Efficacy and safety of B-ultrasound-guided radiofrequency ablation in the treatment of primary liver cancer: Systematic review and metaanalysis

BACKGROUND Primary liver cancer is one of the most lethal malignancies in the world.Tradi-tional treatment methods have limitations in terms of efficacy and safety.Ra-diofrequency ablation(RFA)guided by B-ultrasound,as a minimally invasive treatment,has attracted increasing attention in the treatment of primary liver cancer in recent years.AIM To study the efficacy and safety of RFA were compared with those of traditional surgery(TS)for treating small liver cancer.METHODS At least 2 people were required to search domestic and foreign public databases,including foreign databases such as EMBASE,PubMed and the Cochrane Library,and Chinese databases such as the China National Knowledge Infrastructure database,China Biomedical Literature database,Wanfang database and VIP database.Controlled trials of RFA vs conventional surgery for small liver cancer were retrieved from January 2008 to January 2023.They were screened and eva-luated according to the quality evaluation criteria in the Cochrane Handbook of Systematic Reviews.The meta-analysis was performed using RevMan 5.3 soft-ware.RESULTS A total of 10 studies were included in this study,including 1503 patients in the RFA group and 1657 patients in the surgery group.The results of the meta-ana-lysis showed that there was no significant difference in 1-year overall survival between the two groups(P>0.05),while the 3-year and 5-year overall survival rates and 1-year,3-year and 5-year tumor-free survival rates in the surgery group were greater than those in the RFA group(P<0.05).In terms of complications,the incidence of complications in the RFA group was lower than that in the surgery group(P<0.05).CONCLUSION In terms of long-term survival,TS is better than RFA for small liver cancer patients.However,RFA has fewer complications and is safer.

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.

Nomogram predicting the prognosis of primary liver cancer after radiofrequency ablation combined with transcatheter arterial chemoembolization

BACKGROUND The incidence and mortality rates of primary hepatocellular carcinoma(HCC)are high,and the conventional treatment is radiofrequency ablation(RFA)with transcatheter arterial chemoembolization(TACE);however,the 3-year survival rate is still low.Further,there are no visual methods to effectively predict their prognosis.AIM To explore the factors influencing the prognosis of HCC after RFA and TACE and develop a nomogram prediction model.METHODS Clinical and follow-up information of 150 patients with HCC treated using RFA and TACE in the Hangzhou Linping Hospital of Traditional Chinese Medicine from May 2020 to December 2022 was retrospectively collected and recorded.We examined their prognostic factors using multivariate logistic regression and created a nomogram prognosis prediction model using the R software(version 4.1.2).Internal verification was performed using the bootstrapping technique.The prognostic efficacy of the nomogram prediction model was evaluated using the concordance index(CI),calibration curve,and receiver operating characteristic RESULTS Of the 150 patients treated with RFA and TACE,92(61.33%)developed recurrence and metastasis.Logistic regression analysis identified six variables,and a predictive model was created.The internal validation results of the model showed a CI of 0.882.The correction curve trend of the prognosis prediction model was always near the diagonal,and the mean absolute error before and after internal validation was 0.021.The area under the curve of the prediction model after internal verification was 0.882[95%confidence interval(95%CI):0.820-0.945],with a specificity of 0.828 and sensitivity of 0.656.According to the Hosmer-Lemeshow test,χ^(2)=3.552 and P=0.895.The predictive model demonstrated a satisfactory calibration,and the decision curve analysis demonstrated its clinical applicability.CONCLUSION The prognosis of patients with HCC after RFA and TACE is affected by several factors.The developed prediction model based on the influencing parameters shows a good prognosis predictive efficacy.

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.

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.

Percutaneous transhepatic cholangiography:An effective option for endo-biliary radiofrequency ablation before stent insertion in unresectable biliary cancer?

Biliary cancer is a highly aggressive disease that is typically diagnosed at advanced stages when surgical removal is no longer an option.In these cases,palliative care and mechanical widening of the blocked biliary system are preferred.The insertion of a stent is often necessary to prevent the recurrence of blockages caused by cancer progression.Prior to stent placement,endo-biliary radiofrequency ablation(EB-RFA)appears to result in longer-lasting stent effectiveness without increasing the risk of severe complications.However,its impact on overall survival is not yet clear.Additionally,while endoscopic retrograde cholangiopancreatography is the most common method for performing EB-RFA,percutaneous transhepatic cholangiodrainage seems to be a safe and potentially more efficient alternative,particularly for long,angulated,or significantly narrowed bile ducts.

Benefits and drawbacks of radiofrequency ablation via percutaneous or minimally invasive surgery for treating hepatocellular carcinoma

The management of early stage hepatocellular carcinoma(HCC)presents significant challenges.While radiofrequency ablation(RFA)has shown safety and effectiveness in treating HCC,with lower mortality rates and shorter hospital stays,its high recurrence rate remains a significant impediment.Consequently,achieving improved survival solely through RFA is challenging,particularly in retrospective studies with inherent biases.Ultrasound is commonly used for guiding percutaneous RFA,but its low contrast can lead to missed tumors and the risk of HCC recurrence.To enhance the efficiency of ultrasound-guided percutaneous RFA,various techniques such as artificial ascites and contrast-enhanced ultrasound have been developed to facilitate complete tumor ablation.Minimally invasive surgery(MIS)offers advantages over open surgery and has gained traction in various surgical fields.Recent studies suggest that laparoscopic intraoperative RFA(IORFA)may be more effective than percutaneous RFA in terms of survival for HCC patients unsuitable for surgery,highlighting its significance.Therefore,combining MIS-IORFA with these enhanced percutaneous RFA techniques may hold greater significance for HCC treatment using the MIS-IORFA approach.This article reviews liver resection and RFA in HCC treatment,comparing their merits and proposing a trajectory involving their combination in future therapy.

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.

Analysis of alkaline phosphatase and γ-glutamyltransferase after radiofrequency ablation of primary liver cancer: A retrospective study

BACKGROUND Changes in alkaline phosphatase(ALP)andγ-glutamyltransferase(GGT)levels in patients with primary liver cancer(PLC)after radiofrequency ablation(RFA).Hepatocellular carcinoma is a malignant tumor with high incidence worldwide.As a common local treatment,RFA has attracted much attention for its efficacy and influence on liver function.AIM To investigate the effect of serum ALP and GGT levels on the prognosis of patients with PLC treated by RFA.METHODS The preoperative clinical data of 165 patients who were pathologically or clinically diagnosed with PLC and who received RFA in our hospital between October 2018 and June 2023 were collected.The chi-square test was used to compare the data between groups.The Kaplan-Meier method and Cox regression were used to analyze the associ-ations between serum ALP and GGT levels and overall survival,progression-free survival(PFS)and clinical characteristics of patients before treatment.RESULTS The 1-year survival rates of patients with normal(≤135 U/L)and abnormal(>135 U/L)serum ALP before treatment were 91%and 79%,respectively;the 2-year survival rates were 90%and 68%,respectively;and the 5-year survival rates were 35%and 18%,respectively.The difference between the two groups was statistically significant(P=0.01).Before treatment,the 1-year survival rates of patients with normal serum GGT levels(≤45 U/L)and abnormal serum GGT levels(>45 U/L)were 95%and 87%,the 2-year survival rates were 85%and 71%,and the 5-year survival rates were 37%and 21%,respectively.The difference between the two groups was statist-ically significant(P<0.001).Serum ALP[hazard ratio(HR)=1.766,95%confidence interval(95%CI):1.068-2.921,P=0.027]and GGT(HR=2.312,95%CI:1.367-3.912,P=0.002)is closely related to the overall survival of PLC patients after RF ablation and is an independent prognostic factor.The 1-year PFS rates were 72%and 50%,the 2-year PFS rates were 52%and 21%,and the 5-year PFS rates were 14%and 3%,respectively.The difference between the two groups was statistically significant(P<0001).The 1-year PFS rates were 81%and 56%in patients with normal and abnormal serum GGT levels before treatment,respectively;the 2-year PFS rates were 62%and 35%,respectively;and the 5-year PFS rates were 18%and 7%,respectively,with statistical significance between the two groups(P<0.001).The serum ALP concentration(HR=1.653,95%CI:1.001-2.729,P=0.049)and GGT(HR=1.949,95%CI:1.296-2.930,P=0.001)was closely associated with PFS after RFA in patients with PLC.The proportion of male patients with abnormal ALP levels is high,the Child-Pugh grade of liver function is poor,and the incidence of ascites is high.Among GGT-abnormal patients,the Child-Pugh grade of liver function was poor,the tumor stage was late,the proportion of patients with tumors≥5 cm was high,and the incidence of hepatic encephalopathy was high.CONCLUSION Serum ALP and GGT levels before treatment can be used to predict the prognosis of patients with PLC after RFA,and they have certain guiding significance for the long-term survival of patients with PLC after radiofrequency therapy.

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.

Recurrence and survival following microwave, radiofrequency ablation, and hepatic resection of colorectal liver metastases: A systematic review and network meta-analysis

Background: Gold standard for colorectal liver metastases(CRLM) remains hepatic resection(HR). However, patients with severe comorbidities, unresectable or deep-situated resectable CRLM are candidates for ablation. The aim of the study was to compare recurrence rate and survival benefit of the microwave ablation(MWA), radiofrequency ablation(RFA) and HR by conducting the first network meta-analysis. Data sources: Systematic search of the literature was conducted in the electronic databases. Both updated traditional and network meta-analyses were conducted and the results were compared between them. Results: HR cohort demonstrated significantly less local recurrence rate and better 3-and 5-year diseasefree(DFS) and overall survival(OS) compared to MWA and RFA cohorts. HR cohort included significantly younger patients and with significantly lower preoperative carcinoembryonic antigen(CEA) by 10.28 ng/m L compared to RFA cohort. Subgroup analysis of local recurrence and OS of solitary and ≤3 cm CRLMs did not demonstrate any discrepancies when compared with the whole sample. Conclusions: For resectable CRLM the treatment of choice still remains HR. MWA and RFA can be used as a single or adjunct treatment in patients with unresectable CRLM and/or prohibitive comorbidities.

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.

Outcomes of microwave versus radiofrequency ablation for hepatocellular carcinoma:A systematic review and meta-analysis

BACKGROUND Studies to date comparing outcomes of microwave ablation(MWA)with radiofrequency ablation(RFA)on patients with hepatocellular carcinoma have yielded conflicting results,with no clear superiority of one technique over the other.The aim of this systematic review and meta-analysis was to compare the efficacy and safety of MWA with RFA.AIM To perform a systematic review and meta-analysis comparing the efficacy and safety of MWA with RFA.METHODS A systematic literature search was performed using Ovid Medline,Embase,PubMed,Reference Citation Analysis,Cochrane Central and Cochrane Systematic Review databases,and Web of Science.Abstracts and full manuscripts were screened for inclusion utilising predefined inclusion and exclusion criteria comparing outcomes of MWA and RFA.A random-effects model was used for each outcome.Meta-regression analysis was performed to adjust for the difference in follow-up period between the studies.Primary outcome measures included complete ablation(CA)rate,local recurrence rate(LRR),survival[local recurrence-free survival(LRFS),overall survival(OS)]and adverse events.RESULTS A total of 42 published studies[34 cohort and 8 randomised controlled trials(RCT)]with 6719 patients fulfilled the selection criteria.There was no significant difference in tumour size between the treatment groups.CA rates between MWA and RFA groups were similar in prospective cohort studies[odds ratio(OR)0.95,95%confidence interval(CI)0.28–3.23]and RCTs(OR 1.18,95%CI 0.64–2.18).However,retrospective studies reported higher rates with MWA(OR 1.29,95%CI 1.06–1.57).Retrospective cohort studies reported higher OS(OR 1.54,95%CI 1.15–2.05 and lower LRR(OR 0.67,95%CI 0.51–0.87).No difference in terms of LRFS or 30-d mortality was observed between both arms.MWA had an increased rate of adverse respiratory events when compared to RFA(OR 1.99,95%CI 1.07–3.71,P=0.03).CONCLUSION MWA achieves similar CA rates and as good or better longer-term outcomes in relation to LRR and OS compared to RFA.Apart from an increased rate of respiratory events post procedure,MWA is as safe as RFA.

Past,present,and future perspectives of ultrasound-guided ablation of liver tumors:Where could artificial intelligence lead interventional oncology?

The first ablation procedures for small hepatocellular carcinomas were percutaneous ethanol injection under ultrasound(US)guidance.Later,radiofrequency ablation was shown to achieve larger coagulation areas than percutaneous ethanol injection and became the most used ablation technique worldwide.In the past decade,microwave ablation systems have achieved larger ablation areas than radiofrequency ablation,suggesting that the 3-cm barrier could be broken in the treatment of liver tumors.Likewise,US techniques to guide percutaneous ablation have seen important progress.Contrast-enhanced US(CEUS)can define and target the tumor better than US and can assess the size of the ablation area after the procedure,which allows immediate retreatment of the residual tumor foci.Furthermore,fusion imaging fuses real-time US images with computed tomography or magnetic resonance imaging with significant improvements in detecting and targeting lesions with low conspicuity on CEUS.Recently,software powered by artificial intelligence has been developed to allow three-dimensional segmentation and reconstruction of the anatomical structures,aiding in procedure planning,assessing ablation completeness,and targeting the residual viable foci with greater precision than CEUS.Hopefully,this could lead to the ablation of tumors up to 5-7 cm in size.

Importance of Percutaneous Radiofrequency Ablation for Recurrent Hepatocellular Carcinoma

Objective: To study the importance of percutaneous radiofrequency ablation (PRFA) guided by ultrasound for inoperable recurrent hepatocellular carcinoma.Methods: Forty-seven patients with inoperable recurrent hepatocellular carcinoma underwent percutaneous radiofrequency ablation (PRFA) under ultrasond between October 1999 and July 2001. Twenty-four patients had single recurrent tumor and 23 patients had multiple lesions. Twelve patients had single lesion with less than 3.5 cm in diameter. All patients were followed up to examine the value of AFP, MRI or CT after PRFA. Kaplan-Meier estimation was used to analyze the survival rate.Results: The 1-, 2- and 3-year survival rate in single lesion group was 65.2%, 37.5% and 37.5% respectively. The survival rate of 1 and 2 years was 41.7% and 19.5% in the multiple lesions group. The 1-, 2-and 3-year survival rate in single lesion groups with less than 3.5 cm in diameter was 83.3%, 51.4% and 51.4% respectively.Conclusion: PRFA is one of the important comprehensive methods for recurrent hepatocellular carcinoma. According to the size, number and recurrent time, PRFA can be performed separately or combined with transcatheter arterial chemoembolization for inoperable recurrent hepatocellular carcinoma. This method can control the recurrence and increase the survival rate effectively. Key words recurrence - hepatocellular cacinoma - radiofrequency ablation

Major complications after radiofrequency ablation for liver tumors:Analysis of 255 patients

AIM:To investigate the major complications after radiofrequency ablation(RFA) for the treatment of liver tumors and analyze possible risk factors that precipitate these complications.METHODS:From March 2001 to April 2008,255 patients with liver tumors(205 male,50 female;age range,18-89 years;mean age,56.0 years) who received RFA were enrolled in this study.Of these patients,212 had hepatocellular carcinoma,39 had metastatic liver tumors and four had cholangiocellular carcinoma.One hundred and forty eight patients had a single tumor,and 107 had multiple tumors.Maximum diameter of the tumors ranged 1.3-20 cm(mean,5.1 cm).All patients were treated with a cooled-tip perfusion electrode attached to a radiofrequency generator(Radionics,Burlington,MA,USA).RFA was performed via the percutaneous approach(n = 257),laparoscopy(n = 7),or open surgical treatment(n = 86).The major complications related to RFA were recorded.The resultant data were analyzed to determine risk factors associated these complications.RESULTS:Among the 255 patients,425 liver tumors were treated and 350 RFA sessions were performed.Thirty-seven(10%) major complications were observed which included 13 cases of liver failure,10 cases of hydrothorax requiring drainage,three casesof tumor seeding,one case of upper gastrointestinal bleeding,one case ofintrahepatic abscess,one case of bile duct injury,one case of cardiac arrest,and five cases of hyperglycemia.Seven patients had more than two complications.Liver failure was the most severe complication and was associated with the highest mortality.Eleven patients died due to worsening liver decompensation.Child-Pugh classification(P = 0.001) and choice of approach(P = 0.045) were related to post-treatment liver failure,whereas patient age,tumor size and number were not significant factors precipitating this complication.CONCLUSION:RFA can be accepted as a relatively safe procedure for the treatment of liver tumors.However,attention should be paid to possible complications even though the incidences of these complications are rare.Careful patient selection and the best approach choice(percutaneous,laparoscopy,or laparotomy) will help to minimize the incidence and morbidity rate of complications which occur after RFA.

Radiofrequency ablation or percutaneous ethanol injection for the treatment of liver tumors

The liver is a common location of both primary and secondary malignancies. For unresectable liver cancer, many local ablative therapies have been developed. These include e.g., percutaneous ethanol injection (PEI), percutaneous acetic acid injection, radiofrequency ablation (RFA), cryoablation, microwave ablation, laserinduced thermotherapy, and high-intensity focused ultrasound. RFA has recently gained interest and is the most widely applied thermoablative technique. RFA allows more effective tumor control in fewer treatment sessions compared with PEI, but with a higher rate of complications. However, there are certain circumstances where PEI therapy represents a better strategy to control liver tumors than RFA, especially in situations where RFA is difficult, for example when large vessels surround the tumor. In the context of hepatocellular carcinoma (HCC), both RFA and PEI are feasible and of benefit in non-operable patients. RFA seems superior to PEI in HCC > 2 cm, and the combination of interventions may be of benefit in selected patients. Liver resection is superior to RFA for patients with HCC meeting the Milan criteria, but RFA can be employed in tumors ≤ 3 cm and where there is an increased expected operative mortality. In addition, some lines of evidence indicate that RFA and PEI can be employed as a bridge to liver transplantation. The use of RFA in colorectal liver metastases is currently limited to unresectable disease and for patients unfit for surgery. The aim of this article is to summarize the current status of RFA in the management of liver tumors and compare it to the cheap and readily available technique of PEI.