***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Abstract Background Hepatocellular carcinoma ( HCC ) is a primary tumor of the liver with poor prognosis . For early stage HCC , treatment options include surgical resection , liver transplantation , and percutaneous ablation . Percutaneous ablative techniques ( radiofrequency and microwave techniques ) emerged as best therapeutic options for nonsurgical patients . Aims We aim ed to determine the safety and efficacy of radiofrequency and microwave procedures for ablation of early stage HCC lesions and prospect ively follow up our patients for survival analysis . Patients and methods One Hundred and 11 patients with early HCC are managed in our multidisciplinary clinic using either radiofrequency or microwave ablation . Patients are assessed for efficacy and safety . Complete ablation rate , local recurrence , and overall survival analysis are compared between both procedures . Results Radiofrequency ablation group ( n = 45 ) and microwave ablation group ( n = 66 ) were nearly comparable as regards the tumor and patients characteristics . Complete ablation was achieved in 94.2 and 96.1 % of patients managed by radiofrequency and microwave ablation techniques , respectively ( p value 0.6 ) with a low rate of minor complications ( 11.1 and 3.2 , respectively ) including subcapsular hematoma , thigh burn , abdominal wall skin burn , and pleural effusion . Ablation rates did not differ between ablated lesions ≤3 and 3–5 cm . A lower incidence of local recurrence was observed in microwave group ( 3.9 vs. 13.5 % in radiofrequency group , p value 0.04 ) . No difference between both groups as regards de novo lesions , portal vein thrombosis , and abdominal lymphadenopathy . The overall actuarial probability of survival was 91.6 % at 1 year and 86.1 % at 2 years with a higher survival rates noticed in microwave group but still without significant difference ( p value 0.49 ) . Conclusion Radiofrequency and microwave ablations led to safe and equivalent ablation and survival rates ( with superiority for microwave ablation as regards the incidence of local recurrence ) AIM To retrospectively compare the initial response , local recurrence , and complication rates of radiofrequency ablation ( RFA ) vs microwave ablation ( MWA ) when combined with neoadjuvant bl and transarterial embolization ( TAE ) or drug-eluting microsphere chemoembolization ( TACE ) for the treatment of hepatocellular carcinoma ( HCC ) . METHODS A total of 35 subjects with Barcelona Clinic Liver Cancer ( BCLC ) very early and early-stage HCC ( range : 1.2 - 4.1 cm ) underwent TAE  ( 23 ) or TACE  ( 12 ) with RFA ( 15 ) or microwave ablation ( MWA ) ( 20 ) from January 2009 to June 2015 as either definitive therapy or a bridge to transplant . TAE and TACE were performed with 40 - 400μm particles and 30 - 100μm plus either doxorubicin- or epirubicin-eluting microspheres , respectively . Initial response and local progression were evaluated using modified response evaluation criteria in solid tumors . Complications were grade d using common terminology criteria for adverse events version 5.0 . RESULTS Complete response rates were 80 % ( 12/15 ) for RFA + TAE/TACE and 95 % ( 19/20 ) for MWA + TAE/TACE ( P = 0.29 ) . Local recurrence rate was 30 % ( 4/12 ) for RFA + TAE/TACE and 0 % ( 0/19 ) for MWA + TAE/TACE . Durability of response , defined as local disease control for duration of the study , demonstrated a significant difference in favor of MWA ( P = 0.0091 ) . There was no statistical difference in complication rates ( 3 vs 2 ) . CONCLUSIONS MWA and RFA when combined with neoadjuvant TAE or TACE have similar safety and efficacy in the treatment of early-stage HCC . MWA provided more durable disease control in this study ; however , prospect i ve data remain necessary to evaluate superiority of either modality Purpose To compare MWA and RFA combined with TACE for HCC nodules exceeding 3 cm . Methods 19 lesions su bmi tted to MWA ( G1 ) were retrospectively compared with a combined treatment group ( G2 ) matching by tumor characteristics ( mean size 43 and 45 mm in G1 and G2 , respectively ) . Technical success , complications , complete ablation ( CA ) , and maintained CA ( mCA ) were evaluated . Results Technical success was achieved in all cases . Overall mortality was zero , both in G1 and G2 . No significant differences were found in complications rates ( 3 in G1 and 2 in G2 ) . CA was obtained in 11 ( 58 % ) HCC in G1 and 15 ( 79 % ) in G2 ( p = n.s . ) . CA was obtained in 75.5 % ( G1 ) and 89 % ( G2 ) nodules up to 4 cm , 45 % and 70 % nodules > 4 cm , respectively . At statistical analysis , size result ed as predictor for CA only in G1 ( mean diameter of CA vs non-CA 39.9 vs. 47.7 mm , p = 0.021 ) . During follow-up ( 13.1 and 14.4 months in G1 and G2 ) , mCA occurred in 6/19 ( 32 % ) nodules in G1 , 8/19 ( 42 % ) in G2 . Conclusion MWA and combined therapy are comparable as for safety . No significant differences were found in terms of technique effectiveness . Larger r and omized studies should be design ed to confirm MWA as a valid alternative to combined therapy Background and aim The risk of local tumour progression ( LTP ) and factors predicting LTP following percutaneous thermal ablation ( PTA ) of early-stage hepatocellular carcinoma ( HCC ) have not been well studied in non-trial setting s and may be underestimated . We aim ed to assess these outcomes in a multicentre study . Patients and methods This was a retrospective review of consecutive patients with early-stage HCC treated with a curative intent across three tertiary Australian centres between 2006 and 2012 with either radiofrequency ablation or microwave ablation .  The primary endpoint was LTP and multivariate analysis was carried out to identify the independent predictors of LTP . Results In total 145 HCC nodules were treated in 126 patients ( 78 % men , mean±SD age 62±10 years ) with a mean±SD follow-up of 13.5±13 months . Local recurrence was observed in 23.4 % ( 34/145 ) . Mean±SD LTP-free survival was 46.9±3.6 months . For HCC nodules 2 cm or less , local recurrence rates were lower ( 15.9 % ) , with a mean±SD LTP-free survival of 48.8±4.2 months . Poorly differentiated HCC [ hazard ratio ( 95 % confidence interval)=4.8 ( 1.1–20.4 ) , P=0.032 ] and pretreatment & agr;-fetoprotein more than 50 kIU/l [ 8.2 ( 1.7–39.0 ) , P=0.008 ] were independent predictors of LTP . LTP rates were not significantly different between the radiofrequency ablation and the microwave ablation groups ( 22.8 vs. 25.8 % , P=0.7 ) . There were six ( 4.8 % ) procedure-related adverse events , but no deaths . Conclusion Local recurrence after PTA for early-stage HCC is high in routine clinical practice . Poorly differentiated HCC and pretreatment & agr;-fetoprotein are important , independent predictors of LTP . Further well- design ed r and omized controlled trials with larger sample sizes using adjuvant therapies in combination with PTA to decrease LTP rates are warranted Purpose To compare the ablation area produced by a single application of a microwave ablation ( MWA ) system , equipped with a miniaturized device on the tip of the antenna entrapping reflected microwaves , with that produced by an internally cooled radiofrequency ablation ( RFA ) system . Material s and Methods Forty patients with primary or secondary inoperable liver tumors , selected to undergo percutaneous thermal ablation , were r and omly assigned to MWA or RFA procedure . The ablation areas produced by a single application of MWA ( ablation time 10 min ) or RFA ( ablation time 12 min ) energy were assessed by contrast-enhanced ultrasonography immediately after the end of the procedure . The long- and short-axis diameters of the ablation areas were measured and compared using Student t test . Results Long- and short-axis diameters of the ablation areas produced by MWA were significantly greater than those produced by RFA : 48.5 ± 6.7 versus 30.9 ± 1.1 mm ( p < 0.0001 ) and 38.5 ± 4.6 versus 26.8 ± 2.9 mm ( p < 0.0001 ) , respectively . Conclusion The MWA system can achieve significantly larger ablation areas than the internally cooled RFA system . Broader r and omized trials are strongly warranted to investigate whether such superiority can translate into better long-term outcome of the ablation procedure Abstract Objective To prospect ively compare microwave ( MW ) ablation using a modified internal cooled-shaft antenna with radiofrequency ( RF ) ablation in in vivo porcine liver and in patients with small hepatocellular carcinoma ( sHCC ) . Methods In an animal study , MW and RF ablations using a cooled-shaft antenna or internally cooled electrode were performed in in vivo porcine liver . Coagulation diameters of both ablations were compared . For clinical study , 42 patients with sHCC were treated with MW or RF ablation .  Complete ablation ( CA ) and local tumour progression ( LTP ) were compared . Results MW ablation produced significantly larger ablation zones than RF ablation in both porcine liver and sHCC with an ablated volume of 33.3 ± 15.6 cm3 vs. 18.9 ± 9.1 cm3 and 109.3 ± 58.3 cm3 vs. 48.7 ± 30.5 cm3 , respectively . The CA rate was 95.5 % ( 21/22 ) for MW ablation and 95.0 % ( 19/20 ) for RF ablation . In a 5.1-month follow-up , the LTP rate was 18.2 % ( 4/22 ) in the MW ablation group and 15.0 % ( 3/20 ) in the RF ablation group . Conclusion MW ablation using a modified cooled-shaft antenna produces a larger ablation zone than RF ablation , with an efficacy similar to RF ablation in local tumour control . MW ablation is a safe and promising treatment of sHCC.Key Points• Microwave ablation with a cooled-shaft antenna produces a larger ablation zone than radiofrequency ablation . • Microwave and radiofrequency ablation showed similar local tumour control in small HCC . • Microwave ablation seems safe and efficient for small liver cancers ( <3 cm ) Purpose : To compare the effectiveness of ultrasound (US)-guided percutaneous 915 MHz microwave ( MW ) ablation with the 2450 MHz MW ablation for large hepatocellular carcinoma ( HCC ) ( > 4 cm in diameter ) . Material s and methods : Patients with HCC > 4 cm in diameter who underwent US-guided percutaneous MW ablation with curative intention between March 2007 and December 2008 ( 39 ) were r and omly divided into two groups , 915 MHz MW group and 2450 MHz MW group . We compared the results of ablation between the two groups . Results : Fewer antenna insertions for each tumour were required in the 915 MHz MW group ( 3.69 ± 0.6 ) than in the 2450 MHz MW group ( 4.71 ± 1.61 ) ( p = 0.01 ) . According to the follow-up contrast-enhanced imagings , technique effectiveness rate was 85.7 % ( 18/21 ) and 73.7 % ( 14/19 ) in the 915 MHz MW group and 2450 MHz MW group , respectively ( p = 0.44 ) . The rate of local tumour progression ( LTP ) was 14.3 % ( 3/21 ) and 26.3 % ( 5/19 ) in the 915 MHz MW group and 2450 MHz MW group , respectively ( p = 0.44 ) . There were no deaths and no thrombosis of major vessels in any patient . Conclusions : Compared with 2450 MHz MW ablation , our initial experience showed that percutaneous 915 MHz MW ablation with cooled-shaft antennae was safe and could achieve a high technique effectiveness rate with fewer insertion numbers in the treatment of large HCC . Therefore , percutaneous 915 MHz MW ablation may provide a new method for the treatment of large HCC OBJECTIVES There are no prospect i ve studies of laparoscopic microwave ( MW ) ablation in patients with hepatocellular carcinoma ( HCC ) . The aim of this study was to demonstrate the safety and efficacy of laparoscopic MW ablation . METHODS A prospect i ve study group of consecutive HCC patients considered ineligible for liver resection and 
    Output:
    
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 .
Conclusion MWA is at least as safe and effective as RFA for treating liver cancer and demonstrated significantly reduced LTP rates .