Efficacy and safety of percutaneous transhepatic biliary radiofrequency ablation in patients with malignant obstructive jaundice

BACKGROUND Percutaneous transhepatic cholangiodrainage(PTCD)and endoscopic retrograde cholangiopancreatography/endoscopic nasobiliary drainage are the most common clinical procedures for jaundice control in patients with unresectable malignant obstructive jaundice,yet the safety and effect of endobiliary radiofrequency ablation(EB-RFA)combined PTCD is rarely reported,in this article,we report our experience of EB-RFA combined PTCD in such patients.AIM To retrospectively study the efficacy and safety of EB-RFA combined PTCD in patients with unresectable malignant obstructive jaundice.METHODS Patients with unresectable malignant obstructive jaundice treated with EB-RFA under PTCD were selected,the bile ducts of the right posterior lobe was selected as the target bile ducts in all cases.The general conditions of all patients,preoperative tumour markers,total bilirubin(TBIL),direct bilirubin(DBIL),albumin(ALB),alkaline phosphatase(ALP),and glutamyl transferase(GGT)before and on the 7th day after the procedure,as well as perioperative complications,stent patency time and patient survival were recorded.RESULTS All patients successfully completed the operation,TBIL and DBIL decreased significantly in all patients at the 7th postoperative day(P=0.009 and 0.006,respectively);the values of ALB,ALP and GGT also decreased compared with the preoperative period,but the difference was not statistically significant.Perioperative biliary bleeding occurred in 2 patients,which was improved after transfusion of blood and other conservative treatments,pancreatitis appeared in 1 patient after the operation,no serious complication and death happened after operation.Except for 3 patients with loss of visits,the stent patency rate of the remaining 14 patients was 100%71%and 29%at the 1^(st),3^(rd),and 6^(th)postoperative months respectively,with a median survival of 4 months.CONCLUSION EB-RFA under PTCD in patients with unresectable malignant obstructive jaundice has a satisfactory therapeutic effect and high safety,which is worthy of further clinical practice.

Efficacy of radiofrequency ablation combined with sorafenib for treating liver cancer complicated with portal hypertension and prognostic factors

BACKGROUND Patients with liver cancer complicated by portal hypertension present complex challenges in treatment.AIM To evaluate the efficacy of radiofrequency ablation in combination with sorafenib for improving liver function and its impact on the prognosis of patients with this condition.METHODS Data from 100 patients with liver cancer complicated with portal hypertension from May 2014 to March 2019 were analyzed and divided into a study group(n=50)and a control group(n=50)according to the treatment regimen.The research group received radiofrequency ablation(RFA)in combination with sorafenib,and the control group only received RFA.The short-term efficacy of both the research and control groups was observed.Liver function and portal hypertension were compared before and after treatment.Alpha-fetoprotein(AFP),glypican-3(GPC-3),and AFP-L3 levels were compared between the two groups prior to and after treatment.The occurrence of adverse reactions in both groups was observed.The 3-year survival rate was compared between the two groups.Basic data were compared between the survival and non-surviving groups.To identify the independent risk factors for poor prognosis in patients with liver cancer complicated by portal hypertension,multivariate logistic regression analysis was employed.RESULTS When comparing the two groups,the research group's total effective rate(82.00%)was significantly greater than that of the control group(56.00%;P<0.05).Following treatment,alanine aminotransferase and aspartate aminotransferase levels increased,and portal vein pressure decreased in both groups.The degree of improvement for every index was substantially greater in the research group than in the control group(P<0.05).Following treatment,the AFP,GPC-3,and AFP-L3 levels in both groups decreased,with the research group having significantly lower levels than the control group(P<0.05).The incidence of diarrhea,rash,nausea and vomiting,and fatigue in the research group was significantly greater than that in the control group(P<0.05).The 1-,2-,and 3-year survival rates of the research group(94.00%,84.00%,and 72.00%,respectively)were significantly greater than those of the control group(80.00%,64.00%,and 40.00%,respectively;P<0.05).Significant differences were observed between the survival group and the non-surviving group in terms of Child-Pugh grade,history of hepatitis,number of tumors,tumor size,use of sorafenib,stage of liver cancer,histological differentiation,history of splenectomy and other basic data(P<0.05).Logistic regression analysis demonstrated that high Child-Pugh grade,tumor size(6–10 cm),history of hepatitis,no use of sorafenib,liver cancer stage IIIC,and previous splenectomy were independent risk factors for poor prognosis in patients with liver cancer complicated with portal hypertension(P<0.05).CONCLUSION Patients suffering from liver cancer complicated by portal hypertension benefit from the combination of RFA and sorafenib therapy because it effectively restores liver function and increases survival rates.The prognosis of patients suffering from liver cancer complicated by portal hypertension is strongly associated with factors such as high Child-Pugh grade,tumor size(6-10 cm),history of hepatitis,lack of sorafenib use,liver cancer at stage IIIC,and prior splenectomy.

From Simulation to Reality: A Comprehensive Study on the Efficacy of a Rotating Monopolar and Bipolar Radiofrequency System through In-Silico Modeling and Pre-Clinical and Clinical Validation

Background: Skin aging is an unavoidable process aggravated by environmental agents. Among other energy devices, non-invasive radiofrequency (RF) technology is widely used for skin tightening and body contouring as it is simpler and more affordable than other technologies that also minimize pain and side-effects. However, most of the current RF devices do not provide automatic skin temperature control and it is difficult to achieve controlled, deep, and harmless thermal increase, so treatment performance and safety is dependent on the operator’s movements and expertise. Objective: To show the potential of numerical simulations for optimizing the design of monopolar and bipolar RF electrodes that are capable of providing homogeneous, deep and controlled heating. Materials and methods: In-silico models were developed and analyzed using Comsol Multiphysics software to simulate the RF effect produced in tissue by rotating monopolar and bipolar electrodes with different geometries from the Sculpt & Shape RF device (Sinclair, Spain), operating at frequencies of 0.5 and 1 MHz. Ex-vivo and in-vivo proof-of-concept tests were carried out to validate the simulations. Finally, treatments were performed on 16 subjects and a total of 78 body areas to assess the clinical results generated by the RF electrodes for skin tightening and body contouring. Results: In-silico studies emulated the superficial and deep dispersion of heat due to the release of RF energy into human skin tissue. The rotating electrodes (monopolar and bipolar) and the selected RF frequency (0.5 and 1 MHz) determined the homogeneity of the thermal distribution, the penetration depth (between 4.37 mm and 25.0 mm) and the heating dynamics (between 30 and 100 seconds to reach the target skin temperature), which were confirmed by ex-vivo and in-vivo tests. In addition, real treatments on facial and body areas using skin temperatures of between 43˚C and 44˚C showed consistent results with good clinical efficacy for skin tightening, circumference reduction and cellulite reduction, with no adverse effects and high subject satisfaction. Conclusions: New monopolar and bipolar RF electrodes with rotating technology have been designed and optimized using numerical simulations. The use of in-silico studies and accurate models that reproduce the thermal behavior of human biological tissues can be used to better understand RF devices and to develop superior, efficient, and safer products more quickly.

Severe hypoxemia after radiofrequency ablation for atrial fibrillation in palliatively repaired tetralogy of Fallot: A case report

BACKGROUND Patients with tetralogy of Fallot(TOF)often have arrhythmias,commonly being atrial fibrillation(AF).Radiofrequency ablation is an effective treatment for AF and does not usually cause severe postoperative hypoxemia,but the risk of complications may increase in patients with conditions such as TOF.CASE SUMMARY We report a young male patient with a history of TOF repair who developed severe hypoxemia after radiofrequency ablation for AF and was ultimately confirmed to have a new right-to-left shunt.The patient subsequently underwent atrial septal occlusion and eventually recovered.CONCLUSION Radiofrequency ablation may cause iatrogenic atrial septal injury;thus possible complications should be predicted in order to ensure successful treatment and patient safety.

New Rotative Radiofrequency Technology: A Multicenter Retrospective Study on Efficacy and Safety

Background: Non-ablative radiofrequency (RF) technology is widely used for the treatment of signs of aging, skin laxity, localized fat and cellulite. However, many RF devices suffer from technical limitations that make the results highly dependent on the user’s experience or clinical limitations that compromise safety, efficacy and comfort. Objective: To evaluate the efficacy and safety of a novel semi-automatic non-ablative RF device for skin tightening, body shaping and cellulite reduction. Materials and methods: A retrospective multicenter study was performed using a novel rotative RF device with temperature and impedance control (Sculpt&Shape®, Sinclair, Spain). 58 subjects underwent a minimum of 4 treatments every 1-2 weeks. A total of 120 treatments (56.7% body and 43.3% facial) and 1034 sessions were performed. Efficacy was evaluated by 3 researchers using the Global Aesthetic Improvement Scale (GAIS) and anthropometric measurements were collected. Subject and practitioner satisfaction were recorded. Safety was evaluated by analyzing the perception of pain during the treatment and the side and adverse effects immediately after treatment and over the next 48 hours. Results: Between 25% and 50% improvement was achieved according to the GAIS. Statistically significant (p < 0.01) abdominal fold reduction of 5.1 mm and circumference reduction of 32.0 mm, 16.4 mm and 13.9 mm were recorded for the abdomen, legs and arms, respectively. 77.5% of subjects and 94.9% of practitioners were either satisfied or very satisfied. Minor adverse effects were found in 0.97% of the sessions. Conclusion: This novel semi-automatic rotative RF device has been found to provide treatments that are effective, safe and comfortable for both practitioners and subjects. .

Radiofrequency ablation combined with transcatheter arterial chemoembolization for recurrent liver cancer

BACKGROUND The recurrence rate of liver cancer after surgery is high.Radiofrequency ablation(RFA)combined with transcatheter arterial chemoembolization(TACE)is an effective treatment for liver cancer;however,its efficacy in recurrent liver cancer remains unclear.AIM To investigate the clinical effect of TACE combined with RFA in the treatment of recurrent liver cancer.METHODS Ninety patients with recurrent liver cancer were divided into 2 groups according to treatment plan:Control(RFA alone);and experimental[TACE combined with RFA(TACE+RFA)].The incidence of increased alanine aminotransferase levels,complications,and other indices were compared between the two groups before and after the procedures.RESULTS One month after the procedures,the short-term efficacy rate and Karnofsky Performance Status scores of the experimental group were significantly higher than those of the control group(P<0.05).Alpha-fetoprotein(AFP)and total bilirubin levels were lower than those in the control group(P<0.05);The overall response rate was 82.22%and 66.67%in the experimental and control groups,respectively;The disease control rate was 93.33%and 82.22%in the experimental and control groups,respectively,the differences are statistically significant(P<0.05).And there were no statistical differences in complications between the two groups(P>0.05).CONCLUSION TACE+RFA was effective for the treatment of recurrent liver cancer and significantly reduced AFP levels and improved various indices of liver function.

Endoscopic ultrasound guided radiofrequency ablation for pancreatic tumors: A critical review focusing on safety, efficacy and controversies

The role of endoscopic ultrasound(EUS)in the last two decades has shifted from a diagnostic tool to an important therapeutic tool treating mainly pancreatobiliary disorders.In recent years,its applications for treating pancreatic diseases have broadened,including the implementation of radiofrequency ablation(RFA),which has been traditionally used for treating solid tumors.In this critical indepth review,we summarized all the papers throughout the literature regarding EUS-RFA for pancreatic neuroendocrine neoplasms,adenocarcinoma,and pancreatic cystic lesions.Overall,for pancreatic neuroendocrine neoplasms we identified 16 papers that reported 96 patients who underwent EUS-RFA,with acceptable adverse events that were rated mild to moderate and a high complete radiological resolution rate of 90%.For pancreatic adenocarcinoma,we identified 8 papers with 121 patients.Adverse events occurred in 13%of patients,mostly rated mild.However,no clear survival benefit was demonstrated.For pancreatic cystic lesions,we identified 4 papers with 38 patients.The adverse events were mostly mild and occurred in 9.1%of patients,and complete or partial radiological resolution of the cysts was reported in 36.8%.Notably,the procedure was technically feasible for most of the patients.Nevertheless,a long road remains before this technique finds its definite place in guidelines due to several controversies.EUS-RFA for pancreatic tumors seems to be safe and effective,especially for pancreatic neuroendocrine neoplasms,but multicenter prospective trials are needed to consider this treatment as a gold standard.

Radiofrequency sensing systems based on emerging two-dimensional materials and devices

As one of the most promising platforms for wireless communication,radiofrequency(RF)electronics have been widely advocated for the development of sensing systems.In particular,monolayer and few-layer two-dimensional(2D)materials exhibiting extraordinary electrical properties not only can be integrated to improve the performance of RF circuits,but also to display exceptional sensing capabilities.This review provides an in-depth perspective of current trends and challenges in the application of 2D materials for RF biochemical sensing,including:(i)theoretical bases to achieve different sensing schemes;(ii)unique properties of 2D materials for reasoning their applications in RF sensing;(iii)developments in 2D RF sensors to facilitate the practice of biochemical sensors with ever-demanding sensitivities,as well as their potential uses in meeting the requirements and challenges of biochemical sensors in the Internet-of-Things era.

Non-Ablative Transvaginal Radiofrequency in the Treatment of Stress Urinary Incontinence: Review of the Literature

Background: Urinary incontinence is defined as the involuntary loss of urine, which can affect up to 45% of women after menopause. Radiofrequency is a non-invasive procedure that involves the application of an electromagnetic wave that through heat generation promotes neocollagenesis and neoeslatinogenesis in the vaginal epithelium. This energy-based technology has been studied as a potential alternative for the treatment of genitourinary syndrome of menopause and urinary incontinence. Objective: To review the recent literature (from 2020 to June 2022) on the use of transvaginal radiofrequency in the treatment of stress urinary incontinence, by searching articles at databases of Capes, PubMed Cochrane and Scielo. Methods: The descriptor terms “Urinary Incontinence/therapy” [Majr] AND “Urinary Incontinence, Stress/therapy” [Majr] AND RADIOFREQUENCY-Search Results-PubMed, [“woman” OR “women”] AND [“urinary incontinence” OR “stress urinary incontinence”] AND Radiofrequency were used, with a filter for the period 2020 to 2022. Conclusion: The studies evaluated in this review demonstrated significant results of radiofrequency in the resolution or reduction of complaints of women with urinary incontinence, especially stress urinary incontinence, but most of these studies presented a low methodological quality. There is, therefore, a lack of studies with longer follow-ups, evaluation of cost-effectiveness, randomized clinical trials with objective outcomes and the use of validated questionnaires with international acceptance.

Radiofrequency ablation is an inferior option to liver resection for solitary hepatocellular carcinoma≤5 cm without cirrhosis:A population-based study with stratification by tumor size

Background:About 10%-20%of all individuals who develop hepatocellular carcinoma(HCC)do not have cirrhosis.Comparisons are rarely reported regarding the effectiveness of radiofrequency ablation(RFA)and liver resection(LR)in survival of HCC without cirrhosis and stratification by tumor size≤5 cm.Methods:We used the Surveillance,Epidemiology,and End Results(SEER)database and identified 1505 patients with a solitary HCC tumor≤5 cm who underwent RFA or LR during 2004-2015.Patients were classified into non-cirrhosis and cirrhosis groups and each group was categorized into three subgroups,according to tumor size(≤30 mm,31-40 mm,41-50 mm).Results:In patients without cirrhosis,LR showed better 5-year HCC cancer-specific survival than RFA in all tumor size subgroups(≤30 mm:82.51%vs.56.42%;31-40 mm:71.31%vs.46.83%;41-50 mm:74.7%vs.37.5%;all P<0.05).Compared with RFA,LR was an independent protective factor for HCC cancer-specific survival in multivariate Cox analysis[≤30 mm:hazard ratio(HR)=0.533,95%confidence interval(CI):0.313-0.908;31-40 mm:HR=0.439,95%CI:0.201-0.957;41-50 mm:HR=0.382;95%CI:0.159-0.916;all P<0.05].In patients with cirrhosis,for both tumor size≤30 mm and 31-40 mm groups,there were no significant survival differences between RFA and LR in multivariate analysis(all P>0.05).However,in those with tumor size 41-50 mm,LR showed significantly better 5-year HCC cancer-specific survival than RFA in both univariate(54.72%vs.23.06%;P<0.001)and multivariate analyses(HR=0.297;95%CI:0.136-0.648;P=0.002).Conclusions:RFA is an inferior treatment option to LR for patients without cirrhosis who have a solitary HCC tumor≤5 cm.

Radiofrequency ablation for renal tumours: A retrospective study from a tertiary centre

Objective:This study aimed to evaluate the safety and efficacy outcomes of percutaneous radiofrequency ablation(RFA)for localised renal cell carcinoma(RCC)in a tertiary hospital patient who remained unfit for surgical intervention.Methods:We retrospectively analysed survival outcomes for patients with biopsy proven RCC treated by RFA at Royal Perth Hospital between September 2009 and May 2018.Complication data were gathered for all patients that underwent renal RFA along with 2-and 5-year recurrence-free survival(RFS)rate and compared the outcomes with data from previous studies.Results:A total of 69 patients(73 procedures)were eligible for the study,and those patients had biopsy-proven RCC with a minimum of 2-year follow-up.The complication rate was 8.2%(6/73)and local recurrence rate 9.6%(7/73).Two-year RFS is 95.7% and 5-year RFS is 78.8% on a median 3.82-year follow-up(interquartile range 1.90-5.75 years).Conclusion:RFA performed at our centre was found to be safe and effective with low complication rates and durable RFS in line with expectations from existing research.Our study demonstrated that RFA is an alternative modality of treatment for small renal tumours in patients unfit for surgical approach.

Hemocholecyst caused by accidental injury associated with radiofrequency ablation for hepatocellular carcinoma:A case report

BACKGROUND Radiofrequency ablation(RFA)is an effective and safe treatment for hepatocellular carcinoma that features a lower incidence of serious complications than surgical resection.Hemocholecyst caused by RFA is a rare complication of secondary damage to the intrahepatic bile duct that results in hemobilia.CASE SUMMARY Here we report on a case of a hemocholecyst caused by accidental injury during RFA that induced hematemesis and melena.Digital subtraction angiography revealed no gallbladder arterial injuries.After conservative treatment and transcatheter arterial chemoembolization,the patient’s condition stabilized,and she was discharged 1 wk later.CONCLUSION Therefore,when performing interventional procedures such as RFA,clinicians must be vigilant because even minor injuries can lead to serious complications such as hemocholecyst.

Endoscopic intraductal radiofrequency ablation for extrahepatic cholangiocarcinoma:An update(2023)

Recently,endoscopic intraductal radiofrequency ablation(ID-RFA)has attracted attention as a local treatment method for malignant biliary obstruction(MBO).IDRFA causes coagulative necrosis of the tumor tissue in the stricture and induces exfoliation.Its effects are expected to extend the patency period of biliary stents and prolong the survival period.Evidence for extrahepatic cholangiocarcinoma(eCCA)is gradually accumulating,and some reports show significant therapeutic effects in eCCA patients without distant metastasis.However,it is still far from an established treatment technique,and many unsolved problems remain.Therefore,when performing ID-RFA in clinical practice,it is necessary to understand and grasp the current evidence well and to operate appropriately for the true benefit of the patients.This paper reviews the current status,issues,and prospects of endoscopic ID-RFA for MBO,especially for eCCA.

Long-term radiofrequency electromagnetic fields exposure attenuates cognitive dysfunction in 5×FAD mice by regulating microglial function

We have previously found that long-term effects of exposure to radiofrequency electromagnetic fields in 5xFAD mice with severe late-stage Alzheimer’s disease reduced both amyloid-βdeposition and glial activation,including microglia.To examine whether this therapeutic effect is due to the regulation of activated microglia,we analyzed mic roglial gene expression profiles and the existence of microglia in the brain in this study.5xFAD mice at the age of 1.5 months were assigned to sham-and radiofrequency electromagnetic fields-exposed groups and then animals were exposed to 1950 MHz radiofrequency electromagnetic fields at a specific absorption rate of 5 W/kg for 2 hours/day and 5 days/week for 6 months.We conducted behavioral tests including the object recognition and Y-maze tests and molecular and histopathological analysis of amyloid precursor protein/a myloid-beta metabolism in brain tissue.We confirmed that radiofrequency electromagnetic field exposure for 6 months ameliorated cognitive impairment and amyloid-βdeposition.The expression levels of Iba1(pan-microglial marker)and colony-stimulating factor 1 receptor(CSF1R;regulates microglial prolife ration)in the hippocampus in 5xFAD mice treated with radiofrequency electromagnetic fields were significantly reduced compared with those of the sham-exposed group.Subsequently,we analyzed the expression levels of genes related to mic rogliosis and microglial function in the radiofrequency electromagnetic fields-exposed group compared to those of a CSF1R inhibitor(PLX3397)-treated group.Both radiofrequency electromagnetic fields and PLX3397 suppressed the levels of genes related to microgliosis(Csf1r,CD68,and Ccl6)and pro-inflammatory cytokine interleukin-1β.N otably,the expression levels of genes related to mic roglial function,including Trem2,Fcgr1α,Ctss,and Spi1,were decreased after long-term radiofrequency electromagnetic field exposure,which was also observed in response to microglial suppression by PLX3397.These results showed that radiofrequency electromagnetic fields ameliorated amyloid-βpathology and cognitive impairment by suppressing amyloid-βdeposition-induced microgliosis and their key regulator,CSF1R.

Design of radiofrequency hyperthermia system based on MSP430

In order to solve the problem of inaccurate of the temperature control in radiofrequency hyperthermia,this paper designed MSP430-based radiofrequency hyperthermia system.Using infrared temperature sensor of MLX90615 to measure the target temperature,PID algorithm to adjust the duty cycle of the Pulse Width Modulation(Pulse Width Modulation,PWM)wave from the MSP430,achieved a precise control of temperature of hyperthermia through the closed loop system.Use the keyboard to set the temperature,and the LCD display the measured temperature value real-time.Through the experimental test,this system is stable and reliable,with a temperature control error within±0.5℃,and has good application prospects.

Review of endoscopic radiofrequency in biliopancreatic tumours with emphasis on clinical benefits, controversies and safety

Most pancreatic cancers and extrahepatic cholangiocarcinomas are unresectable at the time of diagnosis, and even in case of a resectable cancer, for elderly or patients with coexistent comorbidities, surgery is not an option. Current treatment alternatives in these scenarios are very limited. Biliary stenting with selfexpanding metal stents(SEMS) is the mainstay palliative treatment of biliary obstruction due to unresectable pancreatic cancer or cholangiocarcinoma. Nevertheless, more than 50% of SEMS become occluded after 6 mo due to tumour over- and ingrowth, leading to hospital readmissions and reinterventions that significantly impair quality of life. Regimes of chemotherapy or chemoradiotherapy also provide minimal survival benefits. Therefore, novel therapies are eagerly awaited. Radiofrequency(RF) energy causes coagulative necrosis leading to local destruction of the accessed malignant tissue and has an established role in the treatment of malignancies in several solid organs, especially liver cancers. However, pancreatic and extrahepatic biliary cancers are not easily accessed by a percutaneous route, making the procedure dangerous. Over the past five years, the development of dedicated devices compatible with endoscopic instruments has offered a minimally invasive option for RF energy delivery in biliopancreatic cancers. Emerging experience with endoscopic RF ablation(RFA) in this setting has been reported in the literature, but little is known about its feasibility, efficacy and safety. A literature review makes it clear that RFA in biliopancreatic tumours is feasible with high rates of technical success and acceptable safety profile. Although available data suggest a benefit of survival with RFA, there is not enough evidence to draw a firm conclusion about its efficacy. For this reason, prospective randomized trials comparing RFA with standard palliative treatments with quality-of-life and survival endpoints are required. Anecdotal reportshave also highlighted a potential curative role of RFA in small pancreatic tumours and benign conditions, such as ductal extension of ampullomas, intrahepatic adenomas or non-tumoural biliary strictures. These newest indications also deserve further examination in larger series of studies.

Meta-analysis of radiofrequency ablation in combination with transarterial chemoembolization for hepatocellular carcinoma

AIM: To compare radiofrequency ablation (RFA) and transcatheter arterial chemoembolization (TACE) with RFA monotherapy in hepatocellular carcinoma (HCC). METHODS: We searched PubMed, Medline, Embase and Chinese databases (CBMdisc and Wanfang data) for randomized controlled trails comparing RFA plus TACE and RFA alone for treatment of HCC from January 2000 to December 2012. The overall survival rate, re-currence-free survival rate, tumor progression rate, and safety were analyzed and compared. The analysis was conducted on dichotomous outcomes and the standard meta-analytical techniques were used. Pooled odds ratios (ORs) with 95%CIs were calculated using either the fixed-effects or random-effects model. For each meta-analysis, the χ2 and I2 tests were first calculated to assess the heterogeneity of the included trials. For P<0.05 and I 2>50%, the assumption of homogeneity was deemed invalid, and the random-effects model wasused; otherwise, data were assessed using the fixed-effects model. All statistical analysis was conducted us-ing Review manager (version 4.2.2.) from the Cochrane collaboration. RESULTS: Eight randomized controlled trials were identified as eligible for inclusion in this analysis and included 598 patients with 306 treated with RFA plus TACE and 292 with RFA alone. Our data analysis indicated that RFA plus TACE was associated a sig-nificantly higher overall survival rate (OR 1-year=2.96, 95%CI: 1.84-7.74, P<0.001; OR 2-year=3.72, 95%CI: 1.24-11.16, P=0.02; OR 3-year=2.65, 95%CI: 1.81-3.86, P<0.001) and recurrence-free survival rate (OR 3-year=3.00, 95%CI: 1.75-5.13, P<0.001; OR 5-year=2.26, 95%CI: 1.43-3.57, P=0.0004) vs that of RFA alone. The tumor progression rate in patients treated with RFA alone was higher than that of RFA plus TACE (OR=0.60, 95%CI: 0.42-0.88, P=0.008) and there was no significant difference on major complications between two different kinds of treatment (OR=1.20, 95%CI: 0.31-4.62, P=0.79). Additionally, the meta-analysis data of subgroups revealed that the survival rate was significantly higher in patients with intermediate-and large-size HCC underwent RFA plus TACE than in those underwent RFA monotherapy; however, there was no significant difference between RFA plus TACE and RFA on survival rate for small HCC. CONCLUSION: The combination of RFA with TACE has advantages in improving overall survival rate, and pro-vides better prognosis for patients with intermediate-and large-size HCC.

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

Hepatocellular cancer ranks fifth among cancers and is related to chronic viral hepatitis, alcohol abuse,steatohepatitis and liver autoimmunity. Surgical resection and orthotopic liver transplantation have curative potential, but fewer than 20% of patients are suitable candidates. Interventional treatments are offered to the vast majority of patients. Radiofrequency(RFA) and microwave ablation(MWA) are among the therapeutic modalities, with similar indications which include the presence of up to three lesions, smaller than 3 cm in size, and the absence of extrahepatic disease. The therapeutic effect of both methods relies on thermal injury, but MWA uses an electromagnetic field as opposed to electrical current used in RFA. Unlike MWA, the effect of RFA is partially limited by the heat-sink effect and increased impedance of the ablated tissue. Compared with RFA, MWA attains a more predictable ablation zone, permits simultaneous treatment of multiple lesions, and achieves larger coagulation volumes in a shorter procedural time. Major complications of both methods are comparable and infrequent(approximately 2%-3%), and they include haemorrhage, infection/abscess, visceral organ injury, liver failure, and pneumothorax. RFA may incur the additional complication of skin burns. Nevertheless, there is no compelling evidence for differences in clinical outcomes, including local recurrence rates and survival.

Radiofrequency ablation of hepatocellular carcinoma in difficult locations:Strategies and long-term outcomes

AIM:To investigate the treatment strategies and longterm outcomes of radiofrequency ablation(RFA) of hepatocellular carcinoma(HCC) in difficult locations and to compare the results with non-difficult HCC.METHODS:From 2004 to 2012,a total of 470 HCC patients underwent ultrasound-guided percutaneous RFA.Among these HCC patients,382 with tumors located ≤ 5 mm from a major vessel/bile duct(n = 87),from peripheral important structures(n = 232) or from the liver capsule(n = 63) were regarded as difficult cases.There were 331 male patients and 51 female patients,with an average age of 55.3 ± 10.1 years old.A total of 235 and 147 patients had ChildPugh class A and class B liver function,respectively.The average tumor size was 3.4 ± 1.2 cm.Individual treatment strategies were developed to treat these difficult cases.During the same period,88 HCC patients with tumors that were not in difficult locations served as the control group.In the control group,74 patients were male,and 14 patients were female,with an average age of 57.4 ± 11.8 years old.Of these,62 patients and 26 patients had Child-Pugh class A and class B liver function,respectively.Regular follow-up after RFA was performed to assess treatment efficacy.Survival results were generated from Kaplan-Meier estimates,and multivariate analysis was performed using the Cox regression model.RESULTS:Early tumor necrosis rate in the difficult group was similar to that in the control group(97.6% vs 94.3%,P = 0.080).The complication rate in the difficult group was significantly higher than that in thecontrol group(4.9% vs 0.8%,P = 0.041).The followup period ranged from 6 to 116 mo,with an average of 28 ± 22.4 mo.Local progression rate in the difficult group was significantly higher than that in the control group(12.7% vs 7.1%,P = 0.046).However,the 1-,3-,5-,and 7-year overall survival rates in the difficult group were not significantly different from those in the control group(84.3%,54.4%,41.2%,and 29.9% vs 92.5%,60.3%,43.2%,and 32.8%,respectively,P = 0.371).Additionally,a multivariate analysis revealed that tumor location was not a significant risk factor for survival.CONCLUSION:There was no significant difference in long-term overall survival between the two groups even though the local progression rate was higher in the difficult group.

Radiofrequency ablation of hepatocellular carcinoma:Current status

Ablation therapy is one of the best curative treatment options for malignant liver tumors,and can be an alternative to resection.Radiofrequency ablation(RFA) of primary and secondary liver cancers can be performed safely using percutaneous,laparoscopic,or open surgical techniques,and RFA has markedly changed the treatment strategy for small hepatocellular carcinoma(HCC).Percutaneous RFA can achieve the same overall and disease-free survival as surgical resection for patients with small HCC.The use of a laparoscopic or open approach allows repeated placements of RFA electrodes at multiple sites to ablate larger tumors.RFA combined with transcatheter arterial chemoembolization will make the treatment of larger tumors a clinically viable treatment alternative.However,an accurate evaluation of treatment response is very important to secure successful RFA therapy.Since a sufficient safety margin(at least 0.5 cm) can prevent local tumor recurrences,an accurate evaluation of treatment response is very important to secure successful RFA therapy.To minimize complications of RFA,clinicians should be familiar with the imaging features of each type of complication.Appropriate management of complications is essential for successful RFA treatment.