Transarterial Radioembolization with Yttrium-90 for the Treatment of Hepatocellular Carcinoma

Hepatocellular Carcinoma: An Overview of the Changing Landscape of Treatment Options

The last three years have seen remarkable progress in comprehending predisposing factors and upgrading our treatment arsenal concerning hepatocellular carcinoma (HCC). Until recently, there were no means to withstand the progression of viral hepatitis-associated liver cirrhosis to HCC. A deeper understanding of the molecular mechanism of the disease, the use of biomarkers, and the follow-up, allowed us to realize that conventional chemotherapy failing to increase survival in patients with advanced HCC tends to be exiled from clinical practice. Multi-kinase inhibitors (TKIs) such as sorafenib, lenvatinib targeting mainly the vascular endothelial growth factor receptors 1–3 VEGFRs 1–3 provided until recently the standard of care for these patients, as first- or second-line treatment. Since May 2020, the atezolizumab plus bevacizumab combination (immunotherapy plus anti-VEGF) has become the new reference standard in first-line HCC treatment. Additionally, anti-programmed cell death protein 1 (anti-PD-1) immunotherapy can be used as a second-line treatment following first-line treatment’s failure. Phase III clinical trials have recently suggested the efficacy of novel anti-angiogenic factors such as cabozantinib and ramucirumab as a second-line treatment option. With considerations about toxicity arising, clinical trials are investigating combinations of the aforementioned targeted therapies with immunotherapy as first-line treatment. This paper aims to perform a systematic review describing the evolving treatment options for HCC over the last decades, ranging from neoadjuvant treatment to systemic therapy of advanced-stage HCC. With the landscape of HCC treatment shifting towards novel agents the forming of a new therapeutic algorithm for HCC seems to be imperative.

Oligometastatic Disease and Interventional Oncology: Rationale and Research Directions

Oligometastatic disease (OMD) is generally defined as a stage of clinically or radiographically demonstrated metastatic disease limited in total disease burden and without rapid spread. Interventional oncology performs local therapies for primary and metastatic cancers, including OMD. Interventional oncology treatments can be pursued both as definitive therapy and for palliative purposes. Applied to OMD, these interventions can offer patients a decreasing overall tumor burden, minimizing cancer morbidity, and early evidence suggests a survival benefit. Here, we discuss the range of interventional oncology treatments, including ablation, chemoembolization, radioembolization, and irreversible electroporation. We describe the rationale for their application to OMD and discuss future directions for research.

Initial Transarterial Chemoembolization (TACE) Using HepaSpheres 20-40 µm and Subsequent Lipiodol TACE in Patients with Hepatocellular Carcinoma > 5 cm

Purpose: To investigate clinical outcomes of drug-eluting bead transarterial chemoembolization (DEB-TACE) using HepaSpheres 20–40 µm in diameter and subsequent cisplatin-based lipiodol TACE (Cis-TACE) in patients with hepatocellular carcinoma (HCC) > 5 cm. Materials and Methods: This study included 39 consecutive patients (34 men, 5 women; mean age, 63.5 years; range, 39–80 years) who underwent DEB-TACE using HepaSpheres 20–40 µm as first-line treatment for HCC > 5 cm (mean diameter, 8.2 cm; range, 5.1–13 cm) between September 2018 and August 2019. Patients with new tumors, residual tumors, or tumor growth after initial DEB-TACE underwent subsequent Cis-TACE. Results: All 39 patients underwent initial DEB-TACE successfully, with 35 (89.7%) and three (7.7%) patients experiencing minor and major complications, respectively. After initial DEB-TACE, one patient (2.6%) achieved complete response (CR), 35 (89.7%) achieved partial response (PR), and three (7.7%) experienced progressive disease (PD). During a median follow-up period of 14.4 months (range, 0.6–23 months), 23 patients underwent Cis-TACE, with 11, three, and nine achieving CR, PR, and PD, respectively. The median overall survival time was 20.9 months (95% confidence interval (CI), 18.6–23.2 months), the median time to progression was 8.8 months (95% CI, 6.5–11.1 months), and the median time to local tumor recurrence was 16 months (95% CI, 7.4–24.6 months). Conclusions: DEB-TACE using HepaSpheres 20–40 µm in diameter can be a safe and effective initial treatment method in patients with HCC > 5 cm. Subsequent Cis-TACE constitutes a good adjuvant method to enhance tumor response after initial DEB-TACE.

Prediction of tumor response and patient outcome after radioembolization of hepatocellular carcinoma using 90Y-PET-computed tomography dosimetry

AIM

90Y-radioembolization using glass or resin microspheres is increasingly used for the treatment of hepatocellular carcinoma (HCC). The aim of this retrospective study is to determine the prognostic relevance of dosimetric parameters defined with 90Y-PET-CT obtained immediately after radioembolization.

METHODS

Forty-five HCC patients, mostly with multiple lesions, were treated by radioembolization between 2011 and 2017. After treatment, all underwent a 90Y PET-CT with time of flight reconstruction (90Y-TOF-PET-CT). Tumor absorbed dose and cumulative tumor dose-volume histogram were calculated using a dose point Kernel convolution algorithm. The radiological tumor response was assessed using modified (m)-RECIST criteria. Progression-free-survival (PFS) and overall survival (OS) were analyzed using the Kaplan-Meier method and Cox regression analysis.

RESULTS

Twenty-six patients were treated with glass microspheres (73 lesions) and nineteen with resin microspheres (60 lesions). Thresholds of 118 and 61 Gy for glass and resin microspheres respectively correlate well with radiological response with a positive predictive value (PPV) of 98 and 80% and discriminate patient outcome with regard to PFS (P = 0.03 and 0.005) and OS (P = 0.003 and 0.007). Using dose volume histogram, a minimal absorbed dose of 40 Gy in 66% of the tumor volume (defined as D66) was highly predictive of radiological response (PPV = 94%), PFS (P < 0.001) and OS (P = 0. 008), for either device.

CONCLUSION

Dosimetric parameters obtained using 90Y-PET-CT are predictive of tumor response, PFS and OS. In clinical practice, a systematic dosimetric evaluation using 90Y PET should be implemented to help predicting patient outcomes.

Medicinal inorganic chemistry: an updated review on the status of metallodrugs and prominent metallodrug candidates

Metallodrugs correspond to a small portion of all available drugs in the market and, yet, some of them are among the most used and important drugs in modern medicine. However, medicinal inorganic chemistry remains an underestimated area within medicinal chemistry and the main reason is the mislead association of metals to toxic agents. Thus, in this review, the potential of medicinal inorganic chemistry in drug designing is highlighted through a description of the current status of metallodrugs and metallodrug candidates in advanced clinical trials. The broad spectrum of application of metal-based drugs in medicine for both therapy and diagnosis is addressed by the extensive list of examples presented herein.

Downstaging treatment for patients with hepatocelluar carcinoma before transplantation

Liver transplantation (LT), one of the radical methods of treating liver cancer, has brought new hope for the treatment of unresectable liver cancer. Currently, patients who meet transplant criteria can achieve a favorable prognosis, but those who exceed transplant criteria tend not to have very satisfactory outcomes. For patients whose tumor burden exceeds the transplant criteria, downstaging treatment is a promising method to reduce tumor burden to within the transplant criteria that may lead to good posttransplant survival. Multiple treatments, such as transcatheter arterial chemoembolization (TACE), transarterial radioembolization (TARE), percutaneous ethanol injection (PEI), and radiofrequency ablation (RFA), have been used as downstaging treatments. However, there are still some issues that limit the effectiveness of downstaging treatments, such as the inclusion criteria for downstaging, which the choice of downstaging treatment method, and the endpoint of downstaging, all of which are worthy of further discussion. Based on the published literature, this review discusses these issues.

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.

A New Option for the Treatment of Intrahepatic Cholangiocarcinoma: Percutaneous Hepatic Perfusion with CHEMOSAT Delivery System

Liver metastases are a major management problem; since they occur in tumors of different origin, they are often multiple, difficult to visualize and can lie dormant for many years. Patients with liver metastases usually die of their disease, mostly due to liver failure, since systemic treatments are unable to eradicate micro-metastasis, and interventional loco-regional procedures cannot treat all existing ones. Cholangiocarcinoma (CCA) is the second most common primary liver tumor, showing a poor overall prognosis. When resection is not possible, treatment options include tumor-focused or local ablative therapy, organ-focused or regional therapy and systemic therapy. We reviewed available loco-regional therapeutic options, with particular focus on the CHEMOSAT® Melphalan/Hepatic Delivery System (CS-HDS), which is uniquely positioned to perform a percutaneous hepatic perfusion (PHP), in order to treat the entire liver as a standalone or as complementary therapy. This system isolates the liver circulation, delivers a high concentration of chemotherapy (melphalan), filters most chemotherapy out of the blood and is a repeatable procedure. Most CS-HDS benefits are demonstrated in liver-predominant diseases, like liver metastasis from uveal melanoma (UM), hepatocarcinoma (HCC) and CCA. More than 650 procedures have been performed in Europe to date, mostly to treat liver metastases from UM. In CCA, experience is still limited, but retrospective analyses have been reported, while phase II and III studies are closed, waiting for results or ongoing.

Monte Carlo 90Y PET/CT dosimetry of unexpected focal radiation-induced lung damage after hepatic radioembolisation

Transarterial radioembolization (TARE) with ⁹⁰Y-loaded microspheres is an established therapeutic option for inoperable hepatic tumors. Increasing knowledge regarding TARE hepatic dose-response and dose-toxicity correlation is available but few studies have investigated dose-toxicity correlation in extra-hepatic tissues. We investigated absorbed dose levels for the appearance of focal lung damage in a case of off-target deposition of ⁹⁰Y microspheres and compared them with the corresponding thresholds recommended to avoiding radiation induced lung injury following TARE. A 64-year-old male patient received 1.6 GBq of ⁹⁰Y-labelled glass microspheres for an inoperable left lobe hepatocellular carcinoma. A focal off-target accumulation of radiolabeled microspheres was detected in the left lung upper lobe at the post-treatment ⁹⁰Y-PET/CT, corresponding to a radiation-induced inflammatory lung lesion at the 3-months ¹⁸F-FDG PET/CT follow-up. ⁹⁰Y-PET/CT data were used as input for Monte-Carlo based absorbed dose estimations. Dose-volume-histograms were computed to characterize the heterogeneity of absorbed dose distribution. The dose level associated with the appearance of lung tissue damage was estimated as the median absorbed dose measured at the edge of the inflammatory nodule. To account for respiratory movements and possible inaccuracy of image co-registration, three different methods were evaluated to define the irradiated off-target volume. Monte Carlo-derived absorbed dose distribution showed a highly heterogeneous absorbed dose pattern at the site of incidental microsphere deposition (volume = 2.13 ml) with a maximum dose of 630 Gy. Absorbed dose levels ranging from 119 Gy to 133 Gy, were estimated at the edge of the inflammatory nodule, depending on the procedure used to define the target volume. This report describes an original Monte Carlo based patient-specific dosimetry methodology for the study of the radiation-induced damage in a focal lung lesion after TARE. In our patient, radiation-induced focal lung damage occurred at significantly higher absorbed doses than those considered for single administration or cumulative lung dose delivered during TARE.

Yttrium-90 Radioembolization Therapy for Combined Hepatocellular and Cholangiocarcinoma

Purpose

To report outcomes of transarterial radioembolization (TARE) using glass microspheres for the treatment of mixed hepatocellular-cholangiocarcinoma (HCC-CC) in a propensity-matched study.

Material and Methods

Between 2013 and 2019, 10 consecutive patients with histologically confirmed HCC-CC received TARE of a targeted territory using glass microspheres as a primary initial treatment. Baseline demographics in addition to tumor distribution, Child Pugh score, and BCLC were recorded. Tumor response was assessed according to modified RECIST criteria. The HCC-CC cohort was matched to the HCC cohort, and objective response and survival analysis was performed.

Results

In the HCC-CC cohort, patients had a 70% objective response rate (ORR), and in the HCC cohort, patients had a 90% ORR after matching (p = 0.54). The median overall survival (OS) for HCC patients was 12.3 months (95% CI: 6.0-17.4 months) in the matched population, and for HCC-CC patients, the median OS was 15.2 months (95% CI: 2.7-20.2 months) (p = 0.98). The median progression-free survival (PFS) for HCC patients was 11.6 months (95% CI: 2.53-19.3 months) in the matched population, and for HCC-CC patients, the median PFS was 15.2 months (95% CI: 2.7-20.2 months) (p = 0.94). The median transplant-free survival (TFS) for HCC patients was 12.3 months (95% CI: 6.0-17.4 months) in the matched population, and for HCC-CC patients, the median TFS was 15.2 months (95% CI: 2.7-20.2 months) (p = 0.98).

Conclusions

While outcomes of combined HCC-CC are poor and optimal treatment remains undefined, TARE appears to represent an effective locoregional treatment with survival outcomes similar to that of HCC treated by TARE.

Recent progress in treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fourth leading cause of cancer-related death worldwide. In the past decade, there have been improvements in non-drug therapies and drug therapies for HCC treatment. Non-drug therapies include hepatic resection, liver transplantation, transarterial chemoembolization (TACE) and ablation. The former two surgical treatments are beneficial for patients with early and mid-stage HCC. As the first choice for non-surgical treatment, different TACE methods has been developed and widely used in combination therapy. Ablation has become an important alternative therapy for the treatment of small HCC or cases of unresectable surgery. Meanwhile, the drugs including small molecule targeted drugs like sorafenib and lenvatinib, monoclonal antibodies such as nivolumab are mainly used for the systematic treatment of advanced HCC. Besides strategies described above are recommended as first-line therapies due to their significant increase in mean overall survival, there are also potential drugs in clinical trials or under preclinical development. In addition, a number of potential preclinical surgical or adjuvant therapies are being studied, such as oncolytic virus, mesenchymal stem cells, biological clock, gut microbiome composition and peptide vaccine, all of which have shown different degrees of inhibition on HCC. With some potential anti-HCC drugs being reported, many promising therapeutic targets in related taxonomic signaling pathways including cell cycle, epigenetics, tyrosine kinase and so on that affect the progression of HCC have also been found. Together, the rational application of existing therapies and drugs as well as the new strategies will bring a bright future for the global cure of HCC in the coming decades.

Successful use of transarterial radioembolization with yttrium-90 (TARE-Y90) in two children with hepatoblastoma

Primary malignant liver tumors are rare but all require surgical resection as part of therapy with curative intent. A minority of patients have resectable tumors at diagnosis. Chemotherapy has a therapeutic role in hepatoblastoma but only one-third of patients have resectable disease at diagnosis. Two children with hepatoblastoma and suboptimal responses to initial chemotherapy received therapy with transarterial radioembolization utilizing yttrium-90 (TARE-Y90) and had significant response leading to resection and remission. The role of TARE-Y90 needs to be studied further to define its use in primary pediatric liver neoplasms.

Locoregional Therapy Protocols With and Without Radioembolization for Hepatocellular Carcinoma as Bridge to Liver Transplantation

OBJECTIVE

The objective of this study was to compare posttransplant outcomes in patients undergoing bridging locoregional therapy (LRT) with Y-90 transarterial radioembolization (TARE) based protocol compared with transarterial chemoembolization based protocol for hepatocellular carcinoma (HCC) prior liver transplantation (LT).

MATERIALS AND METHODS

Patients listed for LT with HCC within the Milan criteria at our center who had bridging LRT were treated according to transarterial chemoembolization (TACE) based protocol from May 2012 to April 2014 and a TARE based protocol from October 2014 to December 2017. Early posttransplant survival and tumor recurrence were compared between the groups. Tumor response to LRT, microvascular invasion (mVI), and the rate of delisting was also evaluated.

RESULTS

One hundred three patients who were listed for LT with HCC within the Milan criteria received LRT. LT was performed in 65 patients, 28 treated with TARE protocol and 37 on TACE protocol. There were no statistical differences in baseline pretransplant characteristics and tumor recurrence. There was a trend toward improved 3-year survival in the TARE group (92.9% vs. 75.7%; P=0.052). The mVI was seen in 1/28 (3.6%) explants in the TARE group compared with 10/37 (27%) in the TACE group (P=0.013). The TARE group also required fewer LRT treatments (1.46 vs. 2.43; P=0.001) despite no difference in time on the transplant list.

CONCLUSIONS

Despite requiring fewer LRT treatments, there was significantly less mVI in the explants of patients treated with TARE protocol LRT as a bridge to LT as well as a trend toward improved 3-year survival. Therefore, TARE may be associated with improved tumor control and reduced post-LT recurrence.

Biodegradable 131 Iodine-Labeled Microspheres: Potential Transarterial Radioembolization Biomaterial for Primary Hepatocellular Carcinoma Treatment

Transarterial radioembolization with radionuclide-labeled microspheres is successfully used in hepatocellular carcinoma (HCC) treatment, but the non-biodegradability and rapid settlement of the microsphere material are associated with unsatisfied distribution and unable for multiple administrations. In this study, a novel biodegradable chitosan-collagen composite microsphere (CCM) with ideal settlement rate is prepared. The Fourier-transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) results indicate CCMs have desirable shapes with diameters around 10 µm, and considerable biodegradability within 12 weeks. These CCMs are successfully radiolabeled with ¹³¹ I and processed efficiency of 70.4 MBq mg^-1 of microspheres as well as favorable stability in vitro. Then, ¹³¹ I-CCMs are injected into rats with orthotopic HCC via the hepatic artery which effectively improves the median overall survival from 19 to 44 days (p < 0.05). Single photon emission computed tomography (SPECT/CT) imaging and immunohistochemical analysis indicate well-localized biodistribution and consistent stability of ¹³¹ I-CCMs in the liver over 28 days. Magnetic resonance imaging (MRI) and gross specimens monitoring confirm the inhibited tumor growth after ¹³¹ I-CCMs treatment. In conclusion, these biodegradable ¹³¹ I-CCMs exhibit optimal radiolabeling efficiency, stability, and favorably radioembolization effect for orthotopic HCC in a rodent model, suggesting potential for interventional cancer therapy.

Lung Metastasis Postradioembolization of Hepatocellular Carcinoma With Tumor in Vein

Transarterial radioembolization (TARE) is one of the few treatment options available for infiltrative hepatocellular carcinoma with tumor in vein. This is backed by the published data showing marginally favorable toxicity profile compared with other locoregional and systemic therapies. Although lung shunt fraction studies are performed to prevent radiation injury to the lungs, TARE-induced embolization/metastasis to the lungs has not been reported before. We report an intriguing case of new lung metastases within 1 month after TARE for infiltrative hepatocellular carcinoma with a tumor in the vein, with only a slightly elevated but acceptable lung shunt fraction. This report brings to light the possibility of such a complication and argues for improved preprocedural assessment of a tumor in vein burden and embolization potential.

Position 1: Transarterial Chemoembolization Should Be the Primary Locoregional Therapy for Unrespectable Hepatocelluar Carcinoma

http://aasldpubs.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2046-2484/video/15-2-reading-skef a video presentation of this article http://aasldpubs.onlinelibrary.wiley.com/hub/journal/10.1002/(ISSN)2046-2484/video/15-2-interview-mikolajczyk an interview with the author.

MRI Assessment of Hepatocellular Carcinoma after Local-Regional Therapy: A Comprehensive Review

Nearly 80% of cirrhotic patients diagnosed with hepatocellular carcinoma (HCC) are not eligible for surgical resection and instead undergo local-regional treatment. After therapy for HCC, patients undergo imaging surveillance to assess treatment efficacy and identify potential sites of progressive tumor elsewhere within the liver. Accurate interpretation of posttreatment imaging is essential for guiding further management decisions, and radiologists must understand expected treatment-specific imaging findings for each of the local-regional therapies. Of interest, expected imaging findings seen after radiation-based therapies (transarterial radioembolization and stereotactic body radiation therapy) are different than those seen after thermal ablation and transarterial chemoembolization. Given differences in expected posttreatment imaging findings, the current radiologic treatment response assessment algorithms used for HCC (modified Response Evaluation Criteria in Solid Tumors classification, European Association for the Study of Liver Diseases criteria, and Liver Imaging and Reporting Data System Treatment Response Algorithm) must be applied cautiously for radiation-based therapies in which persistent arterial phase hyperenhancement in the early posttreatment period is common and expected. This article will review the concept of tumor response assessment for HCC, the forms of local-regional therapy for HCC, and the expected posttreatment findings for each form of therapy. Keywords: Abdomen/GI, Liver, MR-Imaging, Treatment Effects, Tumor Response © RSNA, 2020.

Ablative Transarterial Radioembolization Improves Survival in Patients with HCC and Portal Vein Tumor Thrombus

PURPOSE

Patients with hepatocellular carcinoma and portal vein tumor thrombus have a poor prognosis and limited therapeutic options. We sought to compare survival, tolerability, and safety in such patients treated with conventional yttrium-90 transarterial radioembolization dosimetric techniques or ablative transarterial radioembolization.

MATERIALS AND METHODS

This retrospective, single-center cohort study included patients with hepatocellular carcinoma and right, left, and/or main portal vein tumor thrombus, preserved liver function (Child-Pugh class ≤ B7), and good performance status (Eastern Cooperative Oncology Group score ≤ 1) treated with yttrium-90 microspheres from 2011 to 2018 with ablative intent transarterial radioembolization (A-TARE), or conventional technique (cTARE). Statistical models were used to compare overall survival, post-treatment survival, toxicities, and prognosticators of response.

RESULTS

Fifty-seven patients were included (21 [36.8%] ablative and 36 [63.2%] conventional intent). Median overall survival was 15.7 months. Compared to conventional treatment, ablative radioembolization was associated with longer median overall survival (45.3 vs 18.2 months; P = 0.003), longer post-treatment survival (19.1 vs 4.9 months; P = 0.005), a 70% lower risk of death (hazard ratio 0.30; 95% confidence interval, 0.13-0.70; P = 0.005), and improved 4-year survival (53.9% vs 11.2%). Overall survival did not differ significantly between treatment with resin and glass microspheres (27.5 vs 22.2 months; P = 0.62). Acceptable hepatic toxicities were observed after yttrium-90 administration, without statistical differences between the groups.

CONCLUSION

In patients with advanced hepatocellular carcinoma and portal vein tumor thrombus, A-TARE is associated with longer survival than cTARE. Neither modality is associated with deleterious effects on liver function.

Preparation and In Vitro Evaluation of Neutron-Activated, Theranostic Samarium-153-Labeled Microspheres for Transarterial Radioembolization of Hepatocellular Carcinoma and Liver Metastasis

Introduction: Transarterial radioembolization (TARE) has been proven as an effective treatment for unresectable liver tumor. In this study, neutron activated, ¹⁵³Sm-labeled microspheres were developed as an alternative to ⁹⁰Y-labeled microspheres for hepatic radioembolization. ¹⁵³Sm has a theranostic advantage as it emits both therapeutic beta and diagnostic gamma radiations simultaneously, in comparison to the pure beta emitter, ⁹⁰Y. Methods: Negatively charged acrylic microspheres were labeled with ¹⁵²Sm ions through electrostatic interactions. In another formulation, the Sm-labeled microsphere was treated with sodium carbonate solution to form the insoluble ¹⁵²Sm carbonate (¹⁵²SmC) salt within the porous structures of the microspheres. Both formulations were neutron-activated in a research reactor. Physicochemical characterization, gamma spectrometry, and radiolabel stability tests were carried out to study the performance and stability of the microspheres. Results: The Sm- and SmC-labeled microspheres remained spherical and smooth, with a mean size of 35 µm before and after neutron activation. Fourier transform infrared (FTIR) spectroscopy indicated that the functional groups of the microspheres remained unaffected after neutron activation. The ¹⁵³Sm- and ¹⁵³SmC-labeled microspheres achieved activity of 2.53 ± 0.08 and 2.40 ± 0.13 GBq·g⁻¹, respectively, immediate after 6 h neutron activation in the neutron flux of 2.0 × 10¹² n·cm⁻²·s⁻¹. Energy-dispersive X-ray (EDX) and gamma spectrometry showed that no elemental and radioactive impurities were present in the microspheres after neutron activation. The retention efficiency of ¹⁵³Sm in the ¹⁵³SmC-labeled microspheres was excellent (~99% in distilled water and saline; ~97% in human blood plasma), which was higher than the ¹⁵³Sm-labeled microspheres (~95% and ~85%, respectively). Conclusion: ¹⁵³SmC-labeled microspheres have demonstrated excellent properties for potential application as theranostic agents for hepatic radioembolization.

Folic acid conjugated polymeric drug delivery vehicle for targeted cancer detection in hepatocellular carcinoma

Targeted therapies provide increased efficiency for the detection and treatment of cancer with reduced side effects. Folate receptor (alpha subunit) is overexpressed in multiple tumors including liver cancer. In this study, we evaluated the specificity and toxicity of a folic acid-containing drug delivery vehicle (DDV) in a hepatocellular carcinoma (HCC) model. The DDV was prepared with two units each of folic acid (FA) and fluorescein isothiocyanate (FITC) molecules and conjugated to a central poly (ethylene glycol) (PEG) core via a modified chemo-enzymatic synthetic process. Rat hepatoma (N1S1) and human monocytic (U937) cell lines were used for cell culture-based assays and tested for DDV uptake and toxicity. Folate receptor expressions in liver tissues and cell lines were verified using standard immunohistochemistry techniques. Rat HCC model was used for in vivo assessment. The DDV was injected via intra-arterial or intravenous methods and imaged with IVIS spectrum in vivo imaging system. Strong signals of FITC in the liver tumor region correlated to targeted DDV uptake. The use of PEG enhanced water-solubility and provided flexibility for the interaction of FA ligands with multiple cell surface folate receptors that resulted in increased specific uptake. Our study suggested that PEG incorporation and folate targeting via intra-arterial approach is an efficient strategy for targeted delivery in HCC therapy.

Current State of Liver-Directed Therapies and Combinatory Approaches with Systemic Therapy in Hepatocellular Carcinoma (HCC)

The increasing set of liver-directed therapies (LDT) have become an integral part of hepatocellular carcinoma (HCC) treatment. These range from percutaneous ablative techniques to arterial embolization, and varied radiotherapy strategies. They are now used for local disease control, symptom palliation, and bold curative strategies. The big challenge in the face of these innovative and sometimes overlapping technologies is to identify the best opportunity of use. In real practice, many patients may take benefit from LDT used as a bridge to curative treatment such as resection and liver transplantation. Varying trans-arterial embolization strategies are used, and comparison between established and developing technologies is scarce. Also, radioembolization utilizing yttrium-90 (Y-90) for locally advanced or intermediate-stage HCC needs further evidence of clinical efficacy. There is increasing interest on LDT-led changes in tumor biology that could have implications in systemic therapy efficacy. Foremost, additional to its apoptotic and necrotic properties, LDT could warrant changes in vascular endothelial growth factor (VEGF) expression and release. However, trans-arterial chemoembolization (TACE) used alongside tyrosine-kinase inhibitor (TKI) sorafenib has had its efficacy contested. Most recently, interest in associating Y-90 and TKI has emerged. Furthermore, LDT-led differences in tumor immune microenvironment and immune cell infiltration could be an opportunity to enhance immunotherapy efficacy for HCC patients. Early attempts to coordinate LDT and immunotherapy are being made. We here review LDT techniques exposing current evidence to understand its extant reach and future applications alongside systemic therapy development for HCC.

Neoadjuvant and adjuvant treatment strategies for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common liver malignancy worldwide and a major cause of cancer-related mortality for which liver resection is an important curative-intent treatment option. However, many patients present with advanced disease and with underlying chronic liver disease and/or cirrhosis, limiting the proportion of patients who are surgical candidates. In addition, the development of recurrent or de novo cancers following surgical resection is common. These issues have led investigators to evaluate the benefit of neoadjuvant and adjuvant treatment strategies aimed at improving resectability rates and decreasing recurrence rates. While high-level evidence to guide treatment decision making is lacking, recent advances in locoregional and systemic therapies, including antiviral treatment and immunotherapy, raise the prospect of novel approaches that may improve the outcomes of patients with HCC. In this review, we evaluate the evidence for various neoadjuvant and adjuvant therapies and discuss opportunities for future clinical and translational research.

Transarterial radioembolization with yttrium-90 of unresectable primary hepatic malignancy in children

BACKGROUND

Primary malignant liver tumors are rare, accounting for 1% to 2% of all childhood cancers. When chemotherapy fails, transarterial radioembolization with yttrium-90 (TARE-Y90) may offer an alternative therapy as a bridge to surgical resection or liver transplant or for palliation.

METHODS

We conducted a retrospective review of 10 pediatric patients with histologically confirmed primary liver malignancy who received treatment with TARE-Y90.

RESULTS

The median age at treatment was 5.5 years (range, 2-18 years). Median patient survival from initial diagnosis was 12.5 months (range, 10-28 months), and median patient survival after TARE-Y90 was 4 months (range, 2-20 months). Retreatment was well tolerated in three of 10 patients, with these patients demonstrating the longest survival times (range, 17-20 months). One patient was transplanted 6 weeks after TARE-Y90. By RECIST 1.1 criteria of all target lesions, eight of nine patients had stable disease, and one of nine had progressive disease. By mRECIST criteria (requiring postcontrast arterial phase imaging), two of seven patients had a partial response, four of seven had stable disease, and one of seven had progressive disease.

CONCLUSION

TARE-Y90 of unresectable primary liver malignancy is both technically feasible and demonstrates an anticancer effect, and retreatment is well tolerated. TARE-Y90 could be considered as adjunctive therapy in pediatric patients with unresectable hepatic malignancies and could be used as a bridge to surgical resection or liver transplant. More research is required to determine the efficacy of this treatment in children and to define the clinical scenarios where benefit is likely to be optimized.

Optimizing radiotherapy with immune checkpoint blockade in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the fifth most common cancer, and its incidence is rapidly increasing in North America and Western Europe as well as South-East Asia. Patients with advanced stage HCC have very poor outcomes; therefore, the discovery of new innovative approaches is urgently needed. Cancer immunotherapy has become a game-changer and revolutionized cancer treatment. A comprehensive understanding of tumor-immune interactions led to the development of immune checkpoint inhibitors (ICIs) as new therapeutic tools, which have been used with great success. Targeting immune checkpoint molecules such as programmed cell death-1 (PD-1) and cytotoxic T lymphocyte-associated protein-4 (CTLA-4) reinvigorates anti-tumor immunity by restoring exhausted T cells. Despite their effectiveness in several types of cancer, of the many immune suppressive mechanisms limit the efficacy of ICI monotherapy. Radiation therapy (RT) is an essential local treatment modality for a broad range of malignancies, and it is currently gaining extensive attention as a promising combination partner with ICIs because of its ability to trigger immunogenic cell death. The efficacy of combination approaches using RT and ICIs has been well documented in numerous preclinical and clinical studies on various types of cancers but not HCC. The application of ICIs has now expanded to HCC, and RT is recognized as a promising modality in HCC. This review will highlight the current roles of PD-1 and CTLA-4 therapies and their combination with RT in the treatment of cancers, including HCC. In addition, this review will discuss the future perspectives of the combination of ICIs and RT in HCC treatment.

Automated CT and MRI Liver Segmentation and Biometry Using a Generalized Convolutional Neural Network

Purpose

To assess feasibility of training a convolutional neural network (CNN) to automate liver segmentation across different imaging modalities and techniques used in clinical practice and apply this to enable automation of liver biometry.

Methods

We trained a 2D U-Net CNN for liver segmentation in two stages using 330 abdominal MRI and CT exams acquired at our institution. First, we trained the neural network with non-contrast multi-echo spoiled-gradient-echo (SGPR)images with 300 MRI exams to provide multiple signal-weightings. Then, we used transfer learning to generalize the CNN with additional images from 30 contrast-enhanced MRI and CT exams.We assessed the performance of the CNN using a distinct multi-institutional data set curated from multiple sources (n = 498 subjects). Segmentation accuracy was evaluated by computing Dice scores. Utilizing these segmentations, we computed liver volume from CT and T1-weighted (T1w) MRI exams, and estimated hepatic proton- density-fat-fraction (PDFF) from multi-echo T2*w MRI exams. We compared quantitative volumetry and PDFF estimates between automated and manual segmentation using Pearson correlation and Bland-Altman statistics.

Results

Dice scores were 0.94 ± 0.06 for CT (n = 230), 0.95 ± 0.03 (n = 100) for T1w MR, and 0.92 ± 0.05 for T2*w MR (n = 169). Liver volume measured by manual and automated segmentation agreed closely for CT (95% limit-of-agreement (LoA) = [-298 mL, 180 mL]) and T1w MR (LoA = [-358 mL, 180 mL]). Hepatic PDFF measured by the two segmentations also agreed closely (LoA = [-0.62%, 0.80%]).

Conclusions

Utilizing a transfer-learning strategy, we have demonstrated the feasibility of a CNN to be generalized to perform liver segmentations across different imaging techniques and modalities. With further refinement and validation, CNNs may have broad applicability for multimodal liver volumetry and hepatic tissue characterization.

Technical Aspects and Practical Approach Toward Same-Day Y90 Radioembolization in the Management of Hepatocellular Carcinoma

Radioembolization with Yttrium-90 (Y90) has been proven safe and effective for the treatment of primary and secondary hepatic malignancies. Standard protocols have necessitated planning angiography with Technetium-99m macroaggregated albumin (Tc99m MAA) administration/scan typically 1-2 weeks prior to the radioembolization therapy. The intent of this practice is to ensure appropriate patient selection and treatment candidacy while also confirming best dosimetry approaches. At our center, we started performing "same-day Y90" in 2008; in a subset of international patients with travel hardship, we performed the planning and treatment procedures consecutively on the same day. In this article, we reveal our practical approach to treating patients on the same day as planning angiography. With more than 160 same-day procedures completed between 2008 and 2017, the safety and efficacy of such a paradigm has been established at our center. This approach is appealing to patients, their families, and referring physicians. Appropriate patient selection and proper preprocedure planning based on baseline imaging are key elements in successful same-day radioembolization treatments.

Immune activation underlies a sustained clinical response to Yttrium-90 radioembolisation in hepatocellular carcinoma

OBJECTIVES

Yttrium-90 (Y90)-radioembolisation (RE) significantly regresses locally advanced hepatocellular carcinoma and delays disease progression. The current study is designed to deeply interrogate the immunological impact of Y90-RE, which elicits a sustained therapeutic response.

DESIGN

Time-of-flight mass cytometry and next-generation sequencing (NGS) were used to analyse the immune landscapes of tumour-infiltrating leucocytes (TILs), tumour tissues and peripheral blood mononuclear cells (PBMCs) at different time points before and after Y90-RE.

RESULTS

TILs isolated after Y90-RE exhibited signs of local immune activation: higher expression of granzyme B (GB) and infiltration of CD8⁺ T cells, CD56⁺ NK cells and CD8⁺ CD56⁺ NKT cells. NGS confirmed the upregulation of genes involved in innate and adaptive immune activation in Y90-RE-treated tumours. Chemotactic pathways involving CCL5 and CXCL16 correlated with the recruitment of activated GB⁺CD8⁺ T cells to the Y90-RE-treated tumours. When comparing PBMCs before and after Y90-RE, we observed an increase in tumour necrosis factor-α on both the CD8⁺ and CD4⁺ T cells as well as an increase in percentage of antigen-presenting cells after Y90-RE, implying a systemic immune activation. Interestingly, a high percentage of PD-1⁺/Tim-3⁺CD8⁺ T cells coexpressing the homing receptors CCR5 and CXCR6 denoted Y90-RE responders. A prediction model was also built to identify sustained responders to Y90-RE based on the immune profiles from pretreatment PBMCs.

CONCLUSION

High-dimensional analysis of tumour and systemic immune landscapes identified local and systemic immune activation that corresponded to the sustained response to Y90-RE. Potential biomarkers associated with a positive clinical response were identified and a prediction model was built to identify sustained responders prior to treatment.

Quantitative Imaging Biomarkers for 90Y Distribution on Bremsstrahlung SPECT After Resin-Based Radioembolization

Our purpose was to identify baseline imaging features in patients with liver cancer that correlate with ⁹⁰Y distribution on postprocedural SPECT and predict tumor response to transarterial radioembolization (TARE). Methods: This retrospective study was approved by the institutional review board and included 38 patients with hepatocellular carcinoma (HCC) (n = 23; 18/23 men; mean age, 62.39 ± 8.62 y; 34 dominant tumors) and non-HCC hepatic malignancies (n = 15; 9/15 men; mean age, 61.13 ± 11.51 y; 24 dominant tumors) who underwent 40 resin-based TARE treatments (August 2012 to January 2018). Multiphasic contrast-enhanced MRI or CT was obtained before and Bremsstrahlung SPECT within 2 h after TARE. Total tumor volume (cm³) and enhancing tumor volume (ETV [cm³] and % of total tumor volume), and total and enhancing tumor burden (%), were volumetrically assessed on baseline imaging. Up to 2 dominant tumors per treated lobe were analyzed. After multimodal image registration of baseline imaging and SPECT/CT, ⁹⁰Y distribution was quantified on SPECT as tumor-to-normal-liver ratio (TNR). Response was assessed according to RECIST1.1 and quantitative European Association for the Study of the Liver criteria. Clinical parameters were also assessed. Statistical tests included Mann-Whitney U, Pearson correlation, and linear regression. Results: In HCC patients, high baseline ETV% significantly correlated with high TNR on SPECT, demonstrating greater ⁹⁰Y uptake in the tumor relative to the liver parenchyma (P < 0.001). In non-HCC patients, a correlation between ETV% and TNR was observed as well (P = 0.039). Follow-up imaging for response assessments within 1-4 mo after TARE was available for 23 patients with 25 treatments. The change of ETV% significantly correlated with TNR in HCC (P = 0.039) but not in non-HCC patients (P = 0.886). Additionally, Child-Pugh class B patients demonstrated significantly more ⁹⁰Y deposition in nontumorous liver than Child-Pugh A patients (P = 0.021). Conclusion: This study identified ETV% as a quantifiable imaging biomarker on preprocedural MRI and CT to predict ⁹⁰Y distribution on postprocedural SPECT in HCC and non-HCC. However, the relationship between the preferential uptake of ⁹⁰Y to the tumor and tumor response after radioembolization could be validated only for HCC.

Sorafenib Reduced Significantly Heptopulmonary Shunt in a Large Hepatocelullar Carcinoma

An 81-year-old man with a large hepatocellular carcinoma was referred in our institution for Y radioembolization (RE). The preliminary arteriography using Tc-macroaggregate albumin demonstrated an important hepatopulmonary shunt. It was an exclusion criterion for RE due to high risks of lung radiations. Then, the patient was treated with sorafenib during 4 months, stopped because of grade 3 toxicity. A second liver arteriography was performed, and Tc-macroaggregate albumin imaging showed an important reduction of the lung shunt. Transient therapy with sorafenib permitted to close the lung shunt and was a bridge for RE.

Impact of Y3+-ions on the structure and phase behavior of phospholipid model membranes

Trivalent yttrium-ions reveal a calcium-like membrane interaction by coordinating to the phosphate groups, resulting in a stronger lipid packing and partial dehydration of the headgroup region.

Transarterial Radioembolization (TARE) Agents beyond 90Y-Microspheres

Liver malignancies, either primary tumours (mainly hepatocellular carcinoma and cholangiocarcinoma) or secondary hepatic metastases, are a major cause of death, with an increasing incidence. Among them, hepatocellular carcinoma (HCC) presents with a dark prognosis because of underlying liver diseases and an often late diagnosis. A curative surgical treatment can therefore only be proposed in 20 to 30% of the patients. However, new treatment options for intermediate to advanced stages, such as internal radionuclide therapy, seem particularly attractive. Transarterial radioembolization (TARE), which consists in the use of intra-arterial injection of a radiolabelled embolising agent, has led to very promising results. TARE with 90Y-loaded microspheres is now becoming an established procedure to treat liver tumours, with two commercially available products (namely, SIR-Sphere® and TheraSphere®). However, this technology remains expensive and is thus not available everywhere. The aim of this review is to describe TARE alternative technologies currently developed and investigated in clinical trials, with special emphasis on HCC.

Transarterial radioembolization in patients with hepatocellular carcinoma of intermediate B2 substage

PURPOSE

Patients with hepatocellular carcinoma (HCC) of intermediate stage (BCLC-B according to the Barcelona Clinic Liver Cancer classification) are a heterogeneous group with different degrees of liver function impairment and tumour burden. The recommended treatment is transarterial chemoembolization (TACE). However, patients in this group may be judged as poor candidates for TACE because the risk-benefit ratio is low. Such patients may receive transarterial radioembolization (TARE) only by entering a clinical trial. Experts have proposed that the stage could be further divided into four substages based on available evidence of treatment benefit. We report here, for the first time, the outcome in patients with BCLC-B2 substage HCC treated with TARE.

METHODS

A retrospective analysis of the survival of 126 patients with BCLC-B2 substage HCC treated with TARE in three European hospitals was performed.

RESULTS

Overall median survival in patients with BCLC-B2 substage was not significantly different in relation to tumour characteristics; 19.35 months (95% CI 8.27-30.42 months) in patients with a single large (>7 cm) HCC, and 18.43 months (95% CI 15.08-21.77 months) in patients with multinodular HCC (p = 0.27). However, there was a higher proportion of long-term survivors at 36 months among those with a single large tumour (29%) than among those with multiple tumours (16.8%).

CONCLUSION

Given the poor efficacy of TACE in treating patients with BCLC-B2 substage HCC, TARE treatment could be a better choice, especially in those with a large tumour.

Trends in Interventional Radiology Through the Eye of the Journal of Vascular and Interventional Radiology: A 27-Year History

PURPOSE

To report the quantity, manuscript types, geographic distribution of publications, and published content trends in a major interventional radiology journal over 27 years.

MATERIALS AND METHODS

Available publication data from the Journal of Vascular and Interventional Radiology was collected via Scopus from November 1990 to November 2017. Quantity, manuscript type, geographic distribution, number of citations, and publication content were analyzed.

RESULTS

6925 papers were published in JVIR during the study period. The number of publications increased by 234% from an average of 103 publications/year in the first 5 years to 344 publications/year in the last 5 years. Manuscript types included 4891 original articles (70.6%), 987 letters (14.3%), 360 review articles (5.2%), 324 notes (4.7%), 167 conference papers (2.4%), 102 editorials (1.5%), 61 errata (0.9%), 23 articles in press (0.3%), and 10 short surveys (0.1%). The majority of publications originated in the United States with 3945 articles (57.0%), followed by Canada with 366 articles (5.3%), and Japan and South Korea with 360 (5.2%) and 340 articles (4.9%), respectively. As for article content, arterial disease and interventions were discussed in 2256 publications (32.6%), followed by venous (1237; 17.9%), miscellaneous (1072; 15.5%), oncology (1006; 14.5%), genitourinary (758; 10.9%), portal (337; 4.9%), neurovascular (253; 3.7%), gastrointestinal (232; 3.4%), biliary (210; 3.0%), pediatric (130; 1.9%), clinical trials (119; 1.7%), and guideline development (119; 1.7%).

CONCLUSION

There has been a marked increase in the number of publications in JVIR over 27 years. JVIR has shown continued growth since its inception and has strengthened its international reputation with more global research than ever before.

Skin ischemia and ulceration as a complication of inferior phrenic artery embolization for hepatocellular carcinoma

Nontarget embolization from transarterial liver-directed therapy for hepatocellular carcinoma is a rare complication. We present a case of flank skin ulceration after embolization of the inferior phrenic artery supplying tumor. This complication of inferior phrenic artery embolization underscores caution when using small particles to embolize extrahepatic supply to hepatocellular carcinoma.

Comparison of Cone-Beam Tomography and Cross-Sectional Imaging for Volumetric and Dosimetric Calculations in Resin Yttrium-90 Radioembolization

PURPOSE

To compare the use of cone-beam computed tomography versus contrast-enhanced computed tomography (CT) and magnetic resonance imaging (MRI) in the calculation of liver volume and planned dose for yttrium-90 radioembolization.

MATERIALS AND METHODS

The study retrospectively assessed 47 consecutive patients who underwent resin Y-90 radioembolization consecutively over a 2-year period at a single center. Volume calculation software was used to determine perfused lobar liver volumes from cone-beam CT (CBCT) images obtained during mapping angiography. CBCT-derived volumes were compared with perfused lobar volume derived from contrast-enhanced CT and MRI. Nominal activities as determined by the SIR-Spheres Microspheres Activity Calculator were similarly calculated and compared using both CBCT and conventionally acquired volumes.

RESULTS

A total of 82 hepatic lobes were assessed in 47 patients. The mean percentage difference between combined CT-MRI- and CBCT-derived calculated lobar volumes was 25.3% (p = 0.994). The mean percentage difference in calculated dose between the two methods was 21.8 ± 24.6% (p = 0.42). Combined left and right lobar CT-derived dose difference was less than 10% in 22 lobes, between 10 and 25% in 20 lobes, between 25 and 50% in 13 lobes and greater than 50% in 5 lobes. Combined left and right lobar MRI-derived dose difference was less than 10% in 11 lobes, between 10 and 25% in 7 lobes, between 25 and 50% in 2 lobes and greater than 50% in 1 lobe.

CONCLUSIONS

Although volume measurements derived from CT/MRI did not differ significantly from those derived from CBCT, variability between the two methods led to large and unexpected differences in calculated dose.

Treatment of hepatocellular carcinoma: a cost analysis of yttrium-90 transarterial radioembolization versus sorafenib

Aim: The aim was to evaluate cost–effectiveness of yttrium-90 transarterial radioembolization (TARE) in comparison to sorafenib treatment. Patients & methods: A single-center, retrospective, observational study was performed, 166 patients with intermediate-/advanced-stage hepatocellular carcinoma were treated with sorafenib and 19 with TARE. The patients out of the sorafenib group matching the inclusion criteria for TARE, were reassigned to a subgroup SOR3. Results: Mean costs for SOR3 patients amounted to €27,992 per patient, instead for TARE treatment, mean expense per patient was €17,761 (p = 0.028). Overall survival was similar between the two groups, while midterm survival rates (p = 0.012) were significantly higher with TARE treatment. Conclusion: TARE causes significantly lower treatment costs than sorafenib with better outcome in midterm survival.

Imaging Evaluation Following 90Y Radioembolization of Liver Tumors: What Radiologists Should Know

Radioembolization using beta-emitting yttrium-90 microspheres is being increasingly used for the treatment of primary and metastatic liver cancers. It is a form of intra-arterial brachytherapy which delivers intense radiation to liver tumors with little embolic effect; this mode of action results in unique post-treatment imaging findings. It is important to understand these imaging findings to avoid misinterpretation of tumor response and to determine further management of the disease. Herein, we discuss the current concepts for assessing tumor response, common post-treatment imaging features, and associated complications following radioembolization.

Utility of endoscopic ultrasound and endoscopy in diagnosis and management of hepatocellular carcinoma and its complications: What does endoscopic ultrasonography offer above and beyond conventional cross-sectional imaging?

Hepatocellular carcinoma constitutes over 90% of the primary liver tumors, the rest being cholangiocarcinoma. It has an insidious presentation, which is responsible for the delayed presentation. Hence, the management strategy relies on screening to diagnose it an early stage for curative resection and/or treatment with local ablative techniques or chemotherapy. However, even with different screening programs, more than 60% of tumors are still detected at an advanced stage, leading to an unchanged mortality rate, thereby implying a room for improvement in the screening and diagnostic process. In the last few years, there has been evolution of utility of endoscopy, specifically endoscopic ultrasonography along with Fine needle aspiration, for this purpose, which we comprehensively review in this article.

Treatment options for unresectable HCC with a focus on SIRT with Yttrium-90 resin microspheres

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is the second leading cause of cancer-related deaths across the globe. Only a small percentage of HCC patients (~20%-30%) are diagnosed at an early stage when first-line treatment options may be effective. The majority of HCC patients (>70%) are diagnosed with unresectable disease and given a poor overall prognosis. Current treatment guidelines recommend locoregional therapy with transarterial chemoembolisation (TACE) and systemic therapy with sorafenib as first-line treatment for patients with intermediate and advanced stage HCC. However, multiple factors including contraindications, technical considerations and treatment-related toxicities pose significant challenges in achieving favourable treatment outcomes, underscoring the need for a paradigm shift in managing these patients. In 2002, yttrium-90 (Y-90) resin microspheres was approved by the U.S. Food and Drug Administration (FDA) for the treatment of unresectable metastatic colorectal cancer to the liver with adjuvant floxuridine chemotherapy. However, thousands of patients with unresectable HCC have also been treated with resin Y-90. For over two decades, several small-scale prospective trials and retrospective studies have investigated and reported on the efficacy of locoregional selective internal radiation therapy (SIRT) with Y-90 microspheres in treating unresectable HCC. Although it is currently a treatment option for intermediate-stage HCC patients, mainstream clinical application of resin Y-90 has been largely limited because of the lack of sufficient clinical data from a randomised controlled trial. This could change with the imminent announcement of results from the phase 3 Sorafenib vs Radioembolization in Advanced Hepatocellular carcinoma (SARAH) trial. To provide the foundation and context for interpreting results from the SARAH trial, this article provides an overview of treatment modalities and current challenges in managing unresectable HCC. There is also a review of key prospective and retrospective studies evaluating the use of Y-90 SIRT, specifically Y-90 resin microspheres in unresectable HCC, which led to the development of the SARAH trial.

METHODS

To identify relevant publications, the PubMed database was queried using one or more of the following search terms alone or in combination with Boolean operators: epidemiology, hepatocellular, hepatocellular cancer, hepatocellular carcinoma, unresectable, radioembolisation, selective internal radiation therapy, SIR-Spheres, yttrium 90, TACE, and sorafenib. The results were sorted or filtered by "Author", "Publication dates" or "Article types" to identify articles relevant to each section of the review. To ensure that information on ongoing clinical trials involving Y-90 resin was included, we conducted a search on "ClinicalTrials.gov", by combining the search terms "HCC" OR "hepatocellular carcinoma" with "Y 90" OR "yttrium 90" OR "radioembo", and screened for studies that involved treatment with Y-90 resin microspheres.

Radioembolisation of hepatocellular carcinoma: a primer

Transarterial radioembolisation (TARE) has gained increasing acceptance as an additional/alternative locoregional treatment option for hepatocellular carcinoma, and colorectal hepatic metastases that present beyond potentially curative options. This is a catheter-based transarterial selective internal brachytherapy that involves injection of radioactive microspheres (usually Y-90) that are delivered selectively to the liver tumours. Owing to the combined radioactive and microembolic effect, the findings at follow-up imaging are significantly different from that seen with other transarterial treatment options. Considering increasing confidence among clinicians, refinement in techniques and increasing number of ongoing trials, TARE is expected to gain further acceptance and become an important tool in the armamentarium for the treatment of liver malignancies. So it is imperative that all radiologists involved in the management of liver malignancies are well versed with TARE to facilitate appropriate discussion at multidisciplinary meetings to direct further management. In this article, we provide a comprehensive review on various aspects of radioembolisation with Y-90 for hepatocellular carcinoma including the patient selection, treatment planning, radiation dosimetry and treatment, side effects, follow-up imaging and future direction.

Proton beam therapy for hepatocellular carcinoma

INTRODUCTION

Radiation therapy is an effective treatment option for hepatocellular carcinoma (HCC) patients. However, radiotherapy for HCC still has limited recognition as a standard treatment option in international consensus guidelines due to a paucity of randomized controlled trials and the risk of hepatotoxicity, which is primarily mediated by baseline liver function and dose delivered to non-tumor liver cells. Proton beam therapy (PBT) may offer advantages over photon-based radiation treatments through its dosimetric characteristic of sparing more liver volume at low to moderate doses. PBT has the potential to reduce radiation-related hepatotoxicity and allow for tumor dose escalation. Areas covered: This article reviews the clinical rationale for using PBT for HCC patients and clinical outcome and toxicity data from retrospective and prospective studies. PBT-specific technical challenges for these tumors and appropriate selection of patients to be treated with PBT are discussed. Expert commentary: Local control, overall survival, and toxicity results are promising for liver PBT. Future studies, including ongoing randomized cooperative group trials, will aim to determine the incremental benefit of PBT over photons and which patients are most suitable for PBT.

Loco-regional treatment of HCC: current status

Hepatocellular carcinoma (HCC) represents one of the few cancers for which locoregional treatments are recognised as being able to cure and/or prolong survival and are included in international guidelines. This is due to the unique nature of HCC, in most cases occurring in patients with underlying virus- or alcohol-related cirrhosis. The treatment choice in patients with HCC is therefore driven not only by tumour staging, as in the great majority of cancers, but also by careful evaluation of liver function and physical status. Another specific feature of HCC is that it is the only tumour that can be cured by organ transplantation, with the aim of treating both the cancer and underlying liver disease. These characteristics configure a complex scenario and prompt the need for close cooperation among interventional oncologists, surgeons, hepatologists, and anaesthesiologists. In patients with limited hepatic disease, preserved hepatic function and good performance status, categorised as very early and early-stage HCC according to the Barcelona Clinic Liver Cancer (BCLC) classification, image-guided tumour ablation is included among the curative treatments. More than half of patients with HCC are, however, diagnosed late, despite the widespread implementation of surveillance programmes, when curative treatments cannot be applied. For patients presenting with multinodular HCC and relatively preserved liver function, absence of cancer-related symptoms, and no evidence of vascular invasion or extrahepatic spread transcatheter arterial chemoembolisation (TACE) is the current standard of care. Although anti-tumour activity and promising survival results has been reported in cohorts of patients with advanced HCC treated with radio-embolisation, systemic treatment with the multi-kinase inhibitor, sorafenib, is still recommended for patients at this stage. In this article, current treatment strategies for HCC according to tumour stage are discussed, underlining the latest advances in the literature and technical developments.