Drug-Eluting Particles for Interventional Pharmacology

Tirapazamine-loaded CalliSpheres microspheres enhance synergy between tirapazamine and embolization against liver cancer in an animal model

Tirapazamine (TPZ) is a promising hypoxia-selective cytotoxic agent that may exert synergistic tumor-killing activity with transcatheter arterial embolization (TAE) for liver cancer. To investigated whether TPZ-loaded microspheres enhance the synergy between TPZ and TAE in liver cancer, we prepared TPZ-loaded CalliSpheres microspheres (CSMTPZs) and characterized their properties as a chemoembolization agent in vitro. Tumor hypoxia after TAE was detected in the rabbit VX2 model of liver cancer using a modified Clark-type microelectrode research system. CSMTPZ therapy was performed in the animal model. The plasma and tumor concentrations of TPZ and its metabolites were measured, and the efficacy and safety of CSMTPZ therapy were evaluated and compared with those of the conventional combination of intraarterial TPZ injection and embolization. The results showed that CSMTPZs displayed favorable in vitro properties including drug loading and release and microsphere size, shape, and surface profiles. TAE induced acute tumor hypoxia, but residual tumor cells responded to hypoxia through hypoxia-inducible factor 1α. CSMTPZ therapy improved TPZ delivery into tumor tissue with minimal systemic exposure. Accordingly, CSMTPZ therapy exhibited advantages in terms of hypoxia-selected cytotoxicity, tumor apoptosis and necrosis, animal survival, and safety over the conventional combination of TPZ and TAE. We revealed the improved synergistic anti-tumor effects of CSMTPZ therapy in the rabbit VX2 liver cancer model. Our data support the clinical evaluation of CSMTPZs in the treatment of hepatocellular carcinoma, and CSMTPZ administration might serve as a successful therapeutic strategy for this malignancy.

Local Treatments in the Unresectable Patient with Colorectal Cancer Metastasis: A Review from the Point of View of the Medical Oncologist

For patients with isolated liver metastases from colorectal cancer who are not candidates for potentially curative resections, non-surgical local treatments may be useful. Non-surgical local treatments are classified according to how the treatment is administered. Local treatments are applied directly on hepatic parenchyma, such as radiofrequency, microwave hyperthermia and cryotherapy. Locoregional therapies are delivered through the hepatic artery, such as chemoinfusion, chemoembolization or selective internal radiation with Yttrium 90 radioembolization. The purpose of this review is to describe the different interventional therapies that are available for these patients in routine clinical practice, the most important clinical trials that have tried to demonstrate the effectiveness of each therapy and recommendations from principal medical oncologic societies.

Chemoembolization of liver cancer with doxorubicin-loaded CalliSpheres microspheres: plasma pharmacokinetics, intratumoral drug concentration, and tumor necrosis in a rabbit model

The purpose of this work was to investigate the plasma pharmacokinetics, intratumoral drug concentration, and tumor necrosis after transarterial chemoembolization (TACE) with doxorubicin-loaded CalliSpheres microspheres (CSMs). Sixty rabbits with liver VX2 tumors were assigned into five groups of 12 rabbits each, which received 4 mg of doxorubicin via intravenous injection (IV group), hepatic arterial infusion (IA group), conventional TACE (cTACE group), CSM-TACE (CSM low-dose group), and 8 mg of doxorubicin via CSM-TACE (CSM high-dose group), respectively. Doxorubicin concentrations in plasma, tumor, and adjacent hepatic parenchyma were measured at various timepoints after treatment, and tumor necrosis percentage and liver enzymes were also assessed. The peak plasma concentration of doxorubicin was significantly lower in the three TACE groups compared to IV and IA group (P < 0.05), while doxorubicin concentrations in tumor and adjacent hepatic parenchyma were higher in the two CSM groups compared with IV, IA, and cTACE groups at 3 days and 7 days after treatment (P < 0.05). The percentages of tumor necrosis at 3 and 7 days after treatment were significantly higher in three TACE groups (all higher than 50%) compared with IV group and IA group (both lower than 25%) (P < 0.05), and the highest tumor necrosis percentage was achieved in CSM high-dose group. The three TACE groups showed transient increases in transaminases levels after treatment, in which the peak transaminases levels were significantly lower in the two CSM groups than those in cTACE group (P < 0.05). CSM achieves an effective delivery of doxorubicin into liver cancer. High-dose doxorubicin improves tumoricidal capacity while not impairing the safety of the doxorubicin-loaded CSM.

Bench-to-clinic development of imageable drug-eluting embolization beads: finding the balance

This review describes the historical development of an imageable spherical embolic agent and focuses on work performed in collaboration between Biocompatibles UK Ltd (a BTG International group company) and the NIH to demonstrate radiopaque bead utility and bring a commercial offering to market that meets a clinical need. Various chemistries have been investigated and multiple prototypes evaluated in search of an optimized product with the right balance of handling and imaging properties. Herein, we describe the steps taken in the development of DC Bead LUMI™, the first commercially available radiopaque drug-eluting bead, ultimately leading to the first human experience of this novel embolic agent in the treatment of liver tumors.

Towards Hypoxia-responsive Drug-eluting Embolization Beads

Drug release from chemoembolization microspheres stimulated by the presence of a chemically reducing environment may provide benefits for targeting drug resistant and metastatic hypoxic tumours. A water-soluble disulfide-based bifunctional cross-linker bis(acryloyl)-(l)-cystine (BALC) was synthesised, characterised and incorporated into a modified poly(vinyl) alcohol (PVA) hydrogel beads at varying concentrations using reverse suspension polymerisation. The beads were characterised to confirm the amount of cross-linker within each formulation and its effects on the bead properties. Elemental and UV/visible spectroscopic analysis confirmed the incorporation of BALC within the beads and sizing studies showed that in the presence of a reducing agent, all bead formulations increased in mean diameter. The BALC beads could be loaded with doxorubicin hydrochloride and amounts in excess of 300mg of drug per mL of hydrated beads could be achieved but required conversion of the carboxylic acid groups of the BALC to their sodium carboxylate salt forms. Elution of doxorubicin from the beads demonstrated a controlled release via ionic exchange. Some formulations exhibited an increase in size and release of drug in the presence of a reducing agent, and therefore demonstrated the ability to respond to an in vitro reducing environment.

Review of the Development of Methods for Characterization of Microspheres for Use in Embolotherapy: Translating Bench to Cathlab

Therapeutic embolotherapy is the deliberate occlusion of a blood vessel within the body, which can be for the prevention of internal bleeding, stemming of flow through an arteriovenous malformation, or occlusion of blood vessels feeding a tumor. This is achieved using a wide selection of embolic devices such as balloons, coils, gels, glues, and particles. Particulate embolization is often favored for blocking smaller vessels, particularly within hypervascularized tumors, as they are available in calibrated sizes and can be delivered distally via microcatheters for precise occlusion with associated locoregional drug delivery. Embolic performance has been traditionally evaluated using animal models, but with increasing interest in the 3R's (replacement, reduction, refinement), manufacturers, regulators, and clinicians have shown interest in the development of more sophisticated in vitro methods for evaluation and prediction of in vivo performance. Herein the current progress in developing bespoke techniques incorporating physical handling, fluid dynamics, occlusive behavior, and sustained drug elution kinetics within vascular systems is reviewed. While it is necessary to continue to validate the safety of such devices in vivo, great strides have been made in the development of bench tests that better predict the behavior of these products aligned with the principles of the 3R's.

Endovascular Embolization by Transcatheter Delivery of Particles: Past, Present, and Future

Minimally invasive techniques to occlude flow within blood vessels, initially pioneered in the 1970s with autologous materials and subsequently advanced with increasingly sophisticated engineered biomaterials, are routinely performed for a variety of medical conditions. Contemporary interventional radiologists have at their disposal a wide armamentarium of occlusive agents to treat a range of disease processes through a small incision in the skin. In this review, we provide a historical perspective on endovascular embolization tools, summarize the current state-of-the-art, and highlight burgeoning technologies that promise to advance the field in the near future.

Transcatheter intra-arterial infusion of doxorubicin loaded porous magnetic nano-clusters with iodinated oil for the treatment of liver cancer

A promising strategy for liver cancer treatment is to deliver chemotherapeutic agents with multifunctional carriers into the tumor tissue via intra-arterial (IA) transcatheter infusion. These carriers should release drugs within the target tissue for prolonged periods and permit intra-procedural multi-modal imaging of selective tumor delivery. This targeted transcatheter delivery approach is enabled via the arterial blood supply to liver tumors and utilized in current clinical practice which is called chemoembolization or radioembolization. During our study, we developed Doxorubicin (Dox) loaded porous magnetic nano-clusters (Dox-pMNCs). The porous structure and carboxylic groups on the MNCs achieved high-drug loading efficiency and sustained drug release, along with magnetic properties resulting in high MRI T2-weighted image contrast. Dox-pMNC within iodinated oil, Dox-pMNCs, and Dox within iodinated oil were infused via hepatic arteries to target liver tumors in a rabbit model. MRI and histological evaluations revealed that the long-term drug release and retention of Dox-pMNCs within iodinated oil induced significantly enhanced liver cancer cell death.

Alginate Microspheres Containing Temperature Sensitive Liposomes (TSL) for MR-Guided Embolization and Triggered Release of Doxorubicin

Objective

The objective of this study was to develop and characterize alginate microspheres suitable for embolization with on-demand triggered doxorubicin (DOX) release and whereby the microspheres as well as the drug releasing process can be visualized in vivo using MRI.

Methods and Findings

For this purpose, barium crosslinked alginate microspheres were loaded with temperature sensitive liposomes (TSL/TSL-Ba-ms), which release their payload upon mild hyperthermia. These TSL contained DOX and [Gd(HPDO3A)(H₂O)], a T₁ MRI contrast agent, for real time visualization of the release. Empty alginate microspheres crosslinked with holmium ions (T₂* MRI contrast agent, Ho-ms) were mixed with TSL-Ba-ms to allow microsphere visualization. TSL-Ba-ms and Ho-ms were prepared with a homemade spray device and sized by sieving. Encapsulation of TSL in barium crosslinked microspheres changed the triggered release properties only slightly: 95% of the loaded DOX was released from free TSL vs. 86% release for TSL-Ba-ms within 30 seconds in 50% FBS at 42°C. TSL-Ba-ms (76 ± 41 μm) and Ho-ms (64 ± 29 μm) had a comparable size, which most likely will result in a similar in vivo tissue distribution after an i.v. co-injection and therefore Ho-ms can be used as tracer for the TSL-Ba-ms. MR imaging of a TSL-Ba-ms and Ho-ms mixture (ratio 95:5) before and after hyperthermia allowed in vitro and in vivo visualization of microsphere deposition (T₂*-weighted images) as well as temperature-triggered release (T₁-weighted images). The [Gd(HPDO3A)(H₂O)] release and clusters of microspheres containing holmium ions were visualized in a VX₂ tumor model in a rabbit using MRI.

Conclusions

In conclusion, these TSL-Ba-ms and Ho-ms are promising systems for real-time, MR-guided embolization and triggered release of drugs in vivo.

Surgical and Locoregional Therapy of HCC: TACE

Transcatheter arterial chemoembolization (TACE) is performed worldwide for patients with intermediate-stage hepatocellular carcinoma (HCC). TACE has produced survival advantages in two randomized controlled trials and a meta-analysis, and is currently the mainstay of treatment for this stage of HCC. However, there are currently no global guidelines regarding the dose, choice or combination of cytotoxic agents for TACE; therefore, it is difficult to compare data from different TACE studies. In Japan, most of the TACE procedures have been based on iodized oil as conventional TACE, utilizing the microembolic and drug-carrying characteristic of iodized oil. Superselective TACE with lipiodol is the primary TACE procedure that has reported satisfactory levels of local control associated with a lower risk of complications. Conversely, TACE performed using drug-eluting beads has been widely used in western countries, and this has shown similar tumor response and median survival compared to conventional TACE. Moreover, the combination of TACE and molecular targeted agents is now ongoing to evaluate the synergistic effect. In this review, the indication, technical issues, and complications of TACE are reviewed.

Non-operative therapies for colorectal liver metastases

Locoregional therapies for colorectal liver metastases complement systemic therapy by providing an opportunity for local control of hepatic spread. The armamentarium for liver-directed therapy includes ablative therapies, embolization, and stereotactic body radiation therapy. At this time, prospective studies comparing these modalities are limited and decision-making relies on a multidisciplinary approach for optimal patient management. Herein, we describe multiple therapeutic non-surgical procedures and an overview of the results of these treatments.

The power of genes: a case of unusually severe systemic toxicity after localized hepatic chemoembolization with irinotecan-eluted microspheres for metastatic colon cancer

OBJECTIVE

To report a case of systemic irinotecan toxicity following regional transarterial chemoembolization with drug-eluting beads loaded with irinotecan (DEBIRI-TACE) in a patient later found to have a homozygous mutation for UGT1A1*28.

CASE SUMMARY

An 80-year-old woman presented with a cecal colon cancer with synchronous metastases to the liver. After resection of the primary tumor, the patient underwent DEBIRI-TACE with 100 mg of irinotecan to treat the residual disease in the liver. A week after this procedure, the patient developed grade 4 neutropenia, and later, alopecia. Eventually, it was found that the patient had a mutation of UDP glucuronosyltransferase 1 family polypeptide A1 (UGT1A1), which provided a reasonable explanation for the observed reaction.

DISCUSSION

The toxic effects of irinotecan are well understood. Patients with genetic polymorphisms of the genes encoding for the enzyme UGT1A1 may have increased incidence of irinotecan-associated toxicities because of decreased clearance of the active metabolite SN38 via the glucuronidation pathway. To date, there have been limited publications describing systemic adverse events following TACE or DEBIRI-TACE and, based on a thorough literature search, none following these procedures in patients with UGT1A1 polymorphisms. Based on the scoring results of the Naranjo algorithm (7), we are confident in attributing the observed reaction to the patient's genetic polymorphism.

CONCLUSION

Although genetic testing prior to the initiation of irinotecan therapy is not currently recommended, assessment of UGT1A1 polymorphism is warranted when severe adverse events typical of systemic therapy manifest following DEBIRI-TACE.

Poly(lactide-co-glycolide) microspheres for MRI-monitored transcatheter delivery of sorafenib to liver tumors

The multi-kinase inhibitor (MKI) sorafenib can be an effective palliative therapy for patients with hepatocellular carcinoma (HCC). However, patient tolerance is often poor due to common systemic side effects following oral administration. Local transcatheter delivery of sorafenib to liver tumors has the potential to reduce systemic toxicities while increasing the dose delivered to targeted tumors. We developed sorafenib-eluting PLG microspheres for delivery by intra-hepatic transcatheter infusion in an orthotropic rodent HCC model. The particles also encapsulated iron-oxide nanoparticles permitting magnetic resonance imaging (MRI) of intra-hepatic biodistributions. The PLG microspheres (diameter≈1μm) were loaded with 18.6% (w/w) sorafenib and 0.54% (w/w) ferrofluid and 65.2% of the sorafenib was released within 72h of media exposure. In vitro studies demonstrated significant reductions in HCC cell proliferation with increasing doses of the sorafenib-eluting microspheres, where the estimated IC50 was a 29μg/mL dose of microspheres. During in vivo studies, MRI permitted intra-procedural visualization of intra-hepatic microsphere delivery. At 72h after microsphere infusion, microvessel density was significantly reduced in tumors treated with the sorafenib-eluting microspheres compared to both sham control tumors (by 35%) and controls (by 30%). These PLG microspheres offer the potential to increase the efficacy of molecularly targeted MKI therapies while reducing systemic exposures via selective catheter-directed delivery to HCC.

Current status of embolic agents for liver tumor embolization

Gelatin sponge and polyvinyl alcohol particles have been the most popular particulate embolic agents for transarterial chemoembolization (TACE) of liver tumors. Over the last decade, calibrated microspheres have been introduced and increasingly used in liver tumor embolization in Western countries. In addition, drug-eluting beads (DEB) have been introduced for sustained local drug release. Such long-awaited spherical embolic agents will be introduced in Japan in the near future. The advantages of these microspheres are that particles are uniform in size and shape, and easy to inject through a microcatheter. They can travel distally to vessels corresponding to the particle size; in other words, the occlusion level can be predicted according to the particle size chosen. Thus, new bland microspheres and DEB may bring a significant advancement to embolization for primary liver tumors as well as hepatic metastases from various cancers. However, at this point, the published data suggests that both conventional TACE and DEB-TACE are equally effective for treatment of unresectable hepatocellular carcinoma, when patients are carefully selected. Therefore, indication, patient selection, and embolization techniques will be essential in order to individually adapt newer embolic agents based on oncological, anatomical and technical considerations.

Preparation and characterization of ketoprofen-loaded microspheres for embolization

To deliver drug locally and relieve the syndrome of pain after uterine artery embolization, N-[tris (hydroxymethyl) methyl] acrylamide-gelatin microspheres were prepared based on inverse suspension polymerization and then separated into a number of subgroups (150-350, 350-560, 560-710, 710-1,000, and 1,000-1,430 μm) by wet-sieving. The microspheres were dried by lyophilization or by washing with anhydrous ethanol. And ketoprofen was loaded by soaking dried blank microspheres into concentrated ketoprofen ethanol solution. The ketoprofen loading level in different subgroups of microspheres was measured and found higher when the microspheres were dried by lyophilization. Equilibrium water content and mean diameters of microspheres decreased after drug loading, especially in subgroups with larger size. The microspheres went through the catheter without any difficulty. Compression and relaxation tests were performed on microspheres before lyophilization, embosphere™, microspheres after lyophilization and ketoprofen loading microspheres. The Young's moduli were 54.74, 64.19, 98.15, and 120.44 kPa, respectively. The release of ketoprofen from microspheres in different subgroups was studied by using the USPII method and T-cell apparatus, respectively. The results indicate that the release rate of ketoprofen depends upon the diameter of microspheres, the type of dissolution apparatus and the flow rate of media in the case that T-cell apparatus was applied. The CH50 test shows that the activation of complement by ketoprofen-loaded microspheres was lower than by blank ones.

Microspheres in cancer therapy

Cancer microsphere technology is the latest trend in cancer therapy. It helps the pharmacist to formulate the product with maximum therapeutic value and minimum or negligible range side effects. Cancer is a disease in which the abnormal cells are quite similar to the normal cells, with just minute genetic or functional change. A major disadvantage of anticancer drugs is their lack of selectivity for tumor tissue alone, which causes severe side effects and results in low cure rates. Thus, it is very difficult to target abnormal cells by the conventional method of the drug delivery system. Microsphere technology is probably the only method that can be used for site-specific action, without causing significant side effects on normal cells. This review article describes various microspheres that have been prepared or formulated to exploit microsphere technology for targeted drug therapy in various cancers. We looked at the usefulness of microspheres as a tool for cancer therapy. The current review has been done using PubMed and Medline search with keywords.

Transcatheter arterial chemoembolization for liver cancer: is it time to distinguish conventional from drug-eluting chemoembolization?

Conventional transcatheter arterial chemoembolization and chemoembolization with drug-eluting beads are increasingly being performed interchangeably in many institutions throughout the world. As both therapies continue to being tested in many phase II and III studies and in combination with other therapies, especially targeted agents, for treatment of primary and metastatic liver cancer, it is imperative to review their current status and evaluate their impact on patient survival. This review critically assesses patient selection, indications, contraindications, techniques, materials, safety, and clinical outcomes of patients treated with conventional chemoembolization and chemoembolization with drug-eluting beads.

Experimental evaluation of inhibitory effect of 10-hydroxycamptothecin on hypoxia-inducible factor-1α expression and angiogenesis in liver tumors after transcatheter arterial embolization

PURPOSE

To evaluate the effect of transcatheter administration of 10-hydroxycamptothecin (HCPT), a hypoxia-inducible factor-1α (HIF-1α) inhibitor, on HIF-1α expression and angiogenesis in liver tumors after transcatheter arterial embolization in an animal model.

MATERIALS AND METHODS

VX2 tumors were implanted in the livers of 30 rabbits. The animals were divided randomly into three groups of 10 animals each. Group 1 animals received hepatic intraarterial infusion of distilled water. Group 2 animals received iodized oil infusion followed by embolization with 150-250 μm of polyvinyl alcohol particles. Group 3 animals received infusion of a mixture of HCPT (1 mg/kg body weight) with iodized oil followed by the particle embolization. Six hours or 3 days after transcatheter treatment, the animals were sacrificed, and the tumor samples were harvested. Immunohistochemical staining was performed to evaluate the levels of HIF-1α and vascular endothelial growth factor (VEGF) protein as well as microvessel density.

RESULTS

The levels of HIF-1α and VEGF and microvessel density in tumors of group 2 were significantly higher than those of group 1 or 3 (P < .05). However, no significant differences were noted in tumors between group 1 and 3 (P > .05). HIF-1α levels were significantly correlated with VEGF levels (r = .587, P = .001) and microvessel density (r = .527, P = .003).

CONCLUSIONS

Transcatheter infusion of HCPT has an inhibitory effect on HIF-1α expression and angiogenesis in liver tumors after transcatheter arterial embolization.

Nonoperative therapies for combined modality treatment of hepatocellular cancer: expert consensus statement

Although surgical resection and liver transplantation are the only treatment modalities that enable prolonged survival in patients with hepatocellular carcinoma (HCC), the majority of HCC patients presents with advanced disease and do not undergo resective or ablative therapy. Transarterial chemoembolization (TACE) is indicated in intermediate/advanced stage unresectable HCC even in the setting of portal vein involvement (excluding main portal vein). Sorafenib has been shown to improve survival of patients with advanced HCC in two controlled randomized trials. Yttrium 90 is a safe microembolization treatment that can be used as an alternative to TACE in patients with advanced liver only disease or in case of portal vein thrombosis. External beam radiation can be helpful to provide local control in selected unresectable HCC. These different treatment modalities may be combined in the treatment strategy of HCC and also used as a bridge to resection or liver transplantation. Patients should undergo formal multidisciplinary evaluation prior to initiating any such treatment in order to individualize the best available options.

In vitro characterization of cisplatin-loaded superabsorbent polymer microspheres designed for chemoembolization

PURPOSE

To find appropriate contrast media to load cisplatin into superabsorbent polymer (SAP) and to analyze the absorption and elution kinetics of cisplatin to and from SAP.

MATERIALS AND METHODS

Three contrast media-ioxaglic acid 320 mg/mL, iohexol 300 mg/mL, and iopamidol 300 mg/mL-were tested for solubility of a new highly soluble cisplatin powder. The appropriate concentrations of cisplatin were predetermined according to the solubility in each contrast medium. For each concentration, we assessed the cisplatin elution kinetics with an atomic absorption spectrophotometer. The SAP particle diameters (106-150 microm dry size) before and after drug elution were also measured.

RESULTS

The concentrations of cisplatin were predetermined as 2.5 mg/mL in ioxaglic acid, 2.5 mg/mL in iohexol, and 5.0 mg/mL in iohexol. At these concentrations, 100 mg of SAP carried 5 mg, 25 mg, and 50 mg of cisplatin dissolved in ioxaglic acid (2.5 mg/mL) and iohexol (2.5 mg/mL and 5.0 mg/mL), respectively. Cisplatin-loaded SAP in ioxaglic acid and iohexol exhibited similar elution profiles, with cisplatin fractions of 15%, 40%, 70%, and 95% at 1, 3, 6, and 24 hours, respectively. By drug elution, the mean particle diameter changed from 0.31 mm to 0.61 mm in ioxaglic acid (2.5 mg/mL), from 0.54 mm to 0.60 mm in iohexol 2.5 mg/mL, and from 0.63 mm to 0.59 mm in iohexol 5.0 mg/mL.

CONCLUSIONS

SAP was confirmed to absorb and elute cisplatin within 24 hours. When mixed with iohexol, SAP carried a ten times larger dose of cisplatin and expanded twice as large as when mixed with ioxaglic acid. Cisplatin-loaded SAP may have potential as a drug delivery system for the clinical treatment of liver tumors.

Intra-arterial therapies for hepatocellular carcinoma: where do we stand?

PURPOSE AND DESIGN

Intra-arterial therapies for unresectable hepatocellular carcinoma (HCC) consist of a catheter-based group of treatments where therapeutic and/or embolic agents are intra-arterially directed to target tumors. Here we review these therapies, which may be classified into embolotherapy/chemotherapy-based and radiotherapy-based treatments. Embolotherapy/chemotherapy-based treatments include transcatheter arterial embolization, transarterial chemoembolization, transcatheter arterial chemoeinfusion, and chemoembolization with drug-eluting beads. Radiotherapy-based treatments include radioembolization with yttrium-90 and injection of iodine-131-labeled lipiodol.

RESULTS AND CONCLUSION

Interpretation of the results of clinical trials as well as implementation of meta-analyses involving the efficacy of intra-arterial therapies for unresectable HCC has been challenging and difficult to perform. The levels of evidence for treatment recommendations in oncology provide a common framework to understand the current status of intra-arterial therapies for HCC. Here we use an evidence-based approach to critically review and comprehend the current role and future potential of intra-arterial therapies in unresectable HCC.

DC Bead: a major development in the toolbox for the interventional oncologist

The DC Bead is fast becoming the product of choice for use in the treatment of intermediate-stage hepatocellular carcinoma. It is a drug-eluting embolization system that is delivered intra-arterially and combines the effects of physical occlusion of the blood supply to a tumor with the local controlled delivery of a chemotherapeutic agent. While not suitable for use with all drugs, the components of this device enable rapid loading and sustained elution of therapeutic amounts of a range of clinically relevant anticancer compounds. Extensive preclinical testing has demonstrated the reproducibility and reliability of the device, together with reduced systemic drug exposure and sustained local drug delivery. Moreover, these attributes are translating into the clinic as significant benefits to patients with many types of liver tumors.