Radioembolization for the Treatment of Primary and Metastatic Liver Cancers

Breaking barriers in cancer management: The promising role of microsphere conjugates in cancer diagnosis and therapy

Cancer is a significant worldwide health concern, and there is a demand for ongoing breakthroughs in treatment techniques. Microspheres are among the most studied drug delivery platforms for delivering cargo to a specified location over an extended period of time. They are biocompatible, biodegradable, and capable of surface modifications. Microspheres and their conjugates have emerged as potential cancer therapeutic options throughout the years. This review provides an in-depth look at the current advancements and applications of microspheres and their conjugates in cancer treatment. The review encompasses a wide array of conjugates, ranging from polymers such as ethyl cellulose and Eudragit to stimuli-responsive polymers, proteins, peptides, polysaccharides such as HA and chitosan, inorganic metals, aptamers, quantum dots (QDs), biomimetic conjugates, and radio conjugates designed for radioembolization. Conjugated microspheres precisely deliver chemotherapeutics to the intended target while achieving controlled drug release to prevent side effects. It offers a means of integrating several distinct therapeutic modalities (chemotherapy, photothermal therapy, photodynamic therapy, radiotherapy, immunotherapy, etc.) to provide synergistic effects during cancer treatment. This review offers insights into the prospects and evolving role of microspheres and their conjugates in the dynamic landscape of cancer therapy. This review provides a comprehensive resource for researchers and clinicians working towards advancements in cancer treatment through innovative applications in therapy and translational research.

Chemoembolization, Radioembolization, and Percutaneous Ablation: New Opportunities for Treating Ovarian Cancer Liver Metastasis

OPINION STATEMENT

Parenchymal liver metastases from ovarian cancer, occurring in 2-12.5% of cases, significantly worsen prognosis. While surgery and systemic treatments remain primary options, unresectable or chemotherapy-resistant multiple liver metastases pose a significant challenge. Recent advances in liver-directed therapies, including radiofrequency ablation, microwave ablation, cryoablation, transarterial chemoembolization (TACE), and radioembolization, offer potential treatment alternatives. However, the efficacy of these techniques is limited by factors such as tumor size, number, and location. The ideal candidate for tumor ablation is a patient with paucifocal disease, a single tumor up to 5 cm or up to 3 tumors smaller than 3 cm and tumors 1 cm away from major bile ducts and high-flow vessels. Transarterial chemoembolization could be performed in patients with less than 70% tumor load. Differently, radioembolization is available with less limitation on the sites or number of liver cancers. Radioembolization techniques are also able to downsize liver metastases. However, there are limited data regarding the outcomes of loco-regional therapy in patients with hepatic metastases from ovarian cancer. Advancing liver-directed therapies through interventional oncology, combined with robust data on the oncological efficacy of these local treatments, will validate their potential as effective locoregional therapies for liver metastases. This could offer a promising treatment option for patients with ovarian cancer and unresectable hepatic metastases.

New frontiers in radioembolization

Radioembolization is a locoregional transarterial therapy that combines radionuclide and micron-sized beads to deliver radiation internally to the target tumors based on the arterial blood flow. While initially developed as a palliative treatment option, radioembolization is now used for curative intent treatment, neoadjuvant therapy, and method to downstage or bridge for liver transplant. Radioembolization has become increasingly utilized and is an important therapeutic option for the management of hepatocellular carcinoma and liver metastasis. This article provides an overview of the techniques, challenges, and novel developments in radioembolization, including new dosimetry techniques, radionuclides, and new target tumors.

Functional hydrogels for hepatocellular carcinoma: therapy, imaging, and in vitro model

Hepatocellular carcinoma (HCC) is among the most common malignancies worldwide and is characterized by high rates of morbidity and mortality, posing a serious threat to human health. Interventional embolization therapy is the main treatment against middle- and late-stage liver cancer, but its efficacy is limited by the performance of embolism, hence the new embolic materials have provided hope to the inoperable patients. Especially, hydrogel materials with high embolization strength, appropriate viscosity, reliable security and multifunctionality are widely used as embolic materials, and can improve the efficacy of interventional therapy. In this review, we have described the status of research on hydrogels and challenges in the field of HCC therapy. First, various preparation methods of hydrogels through different cross-linking methods are introduced, then the functions of hydrogels related to HCC are summarized, including different HCC therapies, various imaging techniques, in vitro 3D models, and the shortcomings and prospects of the proposed applications are discussed in relation to HCC. We hope that this review is informative for readers interested in multifunctional hydrogels and will help researchers develop more novel embolic materials for interventional therapy of HCC.

The Future of Interventions for Stage IV Colorectal Cancers

Future options for the management of stage IV colorectal cancer are primarily focused on personalized and directed therapies. Interventions include precision cancer medicine, utilizing nanocarrier platforms for directed chemotherapy, palliative pressurized intraperitoneal aerosol chemotherapy (PIPAC), adjunctive oncolytic virotherapy, and radioembolization techniques. Comprehensive genetic profiling provides specific tumor-directed therapy based on individual genetics. Biomimetic magnetic nanoparticles as chemotherapy delivery systems may reduce systemic side effects of traditional chemotherapy by targeting tumor cells and sparing healthy cells. PIPAC is a newly emerging option for patients with peritoneal metastasis from colorectal cancer and is now being used internationally, showing promising results as a palliative therapy for colorectal cancer. Oncolytic virotherapy is another emerging potential treatment option, especially when combined with standard chemotherapy and/or radiation, as well as immunotherapy. And finally, radioembolization with yttrium-90 ( 90 Y) microspheres has shown some success in treating patients with unresectable liver metastasis from colorectal cancer via selective arterial injection.

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.

Transmission of Lung Adenocarcinoma From a Single Donor in 2 Transplant Recipients: A Case Report With Literature Review

Malignancies transmitted to recipients during solid organ transplants carry significant morbidity and mortality. We present 2 cases of adenocarcinoma of donor lung origin transmitted via liver and kidney transplant from a single donor. Both recipients developed metastatic adenocarcinoma of lung origin with p.L858R mutation in the epidermal growth factor receptor gene and a microsatellite signature of donor origin. Osimertinib was trialed in the liver recipient; however, it was discontinued because of hepatotoxicity and disease progression. Standard donor screening protocols limit malignancy transmission but do not include multicancer detection assays. As these technologies evolve, they may be implemented in donor screening.

RNA-sequencing reveals the expression profiles of tsRNAs and their potential carcinogenic role in cholangiocarcinoma

Background

Recently, the incidence of cholangiocarcinoma (CCA) has gradually increased. As CCA has a poor prognosis, the ideal survival rate is scarce for patients. The abnormal expressed tsRNAs may regulate the progression of a variety of tumors, and tsRNAs is expected to become a new diagnostic biomarker of cancer. However, the expression of tsRNAs is obscure and should be elucidated in CCA.

Methods

High‐throughput RNA sequencing technology (RNA‐seq) was utilized to determine the overall expression profiles of tsRNAs in three pairs CCA and adjacent normal tissues and to screen the tsRNAs that were differentially expressed. The target genes of dysregulated tsRNAs were predicted and the biological effects and potential signaling pathways of these target genes were explored by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses. Quantitative real‐time polymerase chain reaction (qRT‐PCR) was used to validate 11 differentially expressed tRFs with 12 pairs CCA and adjacent normal tissues.

Results

High‐throughput RNA‐seq totally demonstrated 535 dysregulated tsRNAs, of which 241 tsRNAs were upregulated, such as tRF‐21‐YLKZKWE5D，tRF‐16‐9NF5W8B，tRF‐27‐78YLKZKWE52，tRF‐19‐RLXN48KP，tRF‐33‐IK9NJ4S2I7L7DV，tRF‐19‐F8DHXYIV, and 294 tsRNAs were downregulated (tRF‐20‐739P8WQ0, tRF‐34‐JJ6RRNLIK898HR, tRF‐17‐VL8RPY5, tRF‐23‐YP9LON4VDP, tRF‐39‐EH623K76IR3DR2I2, tRF‐17‐18YKISM, tRF‐19‐Q1Q89PJZ, etc.) in CCA compared with adjacent normal tissues (|log2 [fold change] | ≥ 1 and p value <0.05). GO and KEGG enrichment analyses indicated that the target genes of dysregulated tRFs (tRF‐34‐JJ6RRNLIK898HR, tRF‐38‐0668K87SERM492V, and tRF‐39‐0668K87SERM492E2) were mainly enriched in the Notch signaling pathway, Hippo signaling pathway, cAMP signaling pathway and in growth hormone synthesis, secretion and action, etc. qRT‐PCR result showed that tRF‐34‐JJ6RRNLIK898HR/tRF‐38‐0668K87SERM492V/tRF‐39‐0668K87SERM492E2 was downregulated (p = 0.021), and tRF‐20‐LE2WMK81 was upregulated in CCA (p = 0.033).

Conclusion

Differentially expressed tRFs in CCA are enriched in many pathways associated with neoplasms, which may impact the tumor progression and have potential to be diagnostic biomarkers and therapeutic targets of CCA.

Yttrium-90 Radioembolization for Liver-Dominant Metastatic Prostate Cancer: A Case Series

Transarterial radioembolization (TARE) with yttrium-90 glass microspheres is widely used to treat primary and secondary malignancies in the liver. However, the safety and efficacy of TARE in patients with liver-dominant metastatic castration-resistant prostate cancer (mCRPC) is unknown. A proof-of-concept, retrospective analysis of 7 consecutive patients with liver-dominant mCRPC who were treated with TARE was performed. The median overall survival was 27.2, 32.1, and 108.1 months from the time of TARE, the diagnosis of liver metastases, and initial cancer diagnosis, respectively. The median liver progression-free survival was 7.3 months. No grade 3 or higher adverse effects were noted. TARE was found to be a safe and effective tool for treating patients with liver-dominant mCRPC in this limited cohort.

Radioembolization for hepatocellular carcinoma: what clinicians need to know

Transarterial radioembolization (TARE) with yttrium 90 (⁹⁰Y) has been used in the management of hepatocellular carcinoma (HCC) for more than 10 years in Korea. There are two types of ⁹⁰Y radioactive microspheres available, namely, glass and resin microspheres, with comparable clinical outcomes. In general, TARE outperforms transarterial chemoembolization regarding post-embolization syndrome, time to progression, tumor downsizing for liver transplantation, and hospitalization stay. Although TARE is commonly recommended for patients with unresectable large HCCs, it can be an alternative to or performed in combination with ablation, surgical resection, and systemic treatment. This review aimed to address ⁹⁰Y radioactive microspheres, patient selection, clinical outcomes, simulation tests, radioembolization procedures, follow-up imaging, and complications.

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

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

Interventional Radiology Image-Guided Locoregional Therapies (LRTs) and Immunotherapy for the Treatment of HCC

Image-guided locoregional therapies (LRTs) are a crucial asset in the treatment of hepatocellular carcinoma (HCC), which has proven to be characterized by an impaired antitumor immune status. LRTs not only directly destroy tumor cells but also have an immunomodulating role, altering the tumor microenvironment with potential systemic effects. Nevertheless, the immune activation against HCC induced by LRTs is not strong enough on its own to generate a systemic significant antitumor response, and it is incapable of preventing tumor recurrence. Currently, there is great interest in the possibility of combining LRTs with immunotherapy for HCC, as this combination may result in a mutually beneficial and synergistic relationship. On the one hand, immunotherapy could amplify and prolong the antitumoral immune response of LRTs, reducing recurrence cases and improving outcome. On the other hand, LTRs counteract the typical immunosuppressive HCC microenvironment and status and could therefore enhance the efficacy of immunotherapy. Here, after reviewing the current therapeutic options for HCC, we focus on LRTs, describing for each of them the technique and data on its effect on the immune system. Then, we describe the current status of immunotherapy and finally report the recently published and ongoing clinical studies testing this combination.

Use of X-Ray Fluorescence Microscopy for Studies on Research Models of Hepatocellular Carcinoma

Introduction: TheraSphere^® microspheres containing yttrium ⁹⁰Y are among many radioembolization agents used clinically to reduce liver tumor burden, and their effects on cancer volume reduction are well-established. At the same time, concerns about off target tissue injury often limit their use. Deeper investigation into tissue distribution and long-term impact of these microspheres could inform us about additional ways to use them in practice.

Methods: Healthy rat liver and rabbit liver tumor samples from animals treated with TheraSpheres were sectioned and their elemental maps were generated by X-ray fluorescence microscopy (XFM) at the Advanced Photon Source (APS) synchrotron at Argonne National Laboratory (ANL).

Results: Elemental imaging allowed us to identify the presence and distribution of TheraSpheres in animal tissues without the need for additional sample manipulation or staining. Ionizing radiation produced by ⁹⁰Y radioactive contaminants present in these microspheres makes processing TheraSphere treated samples complex. Accumulation of microspheres in macrophages was observed.

Conclusions: This is the first study that used XFM to evaluate the location of microspheres and radionuclides in animal liver and tumor samples introduced through radioembolization. XFM has shown promise in expanding our understanding of radioembolization and could be used for investigation of human patient samples in the future.

Intra- inter-observer repeatability in liver computed tomography volumetry in patients undergoing radioembolization simulation

PURPOSE

The careful evaluation of MDCT is an essential step for the treatment planning in pre-treatment imaging work-up for Trans-Arterial Radio Embolization (TARE). It may provide unique volumetric data (CTVs), which are information useful for an effective and safe TARE. The purpose of this study is to demonstrate that the radiographer is able to calculate CTVs of TARE simulation with the same precision as the interventional radiologist.

METHODS

This study retrospectively considers 17 consecutive patients (8 males, 9 females; mean age 66.3 ± 13.2 years) who underwent pre-treatment work-up for TARE, between May 2019 and February 2020 (trial ID:2234 - protocol). For each patient, four specific parameters are evaluated from MDCT achieved during treatment simulation: healthy liver volume (HLV), the whole hepatic parenchyma (THV = healthy liver and TTV = tumour) involved by TARE, and whole liver volume (WLV). Four independent observers-R1 (expert interventional radiologist), T1, T2, and T3 (radiographers, with different experiences in the field of interventional radiology)-are involved in the imaging analysed.

RESULTS

All the 4 observers detected the same number of hepatic lesion(s) per patient. Regarding the three radiographers, the intra-observer reliability for CTVs is very high 0.997 to 1.000 (95%CI). Also inter-observer reproducibility between radiographers is excellent regarding CTVs, 0.965 to 0.999 (95%CI). The accuracy of radiographer evaluation is very high 0.964 to 0.999 (95%CI).

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

The high intra- and inter-observer reproducibility shows that a properly trained radiographers might have the same accuracy as interventional radiologists, in assessing liver CTV data for planning TARE.

NIR-absorbing Prussian blue nanoparticles for transarterial infusion photothermal therapy of VX2 tumors implanted in rabbits

Nanomaterial-related photothermal therapy has been intensively investigated for treatment of hepatocellular carcinoma (HCC). However, owing to the low specificity to tumors and easy excretion from the systemic circulation, the low dose of photoactive nanomaterials in solid tumors severely hinders the photothermal therapy applications for HCC. Herein, an innovative strategy for transarterial infusion photothermal therapy (TAIPPT) of VX2 tumors implanted in rabbits is reported. NIR-absorbing Prussian blue nanoparticles were prepared by microemulsion methods, which demonstrate excellent photothermal therapy capacity and satisfactory biocompatibility. Prussian blue nanoparticles are transarterially infused into VX2 tumors and irradiated for photothermal therapy. TAIPPT achieves fast and efficient delivery of nanoparticles into tumors and complete ablation by one-time transarterial infusion treatment. Furthermore, TAIPPT could activate the immune cells in rabbits and inhibit distant tumors. Our findings describe a promising strategy for tumor eradication and may benefit future clinical HCC patients.

Hypoxia-Induced Cancer Cell Responses Driving Radioresistance of Hypoxic Tumors: Approaches to Targeting and Radiosensitizing

Simple Summary

Some regions of aggressive malignancies experience hypoxia due to inadequate blood supply. Cancer cells adapting to hypoxic conditions somehow become more resistant to radiation exposure and this decreases the efficacy of radiotherapy toward hypoxic tumors. The present review article helps clarify two intriguing points: why hypoxia-adapted cancer cells turn out radioresistant and how they can be rendered more radiosensitive. The critical molecular targets associated with intratumoral hypoxia and various approaches are here discussed which may be used for sensitizing hypoxic tumors to radiotherapy.

Abstract

Within aggressive malignancies, there usually are the “hypoxic zones”—poorly vascularized regions where tumor cells undergo oxygen deficiency through inadequate blood supply. Besides, hypoxia may arise in tumors as a result of antiangiogenic therapy or transarterial embolization. Adapting to hypoxia, tumor cells acquire a hypoxia-resistant phenotype with the characteristic alterations in signaling, gene expression and metabolism. Both the lack of oxygen by itself and the hypoxia-responsive phenotypic modulations render tumor cells more radioresistant, so that hypoxic tumors are a serious challenge for radiotherapy. An understanding of causes of the radioresistance of hypoxic tumors would help to develop novel ways for overcoming this challenge. Molecular targets for and various approaches to radiosensitizing hypoxic tumors are considered in the present review. It is here analyzed how the hypoxia-induced cellular responses involving hypoxia-inducible factor-1, heat shock transcription factor 1, heat shock proteins, glucose-regulated proteins, epigenetic regulators, autophagy, energy metabolism reprogramming, epithelial–mesenchymal transition and exosome generation contribute to the radioresistance of hypoxic tumors or may be inhibited for attenuating this radioresistance. The pretreatments with a multitarget inhibition of the cancer cell adaptation to hypoxia seem to be a promising approach to sensitizing hypoxic carcinomas, gliomas, lymphomas, sarcomas to radiotherapy and, also, liver tumors to radioembolization.

Radiopharmaceutical therapy in cancer: clinical advances and challenges

Radiopharmaceutical therapy (RPT) is emerging as a safe and effective targeted approach to treating many types of cancer. In RPT, radiation is systemically or locally delivered using pharmaceuticals that either bind preferentially to cancer cells or accumulate by physiological mechanisms. Almost all radionuclides used in RPT emit photons that can be imaged, enabling non-invasive visualization of the biodistribution of the therapeutic agent. Compared with almost all other systemic cancer treatment options, RPT has shown efficacy with minimal toxicity. With the recent FDA approval of several RPT agents, the remarkable potential of this treatment is now being recognized. This Review covers the fundamental properties, clinical development and associated challenges of RPT.