Ablation techniques for primary and metastatic liver tumors

Effect of high blood flow on heat distribution and ablation zone during microwave ablation-numerical approach

Microwave ablation has become a viable alternative for cancer treatment for patients who cannot undergo surgery. During this procedure, a single-slot coaxial antenna is employed to effectively deliver microwave energy to the targeted tissue. The success of the treatment was measured by the amount of ablation zone created during the ablation procedure. The significantly large blood vessel placed near the antenna causes heat dissipation by convection around the blood vessel. The heat sink effect could result in insufficient ablation, raising the risk of local tumor recurrence. In this study, we investigated the heat loss due to large blood vessels and the relationship between blood velocity and temperature distribution. The hepatic artery, with a diameter of 4 mm and a height of 50 mm and two branches, is considered in the computational domain. The temperature profile, localized tissue contraction, and ablation zones were simulated for initial blood velocities 0.05, 0.1, and 0.16 m/s using the 3D Pennes bio-heat equation, temperature-time dependent model, and cell death model, respectively. Temperature-dependent blood velocity is modeled using the Navier-Stokes equation, and the fluid-solid interaction boundary is treated as a convective boundary. For discretization, we utilized H curl Ω elements for the wave propagation model,H 1 Ω elements for the Pennes bio-heat model, andH 1 Ω 3 × L 0 2 Ω elements for the Navier-Stokes equation, where Ω represents the computational domain. The simulated results show that blood vessels and blood velocity have a significant impact on temperature distribution, tissue contraction, and the volume of the ablation zone.

Conventional versus Hepatic Arteriography and C-Arm CT-Guided Ablation of Liver Tumors (HepACAGA): A Comparative Analysis

PURPOSE

Hepatic Arteriography and C-Arm CT-Guided Ablation of liver tumors (HepACAGA) is a novel technique, combining hepatic-arterial contrast injection with C-arm CT-guided navigation. This study compared the outcomes of the HepACAGA technique with patients treated with conventional ultrasound (US) and/or CT-guided ablation.

MATERIALS AND METHODS

In this retrospective cohort study, all consecutive patients with hepatocellular carcinoma (HCC) or colorectal liver metastases (CRLM) treated with conventional US-/CT-guided ablation between 1 January 2015, and 31 December 2020, and patients treated with HepACAGA between 1 January 2021, and 31 October 2023, were included. The primary outcome was local tumor recurrence-free survival (LTRFS). Secondary outcomes included the local tumor recurrence (LTR) rate and complication rate.

RESULTS

68 patients (120 tumors) were included in the HepACAGA cohort and 53 patients (78 tumors) were included in the conventional cohort. In both cohorts, HCC was the predominant tumor type (63% and 73%, respectively). In the HepACAGA cohort, all patients received microwave ablation. Radiofrequency ablation was the main ablation technique in the conventional group (78%). LTRFS was significantly longer for patients treated with the HepACAGA technique (p = 0.015). Both LTR and the complication rate were significantly lower in the HepACAGA cohort compared to the conventional cohort (LTR 5% vs. 26%, respectively; p < 0.001) (complication rate 4% vs. 15%, respectively; p = 0.041).

CONCLUSIONS

In this study, the HepACAGA technique was safer and more effective than conventional ablation for HCC and CRLM, resulting in lower rates of local tumor recurrence, longer local tumor recurrence-free survival and fewer procedure-related complications.

Factors Impacting Microwave Ablation Zone Sizes: A Retrospective Analysis

PURPOSE

Evaluation of the influence of intrinsic and extrinsic conditions on ablation zone volumes (AZV) after microwave ablation (MWA).

METHODS

Retrospective analysis of 38 MWAs of therapy-naïve liver tumours performed with the NeuWave PR probe. Ablations were performed either in the 'standard mode' (65 W, 10 min) or in the 'surgical mode' (95 W, 1 min, then 65 W, 10 min). AZV measurements were obtained from contrast-enhanced computed tomography immediately post-ablation.

RESULTS

AZVs in the 'standard mode' were smaller than predicted by the manufacturer (length 3.6 ± 0.6 cm, 23% below 4.7 cm; width 2.7 ± 0.6, 23% below 3.5 cm). Ablation zone past the tip was limited to 6 mm in 28/32 ablations. Differences in AZV between the 'surgical mode' and 'standard mode' were not significant (15.6 ± 7.8 mL vs. 13.9 ± 8.8 mL, p = 0.6). AZVs were significantly larger in case of hepatocellular carcinomas (HCCs) (n = 19) compared to metastasis (n = 19; 17.8 ± 9.9 mL vs. 10.1 ± 5.1 mL, p = 0.01) and in non-perivascular tumour location (n = 14) compared to perivascular location (n = 24, 18.7 ± 10.4 mL vs. 11.7 ± 6.1 mL, p = 0.012), with both factors remaining significant in two-way analysis of variance (HCC vs. metastasis: p = 0.02; perivascular vs. non-perivascular tumour location: p = 0.044).

CONCLUSION

Larger AZVs can be expected in cases of HCCs compared with metastases and in non-perivascular locations. Using the 'surgical mode' does not increase AZV significantly.

Microwave ablation enhances the systemic immune response in patients with lung cancer

Microwave ablation (MWA) is a key alternative therapy to conventional surgery for the treatment of lung cancer. In addition to eliminating local tumors, MWA may promote antitumor immunological responses, such as abscopal effects in distant lesions. However, the intensity of MWA is limited and the underlying mechanisms are not well-defined. The present study assessed the impact of MWA on immune cell subsets and cytokines in patients with lung cancer. A total of 45 patients with lung cancer who underwent percutaneous lung tumor MWA were enrolled. Peripheral blood samples were collected before and 24 h after MWA and changes in immune cell subsets [lymphocytes, CD3+, CD4+ and CD8+ T cells, B cells and natural killer (NK) cells] and serum cytokine levels (IL-1β, IL-2, IL-4-6, IL-8, IL-10, IL-12p70, IL-17A and F, IL-22, TNF-α, TNF-β and IFN-γ) were assessed by flow cytometry and ELISA. The number of total lymphocytes, CD4+ T and NK cells in the peripheral blood significantly decreased 24 h after MWA, while number of CD8+ T cells remained stable, leading to a higher proportion of CD8+ T cells. In addition, the serum levels of IL-2, IL-1β, IL-6, IL-12p70, IL-22, TNF-α and IFN-γ were significantly increased 24 h after MWA, indicating a T helper 1 type immune response. The immune response in patients with advanced stage disease was comparable with patients in the early stage group; however, the number of total lymphocytes and CD3+ T cells significantly decreased and the ratio of CD4/CD8 and IL-2 levels significantly increased. The early immune response after MWA may contribute to systemic antitumor immunity in patients with both early and advanced disease. Thus, MWA may exhibit potential as a local therapy and trigger abscopal effects in distant lesions in patients with lung cancer.

Smartphone Augmented Reality Outperforms Conventional CT Guidance for Composite Ablation Margins in Phantom Models

PURPOSE

To develop and evaluate a smartphone augmented reality (AR) system for a large 50-mm liver tumor ablation with treatment planning for composite overlapping ablation zones.

MATERIALS AND METHODS

A smartphone AR application was developed to display tumor, probe, projected probe paths, ablated zones, and real-time percentage of the ablated target tumor volume. Fiducial markers were attached to phantoms and an ablation probe hub for tracking. The system was evaluated with tissue-mimicking thermochromic phantoms and gel phantoms. Four interventional radiologists performed 2 trials each of 3 probe insertions per trial using AR guidance versus computed tomography (CT) guidance approaches in 2 gel phantoms. Insertion points and optimal probe paths were predetermined. On Gel Phantom 2, serial ablated zones were saved and continuously displayed after each probe placement/adjustment, enabling feedback and iterative planning. The percentages of tumor ablated for AR guidance versus CT guidance, and with versus without display of recorded ablated zones, were compared among interventional radiologists with pairwise t-tests.

RESULTS

The means of percentages of tumor ablated for CT freehand and AR guidance were 36% ± 7 and 47% ± 4 (P = .004), respectively. The mean composite percentages of tumor ablated for AR guidance were 43% ± 1 (without) and 50% ± 2 (with display of ablation zone) (P = .033). There was no strong correlation between AR-guided percentage of ablation and years of experience (r < 0.5), whereas there was a strong correlation between CT-guided percentage of ablation and years of experience (r > 0.9).

CONCLUSIONS

A smartphone AR guidance system for dynamic iterative large liver tumor ablation was accurate, performed better than conventional CT guidance, especially for less experienced interventional radiologists, and enhanced more standardized performance across experience levels for ablation of a 50-mm tumor.

Therapeutic options in hepatocellular carcinoma: a comprehensive review

Hepatocellular carcinoma (HCC) is a chronic liver disease that is highly fatal if not detected and treated early. The incidence and death rate of HCC have been increasing in recent decades despite the measures taken for preventive screening and effective diagnostic and treatment strategies. The pathophysiology of HCC is multifactorial and highly complex owing to its molecular and immune heterogeneity, and thus the gap in knowledge still precludes making choices between viable therapeutic options and also the development of effective regimens. The treatment of HCC demands multidisciplinary approaches and primarily depends on tumor stage, hepatic functional reserve, and response to treatment by patients. Although curative treatments are limited but critical in the early stages of cancer, there are numerous palliative treatments available for patients with intermediate and advanced-stage HCC. In recent times, the use of combination therapy has succeeded over the use of monotherapy in the treatment of HCC by achieving effective tumor suppression, increasing survival rate, decreasing toxicity, and also aiding in overcoming drug resistance. This work focuses on reviewing the current and emerging treatment strategies for HCC.

Putative role of non-invasive vagus nerve stimulation in cancer pathology and immunotherapy: Can this be a hidden treasure, especially for the elderly?

Cancer is globally a disease of significant public health concern owing to its prevalence, and association with morbidity and mortality. Thus, cost-effective treatments for cancer are important to help reduce its significant morbidity and mortality. However, the current therapeutic options for cancer such as chemotherapy, radiotherapy, and surgery may produce serious adverse events such as nausea, vomiting, fatigue, and peripheral neuropathy, especially in the long term. In addition, these therapeutic options may not be well tolerated by the elderly especially those who are frail. The current article is aimed at discussing an alternative therapeutic option, non-invasive vagus nerve stimulation (VNS), and the roles it plays in cancer pathology and immunotherapy. The VNS does this by reducing oxidative stress via silent information regulator 1 (SIRT1); inhibiting inflammation via both hypothalamic-pituitary-axis (HPA) and the release of corticosteroid from the adrenal gland, and cholinergic anti-inflammatory pathway (CAP), and increasing vagal activity which helps in the regulation of cell proliferation, differentiation, apoptosis, and metabolism, and increase chance of survival. Furthermore, it helps with reducing complications due to cancer or its treatments such as postoperative ileus and severity of peripheral neuropathy induced by chemotherapy, and improves cancer-related fatigue, lymphopenia, and quality of life. These suggest that the importance of non-invasive VNS in cancer pathology and immunotherapy cannot be overemphasized. Therefore, considering the safety of non-invasive VNS and its cost-effectiveness, it is a therapeutic option worth trying for these patients, especially in combination with other therapies.

Liver Transplantation for Colorectal Liver Metastases: Is It Appropriate?

Colorectal cancer with liver metastases is a condition with significant morbidity and mortality that affects many people around the world. Many treatments exist to target liver metastases, including surgical resection, chemotherapy, nonsurgical liver-directed therapies, and liver transplantation. The field of transplant oncology is emerging as a promising alternative to palliative chemotherapy alone in appropriately selected patients. Though few clinical trials have been completed to evaluate safety of liver transplant for colorectal cancer metastases, there are several ongoing trials to hopefully make transplant a viable option for more patients with limited options.

3D modeling of vector/edge finite element method for multi-ablation technique for large tumor-computational approach

Microwave ablation (MWA) is a cancer thermal ablation treatment that uses electromagnetic waves to generate heat within the tissue. The goal of this treatment is to eliminate tumor cells while leaving healthy cells unharmed. During MWA, excess heat generation can kill healthy cells. Hence, mathematical models and numerical techniques are required to analyze the heat distribution in the tissue before the treatment. The aim of this research is to explain the implementation of the 3D vector finite element method in a wave propagation model that simulates the specific absorption rate in the liver. The 3D Nedelec elements from H(curl; Ω) space are used to discretize the wave propagation model, and this implementation is helpful in solving many real-world problems that involve electromagnetic propagation with perfect conducting and absorbing boundary conditions. One of the difficulties in ablation treatment is creating a large ablation zone for a large tumor (diameter greater than 3 cm) in a short period of time with minimum damage to the surrounding tissue. This article addresses the aforementioned issue by introducing four antennas into the different places of the tumor sequentially and producing heat uniformly over the tumor. The results demonstrated that 95.5% of the tumor cells were killed with minimal damage to the healthy cells when the heating time was increased to 4 minutes at each position. Subsequently, we studied the temperature distribution and localised tissue contraction in the tissue using the three-dimensional bio-heat equation and temperature-time dependent model, respectively. The local tissue contraction is measured at arbitrary points in the domain and is more noticeable at temperatures higher than 102°C. The thermal damage in the liver during MWA treatment is investigated using the three-state cell death model. The system of partial differential equations is solved numerically due to the complex geometry of the domain, and the results are compared with experimental data to validate the models and parameters.

Recent Advances in Image-Guided Locoregional Therapies for Primary Liver Tumors

Primary liver cancer is the leading cause of cancer-related deaths worldwide. with incidences predicted to rise over the next several decades. Locoregional therapies, such as radiofrequency or microwave ablation, are described as image-guided percutaneous procedures, which offer either a curative intent for early-stage hepatocellular carcinoma or bridging/downstaging for surgical resection or transplantation. Catheter-driven locoregional therapies, such as transarterial chemoembolization and radioembolization, induce tumor hypoxia, can be palliative, and improve survival for early-to-intermediate hepatocellular carcinoma and unresectable intrahepatic cholangiocarcinoma. Herein, we provide a comprehensive overview of the antineoplastic mechanisms underpinning locoregional therapies, different treatment approaches, and the current state of the literature for the efficacy of locoregional therapies for primary liver cancer. We also discuss emerging advancements, such as the adjuvant use of immunotherapies and molecular targeting agents with locoregional therapy, for the treatment of primary liver cancer.

A vector finite element approach to temperature dependent parameters of microwave ablation for liver cancer

Microwave ablation (MWA) is a minimally invasive treatment for cancer that uses electromagnetic waves to kill the tumor cells without significantly damaging the surrounding healthy cells. A three-state cell death model calculates the thermal damage around the Hepatocellular carcinoma (HCC) tumor in the liver tissue. The temperature profile is simulated for a single-slot co-axial antenna with a 1 mm air slot located near the tip of the antenna to produce an adequate amount of heat. The aims of this study are (1) to use the vector/edge finite element method (VFEM) to simulate the electromagnetic wave propagation to obtain the specific absorption rate, which is an input for the bio-heat equation that predicts the heat distribution in the liver tissue during MWA treatment, and (2) to compare the computational costs of VFEM and the finite element method (FEM) when different types of input powers and dielectric properties are used in the wave propagation equation. This study claims that the accuracy level increases marginally with less computation cost while using VFEM for temperature-dependent wave propagation equation.

The Role of 18F-FLT PET/CT in Assessing Early Response to Transarterial Radioembolization and Chemoembolization in Patients with Primary and Metastatic Liver Tumors

Objectives

Metastases and primary malignancies are common in the liver. Local ablative applications such as transarterial chemoembolization (TACE), and transarterial radioembolization (TARE) provide minimally invasive and safe treatment in unresectable liver tumors. Early detection of response to treatment prevents unnecessary toxicity and cost in non-responder patients and provides an earlier use of other options that may be effective. This study aimed to identify the role of ¹⁸F-fluorothymidine (FLT) positron emission tomography/computed tomography (PET/CT) in the assessment of early response to TACE and TARE treatments in patients with unresectable primary and metastatic liver tumors.

Methods

This single-center study included 63 patients who underwent ¹⁸F-FLT PET/CT for response evaluation after TACE and TARE. After excluding 20 patients whose data were missing 43 TARE-receiving patients were analyzed. The compatibility of change in semi-quantitative values obtained from the ¹⁸F-FLT PET/CT images with the treatment responses detected in ¹⁸F-fluorodeoxyglucose PET/CT, CT, and MR images and survival was evaluated.

Results

There was no correlation between early metabolic, morphological response, and ¹⁸F-FLT uptake pattern, and change in standardized uptake values (SUV) which were ΔSUV_max, ΔSUV_mean, ΔSUV_peak., ΔSUV_mean, Δ SUV_peak values. There was no significant correlation between ¹⁸F-FLT uptake pattern, ΔSUV_max, ΔSUV_mean, ΔSUV_peak, and overall survival, progression-free survival (PFS) for the target lobe PFS for the whole-body. The survival distributions for the patients with >30% change in Δ SUV_max and ΔSUV_peak values were statistically significantly longer than the patients with <30% change (p<0.009 and p<0.024, respectively).

Conclusion

There was significant longer PFS for target liver lobe in patients with more than 30% decrease in ¹⁸F-FLT SUV_max and SUV_peak of the liver lesion in primary and metastatic unresectable liver tumors undergoing TARE.

Needle tract seeding following percutaneous irreversible electroporation for hepatocellular carcinoma

Irreversible electroporation (IRE) is a non-thermal ablative technique for unresectable liver malignancies deemed unsuitable for traditional thermal ablation due to proximity to biliary and/or vascular structures. Needle tract tumour seeding is a well-recognised complication following thermal ablation, while little is known about its risk with IRE use. We present a case of tumour seeding after IRE for unresectable hepatocellular carcinoma in a man in his 70s. The procedure was complicated by bleeding from a pseudoaneurysm, which required coil embolisation and blood transfusion. He initially progressed well, however, imaging at 12 months indicated a new tumour in the right intercostal space along the tract of one of the IRE needles; consistent with seeding. Although the patient subsequently underwent systemic therapy with sorafenib, his disease progressed, and unfortunately he passed away 20 months following IRE. This report adds to mounting evidence of needle tract tumour seeding as a complication following IRE.

Generic surgical process model for minimally invasive liver treatment methods

Surgical process modelling is an innovative approach that aims to simplify the challenges involved in improving surgeries through quantitative analysis of a well-established model of surgical activities. In this paper, surgical process model strategies are applied for the analysis of different Minimally Invasive Liver Treatments (MILTs), including ablation and surgical resection of the liver lesions. Moreover, a generic surgical process model for these differences in MILTs is introduced. The generic surgical process model was established at three different granularity levels. The generic process model, encompassing thirteen phases, was verified against videos of MILT procedures and interviews with surgeons. The established model covers all the surgical and interventional activities and the connections between them and provides a foundation for extensive quantitative analysis and simulations of MILT procedures for improving computer-assisted surgery systems, surgeon training and evaluation, surgeon guidance and planning systems and evaluation of new technologies.

Early assessment of irreversible electroporation ablation outcomes by analyzing MRI texture: preclinical study in an animal model of liver tumor

OBJECTIVES

Accurate differentiation of temporary vs. permanent changes occurring following irreversible electroporation (IRE) holds immense importance for the early assessment of ablative treatment outcomes. Here, we investigated the benefits of advanced statistical learning models for an immediate evaluation of therapeutic outcomes by interpreting quantitative characteristics captured with conventional MRI.

METHODS

The preclinical study integrated twenty-six rabbits with anatomical and perfusion MRI data acquired with a 3T clinical MRI scanner. T1w and T2w MRI data were quantitatively analyzed, and forty-six quantitative features were computed with four feature extraction methods. The candidate key features were determined by graph clustering following the filtering-based feature selection technique, RELIEFF algorithm. Kernel-based support vector machines (SVM) and random forest (RF) classifiers interpreting quantitative features of T1w, T2w, and combination (T1w+T2w) MRI were developed for replicating the underlying characteristics of the tissues to distinguish IRE ablation regions for immediate assessment of treatment response. Accuracy, sensitivity, specificity, and area under the receiver operating characteristics curve were used to evaluate classification performance.

RESULTS

Following the analysis of quantitative variables, three features were integrated to develop a SVM classification model, while five features were utilized for generating RF classifiers. SVM classifiers demonstrated detection accuracy of 91.06%, 96.15%, and 98.04% for individual and combination MRI data, respectively. Besides, RF classifiers obtained slightly lower accuracy compared to SVM which were 95.06%, 89.40%, and 94.38% respectively.

CONCLUSIONS

Quantitative models integrating structural characteristics of conventional T1w and T2w MRI data with statistical learning techniques identified IRE ablation regions allowing early assessment of treatment status.

Efficacy and safety of microwave ablation and radiofrequency ablation in the treatment of hepatocellular carcinoma: A systematic review and meta-analysis

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Surgical resection is often only possible in the early stages of HCC and among those with limited cirrhosis. Radiofrequency ablation and Microwave ablation are 2 main types of percutaneous thermal ablation for the treatment of HCC. The efficacy and safety between these 2 therapy methods are still under a debate.

OBJECTIVE

To compare the efficacy and safety of Radiofrequency ablation and Microwave ablation in treating HCC.

METHODS

PubMed, EMBASE, the Cochrane databases and Web of Science were systematically searched. We included randomized controlled trials and cohort studies comparing the efficacy and safety of Radiofrequency ablation and Microwave ablation in HCC patients. Outcome measures on local tumor progression, complete ablation, disease-free survival, overall survival, or major complications were compared between the 2 groups. The random effect model was used when there was significant heterogeneity between studies, otherwise the fixed effect model was used.

RESULTS

A total of 33 studies, involving a total of 4589 patients were identified, which included studies comprised 7 RCTs, 24 retrospective observational trials, and 2 prospective observational trial. Microwave ablation had a lower local tumor progression than Radiofrequency ablation in cohort studies (OR = 0.78, 95% CI 0.64-0.96, P = .02). Complete ablation rate of Microwave ablation was higher than that of Radiofrequency ablation in cohort studies (OR = 1.54, 95% CI 1.05-2.25, P = .03). There was no significant difference in overall survival and disease-free survival between the 2 groups. Meta-analysis showed that there was no significant difference in the main complications between Microwave ablation and Radiofrequency ablation.

CONCLUSIONS

Microwave ablation has higher complete ablation and lower local tumor progression than Radiofrequency ablation in the ablation treatment of HCC nodules. There was no significant difference in overall survival between the 2 therapy methods.

Nanodroplet-Mediated Low-Energy Mechanical Ultrasound Surgery

Mechanical ultrasound surgery methods use short, high-intensity pulses to fractionate tissues. This study reports the development of a two-step technology for low-energy mechanical ultrasound surgery of tissues using nanodroplets to reduce the pressure threshold. Step 1 consists of vaporizing the nanodroplets into gaseous microbubbles via megahertz ultrasound excitation. Then, low-frequency ultrasound is applied to the microbubbles, which turns them into therapeutic warheads that trigger potent mechanical effects in the surrounding tissue. The use of nanoscale nanodroplets coupled with low-frequency ultrasound reduces the pressure threshold required for mechanical ultrasound surgery by an order of magnitude. In addition, their average diameter of 300 nm can overcome challenges associated with the size of microbubbles. Optimization experiments were performed to determine the ultrasound parameters for nanodroplet vaporization and the subsequent microbubble implosion processes. Optimal vaporization was obtained when transmitting a 2-cycle excitation pulse at a center frequency of 5 MHz and a peak negative pressure of 4.1 MPa (mechanical index = 1.8). Low-frequency insonation of the generated microbubbles at a center frequency of 850, 250 or 80 kHz caused enhanced contrast reduction at a center frequency of 80 kHz, compared with the other frequencies, while operating at the same mechanical index of 0.9. Nanodroplet-mediated insonation of ex vivo chicken liver samples generated mechanical damage. Low-frequency treatment at a mechanical index of 0.9 and a center frequency of 80 kHz induced the largest lesion area (average of 0.59 mm²) compared with 250- and 850-kHz treatments with the same mechanical index (average lesions areas of 0.29 and 0.19 mm², respectively, p < 0.001). The two-step approach makes it possible to conduct both the vaporization and implosion stages at mechanical indices below 1.9, thus avoiding undesired mechanical damage. The findings indicate that coupled with low-frequency ultrasound, nanodroplets can be used for low-energy mechanical ultrasound surgery.

Narrative Review of High-Dose-Rate Interstitial Brachytherapy in Primary or Secondary Liver Tumors

The optimal management of intrahepatic malignancies involves a multidisciplinary approach. Although surgical resection has been considered the only curative approach, the use of several minimally invasive ablative techniques has dramatically increased the last two decades, mainly due to the fact that they provide similar oncological results with significantly decreased morbidity. Among these modalities, interstitial liver brachytherapy, probably the most flexible liver ablative method, with excellent clinical data on its safety and effectiveness, is frequently not even mentioned as an option in the current peer reviewed literature and guidelines. Brachytherapy is a type of radiotherapy utilizing radionuclides that are directly inserted into the tumor. Compared to external beam radiation therapy, brachytherapy has the potential to deliver an ablative radiation dose over a short period of time, with the advantage of a rapid dose fall-off, that allows for sparing of adjacent healthy tissue. For numerous malignancies such as skin, gynecological, breast, prostate, head and neck, bladder, liver and soft-tissue tumors, brachytherapy as a monotherapy or combined with external beam radiation therapy, has become a standard treatment for many decades. This review article aims to describe the high-dose-rate liver brachytherapy technique, its selection criteria, present its advantages and disadvantages, as well as the available clinical data, in order to help physicians to explore and hopefully introduce liver brachytherapy into their clinical routine.

Turning down the heat: The case for mild hyperthermia and thermosensitive liposomes

"A single disappointing study does not mean an end to the future of ThermoDox®", writes Michael Tardugno (CEO of Celsion Corporation), after announcing the termination of Celsion's second Phase III clinical trial. The OPTIMA trial, as it was known, evaluated their thermosensitive liposome (TSL) formulation of doxorubicin (ThermoDox®) in combination with radiofrequency ablation for the treatment of hepatocellular carcinoma (HCC). The purpose of this perspective is to review the case of ThermoDox and to address questions related to its clinical translation. Specifically, what has prevented the clinical translation of this once highly regarded breakthrough technology? Is this the end of TSLs? What can we learn from the challenges faced in the clinical development of this multi-modal therapy? As formulation scientists working in the field, we continue to believe that heat-triggered drug delivery platforms have tremendous potential as chemotherapy. Herein, we highlight potential limitations in the design of many of the Thermodox clinical trials, and we propose that despite these setbacks, TSLs have the potential to become an effective component of cancer therapy.

CT-guided microwave ablation of hepatic malignancies via transpulmonary approach without ancillary techniques

Objectives:

The objectives of the study were to determine the safety and efficacy of computed tomography (CT)-guided transpulmonary percutaneous microwave ablation (MWA) for hepatic malignancies without the use of ancillary techniques.

Material and Methods:

A retrospective review was performed on patients who underwent MWA for hepatic malignancy between January 2014 and February 2020 at a single tertiary center. Imaging was reviewed for each procedure to identify MWA showing transpleural transgression on CT scans. For these patients, demographics, ablation data, pulmonary complication rate, and predictors of pneumothorax were analyzed.

Results:

A total of 71 consecutive sessions (62.1 ± 11.3 years, 79% of males) of MWA were performed to treat 71 tumors (1.90 ± 0.96 cm) via transpulmonary approach under CT guidance. Technical success was achieved in all cases immediately after the procedure. At 1-month follow-up, 65/69 (94.2%) patients had no residual disease (two patients were lost to follow-up). Pulmonary complications occurred in 26/71 (36.6%) sessions, and 15/26 (57.7%) were minor requiring no intervention. Pneumothorax occurred in 14/71 (19.7%) sessions, and the rate of major pneumothorax requiring chest tube was 8/71 (11.3%). Lesions on the left side of the liver (segments I–IV) and intraprocedural probe adjustment were found to be independent predictors of developing major pneumothorax (P = 0.007 and 0.028, respectively). There were no reported pulmonary complications at the 1-month follow-up.

Conclusion:

CT-guided transpulmonary MWA is safe and effective in treating hepatic malignancies. Although it is associated with the risk of developing pulmonary complications, patients underwent successful ablation of their hepatic malignancies without life-threatening complications and mortality.

Combination of natural killer cell-based immunotherapy and irreversible electroporation for the treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is among the most lethal cancer types despite great advancement in overall survival of the patients over the last decades. Surgical resection or partial hepatectomy has been approved as the curative treatment for early-stage HCC patients however only up to 30% of them are eligible for the procedures. Natural killer (NK) cells are cytotoxic lymphocytes recognized for killing virally infected cells and improving immune functions for defending the body against malignant cells. Although autologous NK cells failed to demonstrate significant clinical benefit, transfer of allogeneic adoptive NK cells arises as a promising approach for the treatment of solid tumors. The immunosuppressive tumor microenvironment and inadequate homing efficiency of NK cells to tumors can inhibit adoptive transfer immunotherapy (ATI) efficacy. However, potential of the NK cells is challenged by the transfection efficiency. The local ablation techniques that employ thermal or chemical energy have been investigated for the destruction of solid tumors for three decades and demonstrated promising benefits for individuals not eligible for surgical resection or partial hepatectomy. Irreversible electroporation (IRE) is one of the most recent minimally invasive ablation methods that destruct the cell within the targeted region through non-thermal energy. IRE destroys the tumor cell membrane by delivering high-frequency electrical energy in short pulses and overcomes tumor immunosuppression. The previous studies demonstrated that IRE can induce immune changes which can facilitate activation of specific immune responses and improve transfection efficiency. In this review paper, we have discussed the mechanism of NK cell immunotherapy and IRE ablation methods for the treatment of HCC patients and the combinatorial benefits of NK cell immunotherapy and IRE ablation.

Acoustically Detonated Microbubbles Coupled with Low Frequency Insonation: Multiparameter Evaluation of Low Energy Mechanical Ablation

Noninvasive ultrasound surgery can be achieved using focused ultrasound to locally affect the targeted site without damaging intervening tissues. Mechanical ablation and histotripsy use short and intense acoustic pulses to destroy the tissue via a purely mechanical effect. Here, we show that coupled with low-frequency excitation, targeted microbubbles can serve as mechanical therapeutic warheads that trigger potent mechanical effects in tumors using focused ultrasound. Upon low frequency excitation (250 kHz and below), high amplitude microbubble oscillations occur at substantially lower pressures as compared to higher MHz ultrasonic frequencies. For example, inertial cavitation was initiated at a pressure of 75 kPa for a center frequency of 80 kHz. Low frequency insonation of targeted microbubbles was then used to achieve low energy tumor cell fractionation at pressures below a mechanical index of 1.9, and in accordance with the Food and Drug Administration guidelines. We demonstrate these capabilities in vitro and in vivo. In cell cultures, cell viability was reduced to 16% at a peak negative pressure of 800 kPa at the 250 kHz frequency (mechanical index of 1.6) and to 10% at a peak negative pressure of 250 kPa at a frequency of 80 kHz (mechanical index of 0.9). Following an intratumoral injection of targeted microbubbles into tumor-bearing mice, and coupled with low frequency ultrasound application, significant tumor debulking and cancer cell death was observed. Our findings suggest that reducing the center frequency enhances microbubble-mediated mechanical ablation; thus, this technology provides a unique theranostic platform for safe low energy tumor fractionation, while reducing off-target effects.

Microwave ablation combined with hepatectomy for treatment of neuroendocrine tumor liver metastases

BACKGROUND

Hepatectomy is the first choice for treating neuroendocrine tumor liver metastases. However, most patients with neuroendocrine tumor liver metastases are not suitable for hepatectomy. Ablation combined with hepatectomy can be an alternative to liver resection.

AIM

To explore the clinical effect of microwave ablation combined with hepatectomy for the treatment of neuroendocrine tumor liver metastases.

METHODS

In this study, the data of patients who underwent microwave ablation combined with hepatectomy for the treatment of neuroendocrine tumor liver metastases from June 2015 to January 2018 were reviewed. Before the operation, the patients did not receive any treatment for liver neuroendocrine tumors. After a multidisciplinary expert group discussion, all patients were deemed unsuitable for liver resection. All patients were diagnosed with neuroendocrine tumors by pathology. The overall survival time and progression-free survival time were followed by telephone calls and outpatient visits after surgery.

RESULTS

Eleven patients with neuroendocrine tumor liver metastases were treated by microwave ablation combined with hepatectomy between June 2015 and January 2018. The median number of liver metastatic nodules was 4 (range, 2 to 43). The median number of lesions resected was 1 (range, 1 to 18), and the median number of lesions ablated was 3 (range, 1 to 38). The mean operation time was 405.6 (± 39.4) min. The median intraoperative blood loss was 600 mL (range, 50 to 3000). Ten patients had a fever after surgery. The median duration of fever was 3 d (range, 0 to 21). Elevated bilirubin levels occurred in all patients after surgery. The median bilirubin on the first day after surgery was 28.5 (range, 10.7 to 98.9) µmol/L. One patient developed respiratory failure, renal insufficiency, and pneumonia after the operation. No patient died postoperatively during hospitalization. The mean overall survival time after surgery was 34.1 (± 3.7) mo, and the median progression-free survival time was 8 (range, 2 to 51) mo. One year after surgery, ten patients survived and five patients survived without progression. Three year after surgery, eight patients survived and two patients survived without progression.

CONCLUSION

Microwave ablation combined with hepatectomy not only makes the patients obtain a survival rate similar to that of patients undergoing hepatectomy, but also has a low incidence of postoperative complications.

Combined trans-arterial embolisation and microwave ablation for the treatment of large unresectable hepatic metastases (>3 cm in maximal diameter)

PURPOSE

To assess the safety and efficacy of a two-step single-session procedure, combining transarterial embolization (TAE) and percutaneous microwave ablation (MWA), in the treatment of > 3 cm unresectable liver metastases. We also compared the final volume obtained by the two techniques (V_E-T) and the expected ablation volume of the stand-alone MWA (V_T).

METHODS

From January 2015 to December 2017, 22 consecutive patients, with a total of 24 unresectable hepatic metastases >3 cm in diameter underwent a two-step single-session combined treatment of TAE and MWA. Follow-up computed tomography scans were performed at 1-, 3-, 6-, 12, and 24 months post-procedure. V_E-T as final ablation volume induced by the combined treatment (TAE-MWA), V_N as initial nodule volume, V_T as expected ablation volume of MWA treatment alone were evaluated and compared.

RESULTS

Tumor dimensions ranged from 32 to 73 mm. Technical success was achieved in all treated tumors with no local tumor recurrence. Final ablation volumes ranged from 50 to 450 cm³ and the short-axis diameter of the ablation zone ranged from 12 to 48 mm. The mean ΔV increment in the final ablation volume with respect to the stand-alone MWA was 196% (ranging from 25 cm³ - 210 cm³) (p < 0.05). The V_E-T mean was four times the V_N mean, while the V_T mean was about twice the V_N mean. No recurrence and only one case of post-embolization bleeding were observed.

CONCLUSIONS

This study demonstrated the safety and efficacy of a combined two-step single-session TAE-MWA treatment of unresectable hepatic metastases > 3 cm in diameter.

Relationship of Antenna Work and Ablation Cavity Volume Following Percutaneous Microwave Ablation of Hepatic Tumors

PURPOSE

To formulate a statistical model relating ablation time, power, and work with posttreatment cavity volume following percutaneous microwave ablation of hepatic tumors in vivo.

MATERIALS AND METHODS

A retrospective review (October 2015 to October 2018) yielded 122 hepatic tumors treated with microwave ablation. Ablation cavity dimensions were measured at 1-month follow-up examination and calculated using an ellipsoid volume formula. The antenna manufacturer (Neuwave Medical, Madison, Wisconsin) provided the activation time and energy used to calculate the antenna work. Generalized estimating equations with ordinary least-squares regression models were obtained to relate tumor volume with cumulative antenna work. Coefficient of determination (R²) and mean square error were used as statistical measures of model prediction performance.

RESULTS

There is a logarithmic relationship between postablation cavity volume (cm³) and cumulative work (kJ), represented by the formula: log₁₀ cm³ = -0.4583 + 0.9887 × cumulative work (log10 kJ) (R² = 0.41, mean square error, 0.102). Ablation volumes were predicted as a function of antenna work, calculated using an antilog transformation. When a single antenna was used, ablation cavity volume was predicted using a generalized estimating equation ordinary least-squares regression model of power and time: log₁₀cm³= -0.0546 + 0.0485 × total time (min) + 0.0107 × power (W) (R² = 0.30; mean square error, 0.106). Using this model, a nomogram was developed to predict the postablation cavity volume based on total activation time and target power.

CONCLUSION

There is a logarithmic relationship between the ablation work and posttreatment ablation cavity volume, which can be expressed in a nomogram when using a single probe.

The Potential Gut Microbiota-Mediated Treatment Options for Liver Cancer

Primary liver cancer is one of the leading causes of cancer death worldwide. Surgical and non-surgical treatments are optional for liver cancer therapy based on the cancer stage. Accumulating studies show that the gut–liver axis influences the progression of liver diseases, including liver inflammation, fibrosis, cirrhosis, and cancer. However, the role of gut microbiota and their derived components and metabolites in liver cancer remains to be further clarified. In this review, we discuss the roles of gut microbiota and specific bacterial species in HCC and the strategies to modulate gut microbiota to improve antitumor therapy. Given the limitation of current treatments, gut microbiota-mediated therapy is a potential option for HCC treatment, including fiber diet and vegetable diet, antimicrobials, probiotics, and pharmaceutical inhibitors. Also, gut microbiota can be used as a marker for early diagnosis of HCC. HCC occurs dependent on various environmental and genetic factors, including diet and sex. Furthermore, gut microbiota impacts the immunotherapy of HCC treatment. Therefore, a better understanding of the role of the gut–liver axis in liver cancer is critically important to improve therapeutic efficacy.

Promising abscopal effect of combination therapy with thermal tumour ablation and intratumoural OK-432 injection in the rat osteosarcoma model

Treatment options for metastatic osteosarcoma are limited. The present study aimed to evaluate whether radiofrequency ablation (RFA) combined with intratumoural OK-432 injection induces systemic anti-tumour immunity in rat osteosarcoma model. Eighty of 145 rats were assigned to four groups to evaluate overall survival and tumour size: control (no treatment), RFA-only, OK-432, and RFA-OK-432. The remaining 65 were assigned for histological examination. Maximum diameters of tibial and lung tumours were determined. Tumour samples were histologically examined using haematoxylin-eosin and immunohistochemical staining. Overall survival was significantly prolonged in the RFA-OK-432 group compared to the RFA-only and OK-432 groups. Only rats in the RFA-OK-432 group exhibited significant decreases in maximum tumour diameter after treatment. Ki-67-positive tumour cells in the RFA-OK-432 group were significantly stained negative on immunohistochemical analysis as opposed to those in the RFA-only and OK-432 groups. The number of CD11c+, OX-62+, CD4+, and CD8 + cells significantly increased in the RFA-OK-432 group compared to the RFA-only group. RFA with intratumoural OK-432 injection resulted in distant tumour suppression, prolonged survival, and increased dendritic cells, cytotoxic T cells, IFN-γ, and TNF-α, whereas RFA or OK-432 alone did not produce this effect. This combination may induce an abscopal effect in human osteosarcoma.

Visualization of spatial and temporal temperature distributions with magnetic particle imaging for liver tumor ablation therapy

Temperature-resolved magnetic particle imaging (MPI) represents a promising tool for medical imaging applications. In this study an approach based on a single calibration measurement was applied for highlighting the potential of MPI for monitoring of temperatures during thermal ablation of liver tumors. For this purpose, liver tissue and liver tumor phantoms embedding different superparamagnetic iron oxide nanoparticles (SPION) were prepared, locally heated up to 70 °C and recorded with MPI. Optimal temperature MPI SPIONs and a corresponding linear model for temperature calculation were determined. The temporal and spatial temperature distributions were compared with infrared (IR) camera results yielding quantitative agreements with a mean absolute deviation of 1 °C despite mismatches in boundary areas.

Mechanism of inhibiting proliferation of hepatocellular carcinoma Hepa1-6 cells by embryonic stem cell-conditioned medium

The present study aimed to investigate the antiproliferative effect of embryonic stem cell-conditioned medium (ESC-CM) on the mouse liver cancer Hepa1-6 cells in vitro. Furthermore, in order to elucidate the underlying molecular mechanism, the microRNAs (miRNAs) in ESC-CM associated with the inhibition of Hepa1-6 proliferation were identified. Following the co-culture of ESC-CM and Hepa1-6 in Transwell chambers, the proliferation, cell cycle, apoptosis and associated protein expression were determined in Hepal-6 cells. Moreover, miRNA array analysis was employed to identify differentially expressed miRNAs. Based on the differentially expressed miRNAs, the target genes and potential associated signaling pathways were determined. Finally, RT-qPCR was conducted to confirm the above results. The ESC-CM inhibited Hepal-6 cell proliferation and increased the percentage of cells at G₁ phase and decreased the percentage of cells at the G₂/M phase of the cell cycle. The expression of cyclin D1/cyclin-dependent kinase (CDK)4/CDK6 was decreased following co-culture, with no effect on cell apoptosis. Six significantly regulated miRNAs were identified and 423 putative target genes of these regulated miRNAs were predicted. Gene ontology analysis revealed the putative target genes to be associated with the ‘DNA replication (GO: 0006260)’ GO term, ‘apoptosis’ and ‘signal transduction’. The Kyoto Encyclopedia of Genes and Genomes analysis indicated that deregulated miRNAs were enriched in the Wnt signaling (KEGG entry: Map 04310) and Hippo signaling pathways (KEGG entry: Map 04390), pathways associated with cancer. Overall, the present study demonstrated the inhibition of Hepa1-6 cell line proliferation upon treatment with ESC-CM, by decreasing cell cycle-associated protein cyclin D1/CDK4/CDK6 expression and arresting cells in G₁ phase of the cell cycle, with no effect on cell apoptosis. Furthermore, the inhibition of proliferation by ESC-CM may be mediated by miRNAs that affect cell cycle-associated mRNAs and the Wnt signaling pathway.

Physiological Motion Reduction Using Lagrangian Tracking for Electrode Displacement Elastography

Minimally invasive treatments such as microwave ablation (MWA) have been growing in popularity for extending liver cancer survival rates in patients, when surgery is not an option. As a non-ionizing, real-time alternative to contrast-enhanced computed tomography, electrode displacement elastography (EDE) has shown promise as an imaging modality for MWA. Despite imaging efficacy, motion artifacts caused by physiological motion result in unintended speckle pattern variance, thereby inhibiting consistent and accurate ablated region visualization. To combat these unavoidable motion artifacts, a Lagrangian deformation tracking (LDT) approach based on freehand EDE was developed to track tissue movement and better define tissue properties. For validating LDT efficacy, a spherical inclusion phantom as well as seven in vivo data sets were processed, and strain tensor images were compared with identical time sampled images estimated using a traditional Eulerian approach. In vivo results revealed greater consistency among visualized LDT strain tensor images, with segmented ablated regions exhibiting standard deviation reductions of up to 98% when compared with Eulerian strain tensor images. Additionally, Lagrangian strain tensor images provided Dice coefficient improvements up to 25%, and success rates improved from approximately 50% to nearly 100% for ablated region visualization.

Comparison of anesthetic effects of dexmedetomidine and tramadol, respectively, combined with propofol in percutaneous microwave coagulation therapy for hepatocellular carcinoma

Anesthetic effects and safety of dexmedetomidine and tramadol, respectively, combined with propofol in ultrasound-guided percutaneous microwave coagulation therapy (PMCT) for hepatocellular carcinoma (HCC) were compared. One hundred and seventy-six patients with HCC, treated by ultrasound-guided PMCT in The Affiliated Hospital of Qingdao University from January 2014 to December 2016, were retrospectively analyzed and divided into two groups: dexmedetomidine group (anesthetized with dexmedetomidine combined with propofol, n=91) and tramadol group (anesthetized with tramadol combined with propofol, n=85). Changes in heart rate (HR), mean arterial pressure (MAP), and oxygen saturation (SpO₂) were recorded before oxygen inhalation (T1), intraoperationally (T2), and at 30 min postoperatively (T3), and the recovery time (recorded from the moment the use of anesthetic drugs stopped), hospital stay, visual analogue scale (VAS) score at 48 h after surgery, as well as the adverse reactions in the perioperative period were compared between the two groups. HR and SpO₂ in the dexmedetomidine group at T2 and T3 were significantly lower than those in the tramadol group (P<0.05). HR and SpO₂ at T2 were significantly lower than those at T1 and T3, and HR at T3 was lower than that at T1 (P<0.05). MAP in the dexmedetomidine group at T2 was significantly lower than that in the tramadol group (t=3.836, P<0.001). MAP at T2 was significantly lower than those at T1 and T3, and MAP at T3 was lower than that at T1 (P<0.05). The number of patients with shivering in the dexmedetomidine group was significantly higher than that in the tramadol group (P<0.05). Both tramadol and dexmedetomidine, respectively combined with propofol in PMCT for HCC surgery can achieve satisfactory anesthetic effects. However, tramadol combined with propofol is more effective in stabilizing the vital signs with less side-effects, and is more suitable for PMCT in patients with HCC than dexmedetomidine combined with propofol, which is worth popularizing and applying in clinic.

Electromagnetic navigation to assist with computed tomography-guided thermal ablation of liver tumors

Purpose: To evaluate the advantages and primary technical efficacy of an electromagnetic (EM) navigation system for computed tomography (CT)-guided thermal ablation of liver tumors.Material and methods: From August 2016 to January 2018, 40 patients scheduled for CT- guided thermal ablation were prospectively enrolled and divided into two groups. Twenty patients underwent CT-guided thermal ablation with an EM navigation system (navigation group), while the other 20 patients underwent conventional CT-guided thermal ablation (control group). Data on skin punctures, instrument adjustments, puncture time to target, CT scans, CT fluoroscopy time and dose-length-product (DLP) were compared between the two groups. Any postoperative complications were recorded and the primary technical efficacy was evaluated four to six weeks after the procedure.Results: All 20 patients in the navigation group successfully underwent EM navigation. Compared to the control group, there were fewer instrument adjustments (mean 2.40 vs. 4.95; p = .003), fewer CT scans (mean 7.10 vs. 10.30; p = .006), less CT fluoroscopy time (mean 40.47 vs. 59.98 s, p = .046), and less DLP (mean 807.39 vs. 1578.67 mGy × cm; p = .001). Although not statistically significant, EM navigation resulted in fewer skin punctures (mean 1.20 vs. 1.25; p = .803) and slightly longer puncture time to target (mean 16.50 vs. 15.20 min; p = .725). No patients experienced major complications and the primary efficacy rate was 90% and 84.21% in the navigation and control groups, respectively (p = .661).Conclusions: EM navigation system optimizes the thermal ablation process and reduces radiation exposure in patients. However, further studies are warranted to determine whether an EM navigation system can improve procedure time, complication rates, and primary technical efficiacy of thermal ablation.

Treatment of Primary Liver Tumors and Liver Metastases, Part 2: Non-Nuclear Medicine Techniques

Image-guided procedures are used worldwide in the management of primary liver tumors and liver metastases. These locoregional therapies include local tumor ablation and transarterial therapies and can occasionally downstage an inoperable patient to an operable status. In hepatocellular carcinoma, data have suggested that for tumors smaller than 2 cm ablation may be preferable to surgery. Similar results are emerging for colorectal cancer liver metastases. Catheter-directed therapies such as bland embolization, transarterial chemoembolization, and drug-eluting beads represent potential techniques that can provide survival benefit for inoperable patients. In this review we highlight the most used techniques and the evidence supporting their current indications for the treatment of liver tumors. We briefly review upcoming developments in combination strategies with temperature-sensitive liposomes or immunotherapy for enhancing ablation efficacy.

Irreversible electroporation of malignant liver tumors: Effect on laboratory values

Liver cancer is often associated with chronic liver diseases. Treatment with percutaneous irreversible electroporation (IRE) may preserve liver function. In the present study, the clinical data of 29 patients with liver tumors between July 2015 and December 2016, all of whom underwent liver IRE at Fuda Cancer Hospital, Guangzhou, China was retrospectively reviewed. All the patients survived the treatment. Of the 29 patients, 7 were positive for hepatitis B, 15 had hepatocellular carcinoma (HCC) and 7 had pancreatic cancer with liver metastases. All patients survived IRE. Despite liver-protective treatment prior to IRE, the mean alanine transaminase (ALT) and aspartate transaminase (AST) levels were significantly elevated 1-2 days after IRE, to 540 and 712 U/l, respectively; however they had returned to the preoperative values by 2 weeks following IRE. Prior to IRE, the mean total bilirubin and direct bilirubin measurement levels were normal; however, 8-10 days after IRE, they had increased to 24 U/l and 12 µmol/l, respectively, and had returned back to the preoperative levels by 2 weeks after IRE. This first group included all patients. The result of the 4 subgroups of cancer patients demonstrated a variation between different measurement days and recovery with patients positive for the hepatitis B virus taking the longest duration to recover (17±3 days) meanwhile patients with pancreatic cancer with liver metastases took the shortest time to achieve recovery (10.78±2 days). The findings of the present study indicate that hepatic injury caused by IRE is transient and self-limiting in patients with liver tumors.

A modified surgical approach of hepatopancreatoduodenectomy for advanced gallbladder cancer: Report of two cases and literature review

Gallbladder cancer (GBC) is the most common cancer of the biliary tract, constituting 80%-95% of malignant biliary tract tumors. Surgical resection is currently regarded as the sole curative treatment for GBC. Hepatopancreatoduodenectomy (HPD) has been adopted to remove the advanced gallbladder tumor together with the infiltrated parts within the liver, lower biliary tract and the peripancreatic region of GBC patients. However, patients who underwent HPD were reported to have a distinctly higher postoperative morbidity (71.4%, ranging from 30.8% to 100%) and mortality (13.2%, ranging from 2.4% to 46.9%) than those given pancreatoduodenectomy (PD) alone. We present two patients with advanced GBC who underwent a modified surgical approach of HPD: PD with microwave ablation (MWA) of adjacent liver tissues and the technique of intraductal cooling of major bile ducts. No serious complications like bile leakage, pancreatic fistula, hemorrhage and organ dysfunction, etc. occurred in the two patients. They had a rapid recovery with postoperative hospital stay being 14 days. Application of this approach effectively eliminated tumor-infiltrated adjacent tissues, and maximally reduced the postoperative morbidity and mortality. This modified surgical method is secure and efficacious for the treatment of locally advanced GBC.

Percutaneous Image-Guided Cryoablation of Hepatic Tumors: Single-Center Experience With Intermediate to Long-Term Outcomes

OBJECTIVE

The purpose of this article is to report our intermediate to long-term outcomes with image-guided percutaneous hepatic tumor cryoablation and to evaluate its technical success, technique efficacy, local tumor progression, and adverse event rate.

MATERIALS AND METHODS

Between 1998 and 2014, 299 hepatic tumors (243 metastases and 56 primary tumors; mean diameter, 2.5 cm; median diameter, 2.2 cm; range, 0.3-7.8 cm) in 186 patients (95 women; mean age, 60.9 years; range, 29-88 years) underwent cryoablation during 236 procedures using CT (n = 126), MRI (n = 100), or PET/CT (n = 10) guidance. Technical success, technique efficacy at 3 months, local tumor progression (mean follow-up, 2.5 years; range, 2 months to 14.6 years), and adverse event rates were calculated.

RESULTS

The technical success rate was 94.6% (279/295). The technique efficacy rate was 89.5% (231/258) and was greater for tumors smaller than 4 cm (93.4%; 213/228) than for larger tumors (60.0%; 18/30) (p < 0.0001). Local tumor progression occurred in 23.3% (60/258) of tumors and was significantly more common after the treatment of tumors 4 cm or larger (63.3%; 19/30) compared with smaller tumors (18.0%; 41/228) (p < 0.0001). Adverse events followed 33.8% (80/236) of procedures and were grade 3-5 in 10.6% (25/236) of cases. Grade 3 or greater adverse events more commonly followed the treatment of larger tumors (19.5%; 8/41) compared with smaller tumors (8.7%; 17/195) (p = 0.04).

CONCLUSION

Image-guided percutaneous cryoablation of hepatic tumors is efficacious; however, tumors smaller than 4 cm are more likely to be treated successfully and without an adverse event.

Hepatocellular Carcinoma: a Comprehensive Review of Biomarkers, Clinical Aspects, and Therapy

Hepatocellular carcinoma (HCC) is a cause of several deaths related to cancer worldwidely. In early stage, curative treatments such as surgical resection, liver transplant and local ablation can improve the patient ´s survival. However, the disease is detected in advanced stage; moreover some available therapies are restricted to palliative care and local treatment. Early detections of HCC and adequate therapy are crucial to increase survival as well as to improve the patient´s quality of life. Therefore, researchers have been investigating molecular biomarkers with high sensibility and reliability as Golgi 73 protein (GP73), Glypican-3 (GPC3), Osteopontin (OPN), microRNAs and others. MicroRNAs can regulate important pathways on carcinogenesis, as tumor angiogenesis and progression. So, they can be considered as possible markers of prognosis in HCC, and therapeutic target for this tumor type. In this review, we discuss the recent advances related to the cause (highlighting the main risk factors), treatment, biomarkers, clinic aspects, and outcome in hepatocellular carcinoma.

Treatment efficacy of CT-guided percutaneous microwave ablation for primary hepatocellular carcinoma

AIM

To evaluate the treatment efficacy and potential complications of computed tomography (CT)-guided microwave ablation for primary hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

Data were collected and analysed from 220 HCC patients treated with CT-guided microwave ablation and followed up for 2 years. Independent risk factors for overall survival and progression-free survival (PFS) were analysed.

RESULTS

Among all cases followed, the cumulative overall survival rates at 1 and 2 years were 95.45% and 89.09%. The cumulative 1- and 2-year PFS rates were 80.90% and 62.73%. For patients with Barcelona Clinic Liver Cancer (BCLC) class C (n=60), the cumulative 1- and 2-year overall survival rates were 89.09% and 74.54%. In this group, patients with tumour invasion of blood vessels or tumour-related symptoms suffered a worse overall survival compared to those without (p=0.011). No fatal complications were observed. Child-Pugh score (p=0.030) and BCLC class (p=0.012) were independent risk factors for overall survival. The number of tumour nodules was an independent risk factor for reoccurrence.

CONCLUSION

CT-guided percutaneous microwave ablation could be an effective and safe treatment option for HCC patients.

Percutaneous image-guided cryoablation: current applications and results in the oncologic field

Percutaneous imaging-guided cryoablation (PICA) is a recently developed technique, which applies extreme hypothermia to destroy tumours under close imaging surveillance. It is minimally invasive, safe, repeatable, and does not interrupt or compromise other oncologic therapies. It presents several advantages over more established heat-based thermal ablation techniques (e.g. radiofrequency ablation; RFA) including intrinsic analgesic properties, superior monitoring capability on multi-modal imaging, ability to treat larger tumours, and preservation of tissue collagenous architecture. There has been a recent large increase in reports evaluating the utility of PICA in a wide range of patients and tumours, but systematic analysis of the literature is challenging due to the rapid pace of change and predominance of extensively heterogeneous level III studies. The precise onco-therapeutic role of PICA has not been established. This narrative review outlines the available evidence for PICA in a range of tumours. Current indications include curative therapy of small T1a renal tumours; curative/palliative therapy of small primary/secondary lung tumours where RFA is unsuitable; palliation of painful bone metastases; and urologic treatment of organ-confined prostate cancer. There is growing evidence to support its use for small hepatic tumours, and encouraging results have been obtained for breast tumours, extra-abdominal desmoid tumours, and management of higher-stage tumours and oligometastatic disease. However, the overall evidence base is weak, effectively restricting PICA to cases where standard therapy and RFA are unsuitable. As the technique and evidence continue to mature, the benefits of this emerging technique will hopefully become more widely available to cancer patients in the future.