Yttrium-90 Radioembolization as the Major Treatment of Hepatocellular Carcinoma

Proton beam therapy in the management of hepatocellular carcinoma

INTRODUCTION

Hepatocellular carcinoma (HCC) is the most common form of primary liver cancer. Photon radiotherapy shows efficacy in treating HCC but carries risks of high exit dose and radiation-induced liver disease. Additionally, HCCs with portal vein tumor thrombosis (PVTT) have a poor prognosis and are associated with higher risk of death. In recent years, proton beam therapy (PBT) has emerged as a novel treatment with the ability to downstage HCC for liver transplant (LT).

AREAS COVERED

This review will provide an overview of dosimetric benefits of PBT, efficacy of PBT in treating HCC, downstaging HCC-PVTT for LT, and a comparison of PBT with other non-surgical techniques. A search of PubMed until 3 September 2024 was conducted using free search and the following keywords: hepatocellular carcinoma, proton beam therapy, portal vein tumor thrombosis, local ablative therapy, trans-arterial chemoembolization, stereotactic body radiotherapy, Y-90 radioembolization.

EXPERT OPINION

Various clinical trials using PBT have shown promising tumor local control and overall survival rates. PBT is mostly safe and efficacious for downstaging HCC-PVTT for LT. PBT has also been shown to be non-inferior to various other treatment modalities. Future research should focus on combinations of PBT with other modalities.

The Impact of Radiation Dose and Tumour Burden on Outcomes in Hepatocellular Carcinoma: 11-Year Experience in a 413-Patient Cohort Treated with Yttrium-90 Resin Microsphere Radioembolisation

Introduction

Transarterial radioembolisation (RE) using yttrium-90 (Y-90) microspheres is a widely used locoregional therapy for a broad spectrum of hepatocellular carcinoma (HCC) given its favourable safety profile. We evaluated the real-world outcomes of unresectable HCC treated with resin Y-90 RE and the relationship between tumour absorbed dose and subsequent curative therapy with survival.

Methods

Included were consecutive patients treated with Y-90 resin microspheres RE for unresectable HCC between January 2008 and May 2019 at the National Cancer Centre Singapore/Singapore General Hospital. The outcomes were stratified by tumour burden, distribution, presence of portal vein invasion (PVI) and liver function to improve prognostication.

Results

The median overall survival (OS) evaluated on 413 included patients was 20.9 months (95% CI: 18.2-24.0). More than half of the patients (214/413, 51.8%) had HCC beyond up-to-seven criteria, and 37.3% had portal vein invasion (154/413, 37.3%). Majority (71.7%) had dosimetry calculated based on the partition model. Patients who received ≥150 Gy to tumour had significantly better outcomes (OS 32.2 months, 95% CI: 18.3-46.4) than those who did not (OS 17.5 months, 95% CI: 13.7-22.7, p < 0.001). Seventy patients (17%) received curative therapies after tumour was downstaged by Y-90 RE and had better OS of 79.7 months (95% CI: 40.4 - NE) compared to those who did not receive curative therapies (OS 17.1 months; 95% CI: 13.5-20.4, p < 0.001). RE-induced liver injury was observed in 5.08% of the patients while 3.2% of the patients had possible radiation pneumonitis but none developed Grade 3-4 toxicity. For HCC without PVI, OS differed significantly with performance status, albumin-bilirubin grade, tumour distribution, and radiation dose; for HCC with PVI, Child-Pugh class and AFP were significant predictors of survival.

Conclusions

Treatment outcomes for unresectable HCC using Y-90 RE were favourable. Incorporating tumour burden and distribution improved prognostication. Patients who received tumour absorbed dose above 150 Gy had better OS. Patients who subsequently received curative therapies after being downstaged by Y-90 RE had remarkable clinical outcomes.

Sequencing microsphere selective internal radiotherapy after external beam radiotherapy for hepatocellular carcinoma: proof of concept of a synergistic combination

OBJECTIVES

This study aims to explore the synergistic effects of combining stereotactic body radiation therapy (SBRT) and selective internal radiation therapy (SIRT) in that specific sequence for treating hepatocellular carcinoma (HCC), particularly in patients at high risk of radiation-induced liver disease (RILD).

METHODS

We analysed a case of a patient with HCC who was treated with SBRT at our institution. A virtual 90Y dose distribution was added using our in-house MIDOS model to keep a minimum dose to the healthy liver tissue. BED and EUD metrics were calculated to harmonize the dose distributions of SBRT and SIRT.

RESULTS

Our radiation biology-based models suggest that the combination of SBRT and SIRT could maintain effective tumour control while reducing the dose to normal liver tissue. Specifically, an SBRT plan of 10 Gy×3 fractions combined with SIRT yielded comparable tumour control probability to an SBRT-only plan of 10 Gy×5 fractions.

CONCLUSIONS

The combination of SBRT and SIRT is a promising treatment strategy for HCC patients at high risk of RILD. While the LQ model and associated formalisms provide a useful starting point, further studies are needed to account for factors beyond these models. Nonetheless, the potential for significant dose reduction to normal tissue suggests that this combination therapy could offer substantial clinical benefits.

ADVANCES IN KNOWLEDGE

This article presents a proposal to combine SBRT and SIRT, in this specific order, for HCC, discussing its advantages. A framework for future research into optimizing combination therapy for HCC is provided, utilizing a novel HCC vascular model to simulate 90Y doses.

Progress of immune checkpoint inhibitors in the treatment of advanced hepatocellular carcinoma

Among primary liver cancers, hepatocellular carcinoma is the most common pathological type. Its onset is insidious, and most patients have no obvious discomfort in the early stage, so it is found late, and the opportunity for surgical radical treatment is lost, resulting in a poor prognosis. With the introduction of molecular-targeted drugs represented by sorafenib, patients with middle- and late-stage liver cancer have regained the light of day. However, their therapeutic efficacy is relatively low due to the limited target of drug action, toxic side effects, and other reasons. At this time, the emergence of immunotherapy represented by immune checkpoint inhibitors (ICIs) well breaks this embarrassing situation, which mainly achieves the anti-tumor purpose by improving the tumor immune microenvironment. Currently, ICI monotherapy, as well as combination therapy, has been widely used in the clinic, further prolonging the survival of patients with advanced hepatocellular carcinoma. This article reviews the development of monotherapy and combination therapy for ICIs in advanced hepatocellular carcinoma and the latest research progress.

Diagnosis and management of radiation cholecystitis as a complication of Y90 radioembolization for hepatocellular carcinoma

Radiation induced cholecystitis is a known but rare complication of Yttrium90 (Y90) radioembolization of hepatic tumors due to nontarget embolization. Many documented cases of radiation induced cholecystitis have been treated with cholecystectomy, which is significant given the typical patient population undergoing radioembolization tends to be of higher surgical risk. Here, we present a case of a 68 year old male who developed radiation induced cholecystitis status post hepatic radioembolization that resolved with conservative management alone. This case highlights that radiation induced cholecystitis may be successfully and safely treated conservatively.

PET/CT and SPECT/CT imaging of 90Y hepatic radioembolization at therapeutic and diagnostic activity levels: Anthropomorphic phantom study

PURPOSE

Prior to 90Y radioembolization procedure, a pretherapy simulation using 99mTc-MAA is performed. Alternatively, a small dosage of 90Y microspheres could be used. We aimed to assess the accuracy of lung shunt fraction (LSF) estimation in both high activity 90Y posttreatment and pretreatment scans with isotope activity of ~100 MBq, using different imaging techniques. Additionally, we assessed the feasibility of visualising hot and cold hepatic tumours in PET/CT and Bremsstrahlung SPECT/CT images.

MATERIALS AND METHODS

Anthropomorphic phantom including liver (with two spherical tumours) and lung inserts was filled with 90Y chloride to simulate an LSF of 9.8%. The total initial activity in the liver was 1451 MBq, including 19.4 MBq in the hot sphere. Nine measurement sessions including PET/CT, SPECT/CT, and planar images were acquired at activities in the whole phantom ranging from 1618 MBq down to 43 MBq. The visibility of the tumours was appraised based on independent observers' scores. Quantitatively, contrast-to-noise ratio (CNR) was calculated for both spheres in all images.

RESULTS

LSF estimation. For high activity in the phantom, PET reconstructions slightly underestimated the LSF; absolute difference was <1.5pp (percent point). For activity <100 MBq, the LSF was overestimated. Both SPECT and planar scintigraphy overestimated the LSF for all activities. Lesion visibility. For SPECT/CT, the cold tumour proved too small to be discernible (CNR <0.5) regardless of the 90Y activity in the liver, while hot sphere was visible for activity >200 MBq (CNR>4). For PET/CT, the cold tumour was only visible with the highest 90Y activity (CNR>4), whereas the hot one was seen for activity >100 MBq (CNR>5).

CONCLUSIONS

PET/CT may accurately estimate the LSF in a 90Y posttreatment procedure. However, at low activities of about 100 MBq it seems to provide unreliable estimations. PET imaging provided better visualisation of both hot and cold tumours.

Applications of Yttrium-90 (90Y) in Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver cancer, affecting millions of people worldwide. Due to the lack of systemic radiation therapy in hepatocellular carcinoma, researchers have been investigating the use of yttrium-90 (90Y) radioembolization for local-regional tumor control since the 1960s. With the development of glass and resin 90Y microspheres and the durable local control, good long-term efficacy, and equivalent tumor responsiveness and tolerability of 90Y-selective internal irradiation compared with alternative therapies such as transarterial chemoembolization (TACE) and sorafenib, 90Y radioembolization has gradually been applied in the treatment of hepatocellular carcinoma of all stages. In this article, we summarize the latest progress of 90Y in the treatment of hepatocellular carcinoma in terms of its principle, advantages, indications, contraindications, efficacy and adverse effects.

Pushing the limits of treatment for hepatocellular carcinoma

PURPOSE OF REVIEW

We review existing and newer strategies for treatment and surveillance of hepatocellular carcinoma (HCC) both pre and postliver transplantation.

SUMMARY

HCC is rising in incidence and patients are often diagnosed at later stages. Consequently, there is a need for treatment strategies which include collaboration of multiple specialties. Combinations of locoregional, systemic, and surgical therapies are yielding better postliver transplantation (post-LT) outcomes for patients with HCC than previously seen. Tumor biology (tumor size, number, location, serum markers, response to therapy) can help identify patients who are at high risk for HCC recurrence posttransplantation and may expand transplant eligibility for some patients.

Yttrium-90 Transarterial Radioembolization of Primary Lung Cancer Metastases to the Liver

PURPOSE

To assess whether yttrium-90 transarterial radioembolization (TARE) is safe and effective in the treatment of primary lung cancer metastases to the liver (LCML).

METHODS AND METHODS

This retrospective study included 57 patients with LCML who were treated with 79 TARE treatments. Histology included non-small cell lung cancer (NSCLC) (n = 27), small cell lung cancer (SCLC) (n = 17), and lung carcinoid (LC) (n = 13). Survival was calculated using Kaplan-Meier method; differences between groups were estimated using log rank test. Cox proportional hazards model was used to determine factors influencing survival. Adverse events were graded using the Society of Interventional Radiology Adverse Events Classification.

RESULTS

Median overall survival (OS) was as follows: NSCLC, 8.3 months (95% confidence interval [CI], 6.3-16.4 months); SCLC, 4.1 months (95% CI, 1.9-6.6 months); and LC, 43.5 months (95% CI, 7.8-61.4 months). For NSCLC, presence of bilobar vs unilobar disease (hazard ratio [HR], 5.24; 95% CI, 1.64-16.79; P = .002); more tumors, 2-5 vs 1 (HR, 4.88; 95% CI, 1.17-20.37; P = .003) and >5 vs 1 (HR, 3.75; 95% CI, 0.95-6.92; P = .05); and lobar vs segmental treatment (HR, 2.56; 95% CI, 0-NA; P = .002) were negative predictors of OS. For SCLC, receipt of >2 lines of chemotherapy vs ≤2 lines (HR, 3.16; 95% CI, 0.95-10.47; P = .05) was a negative predictor of OS. For LC, tumor involvement of >50% was a negative predictor of OS (HR, 3.77 × 1015; 95% CI, 0-NA; P = .002). There were 11 of 79 severe or life-threatening adverse events within 30 days (abdominal pain, altered mental status, nausea/vomiting, acalculous/aseptic cholecystitis, hyponatremia, pancreatitis, renal failure, and death from pneumonia).

CONCLUSIONS

TARE has an acceptable safety profile for the treatment of LCML, with survival benefits best seen in LC tumors.

Transarterial Radioembolization (TARE) in Patients with Hepatocellular Carcinoma: A Comparison of Palliative with Bridging-to-Transplant Concepts

We investigated transarterial radioembolization (TARE) as a palliative measure and bridging-to-transplant therapy in hepatocellular carcinoma (HCC) patients. A total of 167 patients (50 bridging, 117 palliative) with 245 TARE procedures were assessed. Fourteen patients underwent subsequent liver transplantation (LT). Patients undergoing LT exhibited significantly prolonged progression-free survival (PFS) compared to those with bridging-without-transplant (p = 0.033). No significant differences were observed between patients with bridging-without-transplant and palliative cases (p = 0.116). Median overall survival (OS) post-TARE was 16.6 months, with estimated OS rates at 6/12 months of 82.0%/60.5%, respectively. Patients who underwent LT demonstrated statistically significantly longer OS compared to those with bridging-without-transplant (p = 0.001). No marked outcome distinctions were found between bridging-without-transplant and palliative groups. The findings underscored the superiority of LT over alternative treatments. TARE served as an important component in non-LT scenarios, allowing for subsequent therapeutic options. The study reflected the highly variable and complex situations of patients with HCC, emphasizing the need for further investigations to define an optimal multimodal approach.

Pre-transarterial Radioembolization of Tumoral Arteriovenous Fistula Associated With Recanalized Umbilical Vein Shunt in a Case of Hepatocellular Carcinoma With Hepatic Vein and Inferior Vena Cava Invasion

Hepatocellular carcinoma (HCC) is the most common liver cancer and has a propensity to develop arteriovenous fistulas with the surrounding vasculature, making targeted intravascular treatment more difficult. HCC can oftentimes be accompanied by portal hypertension and liver cirrhosis, which can, in turn, cause recanalization of the umbilical vein. In rare circumstances, arteriovenous fistula formation and shunting into the recanalized and enlarged umbilical vein can occur. In the following presented case of HCC, an arteriovenous shunt between the anterior division of the right hepatic artery and a recanalized umbilical vein is demonstrated. Subsequent successful endovascular coil embolization of the fistula was performed to avoid shunting and non-target embolization of the radiation particles in the umbilical vein territory. Post-embolization angiogram with DynaCT and lack of Tc-99m macroaggregated albumin deposition in the umbilical vein distribution confirmed the resolution of the shunt. The patient then received targeted Y-90 transarterial radioembolization locoregional therapy in combination with systemic therapy.

Intraoperative diagnosis of early lymphatic metastasis using neodymium-based rare-earth NIR-II fluorescence nanoprobe

The high mortality of breast cancer is closely related to lymph node (LN) metastasis. Sentinel LNs (SLNs) are the first station where tumor cells metastasize through the lymphatic system. As such, achieving precise diagnosis of the early metastatic status of SLNs during surgery is of paramount importance for precision therapy of breast cancer. While invasive SLNs biopsy is the gold standard for evaluating the status of SLNs, its use is often time-consuming and may increase the risk of operation. It is still challenging to develop a means for rapid SLN metastasis diagnosis. Herein, NaGdF4:5%Nd@NaLuF4 rare earth nanoparticles (Gd:Nd-RENPs) with near-infrared-II (NIR-II) fluorescence and magnetic resonance imaging (MRI) properties were fabricated. With the nanoprobe, metastatic SLNs and lymph vessels (LVs) rapidly brighten and can be observed by the NIR-II imaging system, which is totally different from normal LNs and LVs. The remarkable contrast observed via NIR-II imaging serves to swiftly delineate metastatic SLNs from normal ones, subsequently guiding precise surgical resection of metastatic LNs in just 10 minutes. Furthermore, the consistency between the results obtained via MRI and NIR-II imaging further validates the dependability of this nanoprobe as a diagnostic tool for metastatic SLNs. Additionally, the Gd:Nd-RENPs exhibited good biocompatibility in vitro and in vivo. In this study, we demonstrated the advantages and prospects of NIR-II imaging for intraoperative early SLN metastasis assessment and shed light on the potential of the dual-modal Gd:Nd-RENPs as a nanoprobe.