Technology insight: Image-guided therapies for hepatocellular carcinoma--intra-arterial and ablative techniques

Development of an immunosuppressed orthotopic hepatocellular carcinoma rat model for the evaluation of chemo- and radioembolization therapies

Hepatocellular carcinoma (HCC) is widely known to be chemo-resistant and presents with significant liver disease resulting in low tolerability to systemic chemotherapy. As a counter measure, more targeted therapies such as trans-arterial chemoembolization (TACE) and trans-arterial radioembolization (TARE) have been developed. To further optimize these therapies, animal models are critical in elucidating the molecular events in disease progression and test new treatment options. The present study focuses on the development of a hepatoma bearing rat model. N1S1 rat hepatoma cells were transfected by a lentiviral method and injected into the liver of Sprague Dawley (SD) and Rowett Nude (RNU) rats. Longitudinal tumor growth was observed by bioluminescence imaging (BLI) and liver/tumor histology. In both models, tumors were visible within 4 days post cell inoculation. Tumor take rates were 52 % and 73 % for male and female SD rats, respectively, and 100 % for male RNU rats. By day 12 and 15 post inoculation, we recorded complete tumor regression in male and female SD rats. Liver histology showed advanced fibrosis in the tumor regressed SD rats, whilst RNU rats exhibited the characteristic sheet pattern of Novikoff tumor with mild liver fibrosis. Increased CD3 and TUNEL staining observed in SD rat livers may be key factors for tumor regression. Our data reveal that the immunocompetent SD rats are not recommended as a model for therapeutic investigations. The immunosuppressed RNU rats, however, are characterized by consistent and reliable tumor growth and thus a desirable model for future therapeutic investigations.

Ultrasonography-guided radiofrequency ablation of vascular malformations-The moving shot technique

Purpose

To describe a novel ultrasound-guided technique for percutaneous radiofrequency ablation of vascular malformations-the "moving shot technique."

Methods

Preliminary observational cohort study, conducted from June 1, 2019, to January 31, 2021, including all consecutive patients diagnosed with vascular malformations who were treated with ultrasound-guided radiofrequency ablation using the moving shot technique. Only patients who had undergone at least one unsuccessful previous treatment were included (sclerotherapy with ethanol/aethoxysklerol or embolization/surgery).

Results

Eight patients with a median age of 22 years (interquartile range, 13-31) were included. Patients had different vascular malformations consisting of 1 arteriovenous malformation, 4 venous malformations, and 1 each a mixed venous-lymphatic malformation, a glomuvenous malformation and a FAVA (fibroadipose vascular anomaly). Malformations were located at the limbs in 5 patients (62.5%), the subcutaneous/intramuscular tissue of the body in 2 patients (25%) and at the chin in 1 patient (12.5%). Clinical symptoms were pain in 8 patients (100%), swelling in 6 patients (75%), and partial immobility in 4 patients (50%). All patients showed an improvement of clinical symptoms after treatment with 7 (87.5%) being completely asymptomatic and 1 (12.5%) showing improvement of immobility and pain. No procedural complications, such as nerve damage or skin burns occurred.

Conclusion

The moving shot technique using ultrasonography-guided radiofrequency ablation is a promising technique for the interventional treatment of vascular malformations and should be validated in multicenter-approaches.

Locoregional Therapies for Primary and Secondary Hepatic Malignancies

Management of hepatic malignancies is a multidisciplinary task with the involvement of hepatologists, medical/surgical/radiation oncologists, transplant surgeons, and interventional radiologists. Patients should be selected for a specific targeted therapy after multidisciplinary consensus. Interventional oncology, with image-guided locoregional cancer therapies, can decrease systemic toxicity without compromising tumoricidal effect.

Magneto mitochondrial dysfunction mediated cancer cell death using intracellular magnetic nano-transducers

Mitochondria are crucial regulators of the intrinsic pathway of cancer cell death. The high sensitivity of cancer cells to mitochondrial dysfunction offers opportunities for emerging targets in cancer therapy. Herein, magnetic nano-transducers, which convert external magnetic fields into physical stress, are designed to induce mitochondrial dysfunction to remotely kill cancer cells. Spindle-shaped iron oxide nanoparticles were synthesized to maximize cellular internalization and magnetic transduction. The magneto-mechanical transduction of nano-transducers in mitochondria enhances cancer cell apoptosis by promoting a mitochondrial quality control mechanism, referred to as mitophagy. In the liver cancer animal model, nano-transducers are infused into the local liver tumor via the hepatic artery. After treatment with a magnetic field, in vivo mitophagy-mediated cancer cell death was also confirmed by mitophagy markers, mitochondrial DNA damage assay, and TUNEL staining of tissues. This study is expected to contribute to the development of nanoparticle-mediated mitochondria-targeting cancer therapy and biological tools, such as magneto-genetics.

Tumor-suppressing miR-141 gene complex-loaded tissue-adhesive glue for the locoregional treatment of hepatocellular carcinoma

microRNAs (miRNAs) regulate gene expression post-transcriptionally and have been extensively tested as therapeutic molecules against several human diseases. In vivo delivery of miRNAs needs to satisfy the following conditions: safety, efficiency, and long-term therapeutic effectiveness. To satisfy these conditions, we developed a tissue-adhesive nucleotide-polymer complex (NPX-glue) for in vivo delivery of miRNAs to treat hepatocellular carcinoma (HCC). Methods: Polyallylamine (PAA), a cationic polymer, was mixed with tumor-suppressing miR-141 to form NPX and then mixed with partially oxidized alginate (OA) to form NPX-glue. Delivery efficiency of miR-141:NPX-glue was determined in cultured HCC cells and in an implanted HCC tumor model. In vivo tumor-suppressive effects of miR-141 on HCC were examined in mice upon intratumoral injection of miR-141:NPX-glue. Result: NPX-glue was generated by mixing of NPX with OA, which eliminated the inherent cytotoxic effect of NPX. NPX-glue led to the efficient delivery of miR-141 and plasmid to cultured cells and solid tumors in mice, where their expression was maintained for up to 30 days. Upon intratumoral injection of miR-141:NPX-glue, the growth of the tumors was dramatically retarded in comparison with the negative control, NCmiR:NPX-glue, (p < 0.05). Molecular examination proved miR-141:NPX-glue efficiently regulated the target genes including MAP4K4, TM4SF1, KEAP1, HDGF, and TIAM1 and finally induced apoptosis of cancer tissues. Conclusion: Here, we show that NPX-glue delivers therapeutic miR-141 to solid tumors in a safe, stable, and long-term manner and prove that locoregional treatment of HCC is possible using the NPX-glue system.

Transvascular therapy of Hepatocellular Carcinoma (HCC), status and developments

Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. Only 30-40% of patients diagnosed with HCC are candidates for curative treatment options. The remaining majority of patients undergo local, regional or systemic palliative therapies. Transvascular therapy of HCC takes advantage of the fact that hypervascularized HCCs receive their main perfusion from the hepatic artery. In this context transvascular therapy describes different therapies: bland embolization (transarterial embolization, TAE), cTACE (conventional transarterial chemoembolization), DEB-TACE (TACE with drug-eluting beads, DEB) and SIRT (selective internal radiation therapy, radioembolization). cTACE is the most common type of transvascular treatment and represents a combination of the intra-arterial use of a chemotherapeutic agent and embolization. There is no standardized regimen for cTACE. It remains unclear whether the intra-arterial application of a chemotherapeutic agent is definitely required, because bland embolization alone using very small spherical particles shows tumor necrosis comparable to cTACE. For DEB-TACE microparticles loaded with a chemotherapeutic drug combine the advantages of cTACE and bland embolization.

Locoregional Therapies for Primary and Secondary Hepatic Malignancies

Management of hepatic malignancies is a multidisciplinary task with the involvement of hepatologists, medical/surgical oncologists, transplant surgeons, and interventional radiologists. The patients should be selected for a specific targeted therapy after multidisciplinary consensus. Interventional oncology has established its role in the management of hepatic malignancies. Image-guided locoregional therapies decrease the rate of systemic toxicity without compromising tumoricidal effect.

Diagnostic and therapeutic management of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is an increasing health problem, representing the second cause of cancer-related mortality worldwide. The major risk factor for HCC is cirrhosis. In developing countries, viral hepatitis represent the major risk factor, whereas in developed countries, the epidemic of obesity, diabetes and nonalcoholic steatohepatitis contribute to the observed increase in HCC incidence. Cirrhotic patients are recommended to undergo HCC surveillance by abdominal ultrasounds at 6-mo intervals. The current diagnostic algorithms for HCC rely on typical radiological hallmarks in dynamic contrast-enhanced imaging, while the use of α-fetoprotein as an independent tool for HCC surveillance is not recommended by current guidelines due to its low sensitivity and specificity. Early diagnosis is crucial for curative treatments. Surgical resection, radiofrequency ablation and liver transplantation are considered the cornerstones of curative therapy, while for patients with more advanced HCC recommended options include sorafenib and trans-arterial chemo-embolization. A multidisciplinary team, consisting of hepatologists, surgeons, radiologists, oncologists and pathologists, is fundamental for a correct management. In this paper, we review the diagnostic and therapeutic management of HCC, with a focus on the most recent evidences and recommendations from guidelines.

Image-guided therapies in the treatment of hepatocellular carcinoma: A multidisciplinary perspective

A multidisciplinary approach to the treatment of patients with unresectable hepatocellular carcinoma (HCC) has led to improvements in screening, detection, and treatments. Interventional techniques include thermal ablation, transarterial chemoembolization, and radioembolization whilst stereotactic body radiation therapy also uses imaging to target the radiation. Both survival rates and cure rates have improved markedly since the introduction of these techniques. This review article describes the image guided techniques used for the treatment of HCC.

Image-guided interventional therapy for cancer with radiotherapeutic nanoparticles

One of the major limitations of current cancer therapy is the inability to deliver tumoricidal agents throughout the entire tumor mass using traditional intravenous administration. Nanoparticles carrying beta-emitting therapeutic radionuclides that are delivered using advanced image-guidance have significant potential to improve solid tumor therapy. The use of image-guidance in combination with nanoparticle carriers can improve the delivery of localized radiation to tumors. Nanoparticles labeled with certain beta-emitting radionuclides are intrinsically theranostic agents that can provide information regarding distribution and regional dosimetry within the tumor and the body. Image-guided thermal therapy results in increased uptake of intravenous nanoparticles within tumors, improving therapy. In addition, nanoparticles are ideal carriers for direct intratumoral infusion of beta-emitting radionuclides by convection enhanced delivery, permitting the delivery of localized therapeutic radiation without the requirement of the radionuclide exiting from the nanoparticle. With this approach, very high doses of radiation can be delivered to solid tumors while sparing normal organs. Recent technological developments in image-guidance, convection enhanced delivery and newly developed nanoparticles carrying beta-emitting radionuclides will be reviewed. Examples will be shown describing how this new approach has promise for the treatment of brain, head and neck, and other types of solid tumors.

Tumor uptake of hollow gold nanospheres after intravenous and intra-arterial injection: PET/CT study in a rabbit VX2 liver cancer model

PURPOSE

This study was designed to investigate the intratumoral uptake of hollow gold nanospheres (HAuNS) after hepatic intra-arterial (IA) and intravenous (IV) injection in a liver tumor model.

MATERIALS AND METHODS

Fifteen VX2 tumor-bearing rabbits were randomized into five groups (n = 3 in each group) that received either IV (64)Cu-labeled PEG-HAuNS (IV-PEG-HAuNS), IA (64)Cu-labeled PEG-HAuNS (IA-PEG-HAuNS), IV cyclic peptide (RGD)-conjugated (64)Cu-labeled PEG-HAuNS (IV-RGD-PEG-HAuNS), IA RGD-conjugated (64)Cu-labeled PEG-HAuNS (IA-RGD-PEG-HAuNS), or IA (64)Cu-labeled PEG-HAuNS with lipiodol (IA-PEG-HAuNS-lipiodol). The animals underwent PET/CT 1 h after injection, and uptake expressed as percentage of injected dose per gram of tissue (%ID/g) was measured in tumor and major organs. The animals were euthanized 24 h after injection, and tissues were evaluated for radioactivity.

RESULTS

At 1 h after injection, animals in the IA-PEG-HAuNS-lipiodol group showed significantly higher tumor uptake (P < 0.001) and higher ratios of tumor-to-normal liver uptake (P < 0.001) than those in all other groups. The biodistribution of radioactivity 24 h after injection showed that IA delivery of PEG-HAuNS with lipiodol resulted in the highest tumor uptake (0.33 %ID/g; P < 0.001) and tumor-to-normal liver ratio (P < 0.001) among all delivery methods. At 24 h, the IA-RGD-PEG-HAuNS group showed higher tumor uptake than the IA-PEG-HAuNS group (0.20 vs. 0.099 %ID/g; P < 0.001).

CONCLUSION

Adding iodized oil to IA-PEG-HAuNS maximizes nanoparticle delivery to hepatic tumors and therefore may be useful in targeted chemotherapy and photoablative therapy. PET/CT can be used to noninvasively monitor the biodistribution of radiolabeled HAuNS after IV or IA injection.

Gold nanoshelled liquid perfluorocarbon magnetic nanocapsules: a nanotheranostic platform for bimodal ultrasound/magnetic resonance imaging guided photothermal tumor ablation

Imaging guided ablation therapy has been applied in both biomedical research and clinical trials and turned out to be one of the most promising approaches for cancer treatment. Herein, the multifunctional nanocapsules were fabricated through loading perfluorooctylbromide (PFOB) and superparamagnetic iron oxide nanoparticles (SPIOs) into poly(lactic acid) (PLA) nanocapsules (NCs), followed by the formation of PEGylated gold nanoshell on the surface. The resulting multi-component NCs were proved to be able to act as nanotheranostic agent to achieve successful bimodal ultrasound (US)/magnetic resonance imaging (MRI) guided photothermal ablation in human tumor xenograft models non-invasively. Such a single theranostic agent with the combination of real-time US and high-resolution MR imaging would be of great value to offer more comprehensive diagnostic information and dynamics of disease progression for the accurate location of therapeutic focusing spot in the targeted tumor tissue, showing great potential as an effective nanoplatform for contrast imaging guided photothermal therapy.

MR imaging of therapeutic magnetic microcarriers guided by magnetic resonance navigation for targeted liver chemoembolization

PURPOSE

Magnetic resonance navigation (MRN), achieved with an upgraded MRI scanner, aims to guide new therapeutic magnetic microcarriers (TMMC) from their release in the hepatic vascular network to liver tumor. In this technical note, in vitro and in vivo MRI properties of TMMC, loaded with iron-cobalt nanoparticles and doxorubicin, are reported by following three objectives: (1) to evaluate the lengthening of echo-time (TE) on nano/microparticle imaging; (2) to characterize by MRI TMMC distribution in the liver; and (3) to confirm the feasibility of monitoring particle distribution in real time.

METHODS

Phantom studies were conducted to analyze nano/microparticle signals on T 2*-weighted gradient-echo (GRE) MR images according to sample weight and TE. Twelve animal experiments were used to determine in vivo MRI parameters. TMMC tracking was evaluated by magnetic resonance imaging (MRI) in four rabbits, which underwent MRN in the hepatic artery, three without steering, two in real-time, and three as blank controls. TMMC distribution in the right and left liver lobes, determined by ex vivo MR image analysis, was compared to the one obtained by cobalt level analysis.

RESULTS

TMMC induced a hypointense signal that overran the physical size of the sample on MR images. This signal, due to the nanoparticles embedded into the microparticles, increased significantly with echo-time and sample amount (p < 0.05). In vivo, without steering, contrast-to-noise ratio (CNR) values for the right and left lobes were similar. With MRN, the CNR in the targeted lobe was different from that in the untargeted lobe (p = 0.003). Ex vivo, TMMC distribution, based on MRI signal loss volume measurement, was correlated with that quantified by Co level analysis (r = 0.92). TMMC accumulation was tracked in real time with an 8-s GRE sequence.

CONCLUSIONS

MRI signal loss induced by TMMC can serve to track particle accumulation and to assess MRN efficiency.

Photothermal ablation of pancreatic cancer cells with hybrid iron-oxide core gold-shell nanoparticles

Purpose

Photothermal ablation is a minimally invasive approach, which typically involves delivery of photothermal sensitizers to targeted tissues. The purpose of our study was to demonstrate that gold nanoparticles are phagocytosed by pancreatic cancer cells, thus permitting magnetic resonance imaging (MRI) of sensitizer delivery and photothermal ablation.

Patients and methods

Iron-oxide core/gold-shell nanoparticles (GoldMag®, 30 nm diameter; Xi’an GoldMag Biotechnology Co, Xi’an, People’s Republic of China) were used. In a 96-well plate, 3 × 10⁴ PANC-1 (human pancreatic cancer cell line) cells were placed. GoldMag (0, 25, or 50 μg/mL) was added to each well and 24 hours allowed for cellular uptake. Samples were then divided into two groups: one treated with photothermal ablation (7.9 W/cm²) for 5 minutes, the other not treated. Photothermal ablation was performed using laser system (BWF5; B&W Tek, Inc, Newark, DE, USA). Intraprocedural temperature changes were measured using a fiber optic temperature probe (FTP-LN2; Photon Control Inc, Burnaby, BC, Canada). After 24 hours, the remaining number of viable cells was counted using trypan blue staining; cell proliferation percentage was calculated based on the total number of viable cells after treatment compared with control. MRI of GoldMag uptake was performed using a 7.0T ClinScan system (Bruker BioSpin, Ettlingen, Germany).

Results

Temperature curves demonstrated that with increased GoldMag uptake, laser irradiation produced higher temperature elevations in the corresponding samples; temperature elevations of 12.89°C, 35.16°C, and 79.51°C were achieved for 0, 25, and 50 μg/mL GoldMag. Without photothermal ablation, the cell proliferation percentage changed from 100% to 71.3% and 47.0% for cells treated with 25 and 50 μg/mL GoldMag. Photothermal ablation of PANC-1 cells demonstrated an effective treatment response, specifically a reduction to only 61%, 21.9%, and 2.3% cell proliferation for cells treated with 0, 25, and 50 μg/mL GoldMag. MRI was able to visualize GoldMag uptake within PANC-1 cells.

Conclusion

Our findings suggest that photothermal ablation may be effective in the treatment of pancreatic cancer. GoldMag nanoparticles could serve as photothermal sensitizers, and MRI is feasible to quantify delivery.

Pathological changes and cell apoptosis in rabbit VX2 liver tumors after radiofrequency ablation

AIM: To examine pathological changes and cell apoptosis in rabbit VX2 liver tumors after radiofrequency ablation (RFA) to provide a theoretical basis for clinical treatment of liver cancer by RFA.

METHODS: A rabbit model of VX2 liver tumors was induced by injection of VX2 carcinoma cell suspension, and hepatic VX2 tumors were then treated by radiofrequency ablation. After treatment, tissue samples were taken to examine pathological changes in tumor tissue by light microscopy after HE staining, and to detect apoptosis by TdT-mediated dUTP nick end labeling assay.

RESULTS: After RFA, tumor tissues surrounding the ablation electrode showed sequential changes of necrotis, mixed necrosis and apoptosis, and apoptosis. Inflammatory cell invasion occurred in the necrotic area and mixed necrotic and apoptotic area. Residual living tumor cells were visible in the mixed necrotic and apoptotic area. Hepatocytes surrounding tumor cells showed apoptosis and occasionally necrosis. Apoptosis was also visible in vascular endothelial cells in the central vein and portal area and epithelial cells in the intrahepatic bile duct.

CONCLUSION: Assessment of pathological changes and cell apoptosis in rabbit VX2 liver tumors after RFA provides a theoretical basis for clinical treatment of liver cancer by RFA.

Glyceraldehyde-3-phosphate dehydrogenase: a promising target for molecular therapy in hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most highly lethal malignancies ranking as the third leading-cause of cancer-related death worldwide. Although surgical resection and transplantation are effective curative therapies, very few patients qualify for such treatments due to the advanced stage of the disease at diagnosis. In this context, loco-regional therapies provide a viable therapeutic alternative with minimal systemic toxicity. However, as chemoresistance and tumor recurrence negatively impact the success of therapy resulting in poorer patient outcomes it is imperative to identify new molecular target(s) in cancer cells that could be effectively targeted by novel agents. Recent research has demonstrated that proliferation in HCC is associated with increased glucose metabolism. The glycolytic enzyme, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), a multifunctional protein primarily recognized for its role in glucose metabolism, has already been shown to affect the proliferative potential of cancer cells. In human HCC, the increased expression of GAPDH is invariably associated with enhanced glycolytic capacity facilitating tumor progression. Though it is not yet known whether GAPDH up-regulation contributes to tumorigenesis sensu stricto, emerging evidence points to the existence of a link between GAPDH up-regulation and the promotion of survival mechanisms in cancer cells as well as chemoresistance. The involvement of GAPDH in several hepatocarcinogenic mechanisms (e.g. viral hepatitis, metabolic alterations) and its sensitivity to a new class of prospective anticancer agents prompted us to review the current understanding of the therapeutic potential of targeting GAPDH in HCC.

Clinical application of image-enhanced minimally invasive robotic surgery for gastric cancer: a prospective observational study

BACKGROUND

This study was performed to validate the feasibility and role of image-guided robotic surgery using preoperative computed tomography (CT) images for the treatment of gastric cancer.

METHODS

Twelve patients scheduled to undergo robotic gastrectomy for gastric cancer were registered. Vessels encountered during gastrectomy were reconstructed using 3D software and their anatomical variation was evaluated using preoperatively performed CT-angiography. The vascular information was transferred to a robot console using a multi-input display mode. Radiologic findings acquired from preoperative CT by the radiologist were compared with intraoperative findings of the surgeon. This study is registered with www.clinicaltrials.gov as NCT01338948.

RESULTS

All 12 robotic gastrectomies were performed without any problems. All anatomical data acquired using 3D software were transferred successfully during surgery. Intraoperative vascular images depicted vasculatures around the stomach and could identify important vascular variations. During surgery, relevant vascular information led the surgeon to branch sites and facilitated lymphadenectomy around the vessels. Image-guidance during the operation provided a vascular map and enabled the surgeon to avoid accidental bleeding and damage to other organs by preventing vascular injuries.

CONCLUSION

Image-guided robotic surgery for gastric cancer using preoperative CT-angiography reconstructed during operation by a surgically trained radiologist who could adjust the images by anticipating the operative procedure was feasible and improved the efficiency of surgery by eliminating the possibility of vascular injuries.

Enhancement patterns of hepatocellular carcinoma after transarterial chemoembolization using drug-eluting beads on arterial phase CT images: a pilot retrospective study

OBJECTIVE

The purpose of this article is to assess CT enhancement patterns of hepatocellular carcinoma (HCC) within 1 month after transarterial chemoembolization (TACE) using drug-eluting beads and to determine whether enhancement patterns may be useful for predicting local tumor progression.

MATERIALS AND METHODS

Forty-one patients with 50 HCCs underwent CT within 1 month after TACE with drug-eluting beads. Two blinded readers independently reviewed the arterial phase images and classified enhancement patterns as follows: no enhancement, peripheral ring enhancement, and peripheral nodulelike enhancement. Enhancement patterns were correlated with time to tumor progression of enhancing tissue by log-rank test.

RESULTS

In the group with no enhancement, 92.3% (24/26) had not progressed and 7.7% (2/26) showed progression; for peripheral ring enhancement, 83.3% (10/12) had not progressed and 16.7% (2/12) showed progression; and for peripheral nodulelike enhancement, 16.7% (2/12) had not progressed and 83.3% (10/12) showed progression. The time to progression of enhancing tissue was significantly different between the group with no enhancement plus peripheral ring enhancement and the group with peripheral nodulelike enhancement (p < 0.001).

CONCLUSION

Analysis of enhancement patterns at the arterial phase of the first follow-up CT after TACE with drug-eluting beads is helpful for predicting progression of treated HCC.

Advances in image-guided intratumoral drug delivery techniques

Image-guided drug delivery provides a means for treating a variety of diseases with minimal systemic involvement while concurrently monitoring treatment efficacy. These therapies are particularly useful to the field of interventional oncology, where elevation of tumor drug levels, reduction of systemic side effects and post-therapy assessment are essential. This review highlights three such image-guided procedures: transarterial chemoembolization, drug-eluting implants and convection-enhanced delivery. Advancements in medical imaging technology have resulted in a growing number of new applications, including image-guided drug delivery. This minimally invasive approach provides a comprehensive answer to many challenges with local drug delivery. Future evolution of imaging devices, image-acquisition techniques and multifunctional delivery agents will lead to a paradigm shift in patient care.

Surgical treatment for large hepatocellular carcinoma: does size matter?

Despite significant progress in the management of hepatocellular carcinoma (HCC), patients with large HCC (defined as >10 cm) continue to present a significant challenge. The goal of this paper is to review the existing literature regarding large HCC, with emphasis on identifying the issues and challenges involved in approaching these tumours surgically. A computerized search was made of the Medline database from January 1992 to December 2010. The MESH heading 'large' or 'huge' in combination with the keyword 'hepatocellular carcinoma' was used. After excluding further studies that identified 'large' HCC as less than 10 cm and/or sequential publications with overlapping patient populations, the search produced a study population of 22 non-duplicated papers, reporting on a total of 5223 patients with HCC tumours >10 cm. Regarding resection for large HCC, the overall 5-year survival in these studies ranged from 25% to 45%, with few outliers on both sides, whereas in most studies, the 5-year disease-free survival ranged between 15% and 35%, with the only exception being studies with patients with single lesions and no cirrhosis showing disease-free survival of 41% and 56%, respectively. Risk factors identified included vascular invasion, cirrhosis, high level of alpha-fetoprotein and the presence of multiple lesions. Finally, liver transplantation, although an attractive concept, did not appear to offer a survival benefit in any of the studies. In conclusion, identifying the risk factors that affect the outcome in patients undergoing surgery for large HCC is critical. The reason is that surgical resection can have excellent outcomes in carefully selected patients.

Ultrasound-Guided, Video-Assisted Transdiaphragmatic Radiofrequency Ablation for Primary Liver Malignancy or Metastatic Nodules

Objective

Percutaneous radiofrequency ablation (RFA) is among the best options in the treatment of primary liver malignancy and metastases because it is a highly effective and minimally invasive alternative to resection in small, nonresectable tumors or in poor surgical candidates and is associated with low morbidity and mortality. We evaluated the clinical feasibility and safety of thoracoscopic, ultrasound (US)-guided RFA of subdiaphragmatic liver malignancies in advanced cirrhotic patients awaiting transplantation.

Methods

Two patients (one female and one male) with end-stage cirrhosis who developed hepatocellular carcinoma were treated thoracoscopically by US-guided RFA. An endoscopic US probe was inserted into the right pleural space through a 10-mm working channel. An RF-operating needle applicator was inserted through a second 10-mm working port after identification of the lesion, penetrating the diaphragm toward the lesion. The procedure duration, applied energy, and generator output were recorded during the intervention. The treatment result and procedure-related complications were analyzed.

Results

The procedure duration was 74 and 92 minutes, respectively. A mean energy deposition of 353 joules resulted in a mean coagulation volume of 115 cm. Tumor ablation was achieved as determined by the postinterventional lack of contrast enhancement in the target region at the follow-up computed tomographic scans performed after 4 months.

Conclusions

RFA offers definite possibilities in the management of small-sized tumors. Thoracoscopic, US-guided transdiaphragmatic RFA has proven to be clinically feasible and safe and can be an effective modality for treating subdiaphragmatic liver lesions. Its minimally invasive nature is the most important advantage compared with surgical resection, especially for patients with high operative risk.

Intra-arterial brachytherapy of hepatic malignancies: watch the flow

Although the liver possesses a dual blood supply, arterial vessels deliver only a small proportion of blood to normal parenchyma, but they deliver the vast majority of blood to primary and secondary cancers of the liver. This anatomical discrepancy is the basis for intra-arterial brachytherapy of liver cancers using radioactive microspheres, termed radio-embolization (RE). Radioactive microspheres implant preferentially in the terminal arterioles of tumors. Although biological models of the flow dynamics and distribution of microspheres are currently in development, there is a need to improve the imaging biomarkers of flow dynamics used to plan RE. Since a direct consequence of RE is vascular disruption and necrosis, we suggest that imaging protocols sensitive to changes in vasculature are highly likely to represent useful early biomarkers for treatment efficacy. We propose dynamic contrast-enhanced CT as the most appropriate imaging modality for studying vascular parameters in clinical trials of RE treatment.

Radiofrequency ablation of hepatocellular carcinoma: pros and cons

Among locoregional treatments for hepatocellular carcinoma (HCC), radiofrequency ablation (RFA) has been accepted as the most popular alternative to curative transplantation or resection, and it shows an excellent local tumor control rate and acceptable morbidity. The benefits of RFA have been universally validated by the practice guidelines of international societies of hepatology. The main advantages of RFA include 1) it is minimally invasive with acceptable morbidity, 2) it enables excellent local tumor control, 3) it has promising long-term survival, and 4) it is a multimodal approach. Based on these pros, RFA will play an important role in managing the patient with early HCC (smaller than 3 cm with fewer than four tumors). The main limitations of current RFA technology in hepatic ablation include 1) limitation of ablation volume, 2) technically infeasible in some tumors due to conspicuity and dangerous location, and 3) the heat-sink effect. Many technical approaches have been introduced to overcome those limitations, including a novel guiding modality, use of artificial fluid or air, and combined treatment strategies. RFA will continue to play a role as a representative ablative modality in the management of HCC, even in the era of targeted agents.

Radioablation settings affecting the size of lesions created ex vivo in porcine livers with monopolar perfusion electrodes

RATIONALE AND OBJECTIVES

To explore the morphological characteristics of ablated lesions and find which combination of duration, temperature, and power was preferable to create largest lesion size with monopolar perfusion electrodes.

MATERIALS AND METHODS

Using monopolar perfusion electrodes to create 72 lesions in 30 excised porcine livers with radiofrequency radiation at different durations (5, 10, 15, and 20 minutes), temperatures (83 degrees C, 93 degrees C, 103 degrees C, and 113 degrees C), and powers (20, 30, and 40 W). Lesion volumes were calculated from longitudinal diameters and transverse diameters. Morphological characteristics were assessed microscopically from slides stained with hematoxylin and eosin.

RESULTS

Positive correlations were found between duration and longitudinal diameter (r = 0.66; P < .001), transverse diameter (r = 0.66; P < .001), distance of ablation beyond the electrode tip (r = 0.56; P < .001), and volume of lesions (r = 0.66; P < .001). Temperature was also positively correlated with longitudinal diameter (r = 0.70; P < .001), transverse diameter (r = 0.72; P < .001), distance of ablation beyond the electrode tip (r = 0.61; P < .001), and lesion volume (r = 0.711; P < .001). Lesion size did not increase when duration was longer than 15 minutes and temperature was higher than 103 degrees C. Power was not correlated with lesion size. Lesion size did not increase with increasing power. Macroscopically, all lesions were elliptical in cross section and appeared three zones: a central zone (I), a coagulated necrotic zone (II), and a hemorrhagic and edematous zone (III) from inside to outside. Microscopically, cells morphology and the nucleus were irregular or even disappeared in zone I. In zone II and III, cells did not appear deformation.

CONCLUSION

Duration and temperature, not power, affected lesion size. The largest lesion size was about 3.5 cm x 2.5 cm x 2.5 cm as temperature and duration was 15 minutes/103 degrees C.

Interventional therapy of head and neck cancer with lipid nanoparticle-carried rhenium 186 radionuclide

PURPOSE

Minimally invasive interventional cancer therapy with drug-carrying lipid nanoparticles (ie, liposomes) via convection-enhanced delivery by an infusion pump can increase intratumoral drug concentration and retention while facilitating broad distribution throughout solid tumors. The authors investigated the utility of liposome-carrying beta-emitting radionuclides to treat head and neck cancer by direct intratumoral infusion in nude rats.

MATERIALS AND METHODS

Four groups of nude rats were subcutaneously inoculated with human tongue cancer cells. After tumors reached an average size of 1.6 cm(3), the treatment group received an intratumoral infusion of liposomal rhenium-186 ((186)Re) (185 MBq [5 mCi]/cm(3) tumor). Three control groups were intratumorally infused with unlabeled liposomes, unencapsulated (186)Re-perrhenate, or unencapsulated intermediate (186)Re compound ((186)Re-N,N-bis[2-mercaptoethyl]-N',N'-diethyl-ethylenediamine [BMEDA]). In vivo distribution of (186)Re activity was measured by planar gamma-camera imaging. Tumor therapy and toxicity were assessed by tumor size, body weight, and hematology.

RESULTS

Average tumor volume in the (186)Re-liposome group on posttreatment day 14 decreased to 87.7% +/- 20.1%, whereas tumor volumes increased to 395.0%-514.4% on average in the other three groups (P< .001 vs (186)Re-liposome). The (186)Re-liposomes provided much higher intratumoral retention of (186)Re activity, resulting in an average tumor radiation absorbed dose of 526.3 Gy +/- 93.3, whereas (186)Re-perrhenate and (186)Re-BMEDA groups had only 3.3 Gy +/- 1.2 and 13.4 Gy +/- 9.2 tumor doses, respectively. No systemic toxicity was observed.

CONCLUSIONS

Liposomal (186)Re effectively treated head and neck cancer with minimal side effects after convection-enhanced interventional delivery. These results suggest the potential of liposomal (186)Re for clinical application in interventional therapy of cancer.

Current status of radiofrequency ablation of hepatocellular carcinoma

Loco-regional treatments for hepatocellular carcinoma (HCC) are important alternatives to curative transplantation or resection. Among them, radiofrequency ablation (RFA) is accepted as the most popular technique showing excellent local tumor control and acceptable morbidity. The current role of RFA is well documented in the evidence-based practice guidelines of European Association of Study of Liver, American Association of Study of the Liver Disease and Japanese academic societies. Several randomized controlled trials have confirmed that RFA is superior to percutaneous ethanol injections in terms of local tumor control and survival. The overall survival after RFA is comparable to after surgical resection in a selected group of patients with smaller (< 3 cm) tumors. Currently, the clinical benefits of combined RFA with transarterial chemoembolization for intermediate stage HCC are increasingly being explored. Here we review the ongoing technical advancements of RFA and future potential.

Dendritic cells loaded with ultrasound-ablated tumour induce in vivo specific antitumour immune responses

Previous studies have shown that high-intensity focused ultrasound (HIFU) ablation can induce a local inflammation with marked infiltration of dendritic cells (DCs). The purpose of this study was to investigate whether DCs could capture and present activating signals delivered by necrotic tumour cells that remain in situ after HIFU, thus initiating specific antitumour immunity. Tumour debris was derived from a mouse H22 tumour model after HIFU ablation. Bone marrow-derived DCs were loaded with HIFU-treated tumour, tumour lysate and mouse serum. Syngeneic naïve C57BL/6J mice were immunised with three loaded DCs followed by a subsequent H22 tumour challenge. Tumour size and survival were then recorded in each vaccinated mouse. The results showed that both HIFU-ablated tumour and tumour lysate could significantly increase the number of mature DCs and the secretion of IL-12 and IFN-gamma (p<0.001). The proliferation of splenic lymphocytes co-incubated with the loaded-DCs was significantly higher in both HIFU-ablated tumour and tumour lysate groups (p<0.01). Cytotoxocity and TNF-alpha and IFN-gamma secretion of cytotoxic T lymphocytes against H22 cells were significantly higher in HIFU-ablated tumour group than that in tumour lysate group (p<0.01). After the H22 tumour challenge, a significant decrease of tumour volume was observed in HIFU-ablated tumour group (p<0.01). However, there was no statistical difference of long-term survival rates among three groups (p>0.05). It is concluded that DCs can be activated by HIFU-ablated tumour debris and, thus, initiate host specific antitumour immune response after HIFU therapy.

Transarterial embolisation of hepatocellular carcinoma with doxorubicin-eluting beads: single centre early experience

Purpose:

This is a retrospective study to evaluate the results of our early experience of using doxorubicin eluting beads (DEB) to treat patients with early and intermediate hepatocellular carcinoma (HCC).

Material and methods: A cohort of 19 patients (84.2% male; 15.8% female; mean age 59.2 years ± 11.0; range, 32-80 years) with documented HCC of size 1.8-10cm (mean, 4.0cm ± 1.8 ) undergoing DEB transarterial chembolisation (TACE) was reviewed. All patients had at least one image examination (multiphase computed tomography or magnetic resonance imaging) after embolisation.

Results:

A total of 32 procedures were performed. The objective response according to the European Association for the Study of the Liver criteria was 57.9% at 1-month, 42.8% at 6-month and 50.0% at 1-year follow up. There were 4 (21.1%) treatment-related complications (1 liver abscess, 2 pancreatitis and 1 tumour rupture) which resulted in 2 deaths. One death occurred 3 weeks after second embolisation, due to ruptured pancreatic pseudocyst, giving a 5.3% 30-day mortality rate. Another patient died 2 months after embolisation caused by tumour rupture. Eight patients received radiofrequency ablation after embolisation for residual or recurrent tumours. The 1-year survival rate in the DEB TACE only group was 80% while the 1- and 2-year survival rate in the group that received radiofrequency after DEB TACE was 85.7% and 100% respectively.

Conclusion:

DEB TACE is safe and effective in select group of patients. Survival may be improved when combined with other treatment modality.

Liver metastases from colorectal cancer: radioembolization with systemic therapy

The majority of patients with advanced colorectal cancer die from hepatic metastases caused by disease progression; therefore, several novel technologies are in clinical development to potentially improve local control of liver disease. Radioembolization is a technique for administering radiotherapy internally to unresectable primary or secondary hepatic malignancies in a single procedure. This technique involves the injection of resin or glass microspheres that contain (90)Y into the arterial supply of the liver. Clinical trials of radioembolization used with concomitant radiosensitizing chemotherapy have shown promising results in patients with metastatic colorectal cancer. Several reports suggest that radioembolization is associated with significant downsizing of liver metastases to permit subsequent surgical resection. In this article, the rationale for combining radioembolization with the cytotoxic and molecularly targeted agents licensed for the systemic treatment of colorectal cancer is outlined. Clinical data from trials of radioembolization with concomitant systemic treatment are reviewed, with an emphasis on the appropriateness of primary end points in large-scale trials and the practical aspects of surgical resection in patients whose tumors are successfully downsized by this chemoradiation approach.

Radiofrequency ablation: post-ablation assessment using CT perfusion with pharmacological modulation in a rat subcutaneous tumor model

RATIONALE AND OBJECTIVES

Inflammatory reaction surrounding the ablated area is a major confounding factor in the early detection of viable tumor after radiofrequency (RF) ablation. A difference in the responsiveness of normal and tumor blood vessels to vasoactive agents may be used to distinguish these regions in post-ablation follow-up. The goal of this study was to examine longitudinal perfusion changes in untreated viable tumor and the peripheral hyperemic rim of RF-ablated tumor in response to a vasoconstrictor (phenylephrine) or vasodilator (hydralazine) in a subcutaneous rat tumor model.

MATERIALS AND METHODS

Bilateral subcutaneous shoulder tumors were inoculated in 24 BDIX rats and evenly divided into two groups (phenylephrine and hydralazine groups). One tumor in each animal was completely treated with RF ablation (at 90 +/- 2 degrees C for 3 minutes), and the other remained untreated. Computed tomographic perfusion scans before and after phenylephrine (10 microg/kg) or hydralazine (5 mg/kg) administration were performed 2, 7, and 14 days after ablation. Four rats per group were euthanized on each scan day, and pathologic evaluation was performed. The changes of blood flow in the peripheral rim of ablated tumor and untreated viable tumor in response to phenylephrine or hydralazine at each time point were compared. The diagnostic accuracy of viable tumor using the percentage change of blood flow in response to phenylephrine and hydralazine was compared using receiver-operating characteristic analysis.

RESULTS

The peripheral rim of ablated tumor presented with a hyperemic reaction with dilated vessels and congestion on day 2 after ablation, numerous inflammatory vessels on day 7, and granulation tissue formation on day 14. Phenylephrine significantly decreased the blood flow in the peripheral hyperemic rim of ablated tumor on days 2, 7, and 14 by 16.3 +/- 9.7% (P = .001), 24.0 +/- 22.6% (P = .007), and 31.1 +/- 25.4% (P = .045), respectively. In untreated viable tumor, the change in blood flow after phenylephrine was irregular and insignificant. Hydralazine decreased the blood flow in the peripheral rim of both ablated tumor and untreated viable tumor. Receiver-operating characteristic analysis showed that reliable tumor diagnosis using the percentage change of blood flow in response to phenylephrine was noted on days 2 and 7, for which the areas under the curve were 0.82 (95% confidence interval, 0.64-1.00) and 0.81 (95% confidence interval, 0.56-1.00), respectively. However, tumor diagnosis using the blood flow change in response to hydralazine was unreliable.

CONCLUSION

Phenylephrine markedly decreased blood flow in the peripheral hyperemic rim of ablated tumor but had little effect on the untreated viable tumor. Computed tomographic perfusion with phenylephrine may be useful in the long-term treatment assessment of RF ablation.

Radiofrequency ablation and chemoembolization for hepatocellular carcinoma

PURPOSE

To provide an up-to-date review of the technique, efficacy, safety and clinical applications for radiofrequency ablation (RFA) and transarterial chemoembolization (TACE) for hepatocellular carcinoma (HCC).

METHODS

A thorough review of the literature was performed as related to RFA and TACE for the treatment of HCC. We mixed these findings with our own extensive research and clinical experience on this subject by drawing from a pool of more than 1000 patients treated with both modalities.

RESULTS

TACE has been shown with the work of Llovet, Camma, and Lo to provide a significant survival benefit for patients with unresectable HCC. The former showed a 1-, 2-, and 3-year survival at 57%, 31%, and 26% in the treatment group vs. 32%, 11%, and 3% in the supportive treatment alone group, respectively. Repeatedly, RFA has been shown to be very effective in the treatment of small (<or=3 cm) HCC lesions with a complete response rate of about 90%. Studies have shown that RFA may be equivalent to surgical resection in this subgroup of patients. For both modalities, patient selection and proper technique are important in minimizing the possible complications associated with them, which rarely includes liver failure, abscess formation, and hemorrhage.

DISCUSSION

RFA and TACE have both been shown to provide a survival benefit for patients with unresectable HCC. More recent studies have paired these modalities with surgical resection with favorable results. Refined technique, improvements in technology, and research on better-targeted chemotherapy will likely result in further improved survival benefit. Additionally, the scope of this treatment is broadening to include resectable patients, patients awaiting liver transplantation, and, in combination with other systemic (bevacizumab, sorafenib, etc) or locoregional (RFA-TACE combination, RFA-resection etc) treatments.

Recent advances in transarterial therapy of primary and secondary liver malignancies

The management of liver malignancies presents many challenges. Few patients with primary hepatocellular carcinoma or metastatic disease of the liver are eligible for surgery, which is the only curative therapeutic option. Because the hepatic tumor burden is often a determinant of eligibility for surgery and is a primary contributor to morbidity and mortality, an increasing number of innovative techniques based on the transarterial administration of liver-directed drug-eluting or radiation-emitting microspheres are being tested for use in cytoreductive and palliative therapy. The delivery of therapy via a transarterial route takes advantage of the fact that hepatic malignancies are primarily supplied by the hepatic artery. The early results of clinical trials are promising; the clinical effectiveness and safety of drug-eluting and yttrium-90-bearing microspheres have been demonstrated; however, further clinical investigation is needed to verify a benefit in survival. Transarterially administered gene therapy holds promise but is still in the early stages of investigation. For all transarterial therapies, the outcome depends heavily on meticulous patient selection, careful preparation and administration of therapy, and early and regular follow-up evaluations by using an interdisciplinary approach.

Drug-loaded microspheres for the treatment of liver cancer: review of current results

Transarterial chemoembolization (TACE) involves the emulsification of a chemotherapeutic agent in a viscous drug carrier, delivered intra-arterially to liver tumor for maximum effect. TACE reduces arterial inflow, diminishes washout of the chemotherapeutic agent, and decreases systemic exposure. Despite evidence of some clinical success with TACE, a new type of microspheres with drug-eluting capabilities may offer a precisely controlled and sustainable release of the chemotherapeutic agent into the tumor bed. In animal trials tumor necrosis (approaching 100%) was greatest at 7 days, with significantly lower plasma concentrations of doxorubicin than in control animals treated with doxorubicin intra-arterially. Clinically, drug-eluting microspheres loaded with doxorubicin, either at 75 mg/m(2) or at a fixed dose of 150 mg, were used recently and no severe disorders of the hepatic function were observed postprocedure, while a substantial reduction of the fetoprotein levels occurred. An interim analysis of the first 15 patients from the Hong Kong group at 3 months showed an objective response rate of 61.54% and 53.84% according to EASL criteria and RECIST criteria, respectively, and a survival rate of 93.3%. In this paper we present how to use microspheres loaded with doxorubicin and review their clinical value and preliminary performance for treatment of unresectable liver cancer.