History and Evolution of Yttrium-90 Radioembolization for Hepatocellular Carcinoma

Safety and efficacy of repeat Y90 radioembolization to the same hepatic arterial territory

OBJECTIVE

To study the efficacy and safety of repeat transarterial radioembolization (TARE) to similar hepatic arterial territories.

METHODS

Between 3/2011 and 4/2019, 26 patients (25 males and 1 Female, Mean Age: 65 yo, SD: 11.7 yo, Range: 18-83.0 yo) received TARE with Y90 glass microspheres to treat recurrent or residual primary disease in similar hepatic arterial lobe or segments. Tumor response was evaluated by imaging using the modified-RECIST criteria. Incidence of RILD and adverse events were categorized by a standardized scale using the Common Terminology Criteria for Adverse Events (CTCAE) v.4.0.

RESULTS

Mean cumulative activity after the first treatment was 2.50 GBq (SD:1.04 GBq, Range:0.61-4.93 GBq) and second treatment was 2.27 GBq (SD:1.01 GBq, Range:0.92-5.46 GBq). Mean interval time between initial and repeat treatments was 9.6 months (Range: 1-53 months). Tumor responses were complete, partial, or progression in 73% (n = 19/26), 23% (n = 6/26), and 4% (n = 1/26) in repeat treatment patients, respectively. The incidence of RILD was 0%. Toxicity after first and second treatment was seen in 19% (n = 5/26) & 23% (n = 6/26) patients, respectively, and were all of CTCAE Grade 2. No significant predictors of treatment toxicity for repeat treatment were identified except increased MELD score (p = 0.04). Kaplan-Meier survival analysis in patients with repeat treatment showed a median survival of 15.0 months (95% CI 8.8-21.1 months) and 19.0 months (95% CI 8.1-29.9 months) in patients who only received one treatment with a p value of 0.485.

CONCLUSION

Repeat TARE with glass microspheres was an effective and safe treatment strategy for disease management in patients with residual or recurrent disease to the similar hepatic arterial territories without any major treatment related toxicity.

ADVANCES IN KNOWLEDGE

Although safety and efficacy of repeat radioembolism has been studied, no study has focused on repeat treatment to similar hepatic arterial territories. The current study shows that repeat treatment to the same hepatic arterial territory is as safe as single treatment to the same territory.

Highly Tumor-Specific and Long-Acting Iodine-131 Microbeads for Enhanced Treatment of Hepatocellular Carcinoma with Low-Dose Radio-Chemoembolization

Transarterial radioembolization (TARE) is considered the standard treatment for intermediate-stage hepatocellular carcinoma (HCC). Iodine-131 (¹³¹I)-labeled lipiodol TARE is an effective treatment for HCC but has been withdrawn due to its poor retention in tumor lesions and significant distribution in normal tissues with severe side effects. In this work, a highly tumor-specific ¹³¹I-TARE agent with long-time retention is developed by simply introducing tyrosine to poly(vinyl alcohol) (PVA) drug-eluting microbeads (Tyr-PVA-DEBs). The labeling efficiency of ¹³¹I-labeled microbeads remains above 85% in 50% serum for 31 days. Micro-single-photon emission computed tomography/computed tomography (μSPECT/CT) evidences that the ¹³¹I-labeled microbeads accumulate in the orthotopic N1S1 hepatoma of rats for 31 days following intra-arterial injection. The cumulative radiation dose per cubic centimeter of the tumor is at least 13 678-fold higher than that of normal tissues. The highly tumor-selective radiation of the ¹³¹I-labeled microbeads allows localized delivery of 345.04 ± 139.16 Gy to the tumor following a single injection dose as low as 0.2 mCi of ¹³¹I. Moreover, the ¹³¹I-labeled microbeads are loaded with doxorubicin hydrochloride (DOX) through the carboxy groups on tyrosine of the polymer. The ¹³¹I-DOX-loaded microbeads present a synergetic antitumor effect without recurrence in comparison with the microbeads labeled with ¹³¹I or loading DOX alone, attributed to the sensitization of DOX to ¹³¹I-induced ionizing radiation damage to DNA under the embolization-induced hypoxia. Our results demonstrate a high tumor retention of ¹³¹I-labeled embolic agent for low-dose transarterial radio-chemoembolization (TARCE) with a synergetic therapeutic effect on treating HCC, showing potential for clinical application.

Changing trends in hepatocellular carcinoma management: Results from a nationwide database in the last decade

OBJECTIVE

The therapeutic strategies for hepatocellular carcinoma (HCC) have greatly expanded in recent years. However, the actual usage of each of these treatments in clinical routine remains unknown. Here, we analysed the distribution and changes of the main surgical and radiological therapeutic procedures nationwide during the last decade.

METHODS

Retrospectively, analysis of the data on all >18-year-old patients with a diagnosis of HCC identified in the French Program for the Medicalization of Information Systems database that contains all discharge summaries from all French hospitals. The number and percentage of the therapeutic procedures performed from January 2010 to December 2019 were extracted.

RESULTS

A total of 68,416 therapeutic procedures were performed in 34,000 HCC patients. Whereas HCC incidence remained stable, the annual number of procedures frankly increased over the decade (from 4267 to 8042). Trans-arterial chemoembolization was the most frequently performed technical procedure, with a double-digit annual growth from 2010 (n = 1932) to 2015 (n = 4085), before stabilization from 2016. Selective internal radiation therapy displayed the highest increase in the decade (+475%). Among curative treatments, the annual number of percutaneous tumour ablations more than doubled in 10 years, till representing 64% of curative treatments in cirrhotic patients in 2019. Surgical tumour resections showed a 1.5-fold increase in 10 years, due to the great increase in minimally invasive approaches, whereas the proportion of open resection progressively decreased.

CONCLUSION

Minimally invasive procedures have gained major importance in HCC management during the last decade. Percutaneous thermal ablation has emerged as the first curative treatment performed for patients with HCC.

Diagnostic Performance of Theranostic Radionuclides Used in Transarterial Radioembolization for Liver Cancer

Primary liver tumor with hepatocellular carcinoma accounting for 75–80% of all such tumors, is one of the global leading causes of cancer-related death, especially in cirrhotic patients. Liver tumors are highly hypervascularized via the hepatic artery, while normal liver tissues are mainly supplied by the portal vein; consequently, intra-arterially delivered treatment, which includes transarterial chemoembolization (TACE) and transarterial radioembolization (TARE), is deemed as a palliative treatment. With the development of nuclear technology and radiochemistry, TARE has become an alternative for patients with hepatic cancer, especially for patients who failed other therapies, or for patients who need tumor downstaging treatment. In practice, some radionuclides have suitable physicochemical characteristics to act as radioactive embolism agents. Among them, ⁹⁰Y emits β rays only and is suitable for bremsstrahlung single photon emission computed tomography (BS SPECT) and positron emission tomography (PET); meanwhile, some others, such as ¹³¹I, ¹⁵³Sm, ¹⁶⁶Ho, ¹⁷⁷Lu, ¹⁸⁶Re, and ¹⁸⁸Re, emit both β and γ rays, enabling embolism beads to play a role in both therapy and single photon emission computed tomography (SPECT) imaging. During TARE, concomitant imaging provide additive diagnostic information and help to guide the course of liver cancer treatment. Therefore, we review the theranostic radionuclides that have been used or could potentially be used in TARE for liver cancer and focus on the clinical benefits of diagnostic applications, including real-time monitoring of embolism beads, evaluating irradiation dose, predicting therapy effects, and corresponding adjustments to TARE.

MiRNA Polymorphisms and Hepatocellular Carcinoma Susceptibility: A Systematic Review and Network Meta-Analysis

Background

Hepatocellular carcinoma (HCC) is an intractable public health threat worldwide, representing the second leading cause of cancer-related mortality, with limited early detection and therapeutic options. Recent findings have revealed that the susceptibility of HCC is closely related to microRNA (miRNA). We performed this systematic review with a network meta-analysis to investigated four single nucleotide polymorphisms (SNPs) that most regularly reported in miRNAs, exploring their involvement in HCC susceptibility and interaction with hepatitis B virus (HBV).

Methods

Databases were reviewed for related studies published up to May 2019 to identify all studies that compared genotypes of miR-146a rs2910164, miR-149 rs2292832, miR-196a2 rs11614913, and miR-499 rs3746444 with no language and date restrictions. A pairwise meta-analysis was performed to estimate pooled odds ratios and 95% confidence intervals incorporating heterogeneity to assess the relationship between four miRNA polymorphisms and HCC. To further clarify the effect of polymorphisms on HCC, a Bayesian network meta-analysis was conducted to combine the effective sizes of direct and indirect comparisons. Calculations were performed by R version 3.6.1 and STATA 14.0. All steps were performed according to PRISMA guidelines.

Results

A total of 20 studies were enrolled in this network meta-analysis, providing 5,337 hepatocellular carcinoma cases and 6,585 controls. All included studies had an acceptable quality. Pairwise meta-analysis demonstrated that miR-196a2 rs11614913 was significantly associated with the susceptibility of HCC, while the other three SNPs were not found to have a significant association. In the analysis of HCC patients under different HBV infection status, only miR-196a2 revealed correlation of threefold risk. The network results showed no significant difference in the distribution of genotype frequencies except for miR-196a2, which appeared to have the highest superiority index when comparing and ranking four SNPs.

Conclusion

MiR-196a2 rs11614913 was significantly associated with the susceptibility of HCC, especially for HBV- related HCC, and that individuals with TC/CC were more susceptible. No significant association was found in the other three miRNA genes. MiR-196a2 could serve as the best predictor of susceptibility in HCC.

Planning dosimetry for 90 Y radioembolization with glass microspheres: Evaluating the fidelity of 99m Tc-MAA and partition model predictions

PURPOSE

^99m Tc-MAA-SPECT/CT may be used in ⁹⁰ Y-glass microsphere radioembolization treatment planning to assess perfused liver volumes and absorbed dose distributions. The partition model (PM) offers a more detailed planning dosimetry option beyond the single-compartment model more traditionally used in ⁹⁰ Y radioembolization. As ⁹⁰ Y radioembolization treatments shift toward activities and doses that aim to achieve tumor control, accurate and reliable treatment planning dosimetry for both tumors and normal liver (NL) becomes more critical. In this work, we explore the accuracy and precision of ⁹⁰ Y dosimetry predictions from pretherapy ^99m Tc-MAA and PM.

METHODS

Both PM and voxel dosimetry models were used to calculate tumor and NL mean doses using both planning ^99m Tc-MAA and verification ⁹⁰ Y-SPECT/CT in this retrospective analysis of hepatocellular carcinoma cases treated with glass microspheres (NCT01900002, n = 32). Linear regression models were developed at first access, and then later correct, the estimates by (a) ^99m Tc-MAA for ⁹⁰ Y voxel dosimetry and (b) ^99m Tc-MAA PM for voxel dosimetry, separately for both tumors and NL. Bland-Altman analysis was then used to evaluate the accuracy and precision of the regression model predictions with the mean bias and 95% prediction intervals (PI, ±1.96σ). Two categories of cases were stratified (catheter matched vs catheter unmatched) by establishing the level of ^99m Tc-MAA and ⁹⁰ Y catheter position alignment. Only catheter-matched cases were included in the ^99m Tc-MAA vs ⁹⁰ Y voxel dosimetry comparison, while all cases were used to compare dosimetry models (PM vs voxel).

RESULTS

Half (16/32) of cases were deemed catheter matched. ^99m Tc-MAA could reliably predict NL doses in catheter-matched cases after application of the linear model, with mean bias (PI) of -1% (±31%). PM was equivalent to voxel dosimetry for NL doses with mean bias (PI) of 0% (±1%). Even among catheter-matched cases, ^99m Tc-MAA planning for ⁹⁰ Y tumor voxel doses was poor, overestimating dose by an average of nearly 40%. Upon application of the linear model, ^99m Tc-MAA predictions for ⁹⁰ Y tumor voxel dose were only minimally biased (-4%) but possessed very large PI (±104%). PM predictions for tumor voxel dose using the linear model also showed small bias (-6%) but maintained similarly high PI of ±90%. Cases with tumors representing a large majority (>80%) of the total tumor volume demonstrated the best scenarios for ^99m Tc-MAA and PM tumor dose predictions, with mean biases (PI) of -3% (±53%) and -4% (±21%), respectively.

CONCLUSION

The unconditional use of ^99m Tc-MAA to predict ⁹⁰ Y dosimetry across all cases is not recommended due to: (a) demonstrated the risk of unmatched catheter positions between procedures, and (b) large bias and uncertainty in ^99m Tc-MAA predictions in cases with matched catheter locations. However, NL voxel dose predictions with ^99m Tc-MAA are clinically viable and either PM or voxel dosimetry can be used to produce equivalent predictions. Both ^99m Tc-MAA and PM can provide tumor dose predictions with potential clinical utility, but only in catheter-matched cases and with tumors comprising a clear majority (>80%) of the total tumor volume. These findings stratify the predictive fidelity of ^99m Tc-MAA- and PM-based treatment planning for ⁹⁰ Y dosimetry in improving treatment outcomes.

The evolution of interventional oncology in the 21st century

Interventional oncology (IO) has proven to be highly efficient in the local therapy of numerous malignant tumors in addition to surgery, chemotherapy, and radiotherapy. Due to the advent of immune-oncology with the possibility of tumor control at the molecular and cellular levels, a system change is currently emerging. This will significantly rule oncology in the coming decades. Therefore, one cannot think about IO in the 21st century without considering immunology. For IO, this means paying much more attention to the immunomodulatory effects of the interventional techniques, which have so far been neglected, and to explore the synergistic possibilities with immuno-oncology. It can be expected that the combined use of IO and immuno-oncology will help to overcome the limitations of the latter, such as limited local effects and a high rate of side-effects. To do this, however, sectoral boundaries must be removed and interdisciplinary research efforts must be strengthened. In case of success, IO will face an exciting future.

Radiotheranostics: a roadmap for future development

Radiotheranostics, injectable radiopharmaceuticals with antitumour effects, have seen rapid development over the past decade. Although some formulations are already approved for human use, more radiopharmaceuticals will enter clinical practice in the next 5 years, potentially introducing new therapeutic choices for patients. Despite these advances, several challenges remain, including logistics, supply chain, regulatory issues, and education and training. By highlighting active developments in the field, this Review aims to alert practitioners to the value of radiotheranostics and to outline a roadmap for future development. Multidisciplinary approaches in clinical trial design and therapeutic administration will become essential to the continued progress of this evolving therapeutic approach.

Highlighting Survival with Yttrium-90 Radioembolization Therapy in Unresectable Hepatocellular Carcinoma

Unresectable hepatocellular carcinoma has several different therapeutic options, including targeted agents as well as locoregional therapy. Yttrium-90 (Y90) radioembolization therapy is an established treatment for unresectable disease and has been compared to other locoregional options as well as different targeted therapies. Newer case series are also reporting a potential benefit to the addition of immunotherapy to Y90 radioembolization. Here we report a case of prolonged survival in a patient whose treatment course included Y90 radioembolization along with sorafenib and nivolumab.

Yttrium-90 Radioembolization of Metastatic Adrenocortical Carcinoma to the Liver following Systemic Chemotherapy and Surgical Resection of the Primary Lesion

Use of yttrium-90 (Y-90) is used for primary liver tumors and a handful of liver metastatic lesions. Y-90 treatment for metastatic adrenocortical carcinoma (ACC) to the liver is currently off-label, with one previously documented case report. In this case report, we present a 52-year-old woman with ACC and extensive liver metastatic disease. After failed chemotherapy, multidisciplinary discussion suggested potential Y-90 treatment for palliative purposes. After undergoing Y-90 treatment separately to the right and then the left hepatic lobes, subsequent patient visits demonstrated significantly improved clinical function as well as complete radiographic resolution of liver metastatic disease mainly from ACC. This case report demonstrates the potential efficacy of Y-90 for off-label uses in liver metastatic disease. This case and similar cases may open the door to a wide variety of potential indications for Y-90 treatment.

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

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

Yttrium-90 microsphere radioembolisation for unresectable hepatocellular carcinoma

BACKGROUND

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

OBJECTIVES

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

SEARCH METHODS

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

SELECTION CRITERIA

We searched for randomised clinical trials.

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

AUTHORS' CONCLUSIONS

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

[Locoregional and local ablative treatment options for liver tumors]

Interventional radiology offers a large variety of locoregional and local ablative treatment options for liver tumors. These can be applied as stand-alone minimally invasive procedures or in combination with other treatment options and with curative as well as palliative intent depending on the respective tumor stage. This review article presents the various locoregional and local ablative treatment techniques and describes the clinical value in the treatment of hepatocellular carcinoma and intrahepatic cholangiocarcinoma.

Hepatic Flow Redistribution is Feasible in Patients with Hepatic Malignancies Undergoing Same-Day Work-Up Angiography and Yttrium-90 Microsphere Radioembolization

PURPOSE

To assess the feasibility of performing same-day vascular flow redistribution and Yttrium-90 radioembolization (90Y-RE) for hepatic malignancies.

MATERIALS AND METHODS

From November 2015 to February 2019, patients undergoing same-day hepatic flow redistribution during work-up angiography, ^99mTechnetium-labeled macroaggregated albumin (^99mTc-MAA) SPECT/CT and 90Y microsphere-RE, were recruited. Within 18 h following the delivery of 90Y resin microspheres, an 90Y-PET/CT study was performed. According to patients' vascular anatomy, flow redistribution was performed by microcoil embolization of extrahepatic branches (group A), intrahepatic non-tumoral vessels (group B) and intrahepatic tumoral arteries (group C). The accumulation of ^99mTc-MAA particles and microspheres in the redistributed areas was qualitatively evaluated using a 5-point visual scale (grade 1 = < 25% accumulation; grade 5 = 100% accumulation). Differences in the distribution of microspheres among groups were assessed with Mann-Whitney U test.

RESULTS

Twenty-two patients were treated for primary (n = 17) and secondary (n = 5) hepatic malignancies. The MAA-SPECT/CT showed uptake in all the redistributed areas. Regarding the accumulation of microspheres within the redistributed segments in all the groups, perfusion patterns were classified as 2 in 1 case, 4 in 6 cases and 5 in 15 cases. No statistically significant differences were observed between groups A and B-C (U value = 34, p = 0.32) and between groups B and C (U value = 26, p = 0.7). Mean predicted absorbed doses by the tumoral and normal hepatic tissues were 163.5 ± 131.2 Gy and 60.4 ± 69.3 Gy, respectively. Mean total procedure time (from work-up angiography to 90Y delivery) was 401 ± 0.055 min.

CONCLUSION

Performing same-day redistribution of the arterial hepatic flow to the target and 90Y-microsphere delivery is feasible in the treatment of liver tumors. Clinical Trials Registry NCT03380130.

Radioembolization for the Treatment of Primary and Metastatic Liver Cancers

Radioembolization using ⁹⁰Y microspheres (glass or resin) has been introduced as an effective intraarterial therapy for unresectable primary and metastatic liver cancers. Although the basic therapeutic effect of chemoembolization results from ischemia, the therapeutic efficacy of radioembolization comes from radiation. Furthermore, compared with surgical resection and local ablation therapy, radioembolization is available with less limitation on the sites or number of liver cancers. The radioisotope ⁹⁰Y is a β-radiation emitter without γ-radiation, with the emission of secondary bremsstrahlung photons and small numbers of positrons. Administration of ⁹⁰Y microspheres into the hepatic artery can deliver a high dose of radiation selectively to the target tumor with limited radiation exposure to the surrounding normal parenchyma, and has low systemic toxicity. In general, radioembolization has been considered for patients with unresectable primary or metastatic liver-only or liver-dominant cancers with no ascites or other clinical signs of liver failure, life expectancy of > 12 weeks, and good performance status. Here, we review the current radioactive compounds, pretreatment assessment, and indications for radioembolization in patients with hepatocellular carcinoma, intrahepatic cholangiocarcinoma, and liver metastases from colorectal cancer.

Yttrium-90-Labeled Anti-Glypican 3 Radioimmunotherapy Halts Tumor Growth in an Orthotopic Xenograft Model of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the second most lethal malignancy globally and is increasing in incidence in the United States. Unfortunately, there are few effective systemic treatment options, particularly for disseminated disease. Glypican-3 (GPC3) is a proteoglycan cell surface receptor overexpressed in most HCCs and provides a unique target for molecular therapies. We have previously demonstrated that PET imaging using a 89Zr-conjugated monoclonal anti-GPC3 antibody (αGPC3) can bind to minute tumors and allow imaging with high sensitivity and specificity in an orthotopic xenograft mouse model of HCC and that serum alpha-fetoprotein (AFP) levels are highly correlated with tumor size in this model. In the present study, we conjugated 90Y, a high-energy beta-particle-emitting radionuclide, to our αGPC3 antibody to develop a novel antibody-directed radiotherapeutic approach for HCC. Luciferase-expressing HepG2 human hepatoblastoma cells were orthotopically implanted in the livers of athymic nude mice, and tumor establishment was verified at 6 weeks after implantation by bioluminescent imaging and serum AFP concentration. Tumor burden by bioluminescence and serum AFP concentration was highly correlated in our model. Yttrium-90 was conjugated to αGPC3 using the chelating agent 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) and injected via the tail vein into the experimental mice at a dose of 200 μCi/mouse or 300 μCi/mouse. Control mice received DOTA-αGPC3 without radionuclide. At 30 days after a single dose of the radioimmunotherapy agent, mean serum AFP levels in control animals increased dramatically, while animals treated with 200 μCi only experienced a minor increase, indicating cessation of tumor growth, and animals treated with 300 μCi experienced a reduction in serum AFP concentration, indicating tumor shrinkage. Mean tumor-bearing liver weight in control animals was also significantly greater than that in animals that received either dose of 90Y-αGPC3. These results were achieved without significant toxicity as measured by body condition scoring and body weight. The results of this preclinical pilot demonstrate that GPC3 can be used as a target for radioimmunotherapy in an orthotopic mouse model of HCC and may be a target of clinical significance, particularly for disseminated HCC.

Current status of the combination therapy of transarterial chemoembolization and local ablation for hepatocellular carcinoma

PURPOSE OF REVIEW

To review the current status and ideal time interval of the combination therapy of transarterial chemoembolization (TACE) and local ablation for patients with HCCs.

RECENT FINDINGS

In recent years, local ablation has been proposed as an alternative curative treatment in the management of HCC. Additionally, many treatment options are available including TACE molecular targeted agents and immune checkpoint inhibitors. Similar overall survival rates and prognoses have been obtained with radiofrequency ablation (RFA) microwave ablation (MWA) and cryoablation for patients with HCCs up to 3 cm in diameter. Yet, MWA has shown superiority in treating large HCCs while cryoablation has several advantages compared with RFA or MWA. Furthermore, the treatment strategy of TACE combined with local ablation is widely accepted by many physicians in order to further increase the survival rate and improve the prognosis of patients with HCCs. However, the time interval between the two sessions of combination therapy remains uncertain in the current guidelines. Combination therapy of TACE and local ablation has advantages on survival and prognosis in patients with HCC compared with monotherapy. Good patient selection for the right modality needs to be carried out to guarantee the most efficacious treatment for HCC patients. Further studies are needed to find the ideal time interval between TACE and local ablation for HCC patients.