) with resection for patients with large HCC. Methods: This retrospective cohort study included a total of 557 patients who were initially treated with either resection (the resection group, n = 500) or TARE (the TARE group, n = 57) for large (≥5 cm) single nodular HCC at two tertiary centers in Korea. Patients with major portal vein tumor thrombosis or extrahepatic metastasis were excluded. The primary endpoint was overall survival (OS), and secondary endpoints were time to progression (TTP), time to intrahepatic progression (TTIP), and safety. Results: The resection group were younger (median, 60 years vs. 69 years) with smaller tumor size (median, 7.0 cm vs. 10.0 cm) (all P<0.05). After baseline characteristics were balanced using inverse probability of treatment weighting (IPTW), the TARE group showed comparable OS (hazard ratio [HR], 0.98; 95% confidence interval [CI], 0.40-2.43; P = 0.97), TTP (HR, 1.10; 95% CI, 0.55-2.20; P = 0.80), and TTIP (HR, 1.45; 95% CI, 0.72-2.93; P = 0.30) to the resection group. TARE was not an independent risk for OS (adjusted-HR, 1.04; 95% CI, 0.42-2.59; P = 0.93), TTP (adjusted-HR, 0.98; 95% CI, 0.50-1.95; P = 0.96), or TTIP (adjusted-HR, 1.30; 95% CI, 0.65-2.58; P = 0.46). The TARE group showed shorter hospital stay and fewer adverse events than the resection group. Conclusion: TARE showed comparable OS, TTP, and TTIP with better safety profile compared to surgical resection for large single nodular HCC.

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.

Vascular surgery in liver resection

Vascular surgery in liver resection is a standard part of liver transplantation, but is also used in oncological liver surgery. Malignant liver tumors with vascular involvement have a poor prognosis without resection. Surgery is currently the only treatment to provide long-term survival in advanced hepatic malignancy. Even though extended liver resections are increasingly performed, vascular involvement with need of vascular reconstruction is still considered a contraindication for surgery in many institutions. However, vascular resection and reconstruction in liver surgery-despite being complex procedures-are safely performed in specialized centers. The improvements of the postoperative results with reduced postoperative morbidity and mortality are a result of rising surgical and anesthesiological experience and advancements in multimodal treatment concepts with preconditioning measures regarding liver function and systemic treatment options. This review focuses on vascular surgery in oncological liver resections. Even though many surgical techniques were developed and are also used during liver transplantation, this special procedure is not particularly covered within this review article. We provide a summary of vascular reconstruction techniques in oncological liver surgery according to the literature and present also our own experience. We aim to outline the current advances and standards in extended surgical procedures for liver tumors with vascular involvement established in specialized centers, since curative resection improves long-term survival and shifts palliative concepts to curative therapy.

Current State of Multidisciplinary Treatment in Cholangiocarcinoma

BACKGROUND

Cholangiocarcinoma (CCA) is a highly aggressive malignancy, and its incidence seems to be increasing over the last years. Given the high rate of irresectability at the time of initial diagnosis, new treatment approaches are important to achieve better patient outcomes. Our review provides an overview of current multimodal therapy options across different specialties of gastroenterology/oncology, surgery, and interventional radiology.

SUMMARY

CCA is subdivided into clinically and molecularly distinct phenotypes. Surgical treatment currently is the only potentially curative therapy, but unfortunately, the majority of all patients are not eligible for resection at the time of initial diagnosis due to anatomic location, inadequate hepatic reserve, metastatic disease, or limiting comorbidities. However, multimodal treatment options are available to prolong survival, relieve symptoms, and maintain life quality.

KEY MESSAGES

The treatment of CCA is complex and requires close interdisciplinary collaboration and individualized treatment planning to ensure optimal patient care at specialized centers. Molecular profiling of patients and inclusion into clinical trials is highly recommended.

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.

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.

Prognostic factors of unresectable hepatocellular carcinoma treated with yttrium-90 radioembolization: results from a large cohort over 13 years at a single center

Background

A previous study of patients with unresectable hepatocellular carcinoma (HCC) was extended to further examine factors associated with overall survival (OS) after selective internal radiation therapy with yttrium-90 resin microspheres (Y90 SIRT).

Methods

Data from patients of any age diagnosed with unresectable HCC and treated with Y90 SIRT at our institution from 2004 through 2017 were retrospectively analyzed. Among other criteria, patients had to have Eastern Cooperative Oncology Group performance status 0 to 2, not have received Y90 SIRT previously, and not have extrahepatic disease. Primary outcome was OS; secondary outcomes included tumor response and adverse events (AEs). Kaplan-Meier survival analyses and multivariable Cox proportional hazards models were used to evaluate prognostic factors for OS.

Results

Of the 226 patients, 59% were White, 77% were male, and the mean age at first SIRT procedure was 65.1±9.4 years. More than half had received previous treatment for HCC. The most common etiology was hepatitis C (n=138/224 available, 62%), followed by alcohol use (n=45, 20%), and nonalcoholic steatohepatitis (n=27, 12%). The mean model for end-stage liver disease score at baseline was 8.8±2.2. Patients were followed-up for a median of 12.2 months (95% CI, 0.0-62.6). Median OS was 16.6 months (95% CI, 13.1 to not reached). Bilobar disease, higher albumin-bilirubin score at baseline, prior treatment with sorafenib, alcohol use etiology, and higher administered dose were associated with shorter survival, whereas subsequent liver transplant [in 26 patients (11.5%)] was associated with longer survival. Of the 186 patients with AEs data, 75 (40.3%) patients reported an event and, of these, 13 (17.3%) patients had grade 4 bilirubin values.

Conclusions

In a large, diverse population treated at a single center over 13 years, Y90 SIRT produced a median OS of 16.6 months in patients with unresectable HCC and enabled subsequent transplantation in a subset of patients. Factors affecting the length of survival should be considered when making treatment decisions for unresectable HCC.

The Impact of Unilateral 90Y-radioembolization on Functional Changes in the Contralateral Hepatic Lobe: The Prospective, Open-label RadioEmbolization, Volumetry, and Liver FuncTion Measurements (REVoluTion) Study

Objectives

To investigate how metabolic function of the contralateral liver lobe is affected by unilateral radioembolization (RE), and to compare the changes in volume and metabolic function.

Background

Unilateral RE induces contralateral liver hypertrophy, but it is unknown if metabolic liver function improves in line with volume increases.

Methods

This prospective open-label, nonrandomized, therapy-optimizing study included all consecutive patients undergoing right-sided or sequential 90Y-RE for liver malignancies without underlying liver disease or biliary obstruction at a single center in Germany. Magnetic resonance imaging volumetry and hepatobiliary scintigraphy were performed immediately before RE and approximately 6 weeks after RE.

Results

Twenty-three patients were evaluated (11 metastatic colorectal cancer, 4 cholangiocellular carcinoma, 3 metastatic breast cancer, 1 each of metastatic neuroendocrine tumor, hepatocellular carcinoma, renal cell carcinoma, oesophageal cancer, pancreatic ductal adenocarcinoma). In the untreated contralateral left liver lobe, mean (SD) metabolic function significantly increased from 1.34 (0.76) %/min/m2 at baseline to 1.56 (0.75) %/min/m2 6 weeks after RE (P = 0.024). The mean (SD) functional volume (liver volume minus tumor volume) of the left liver lobe significantly increased from baseline (407.3 [170.3] mL) to follow-up (499.1 [209.8] mL; P < 0.01), with an equivalent magnitude to the metabolic function increase. There were no reports of grade ≥3 adverse events.

Conclusion

This study indicates that unilobar RE produces a significant increase in the metabolic function, and equivalent volume increase, of the contralateral lobe. RE may be a useful option to induce hypertrophy of the future liver remnant before surgical resection of primary or secondary liver malignancies.

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 versus portal vein embolization for contralateral liver lobe hypertrophy: effect of cirrhosis

PURPOSE

Preoperative hypertrophy induction of future liver remnant (FLR) reduces the risk of postoperative liver insufficiency after partial hepatectomy. One of the most commonly used methods to induce hypertrophy of FLR is portal vein embolization (PVE). Recent studies have shown that transarterial radioembolization (TARE) also induces hypertrophy of the contralateral liver lobe. The aim of our study was to evaluate contralateral hypertrophy after TARE versus after PVE taking into account the effect of cirrhosis.

METHODS

Forty-nine patients undergoing PVE before hemihepatectomy and 24 patients with TARE as palliative treatment for liver malignancy were retrospectively included. Semi-automated volumetry of the FLR/contralateral liver lobe before and after intervention (20 to 65 days) was performed on CT or MRI, and the relative increase in volume was calculated. Cirrhosis was evaluated independently by two radiologists on CT/MRI, and interrater reliability was calculated.

RESULTS

Hypertrophy after PVE was significantly more pronounced than after TARE (25.3% vs. 7.4%; p < 0.001). In the subgroup of patients without cirrhosis, the difference was also statistically significant (25.9% vs. 8.6%; p = 0.002), whereas in patients with cirrhosis, the difference was not statistically significant (18.2% vs. 7.4%; p = 0.212). After PVE, hypertrophy in patients without cirrhosis was more pronounced than in patients with cirrhosis (25.9% vs. 18.2%; p = 0.203), while after TARE, hypertrophy was comparable in patients with and without cirrhosis (7.4% vs. 8.6%; p = 0.928).

CONCLUSION

TARE induces less pronounced hypertrophy of the FLR compared to PVE. Cirrhosis seems to be less of a limiting factor for hypertrophy after TARE, compared to PVE.

Evaluation of Hepatocellular Carcinoma Treatment Response After Locoregional Therapy

Locoregional therapy (LRT) for hepatocellular carcinoma can be used alone or with other treatment modalities to reduce rates of progression, improve survival, or act as a bridge to cure. As the use of LRT expands, so too has the need for systems to evaluate treatment response, such as the World Health Organization and modified Response Evaluation Criteria In Solid Tumors systems and more recently, the Liver Imaging Reporting and Data System (LI-RADS) treatment response algorithm (TRA). Early validation results for LI-RADS TRA have been promising, and as research accrues, the TRA is expected to evolve in the near future.

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.

Diagnosis and treatment of hepatocellular carcinoma. Update of the consensus document of the AEEH, AEC, SEOM, SERAM, SERVEI, and SETH

Hepatocellular carcinoma (HCC) is the most common primary liver neoplasm and one of the most common causes of death in patients with cirrhosis of the liver. In parallel, with recognition of the clinical relevance of this cancer, major new developments have recently appeared in its diagnosis, prognostic assessment and in particular, in its treatment. Therefore, the Spanish Association for the Study of the Liver (AEEH) has driven the need to update the clinical practice guidelines, once again inviting all the societies involved in the diagnosis and treatment of this disease to participate in the drafting and approval of the document: Spanish Society for Liver Transplantation (SETH), Spanish Society of Diagnostic Radiology (SERAM), Spanish Society of Vascular and Interventional Radiology (SERVEI), Spanish Association of Surgeons (AEC) and Spanish Society of Medical Oncology (SEOM). The clinical practice guidelines published in 2016 and accepted as National Health System Clinical Practice Guidelines were taken as the reference documents, incorporating the most important recent advances. The scientific evidence and the strength of the recommendation is based on the GRADE system.

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.

A comparative study of portal vein embolization versus radiation lobectomy with Yttrium-90 micropheres in preparation for liver resection for initially unresectable hepatocellular carcinoma

BACKGROUND

Portal vein embolization before liver resection is considered the therapy of choice for patients with inadequate future liver remnants. The concept of radioembolization with Yttrium-90 to achieve the same goal has limited data.

METHODS

We retrospectively compared patients who underwent portal vein embolization and Yttrium-90 lobectomy before resection of hepatocellular carcinoma in patients with chronic liver disease.

RESULTS

Seventy-three patients underwent portal vein embolization and 22 patients underwent Yttrium-90. Forty-seven percent of patients before portal vein embolization required additional procedures for tumor control, and 27% of patients after Yttrium-90 required additional procedure to mainly induce further hypertrophy. Both therapies achieved the goal of future liver remnants >40%, but the degree of hypertrophy was significantly higher in Yttrium-90 patients (63% for Yttrium-90, 36% for portal vein embolization, P < .01). Tumor response was significantly better with Yttrium-90, achieving complete response in 50% of patients. Resectability rate was higher after portal vein embolization (85% for portal vein embolization, 64% for Yttrium-90, P = .03). Tumor progression was the most common reason precluding surgery. Complete tumor control was the reason not to pursue surgery in 18% of patients after Yttrium-90.

CONCLUSION

Both preoperative portal vein embolization and Yttrium-90, increases liver resectability rates by inducing hypertrophy of future liver remnants in patients with hepatocellular carcinoma and chronic liver disease. Yttrium-90 lobectomy achieved better tumor control and provided more time to assess therapy response, optimizing the indication for surgery.

Treatment Options for Early-Stage Hepatocellular Carcinoma

Patients with early stage hepatocellular carcinoma have good prognosis and are treated with curative intent. Although this cohort of patients is generally defined by limited tumor burden, good liver function, and preserved functional status, there remains utility in further stratification to optimize overall survival and limit post-operative morbidity and mortality. Transplant, resection, ablation, transarterial radioembolization, and transarterial chemoembolization, either as monotherapy or in combination, may play a crucial role in treating this cohort of patients depending on a multitude of factors. In this section, we review each treatment modality and provide general guidelines for patient selection.

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.

Intrahepatic Cholangiocarcinoma

Cholangiocarcinoma is the second most common primary malignancy of the liver. This review will focus on the mass-forming intrahepatic type of this disease and discuss the role of medical, surgical, and radiation oncology in managing this difficult disease. A global understanding to the management of intrahepatic cholangiocarcinoma (ICC) can help the interventional radiologist understand the role of locoregional therapies such as ablation, transarterial chemoembolization, and radioembolization in the management of ICC.

Efficacy and safety of Yttrium-90 radioembolization in the treatment of neuroendocrine liver metastases. Long-term monitoring and impact on survival

INTRODUCTION AND OBJECTIVE

Neuroendocrine tumors (NETs) debut in 75% of cases with liver metastases (LMNETs), whose therapeutic approach includes surgical resection and liver transplantation, while liver radioembolization with 90 Y-microspheres (TARE) is reserved for non-operable patients usually due to high tumor burden. We present the accumulated experience of 10 years in TARE treatment of LMNETs in order to describe the safety and the effectiveness of the oncological response in terms of survival, as well as to detect the prognostic factors involved.

MATERIAL AND METHODS

Of 136 TARE procedures, performed between January 2006 and December 2016, 30 LMNETs (11.1%) were retrospectively analyzed. The study variables were: Tumor response, time to liver progression, survival at 3 and 5 years, overall mortality and mortality associated with TARE. The radiological response assessment was assessed using RECIST 1.1 and mRECIST criteria.

RESULTS

An average activity of 2.4 ± 1.3 GBq of 90 Y was administered. No patient presented postembolization syndrome or carcinoid syndrome. There were also no vascular complications associated with the procedure. According to RECIST 1.1 criteria at 6 months, 78.6% presented partial response and 21.4% stable disease, there was no progression or complete response (1 by mRECIST). Survival at 3 and 5 years was 73% in both cases.

CONCLUSION

TARE treatment with 90 Y-microspheres in LMNETs, applied within a multidisciplinary approach, is a safe procedure, with low morbidity, capable of achieving a high rate of radiological response and achieving lasting tumor responses.

Management of patients with intermediate stage hepatocellular carcinoma

Hepatocellular carcinoma (HCC) causes a significant health burden globally and its impact is expected to increase in the coming years. Intermediate stage HCC, as defined by the Barcelona Clinic Liver Cancer (BCLC) system stage B, represents up to 30% of patients at diagnosis and encompasses a broad spectrum of tumor burden. Several attempts have been made to further subclassify this heterogenous group. The current standard of care recommended by BCLC for intermediate stage HCC patients is transarterial chemoembolization (TACE), with modest outcomes reported. While refinements have been made to TACE technique and patient selection, it remains non-curative. In the real-world setting, only 60% of patients with intermediate stage HCC receive TACE, with the remainder deviating to a range of other therapies that have shown promise in select patient subgroups. These include curative treatments (resection, ablation, and liver transplantation), radiotherapy (stereotactic and radioembolization), systemic therapies, and their combination. In this review, we summarize the classifications and current management for patients with intermediate stage HCC as well as highlight recent key developments in this space.

Liver Resection After Selective Internal Radiation Therapy with Yttrium-90: Safety and Outcomes

Introduction

Selective internal radiotherapy (SIRT) with yttrium-90 (Y-90) is an intra-arterial therapy for hepatic malignancy in patients who are unsuitable for surgical resection. This treatment is considered palliative, although some patients can demonstrate a response that is adequate to facilitate surgical resection with curative intent.

Methods

All patients who underwent liver resection post SIRT were reviewed. Data gathered included patient demographics, tumor type, surgical details, and post-operative outcomes.

Results

Twelve patients underwent SIRT followed by liver resection (7 males and 5 females). Pathologies were hepatocellular carcinoma (n = 5), metastatic colorectal cancer (n = 5), and neuroendocrine tumor (n = 2). Lesional response (size, volume, and RECIST (response evaluation criteria in solid tumors)) was calculated and where appropriate functional liver remnant (FLR) is presented. Mean FLR increase was 264cm³ (range − 123 to 909), and all cases demonstrated a partial response according to RECIST with a mean largest lesion volume reduction of 475cm³ (range 14–1632). No post-SIRT complications were noted. Hepatectomy occurred at a mean of 322 days from SIRT treatment. Ninety-day morbidity was 67% (n = 6), complications post-surgery were analyzed according to the Clavien-Dindo classification scale; a total of 15 events occurred in 6 patients. Ninety-day mortality of 11% (n = 1).

Conclusion

In selected cases, liver resection is possible post SIRT. As this can represent a potentially curative option, it is important to reconsider resection in the follow-up of patients undergoing SIRT. Post-operative complications are noted following major and extended liver resection. Therefore, further studies are needed to improve patient selection.

Locoregional Therapies for Hepatocellular Carcinoma: What Has Changed in the Past Ten Years?

The evolution of locoregional therapies in the last decade has been refined with improved patient selection and a development of a more personalized approach. In doing so, there has been associated improved outcomes and less toxicity. With the rapidly changing landscape of systemic therapy, the role of locoregional therapies alone or in combination for downstaging and curative intent will continue to evolve.

Yttrium-90 Portal Vein Radioembolization in Sprague-Dawley Rats: Dose-Dependent Imaging and Pathological Changes in Normal Liver

PURPOSE

Portal vein embolization (PVE) is an established neoadjuvant method to induce future liver remnant hypertrophy prior to surgical resection of hepatic tumors. The purpose of our study was to examine the feasibility of PVE with glass ⁹⁰Y microspheres (Y90 PVE) in Sprague-Dawley rats. We tested the hypothesis that increased doses of Y90 PVE would increase target lobe fibrosis and atrophy.

METHODS

Twenty-two rats were assigned to four groups for Y90 PVE to the right median lobe: very high- (273.8 MBq; n = 2), high- (99.9 MBq; n = 10), medium- (48.1 MBq; n = 5), and low-dose (14.8 MBq; n = 5). An untreated control group included seven rats. ⁹⁰Y PET/CT of ⁹⁰Y distributions confirmed lobar targeting. MRI volumes were measured at baseline, 2-, 4-, 8- and 12-weeks. Explanted hepatic lobes were weighed, sectioned, and stained for H&E and immunohistochemistry. Digitized slides allowed quantitative measurements of fibrosis (20 foci/slide).

RESULTS

Ex vivo measurements confirmed 91-97% activity was localized to the target lobe (n = 4). The percent growth of the target lobe relative to baseline was - 5.0% (95% CI - 17.0-6.9%) for high-, medium dose rats compared to + 18.6% (95% CI + 7.6-29.7%) in the low-dose group at 12-weeks (p = 0.0043). Radiation fibrosis increased in a dose-dependent fashion. Fibrotic area/microsphere was 22,893.5, 14,946.2 ± 2253.3, 15,304.5 ± 4716.6, and 5268.8 ± 2297.2 μm² for very high- (n = 1), high- (n = 4), medium- (n = 3), and low-dose groups (n = 5), respectively.

CONCLUSION

Y90 PVE was feasible in the rat model, resulted in target lobe atrophy, and dose-dependent increases in hepatic fibrosis at 12 weeks. The onset of imaging-based volumetric changes was 8-12 weeks.