Percutaneous microwave ablation vs radiofrequency ablation in the treatment of hepatocellular carcinoma

[Ablative treatment options for locally advanced unresectable and borderline resectable pancreatic carcinoma]

BACKGROUND

Locally advanced unresectable (nonmetastatic) and borderline resectable pancreatic carcinomas represent a therapeutic challenge. Several minimally invasive local ablative techniques are available for local treatment in these situations.

OBJECTIVE

Which interventional techniques and application options are currently available for pancreatic carcinoma and which oncological results could be achieved so far?

MATERIAL AND METHODS

An analysis of reviews and studies was carried out. The selection of literature was based on searches in PubMed and the Cochrane library. The studies analyzed were reviews, meta-analyses and original articles mainly from the period between 2013 and 2018. Single case reports were not included in this review.

RESULTS

Local ablative techniques are performed with various forms of energy and are associated with specific advantages and disadvantages. They have to be individually tailored to the specific patient and situation. Noninvasive thermal ablation with high-intensity focused ultrasound (HIFU) is primarily used for palliative pain relief. Solid tumors are the main indication for thermal necrosis with microwave ablation (MWA) and radiofrequency ablation (RFA). The use of irreversible electroporation (IRE) enables a selective destruction of tumor cells and can be performed in the vicinity of sensitive structures. This technique is applied for primary tumor control and also for accentuation of tumor margins during resection.

CONCLUSION

With local ablative techniques an improvement in the quality of life and possibly the prognosis can be achieved in patients with unresectable pancreatic cancer; however, the latter aspect has to be viewed with caution due to a current lack of well-founded data.

Laparoscopic thermoablation for hepatocellular carcinoma in patients with liver cirrhosis: an effective procedure for tricky tumors

The optimal treatment for hepatocellular carcinoma (HCC) is surgical resection. However, only a small percentage of patients are amenable to this option. Percutaneous radiofrequency interstitial thermal ablation (TA) proved to be effective in the treatment of unresectable HCC. Recent advances in laparoscopic ultrasound have improved the accuracy in detecting small intrahepatic HCC nodules missed by pre-operative imaging techniques. Our objective was to evaluate an operative combination of laparoscopic ultrasound with laparoscopic thermoablation (LTA) in the treatment of HCC not amenable to liver resection. The aim of our review was to evaluate the advantages and limits of the laparoscopic approach according the criteria of the evidence-based medicine. LTA of HCC proved to be a safe and effective technique both in the short- and long-term follow-up period. This technique may be indicated in selected cases when the percutaneous approach to the lesion is very difficult or contraindicated.

Ablation for hepatocellular carcinoma: beyond the standard indications

Hepatocellular carcinoma (HCC), the most common primary liver neoplasia, represents the fifth most common malignant disease in men. Percutaneous ablation treatment is recommended among the treatments suggested for HCC patients in the very early/early stage. In the last decade, very important results in terms of survival benefits have been obtained with local ablative therapies, also outside the standard indications, thanks to many technical innovations. In particular, important results of ablation as a safe and effective technique have been obtained in the treatment of intermediate- or advanced-stage patients with HCC, and in the treatment of unfavourable tumour locations. Moreover, awareness is growing regarding the necessity of overcoming the rigidity of traditional guidelines in the treatment of HCC due to the complexity of patients with HCC, focusing on Precision Medicine. In this context, it is important to know the standard and non-standard indications of ablation in the treatment of HCC in order to offer the best therapeutic option tailored for each patient. The aim of this study was to analyse the possible clinical applications of ablative therapies for HCC patients, beyond the traditional indications recommended in the most widespread clinical practice guidelines for the management of HCC.

The early evaluation of ultrasound-guided iodine-125 interstitial implants for high-risk hepatocellular carcinoma

INTRODUCTION

To evaluate the feasibility and safety of ultrasound-guided iodine-125 interstitial implants for high-risk hepatocellular carcinoma.

METHODS

From October, 2016, to August, 2018, 49 patients suffering from a total of 66 hepatocellular carcinoma lesions were treated with ultrasound-guided iodine-125 interstitial implantation. Treatment planning system was applied to make preoperative plan. The response evaluation criteria in solid tumors were used to evaluate the curative effect. The evaluated outcomes included postoperative complications and complete disease control rate, 6-month disease-free survival, and 6-month overall survival.

RESULTS

All 49 patients underwent iodine-125 seed implantation successfully. Patients were followed up for 5 to 27.5 months. No patients developed serious complications and only 2 (4.1%) patients had slight pain. The complete response was seen in 21 lesions (31.8%), partial response in 26 lesions (39.4%), stable disease in eight lesions (12.1%), and progressive disease in 11 lesions (16.7%). The overall disease control rate was reached to 83.3%. The 6-month disease-free survival rate was 46.4% with a median disease-free survival time of 5.0 months. The 6-month overall survival rate was 83.6% with a median overall survival time of 15.0 months.

CONCLUSIONS

Iodine-125 interstitial implantation is a kind of safe and feasible treatment for high-risk hepatocellular carcinoma.

MRI Assessment of Hepatocellular Carcinoma after Local-Regional Therapy: A Comprehensive Review

Nearly 80% of cirrhotic patients diagnosed with hepatocellular carcinoma (HCC) are not eligible for surgical resection and instead undergo local-regional treatment. After therapy for HCC, patients undergo imaging surveillance to assess treatment efficacy and identify potential sites of progressive tumor elsewhere within the liver. Accurate interpretation of posttreatment imaging is essential for guiding further management decisions, and radiologists must understand expected treatment-specific imaging findings for each of the local-regional therapies. Of interest, expected imaging findings seen after radiation-based therapies (transarterial radioembolization and stereotactic body radiation therapy) are different than those seen after thermal ablation and transarterial chemoembolization. Given differences in expected posttreatment imaging findings, the current radiologic treatment response assessment algorithms used for HCC (modified Response Evaluation Criteria in Solid Tumors classification, European Association for the Study of Liver Diseases criteria, and Liver Imaging and Reporting Data System Treatment Response Algorithm) must be applied cautiously for radiation-based therapies in which persistent arterial phase hyperenhancement in the early posttreatment period is common and expected. This article will review the concept of tumor response assessment for HCC, the forms of local-regional therapy for HCC, and the expected posttreatment findings for each form of therapy. Keywords: Abdomen/GI, Liver, MR-Imaging, Treatment Effects, Tumor Response © RSNA, 2020.

Safety and efficacy of stereotactic radiofrequency ablation for very large (≥8 cm) primary and metastatic liver tumors

To assess the safety and clinical outcomes of multi-probe stereotactic radiofrequency ablation (SRFA) for very large (≥8 cm) primary and metastatic liver tumors with curative treatment intent. A retrospective, single center study carried out between 01.2005 and 06.2018. 34 consecutive patients had a total of 41 primary and metastatic liver tumors with a median size of 9.0 cm (8.0–18.0 cm) at initial SRFA. Patients were treated under CT guidance using a 3D navigation system. Endpoints consisted of (i) technical efficacy; primary - requiring one treatment, and secondary – requiring two treatments (ii) complication and mortality rates (iii) local and distant recurrence (LR), (iv) disease free survival (DFS), (v) overall survival (OS). 33/41 tumors were successfully ablated at initial SRFA (80.5% primary technical efficacy rate (PTE)). Four tumors required repeat ablation, resulting in a secondary technical efficacy (STE) rate of 90.2%. Local tumor recurrence (LR) developed in 4 of 41 tumors (9.8%). The 30-day perioperative mortality was 2.3% (1/ 44 ablations). The total major complication rate was 20.5% (9 of 44 ablations). Three of nine (33.3%) major complications, such as pleural effusion, pneumothoraces or perihepatic hemorrhages were relatively easy to treat. The overall survival (OS) rates at 1-, 3-, and 5- years from the date of the first SRFA were 87.1%, 71.8%, and 62.8% for patients with hepatocellular carcinoma (HCC) and 87.5%, 70.0% and 70.0% for patients with intrahepatic cholangiocarcinoma (ICC) respectively. Patients with metastatic disease had OS rates of 77.8% and 22.2% at 1- and 3- years. The clinical results of SRFA in this study are encouraging and warrant a prospective multicenter study. SRFA may become one of the best therapeutic choices for a growing number of patients with primary and metastatic liver cancer.

A Review of Hepatocellular Carcinoma in Elderly Patients Focused on Management and Outcomes

Recent studies report a significant age-specific increase in hepatocellular carcinoma (HCC) development among persons over 75 years old. Therefore, there is an urgent need to determine the optimal treatment strategy in elderly patients with HCC. This systemic review examines the clinical characteristics, efficacy, and safety of first-line treatment modalities. The literature was searched regarding epidemiology and clinical outcomes in elderly patients (age ≥75 years) undergoing first-line treatment for HCC. Causative or comorbid conditions of HCC in elderly patients differed from those in younger patients. Radiofrequency ablation may be effective and safe in early stages. Surgical resection may also be feasible in the early stages for selected patients. Transarterial chemoembolization may be safe and effective for intermediate HCC, and sorafenib may be feasible in elderly patients with advanced HCC. Prospective randomized trials are needed to establish the treatment strategy for elderly patients with HCC.

Subsequent cooling-circulation after radiofrequency and microwave ablation avoids secondary indirect damage induced by residual thermal energy

PURPOSE

We aimed to investigate the exact role of residual thermal energy following microwave ablation (MWA) and radiofrequency ablation (RFA) at the final ablation and transition zones and determine whether residual thermal energy could be dissipated by subsequent cooling-circulation.

METHODS

In an ex vivo study, MWA and RFA were performed on fresh porcine liver, and central and border temperatures were compared. In an in vivo study, MWA and RFA were performed to the livers of New Zealand white rabbits. Tissue samples were stained with α-NADH-diaphorase. The coagulation zones (NADH-negative) and transition zones (lightly NADH-stained) of different groups were compared at different time points.

RESULTS

In the ex vivo model, the residual thermal energy after MWA and RFA could be dispersed by subsequent cooling-circulation due to the temperature decreasing rapidly. In the in vivo study, the coagulation volume in the ablation group was larger than that in the cooling-circulation group (P < 0.05) 2 days after ablation. In the ablation group, the damaged zone (the transition zone plus the coagulation zone) on α-NADH-diaphorase-stained images increased rapidly within 2 hours after ablation and slowly reached the maximum on day 2. However, the damaged zones did not change significantly at the three time points observed in the cooling-circulation group.

CONCLUSION

The residual thermal energy in MWA and RFA induced secondary damage beyond the direct coagulation zone, and it could be dissipated by subsequent cooling-circulation, contributing to smaller ablation and transition zones.

Transarterial chemoembolization, ablation, tyrosine kinase inhibitors, and immunotherapy (TATI): A novel treatment for patients with advanced hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors. Currently, the main effective treatment options for HCC include resection, liver transplantation, various percutaneous modalities (such as transarterial chemoembolization [TACE] and thermal ablation), and tyrosine kinase inhibitors (TKIs). Herein, we have proposed a novel therapy which consists of TACE, ablation, tyrosine kinase inhibitors, and immunotherapy (TATI) for patients with advanced HCC). We reported the therapeutic effects of TATI in four patients with advanced HCC. All patients underwent TACE treatment at the beginning of disease diagnosis. During follow-up, all patients were treated with microwave ablation because of a residual tumor or recurrence. For tumor control, apatinib, a TKI, was administered after ablation. If the tumor was resistant to the TKI, we continued to apatinib therapy in combination with immunotherapy (camrelizumab). All the four patients had better survival benefits and no serious adverse effects.

Assessment of hepatocellular carcinoma treatment response with LI-RADS: a pictorial review

Computed tomography (CT) and magnetic resonance imaging (MRI) play critical roles for assessing treatment response of hepatocellular carcinoma (HCC) after locoregional therapy. Interpretation is challenging because posttreatment imaging findings depend on the type of treatment, magnitude of treatment response, time interval after treatment, and other factors. To help radiologists interpret and report treatment response in a clear, simple, and standardized manner, the Liver Imaging Reporting and Data System (LI-RADS) has developed a Treatment Response (LR-TR) algorithm. Introduced in 2017, the system provides criteria to categorize response of HCC to locoregional treatment (e.g., chemical ablation, energy-based ablation, transcatheter therapy, and radiation therapy). LR-TR categories include Nonevaluable, Nonviable, Equivocal, and Viable. LR-TR does not apply to patients on systemic therapies. This article reviews the LR-TR algorithm; discusses locoregional therapies for HCC, treatment concepts, and expected posttreatment findings; and illustrates LI-RADS treatment response assessment with CT and MRI.

Critical review of multidisciplinary non-surgical local interventional ablation techniques in primary or secondary liver malignancies

Local non-surgical interventional percutaneous ablation represents nowadays an important part of the potential treatment strategies. Although surgical ablation represents the gold standard, in the past decade there was an expansion in the use of non-surgical ablative techniques: radiofrequency, microwave, laser, cryoablation, irreversible electroporation, and interventional radiotherapy (brachytherapy) in primary as well as secondary liver cancers. With the growing experience in the field, there was implemented a new pillar for cancer treatment, together with surgery, chemotherapy as well as radiotherapy, so-called interventional oncology (IO). To date, there are no published papers regarding a comparative interdisciplinary evaluation of all these non-surgical interventional local ablation therapies. Our paper offers a critical interdisciplinary overview of the treatments in both primary and secondary liver tumors, including from a cost-effective point of view. Furthermore, the present status of education in IO and a comparison of actual economic aspects of the treatments are also provided.

Down-regulation of MARCO associates with tumor progression in hepatocellular carcinoma

Hepatocellular carcinoma(HCC) is a malignant tumor with high mortality due to lack of early diagnostic methods and effective treatments, and the molecular mechanisms are intricate and remain unclear. In the present study, the role of macrophage receptor with collagenous structure (MARCO) in tumor advancement of HCC was investigated. We examined expression level of MARCO in HCC samples, corresponding adjacent nontumor tissues and six hepatoma cell lines by polymerase chain reaction and immunohistochemistry (IHC). Clinical information of HCC patients was also analyzed. The role of MARCO involved in HCC progression via multiple functional experiments in vitro and in vivo was investigated. Bioinformatics analysis was conducted to further explore biological functions of MARCO. We found MARCO was suggestively down-regulated in HCC and associated with favorable prognosis, and MARCO upregulation oppressed tumor cell migration and invasion. Besides, overexpression of MARCO not only promoted apoptosis of hepatoma cells but also suppressed proliferation in vivo and in vitro. Furthermore, gene set enrichment analysis (GSEA) analysis suggested that MARCO may be related to the P53 signaling pathway, and this prediction was confirmed in this study as well. In sum, our study indicated that MARCO was involved in HCC progression and it can be defined as a novel probable biomarker as well as treatment target for HCC.

Lower Extremity Paralysis After Radiofrequency Ablation of Vertebral Metastases

BACKGROUND

Radiofrequency ablation (RFA) focally destroys abnormal or dysfunctional tissue using thermal energy generated from alternating current. The utilization of RFA has gained popularity as a minimally invasive procedure for the treatment of skeletal metastases with a particular focus on palliative pain treatments to the spine, pelvis, long bones, sternum, and glenoid. More recently, single-session procedures that combine RFA with vertebral augmentation techniques have allowed treatment to areas of pain associated with pathologic fractures secondary to metastatic disease. Although many studies have been done to investigate the safety and efficacy of RFA, there have been no reported cases to date in which the use of RFA for the treatment of spinal metastases has led to any major permanent neurological injury.

CASE DESCRIPTION

This report describes a case of a 61-year-old woman who underwent RFA and kyphoplasty for spinal metastases and noted the immediate onset of lower extremity paralysis after the procedure. To the best of our knowledge, this is the first documented case of permanent lower extremity paralysis in the medical literature after radiofrequency thermal ablation of spine metastases.

CONCLUSIONS

Postoperative magnetic resonance imaging and physical examination suggest RFA-induced thermal injury as the most likely mechanism of paralysis. In this report, a review of previous in vivo models used in studying the efficacy and safety of spine RFA is conducted. Additionally, the literature has been reviewed for any neurological events reported with the use of RFA in the treatment of patients with vertebral pathology.

The Combination Strategy of Transarterial Chemoembolization and Radiofrequency Ablation or Microwave Ablation against Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver. Hepatectomy and liver transplantation (LT) are regarded as the radical treatment, but great majority of patients are already in advanced stage on the first diagnosis and lose the surgery opportunity. Multifarious image-guided interventional therapies, termed as locoregional ablations, are recommended by various HCC guidelines for the clinical practice. Transarterial chemoembolization (TACE) is firstly recommended for intermediate-stage (Barcelona Clinic Liver Cancer (BCLC) B class) HCC but has lower necrosis rates. Radiofrequency ablation (RFA) is effective in treating HCCs smaller than 3 cm in size. Microwave ablation (MWA) can ablate larger tumor within a shorter time. Combination of TACE with RFA or MWA is effective and promising in treating larger HCC lesions but needs more clinical data to confirm its long-term outcome. The combination of TACE and RFA or MWA against hepatocellular carcinoma needs more clinical data for a better strategy. The characters and advantages of TACE, RFA, MWA, and TACE combined with RFA or MWA are reviewed to provide physician a better background on decision.

Rhein-based necrosis-avid MRI contrast agents for early evaluation of tumor response to microwave ablation therapy

PURPOSE

Early evaluation of tumor response to thermal ablation therapy can help identify untreated tumor cells and then perform repeated treatment as soon as possible. The purpose of this work was to explore the potential of rhein-based necrosis-avid contrast agents (NACAs) for early evaluation of tumor response to microwave ablation (MWA).

METHODS

3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide (MTT) assay was performed to test the cytotoxicity of rhein-based NACAs against HepG2 cells. Rat models of liver MWA were used for investigating the effectiveness of rhein-based NACAs in imaging the MWA lesion, the optimal time period for post-MWA MRI examination, and the metabolic behaviors of ⁶⁸ Ga-labeled rhein-based NACAs. Rat models of orthotopic liver W256 tumor MWA were used for investigating the time window of rhein-based NACAs for imaging the MWA lesion, the effectiveness of these NACAs in distinguishing the residual tumor and the MWA lesion, and their feasibility in early evaluating the tumor response to MWA.

RESULTS

Gadolinium 2,2',2''-(10-(2-((4-(4,5-Dihydroxy-9,10-dioxo-9,10-dihydroanthracene-2-carboxamido)butyl)amino)-2-oxoethyl)-1,4,7,10-tetraazacyclododecane-1,4,7-triyl)triacetic acid (GdL₂ ) showed low cytotoxicity and high quality in imaging the MWA region. The optimal time period for post-MWA MRI examination using GdL₂ was 2 to 24 h after the treatment. During 2.5 to 3.5 h postinjection, GdL₂ can better visualize the MWA lesion in comparison with gadolinium 2-[4,7,10-tris(carboxymethyl)-1,4,7,10-tetraazacyclododec-1-yl]acetic acid (Gd-DOTA), and the residual tumor would not be enhanced. The tumor response to MWA as evaluated by using GdL₂ -enhanced MRI was consistent with histological examination.

CONCLUSION

GdL₂ appears to be a promising NACA for the tumor response assessment after thermal ablation therapies.

Microwave ablation compared with radiofrequency ablation for treatment of hepatocellular carcinoma and liver metastases: a systematic review and meta-analysis

Purpose

Percutaneous ablation techniques, including microwave ablation (MWA) and radiofrequency ablation (RFA), have become important minimally invasive treatment options for liver cancer. This systematic review compared MWA with RFA for treatment of liver cancer.

Methods

The systematic review and meta-analysis followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A systematic search of MEDLINE, EMBASE, and Cochrane Central Register of Controlled Trials was conducted for randomized and observational studies published from 2006 onwards. A random-effects model was used for meta-analyses and local tumor progression (LTP), technique efficacy, overall survival (OS), disease-free survival (DFS), intrahepatic de novo lesions (IDL), extrahepatic metastases (EHM), length of stay (LOS), and complications were analyzed. Subgroup and sensitivity analyses were also conducted.

Results

Of 1379 studies identified, 28 randomized and observational studies met inclusion criteria. The main analysis demonstrated that LTP was significantly reduced by 30% with MWA versus RFA (RR=0.70; P=0.02) (all studies) and by 45% with MWA versus RFA (RR=0.55; P=0.007) (randomized studies only). There were no significant differences between MWA and RFA for other efficacy and safety outcomes. Higher frequency (2450 MHz) and larger tumor size (≥2.5 cm) are amongst variables that may be associated with improved outcomes for MWA. Sensitivity analyses were generally congruent with the main results.

Conclusion

MWA is at least as safe and effective as RFA for treating liver cancer and demonstrated significantly reduced LTP rates. Future studies should assess time and costs associated with these two treatment modalities.

Comparison of parallel and crossed placement of antennas in microwave ablation of 3-5 cm hepatocellular carcinoma

PURPOSE

To evaluate the effects of ablation strategies on local tumor progression (LTP) after microwave ablation (MWA) of hepatocellular carcinomas (HCCs) measuring 3-5 cm.

MATERIALS AND METHODS

Between December 2011 and May 2017, 71 HCC patients with 71 nodules treated by ultrasound(US)-guided percutaneous MWA were divided into parallel (group A) and crossed (group B) antenna placement groups. All patients underwent MWA using two antennas with four insertions. LTP and overall survival (OS) rates were compared between the two groups.

RESULTS

The median follow-up time was 16.8 months. There was no significant difference in the complete ablation rate and treatment sessions between the two groups. LTP was diagnosed in 8 of 48 nodules (16.7%) in group A and 1 of 23 nodules (4.3%) in group B, with no significant difference between two groups (P = 0.115). The 1-, 2-, and 3-year OS rates were 88.5%, 79%, and 71.8% in group A and 93.8%, 87.5%, and 87.5% in group B, respectively (P = 0.236). Multivariate analysis showed that the tumor diameter (P = 0.017), the distance between the antennas (P = 0.032), and the total emission time (P = 0.015) were associated with LTP.

CONCLUSIONS

There were trends with lower LTP and improved OS in group B, despite the lack of statistically significant differences between the two strategies at a level of P < 0.05. The increase of distance between antennas and total emission time will facilitate reductions in LTP rate.

Percutaneous radiofrequency versus microwave ablation for management of hepatocellular carcinoma: a randomized controlled trial

BACKGROUND

Hepatocellular carcinoma (HCC) is the fifth most common cancer in the world and the third most common cause of cancer related deaths. Radiofrequency ablation (RFA) and microwave ablation (MWA) are effective measures for HCC management. Although MWA is usually considered to be superior to RFA in the medical community, clinical studies showed contradictory results. We aimed to compare the efficacy of both techniques using a randomized controlled trial.

METHODS

We had assessed all patients with definite HCC who were referred to our unit during the period from mid-June 2017 to mid-December 2017 for inclusion in the study. After fulfilling the criteria, patients were randomized to either RFA or MWA. Achieving complete ablation was ensured. Patients were followed up every 3 months after the procedure to detect any tumor recurrence.

RESULTS

There were no statistically significant differences between both techniques regarding complications, local tumor recurrence, development of de novo HCC lesions and changes in the modified Child-Pugh score. Time of ablation using MWA was significantly shorter than RFA (P<0.001).

CONCLUSIONS

RFA and MWA are comparable techniques for HCC treatment. Our group couldn't prove any superiority of MWA over RFA except for the shorter time needed for ablation.

Liver stiffness measurement changes following hepatocellular carcinoma treatment with percutaneous microwave ablation or transarterial chemoembolization: a cohort study

BACKGROUND

Liver stiffness increases after the development of hepatocellular carcinoma (HCC). Transient elastography for liver stiffness measurement (LSM) using fibroscan is a simple noninvasive method of proven efficacy. This study aims to assess the changes in LSM following HCC treatment.

PATIENTS AND METHODS

This study included 150 patients with hepatitis C virus related HCC attending the multidisciplinary HCC clinic, Kasr Al-Ainy Hospital between March 2014 and October 2015 who underwent either transarterial chemoembolization (TACE) or microwave ablation (MWA). Baseline LSM was carried out 3 and 6 months after treatment. The response rate was calculated according to the modified Response Evaluation Criteria in Solid Tumors criteria; overall survival and LSM changes were then compared between the two procedures.

RESULTS

MWA showed higher rates of complete ablation (77.4%) than did TACE (31.7%) (P=0.004). Increase in LSM 3 and 6 months after treatment was statistically significant in the TACE group (P<0.001) but not in the MWA group (P=0.4). Patients who showed complete ablation had statistically significant lower baseline LSM than those with incomplete ablation, and their 6 months increase in LSM was also significantly lower. Logistic regression revealed that with each unit increase in baseline stiffness, 3% reduction in the odds of complete ablation is expected, and this did not change after controlling for the type of treatment. Child-Pugh class, number, and size of HCCs were our independent prognostic factors by Cox proportional analysis.

CONCLUSION

The increase in LSM is significant after TACE than after MWA. Moreover, lower pre-ablation LSM is a predictor of complete ablation.

Effects of thermal ablation on Treg/Th17 in hepatocellular carcinoma of mice

The study was aimed to explore the possible function of thermal ablation treatment on T helper 17 (Th17) cells and regulatory T (Treg) cells in transplantation of hepatocellular carcinoma in mice. In total, 60 male C57BL/6 mice were divided into control group, model group, and treat group. Flow cytometry was used to detect the frequency of Th17 and Treg cells in peripheral blood. The levels of interleukin (IL)-17, IL-23, IL-10, and transforming growth factor beta (TGF-β) in serum were detected by enzyme-linked immunosorbent assay (ELISA).The levels of IL-17, RORγt, Foxp3, and TGF-β mRNA in tumor tissues were detected by real-time fluorescence quantitative PCR (qRT-PCR). Compared with the model group, tumor size was significantly decreased after thermal ablation treatment. After treatment, the frequency of Th17 cells in peripheral blood was significantly decreased, while the frequency of Treg cells was profoundly increased ( P < 0.05). The levels of IL-17 and IL-23 were significantly downregulated, while IL-10 and TGF-β levels were upregulated ( P < 0.05). IL-17 and RORγt mRNA levels in tumor tissues were significantly decreased ( P < 0.05), and Foxp3 and TGF-β mRNA levels were significantly increased ( P < 0.05). Thermal ablation treatment plays a positive role in the treatment of hepatoma in mice through affecting the imbalance of Th17/Treg cells.

Electrochemotherapy: A Review of Current Status, Alternative IGP Approaches, and Future Perspectives

The efficiency of electroporation (EP) has made it a widely used therapeutic procedure to transfer cell killing substances effectively to the target site. A lot of researches are being done on EP-based cancer treatment techniques. Electrochemotherapy (ECT) is the first EP-based application in the field of drug administration. ECT is a local and nonthermal treatment of cancer that combines the use of a medical device with pharmaceutical agents to obtain local tumor control in solid cancers. It involves the application of eight, 100µs, pulses at 1 or 5000 Hz frequency and specified electric field (V/cm) with a median duration of 25 minutes. The efficacy of chemotherapeutic drugs increases by applying short and intense electrical pulses. Several clinical studies proposed ECT as a safe and complementary curative or palliative treatment option (curative intent of 50% to 63% in the treatment of Basal Cell Carcinoma (BCC)) to treat a number of solid tumors and skin malignancies, which are not suitable for conventional treatments. It is used currently for treatment of cutaneous and subcutaneous lesions, without consideration of their histology. On the contrary, it is also becoming a practical method for treatment of internal, deep-seated tumors and tissues. A review of this method, needed instruments, alternative image-guided procedures (IGP) approaches, and future perspectives and recommendations are discussed in this paper.

Safety and Short-Term Efficacy of Irreversible Electroporation and Allogenic Natural Killer Cell Immunotherapy Combination in the Treatment of Patients with Unresectable Primary Liver Cancer

PURPOSE

This study aimed to investigate the safety and short-term efficacy of irreversible electroporation (IRE) combined with allogenic natural killer (NK) cell immunotherapy in the treatment of patients with unresectable primary liver cancer.

MATERIALS AND METHODS

Between October 2015 and December 2016, 40 patients were enrolled and randomly allocated to either the IRE group (n = 22) or the IRE-NK group (n = 18). All adverse events experienced by the patients were recorded; the changes in tumor biomarkers [AFP, CA 19-9, circulating tumor cells (CTCs)], lymphocyte number and function, quality of life, clinical response, progression-free survival (PFS) and overall survival (OS) were assessed.

RESULTS

Patients who received combination therapy exhibited significantly longer median PFS and OS than who just received IRE (PFS 15.1 vs. 10.6 months, P < 0.05, OS 17.9 vs. 23.2 months, P < 0.05). The combination therapy of IRE and NK cell immunotherapy significantly reduced CTCs and increased immune function and Karnofsky performance status.

CONCLUSION

Our data suggest a novel, promising combination therapy using IRE and allogenic NK cell immunotherapy. Larger clinical trials are required to confirm these conclusions.

Thermal ablation of intrahepatic cholangiocarcinoma: Safety, efficacy, and factors affecting local tumor progression

PURPOSE

To evaluate the safety and oncologic efficacy of percutaneous thermal ablation of intrahepatic cholangiocarcinoma (ICC) and identify risk factors for local tumor progression (LTP).

MATERIALS AND METHODS

Retrospective review of an institutional tumor ablation registry demonstrated that 20 patients (9 males, 11 females; mean age 62.5 ± 15.8 years) with 50 ICCs (mean size 1.8 ± 1.3 cm) were treated with percutaneous radiofrequency ablation (RFA) or microwave ablation (MWA) between 2006 and 2015. Thirty-eight of the treated ICCs (76%) were metastases that developed after surgical resection of the primary tumor. Patient demographics, procedure technical parameters, and clinical outcomes were reviewed. A Cox proportional hazards model was used to examine the risk of LTP by ablation modality. Survival analyses were performed using the Kaplan-Meier method.

RESULTS

Mean imaging follow-up time was 41.5 ± 42.7 months. Forty-four (88%) ICCs were treated with RFA, and 6 (12%) with MWA. Eleven (22%) cases of LTP developed in 5 (25%) patients. The median time to LTP among these 11 tumors was 7.1 months (range, 2.3-22.9 months). Risk of LTP was not significantly different for ICCs treated with MWA compared to RFA (HR 2.72; 95% CI 0.58-12.84; p = 03.21). Median disease-free survival was 8.2 months (1.1-70.4 months), and median overall survival was 23.6 months (7.4-122.5 months). No major complication occurred.

CONCLUSIONS

Percutaneous thermal ablation is a safe and effective treatment for patients with ICCs and may be particularly valuable in unresectable patients, or those who have already undergone hepatic surgery. Tumor size and ablation modality were not associated with LTP, whereas primary tumors and superficially located tumors were more likely to subsequently recur.

Percutaneous Irreversible Electroporation (IRE) of Hepatic Malignancy: A Bi-institutional Analysis of Safety and Outcomes

Aim

Irreversible electroporation (IRE) is a non-thermal ablative option in patients unsuitable for standard thermal ablation, due to its potential to preserve collagenous structures (vessels and ducts) and a reduced susceptibility to heat sink effects. In this series from two large tertiary referral hepatobiliary centres, we aim to assess the safety/outcomes of hepatic IRE.

Materials and Methods

Bi-institutional retrospective, longitudinal follow-up series of IRE for primary hepatic malignancy; [hepatocellular carcinoma (n = 20), cholangiocarcinoma (n = 3)] and secondary metastatic disease; colorectal (n = 28), neuroendocrine (n = 1), pancreatic (n = 1), breast (n = 1), gastrointestinal stromal tumour (GIST, n = 1) and malignant thymoma (n = 1). Outcome measures included procedural safety/effectiveness, time to progression and time to death.

Results

Between 2013 and 2017, 52 patients underwent percutaneous IRE of 59 liver tumours in 53 sessions. All tumours were deemed unsuitable for thermal ablation. Cases were performed using ultrasound (US) or computed tomography (CT) guidance. A complete ablation was achieved in n = 44, (75%) of cases with an overall complication rate of 17% (n = 9). Of the complete ablation group, median time to progression was 8 months. At 12 months, 44% were progression-free (95% CI 30–66%). The data suggest that larger lesion size (> 2 cm) is associated with shorter time to progression and there is highly significant difference with faster time to progression in mCRC compared with HCC. Median survival time was 38 months.

Conclusion

This bi-institutional review is the largest UK series of IRE and suggests this ablative technology can be a useful tool, but appears to mainly induce local tumour control rather than cure with HCC having better outcomes than mCRC.

The efficacy and safety of microwave ablation in patients with retroperitoneal metastases

BACKGROUND

Retroperitoneal metastases are common, and most present with symptoms; however, treatments for this condition are limited. This retrospective study verified the efficacy and safety of microwave ablation (MWA) in retroperitoneal metastases patients.

METHODS

Patients with pathologically confirmed malignant carcinoma and imaging showing retroperitoneal metastases were enrolled and underwent MWA. The end-points included objective response rate, time to local progression (TTLP), overall survival, visual analogue scale (VAS) score, dose of morphine pre- and post-ablation and complications.

RESULTS

Twenty-three patients were enrolled. The mean tumour diameter was 3.6 cm. Altogether, 29 tumour sites in 23 patients were ablated during 23 procedures; technical success was achieved in all 23 patients. The objective response and disease control rates were 95.7% and 100.0%, respectively. The mean TTLP and median OS were 22.8 months (95% CI: 16.1-29.6 months) and 10.6 months (95% CI: 7.4-13.8 months), respectively. In 13 patients with symptoms, the VAS values before ablation and 48 h, 1 month, 2 months, 3 months and 6 months after ablation were 5.38, 2.77 (p = 0.015), 2.15 (p = 0.001), 2.17 (p = 0.001), 1.40 (p = 0.000) and 1.71 (p = 0.006), respectively. The corresponding morphine doses were 76.9 mg, 70.7 mg (p = 0.584), 50.7 mg (p = 0.031), 55.0 mg (p = 0.097), 46.0 mg (p = 0.057) and 40.0 mg (p = 0.363), respectively. No ablation-associated mortality was observed. Major complications, minor complications and adverse events were observed in eight (34.8%), five (21.7%) and four (17.4%) patients, respectively.

CONCLUSION

MWA for the treatment of retroperitoneal metastases was effective and the complications were common.

Transcatheter arterial chemoembolization combined with radiofrequency or microwave ablation for hepatocellular carcinoma: a review

Hepatocellular carcinoma (HCC) is the sixth most common type of malignancy. Several therapies are available for HCC and are determined by stage of presentation, patient clinical status and liver function. Local–regional treatment options, including transcatheter arterial chemoembolization, radiofrequency ablation or microwave ablation, are safe and effective for HCC but are accompanied by limitations. The synergistic effects of combined transcatheter arterial chemoembolization and radiofrequency ablation/microwave ablation may overcome these limitations and improve the therapeutic outcome. The purpose of this article is to review the current literature on these combined therapies and examine their efficacy, safety and influence on the overall and recurrence-free survival in patients with HCC.

Magnetic Resonance Imaging Evaluation of Hepatocellular Carcinoma Treated With Stereotactic Body Radiation Therapy: Long Term Imaging Follow-Up

PURPOSE

To determine the natural history of imaging findings seen on magnetic resonance imaging (MRI) of hepatocellular carcinoma (HCC) treated with stereotactic body radiation therapy (SBRT). Although arterial hyperenhancement is a key feature of untreated HCC, our clinical experience suggested that tumors that never progressed could still show hyperenhancement. Therefore, we undertook a systematic study to test the hypothesis that persistent arterial phase hyperenhancement (APHE) after SBRT is an expected finding that does not suggest failure of treatment.

METHODS AND MATERIALS

One hundred forty-six patients undergoing SBRT for HCC between January 1, 2007, and December 31, 2015, were screened retrospectively using an institutional review board-approved prospectively maintained registry. Inclusion criteria were (1) HCC treated with SBRT, (2) multiphasic MRI ≤3 months before SBRT, (3) up to 1 year of follow-up MRI post-SBRT, and (4) cirrhosis. The exclusion criterion was ≤3 months of locoregional therapy to the liver segment containing the SBRT-treated HCC. Pre- and post-SBRT MRI from up to 3 years were analyzed in consensus by independent pairs of subspecialty-trained radiologists to determine the temporal evolution of major features for HCC and imaging findings in off-target parenchyma.

RESULTS

Sixty-two patients with 67 HCCs (Organ Procurement and Transplantation Network imaging criteria [OPTN] 5a [n = 26], OPTN 5b [n = 28], OPTN 5x [n = 7]; Liver Imaging Reporting Data System [LI-RAD]-M [n = 4] and LiRADs-4 [n = 2]) were studied. Tumor size either decreased (66% [44 of 67]) or remained unchanged (34% [23 of 67]) within the first 12 months. Post-SBRT APHE was common (58% [39 of 67]). When graded using modified Response Evaluation Criteria in Solid Tumors at 3 to 6 months, 25% (17 of 67) met criteria for complete response and 75% (50 of 67) met criteria for stable disease.

CONCLUSIONS

SBRT is an effective locoregional treatment option for HCC. Persistent APHE is common and does not necessarily indicate viable neoplasm; thus, standard response assessment such as modified Response Evaluation Criteria should be used with caution, particularly in the early phases after SBRT therapy.

Percutaneous Microwave Ablation Under CT Guidance for Hepatocellular Carcinoma: a Single Institutional Experience

BACKGROUND

Microwave ablation (MWA) is an emerging treatment for treatment of patients with hepatocellular carcinoma (HCC) not amenable of surgical resection.

PATIENTS AND METHODS

We searched for patients diagnosed as having small-, medium-, and large HCCs treated with MWA under CT guidance between 2010 and 2014. The main outcomes of interest were rates of complete ablation, complications, and overall survival. Rates of complete ablation were compared with Chi-square test, and estimated survival rates were calculated by means of Kaplan-Meier method.

RESULTS

Thirty-two patients with 45 HCC nodules received MWA. Seventeen (37.8%) nodules were <3 cm (small), 15 (33.3%) between 3 and 5 cm (medium), and 13 (28.9%) > 5 cm (large). Complete ablation was obtained in 94.1% of small tumors, 80% of medium tumors, and 53.8% of large tumors (p = 0.03). Two patients had HCC located in risk area (paracardiac position). Minor complications occurred after seven procedures (15.5%). Estimated median survival was 37 months (95% confidence interval 11.97-62.02). One-year OS was 82.7%, 2-year survival 68.9%, and 3-year survival 55.2%.

CONCLUSION

MWA is a versatile ablative method that can be applied in HCC at various stages, and also in lesions located in risk areas.

Mitochondria-targeting nanoparticles for enhanced microwave ablation of cancer

Although microwave ablation is widely used in the treatment of hepatocellular carcinoma, it is only recommended for the therapy of cancer with a diameter of 3 cm or less because of the limited heat transmission radius. Mitochondria play an important role in the apoptotic events of tumor cells. Here, we developed mitochondria-targeting zirconia (ZrO2) complex nanoparticles (MZCNs) as nanoagents for efficient cancer therapy by microwave ablation. The MZCNs are composed of ZrO2 nanoparticles encapsulating the microwave-sensitive ionic liquid (IL) and co-decorated with the mitochondria-targeting molecule of triphenylphosphonium (TPP), and the tumor cell-targeting peptide iRGD. The cell experiment results reveal that the amount of MZCNs accumulated in the tumor is obviously increased by the synergistically targeted delivery of TPP and iRGD peptide after administration by intravenous injection. Besides, the in vitro experiments demonstrate that MZCNs are distributed preferentially in the mitochondria with the assistance of TPP molecules. More importantly, the in vivo experiments in mice administered with MZCNs show that the effective area with a temperature above 42 °C was about 2.8-fold larger than that of the controls due to the targeting effect and better microwave sensitivity of the MZCNs. As such, the cancer in mice can be eradicated without recurrence, demonstrating the MZCNs as promising nanoagents for efficient cancer therapy by microwave ablation.

Clinical outcome in elderly Chinese patients with primary hepatocellular carcinoma treated with percutaneous microwave coagulation therapy (PMCT): A Strobe-compliant observational study

Percutaneous microwave ablation therapy (PMCT) has been recommended for elderly hepatocellular carcinoma (HCC) patients who cannot tolerate surgery due to their age or presence of comorbidities. Few studies have investigated efficacy and treatment outcomes for PMCT treatment in these patients, especially in China, where patients are more often diagnosed and treated early in life. This study evaluated the safety and efficacy of ultrasound-guided PMCT in treatment-naive elderly HCC patients, and analyzed risk factors associated with poor treatment outcomes.The 65 HCC patients in this retrospective study were divided into 2 groups: <65 years old or ≥65 years old. Patients received PMCT every month until tumor was unobservable and were then followed for 1 month after ablation. The primary clinical endpoint was the rate of complete tumor ablation, and secondary endpoints were progression-free survival and overall survival.Patients ≥65 years old had significantly poorer performance status than younger patients, but similar rates of complete ablation. Multiple tumors and hypertension were associated with a significantly higher risk of death, while higher postoperative alanine aminotransferase levels were associated with a significantly lower risk of death. Patients with tumor sizes >5 to ≤ 10 cm were at a significantly higher risk for disease progression than patients with tumor sizes >1 to ≤ 3 cm. Complete ablation significantly lowered the risk of disease progression.PMCT is safe and effective for patients ≥65 years of age, achieving total ablation in more than 90% of patients. Age and comorbidities did not affect clinical outcome.

Percutaneous thermal ablation combined with TACE versus TACE monotherapy in the treatment for liver cancer with hepatic vein tumor thrombus: A retrospective study

Purpose

To investigate the efficacy of percutaneous thermal ablation combined with transarterial chemoembolization (TACE) versus TACE monotherapy in treating primary liver cancer with hepatic vein tumor thrombus (HVTT), and to identify potential factors of overall survival after combination therapy.

Materials and methods

Patients with primary liver cancer and HVTT from 2011 to 2016 at our institute were retrospectively identified. They were divided into two groups (group A and group B). Patients in group A underwent TACE with subsequent percutaneous thermal ablation, while patients in group B who were unsuitable for ablation received TACE monotherapy. Characteristics and survival data of the two groups were analyzed and compared. Relevant factors for overall survival (OS) of group A were explored by univariate analysis.

Results

Twenty-six patients were included and analyzed. The median OS for group A (n = 13) was 18 months, while the 1-, 2- and 3-year survival rates were 58.6%, 46.9% and 46.9%, respectively. The median OS for group B (n = 13) was 6.5 months and the 1-year survival rate was 10.9%. The survival of group A was significantly better than group B (P = 0.02). The following factors were related with overall survival of group A: ablation technique, complete response of tumor and HVTT, Child-pugh grade, pre-operative extrahepatic metastases and lymph node metastases. In group A, patients who achieved complete response had the longest average survival time (42.1 months).

Conclusion

For patients with primary liver cancer and HVTT, percutaneous thermal ablation and TACE present better efficacy than TACE monotherapy. Long-term survival could be achieved in selected patients.

Recent Advances in the Image-Guided Tumor Ablation of Liver Malignancies: Radiofrequency Ablation with Multiple Electrodes, Real-Time Multimodality Fusion Imaging, and New Energy Sources

Radiofrequency ablation (RFA) has emerged as an effective loco-regional treatment modality for malignant hepatic tumors. Indeed, studies have demonstrated that RFA of early stage hepatocellular carcinomas can provide comparable overall survival to surgical resection. However, the incidence of local tumor progression (LTP) after RFA is significantly higher than that of surgical resection. Thus, to overcome this limitation, multiple electrode radiofrequency (RF) systems that use a multi-channel RF generator have been developed, and they demonstrate better efficiency in creating larger ablation zones than that using the conventional RFA with a single electrode. Furthermore, RFA with multiple electrodes can allow the “no-touch” ablation technique which may also help to reduce LTP. Another technique that would be helpful in this regard is multi-modality-ultrasound fusion imaging, which helps to not only more accurately determine the target lesion by enabling the RFA of small, poorly visible or invisible tumors, but also improve the monitoring of procedures and determine the appropriateness of the ablation margin. In addition, new energy sources, including microwave and cryoablation, have been introduced in imaging-guided tumor ablation. In this review, these recently introduced ablation techniques and the results of the most current animal and clinical studies are discussed.

Feasibility and outcomes of percutaneous thermal ablation of hepatocellular carcinoma in a transplanted allograft

PURPOSE

To examine the safety, feasibility, and oncologic control following percutaneous image-guided thermal ablation of hepatocellular carcinoma (HCC) in a transplanted allograft.

MATERIALS AND METHODS

Retrospective review was performed to identify patients who underwent liver transplantation for HCC and subsequently underwent percutaneous hepatic thermal ablation for recurrent HCC within the allograft between January 1st, 2000-September 1st, 2016. Eleven patients with hepatic allograft HCC underwent twelve percutaneous thermal ablation procedures to treat 16 lesions. Patient, procedural characteristics, and local oncologic efficacy were reviewed. Complications were characterized via the Common Terminology for Clinically Adverse Events nomenclature [CTCAE] v4.03).

RESULTS

Eleven transplant recipients underwent treatment of 16 HCC tumors in their allografts during 12 ablation sessions. Mean follow-up time was 25 months (range 2-96 months). Local oncologic control was achieved in 10 of 11 tumors (91%) with imaging follow-up. One patient (8%) with Roux-en-Y biliary reconstruction developed a major complication with hepatic abscess.

CONCLUSION

Thermal ablation of recurrent HCC in transplanted allografts can be accomplished safely with acceptable rates of local control for patients with duct-to-duct biliary reconstruction. Due to the high number of patients deemed surgically unresectable, the morbidity of surgical resection, the side effects of targeted therapies, and significant mortality associated with recurrences in the transplanted allograft, patients may benefit from percutaneous thermal ablative treatments. Further study is needed to assess the role of thermal ablation in allograft HCC recurrences as primary therapy or in a multimodality approach with emerging systemic therapies.

Increasing radiofrequency ablation volumes with the use of internally cooled electrodes and injected hydrochloric acid in ex vivo bovine livers

PURPOSE

We used an impedance-controlled generator with an internally cooled electrode to perform radiofrequency ablation (RFA) in ex vivo bovine livers, with a single injection of either 38.5% sodium chloride (NaCl) or 10% hydrochloric acid (HCl), to determine the relative effects of these two solutions on tissue impedance, temperature and ablation volume.

MATERIALS AND METHODS

We performed 10 ablations each with injections of NaCl (NaCl-RFA), HCl (HCl-RFA) or nothing (RFA-alone), with a power setting of 200 W for 15 minutes. We recorded tissue impedance before and after injection. We logged temperatures obtained from thermocouple probes positioned 5, 10, 15 and 20 mm from the internally cooled RF electrode. After ablation, we measured ablation zone longitudinal and transverse diameters, and we calculated a spherical ratio (SR) for each ablation.

RESULTS

Mean post-injection impedance of 30.3 (standard deviation [SD] 2.5) ohms for HCl was significantly lower than that of 55.4 (SD 3.5) ohms for NaCl (p < .001). Mean maximum temperatures recorded at each respective distance from the RFA electrode were all highest for HCl-RFA and lowest for RFA-alone (p < .001). Mean longitudinal and transverse diameters after HCl-RFA (5.50 [SD 0.25] cm and 5.28 [SD 0.22] cm, respectively) were significantly larger than those after NaCl-RFA (4.24 [SD 0.35] cm and 3.55 [SD 0.43] cm, respectively) and after RFA-alone (3.60 [SD 0.10] cm and 2.70 [SD 0.13] cm, respectively) (p < .001). Mean SR after HCl-RFA (0.93, SD 0.02) was significantly higher than mean SR after NaCl-RFA (0.76, SD 0.06) and RFA-alone (0.72, SD 0.04) (p < .001).

CONCLUSION

Monopolar, impedance-controlled RFA, with an internally cooled electrode and a single 10% HCl injection may allow larger tumors to be treated, potentially resulting in improved patient outcomes.

Droplet digital PCR detects high rate of TP53 R249S mutants in cell-free DNA of middle African patients with hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is still a major killing malignancy in sub-Saharan Africa. Lifelong intoxication with aflatoxin B1 is considered as one of the primary causes of this situation. The role of aflatoxin in HCC from a given population is commonly estimated through the prevalence of R249S mutation of TP53, a hallmark for previous exposure to the mycotoxin. However, the role of AFB1 is barely known in large part of Africa. We conducted a survey on circulating cell-free DNA from 149 patients with HCC and 213 control subjects with and without liver diseases from Cameroon and Central African Republic using droplet digital PCR technique. We observed a mutation prevalence of 24.8% (n = 37/149) in patients with tumor and 5.6% (n = 12/213) in controls (P = 2.2E-07). Patients with mutations usually displayed significantly increased circulating alpha-fetoprotein (AFP) values, high hepatitis B virus (HBV) DNA loads as well as worsened values of blood cells count. Interestingly, the fraction of droplets positive for R249S was significantly larger in patients with liver cancer (15.3 ± 3.7%) than in controls (0.5 ± 0.3%, P = 7.1E-04). Our survey indicates that AFB1 is instrumental for HCC development in Middle Africa and that droplet digital PCR might be used in the region both to diagnose HCC and to conduct public health surveys on populations at risk of chronic aflatoxin intoxication.

Microwave ablation for lung cancer patients with a single lung: Clinical evaluation of 11 cases

BACKGROUND

The study was conducted to retrospectively evaluate the safety and effectiveness of computed tomography (CT)-guided percutaneous microwave ablation (MWA) for peripheral non-small cell lung cancer (NSCLC) in 11 patients with a single lung after pneumonectomy.

METHODS

From May 2011 to March 2015, 11 single-lung patients (8 men and 3 women; mean age 60.3 years, range 46-71) with peripheral NSCLC underwent 12 sessions of MWA. Eleven tumors measuring 13-52 mm (mean 30.2 mm) were treated. Follow-up was performed via CT scan at 1, 3, 6, 12, 18, and 24 months after the procedure and annually thereafter. Clinical outcomes were evaluated and complications after MWA were summarized.

RESULTS

At a median follow-up period of 20 months (range 6-38), four patients showed evidence of local recurrence at a rate of 36.4% (4/11). Median overall survival was 20 months. The overall survival rates at one, two, and three years after MWA were 88.7%, 63.6%, and 42.3%, respectively. Complications after MWA included pneumothorax (33.3%), hemoptysis (33.3%), intrapulmonary bleeding (25%), pleural effusion (16.7%), and pulmonary infection (8.3%). None of the patients died during the procedure or in the 30 days after MWA.

CONCLUSION

CT-guided percutaneous MWA is safe and effective for the treatment of peripheral NSCLC in patients with a single lung after prior pneumonectomy.

Radiofrequency ablation (RFA)-induced systemic tumor growth can be reduced by suppression of resultant heat shock proteins

PURPOSE

To determine the role of hepatic radiofrequency ablation (RFA) heating parameters and their activation of heat shock proteins (HSPs) in modulating distant tumor growth.

METHODS AND MATERIALS

First, to study the effects of RFA dose on distant tumor growth, rats with subcutaneous R3230 adenocarcinoma (10 ± 1 mm) were assigned to 3 different hepatic RF doses (60 °C × 10 min, 70 °C × 5 min or 90 °C × 2 min) that induced identical sized ablation or sham (n = 6/arm). Post-RFA tumor growth rates, cellular proliferation (Ki-67) and microvascular density (MVD) were compared at 7d. Next, the effect of low and high power doses on local HSP70 expression and cellular infiltration (α-SMA + myofibroblasts and CD68 + macrophages), cytokine (IL-6) and growth factor (HGF and VEGF) expression was assessed. Finally, 60 °C × 10 min and 90 °C × 2 min RFA were combined with anti-HSP micellar quercetin (MicQ, 2 mg/ml). A total of 150 animals were used.

RESULTS

Lower RF heating (70 °C × 5 min and 60 °C × 10 min) resulted in larger distant tumors at 7d (19.2 ± 0.8 mm for both) while higher RF heating (90 °C × 2) led to less distant tumor growth (16.7 ± 1.5 mm, p < .01 for both), though increased over sham (13.5 ± 0.5 mm, p < .01). Ki-67 and MVD correlated with tumor growth (p < .01 for all). Additionally, lower dose 60 °C × 10 min hepatic RFA had more periablational HSP70 compared to 90 °C × 2 min (rim: 1.106 ± 163 µm vs. 360 ± 18 µm, p < .001), with similar trends for periablational α-SMA, CD68 and CDC47 (p < .01 for all). Anti-HSP70 MicQ blocked distant tumor growth for lower dose (60 °C × 10: RF/MicQ 14.6 ± 0.4 mm vs. RF alone: 18.1 ± 0.4 mm, p < .01) and higher dose RFA (90 °C × 2 min: RF/MicQ 14.6 ± 0.5 mm vs. RF alone: 16.4 ± 0.7 mm, p < .01).

CONCLUSION

Hepatic RF heating parameters alter periablational HSP70, which can influence and stimulate distant tumor growth. Modulation of RF heating parameters alone or in combination with adjuvant HSP inhibition can reduce unwanted, off-target systemic tumorigenic effects.