***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: This document , on the diagnosis and treatment of patients with hepatocellular carcinoma ( HCC ) , was commissioned by the British Society of Gastroenterology as part of a wider initiative to develop guidelines for clinicians in several areas of clinical practice . Cancer care has been the subject of increased scrutiny , with the development of care guidelines forming a major part of the strategy to reduce cancer related mortality in the UK . There is a strong suggestion that HCC is a disease which will be seen more frequently over the next few years , mainly as a result of the hepatitis C virus ( HCV ) epidemic . Previously , HCC has been a relatively rare tumour in the UK and much of the data pertaining to its diagnosis and therapy are derived from studies outside of the UK . Because of the lack of screening programmes and the fact that a significant proportion of HCC presents as symptomatic disease in individuals not known to have liver disease , most non-surgical therapies have been used in patients with advanced disease . There are a significant number of variables known to influence prognosis , with stage of underlying liver disease and tumour size at presentation being the most important . Controlling for these variables is difficult and these factors have contributed to a dearth of r and omised controlled trials of treatment for this tumour . There is however a substantial amount of evidence available which can form the basis of a framework for diagnosis and management . Guidelines are not rigid protocol s and they should not be construed as interfering with local clinical judgement . Hence they do not represent a directive of proscribed routes but a basis on which clinicians can consider the options available more clearly . These guidelines cover two areas of clinical practice relating to HCC : firstly , its diagnosis , including surveillance of high risk individuals ; and Radiofrequency ablation ( RFA ) is an effective modality for the treatment of hepatocellular carcinoma ( HCC ) , because it can induce large coagulated necrosis in a few sessions . We have recently reported that the combination therapy of percutaneous ethanol injection ( PEI ) with RFA ( PEI-RFA ) created enhancement of coagulated necrosis compared with RFA alone . In the present study , we adopted PEI-RFA for the treatment of HCCs located in the regions that are difficult to treat with RFA alone . Five patients with biopsy-proven HCC and liver cirrhosis underwent PEI-RFA therapy . In these patients , HCCs were located beside the gallbladder , inferior vena cava or portal vein or kidney , or immediately under the diaphragm . Prior to RFA , 99.5 % ethanol was injected into the region of HCC located in the regions where RFA energy appears to be difficult to reach . In all cases , HCC was totally coagulated by PEI-RFA . Injecting ethanol prior to RFA therapy caused no major side effects . These results indicate that PEI-RFA may be effective for the treatment of HCCs located in the regions that are difficult to treat with RFA alone as well as large-sized HCCs Background R and omized trials suggest that radiofrequency ablation ( RFA ) may be more effective than percutaneous ethanol injection ( PEI ) in the treatment of hepatocellular carcinoma ( HCC ) . However , the survival advantage of RFA needs confirmation in daily practice . Methods We conducted a population -based cohort study using the Taiwan Cancer Registry , National Health Insurance cl aim data base and National Death Registry data from 2004 through 2009 . Patients receiving PEI or RFA as first-line treatment for newly-diagnosed stage I-II HCC were enrolled . Results A total of 658 patients receiving RFA and 378 patients receiving PEI treatment were included for final analysis . The overall survival ( OS ) rates of patients in the RFA and PEI groups at 5-year were 55 % and 42 % , respectively ( p < 0.01 ) . Compared to patients that received PEI , those that received RFA had lower risks of overall mortality and first-line treatment failure ( FTF ) , with adjusted hazard ratios ( HRs ) [ 95 % confidence interval ( CI ) ] of 0.60 ( 0.50 - 0.73 ) for OS and 0.54 ( 0.46 - 0.64 ) for FTF . The favorable outcomes for the RFA group were consistently significant for patients with tumors > 2 cm as well as for those with tumors < 2 cm . Consistent results were also observed in other subgroup analyses defined by gender , age , tumor stage , and co-morbidity status . Conclusion RFA provides better survival benefits  than PEI for patients with unresectable stage I-II HCC , irrespective of tumors > 2 cm or ≤ 2 cm , in contemporary clinical practice BACKGROUND AND STUDY AIMS Hepatocellular carcinoma ( HCC ) is a major burden on health-care systems worldwide . Although radiofrequency ablation ( RFA ) is currently considered the best technique for coagulative necrosis , the superiority of concomitant use of RFA and percutaneous ethanol injection ( PEI ) needs to be determined . The study was design ed to compare efficacy , safety and rate of survival of patients with HCC assigned to receive combined PEI-RFA versus RFA alone and versus PEI alone . PATIENTS AND METHODS This 3-year study enrolled 90 cirrhotic patients with HCC ( Child 's class A or B , but not class C ) . They were r and omly assigned for either PEI-RFA ( group I ) , RFA alone ( group II ) or PEI alone ( group III ) . The primary end point was ablation of the tumour . The secondary end point was rate of survival and recurrence . RESULTS After the first session , complete ablation was significantly higher in the combination group ( 87.9 % ) compared with the RFA group ( 54.54 % ) . After the second session , complete ablation was achieved in 97.0 % of the combination group and in 84.8 % of the RFA group . Regarding the PEI group , 75 % had complete ablation , whereas 25 % had partial ablation after multiple sessions . The survival rate , 1.5 years later , was significantly higher in group I ( 86.7 % ) compared with group III ( 63.3 % ) . The overall incidence of serious adverse events was nil . CONCLUSION Combined treatment is superior to RFA alone and to PEI alone , in safety and efficacy in patients with HCC Aims : The aim of this study was to compare the outcomes of radiofrequency thermal ablation ( RFTA ) , percutaneous ethanol injection ( PEI ) , and percutaneous acetic acid injection ( PAI ) in the treatment of hepatocellular carcinoma ( HCC ) . Patients and methods : A total of 187 patients with HCCs of 3 cm or less were r and omly assigned to RFTA ( n = 62 ) , PEI ( n = 62 ) , or PAI ( n = 63 ) . Tumour recurrence and survival rates were assessed . Results : One , two , and three year local recurrence rates were 10 % , 14 % , and 14 % in the RFTA group , 16 % , 34 % , and 34 % in the PEI group , and 14 % , 31 % , and 31 % in the PAI group ( RFTA v PEI , p = 0.012 ; RFTA v PAI , p = 0.017 ) . One , two , and three year survival rates were 93 % , 81 % , and 74 % in the RFTA group , 88 % , 66 % , and 51 % in the PEI group , and 90 % , 67 % , and 53 % in the PAI group ( RFTA v PEI , p = 0.031 ; RFTA v PAI , p = 0.038 ) . One , two , and three year cancer free survival rates were 74 % , 60 % , and 43 % in the RFTA group , 70 % , 41 % , and 21 % in the PEI group , and 71 % , 43 % , and 23 % in the PAI group ( RFTA v PEI , p = 0.038 ; RFTA v PAI , p = 0.041 ) . Tumour size , tumour differentiation , and treatment methods ( RFTA v PEI and PAI ) were significant factors for local recurrence , overall survival , and cancer free survival . Major complications occurred in 4.8 % of patients ( two with haemothorax , one gastric perforation ) in the RFTA group and in none in two other groups ( RFTA v PEI and PAI , p = 0.035 ) . Conclusions : RFTA was superior to PEI and PAI with respect to local recurrence , overall survival , and cancer free survival rates , but RFTA also caused more major complications AIM In the present study , the characteristics of PEI-RFA treatment were further eluci date d by analyzing the relationship between the volume of coagulated necrosis and the energy requirement for ablation or the amount of ethanol injected into HCC . METHODS The volume of coagulated necrosis , total energy requirement and energy requirement for coagulation of per unit volume were examined in the groups of PEI-RFA and RFA alone  using the Cool-tip RF system . RESULTS The results showed that the volume of coagulated necrosis induced was significantly larger in PEI-RFA group than in routine RFA group , when the total energy administered was comparable in both groups . In PEI-RFA , enlargement of coagulated necrosis was admitted in 3 dimensions and the amount of energy requirement per unit volume of coagulated necrosis was negatively correlated with the amount of ethanol injected into HCC . CONCLUSION These results suggest that , compared to RFA alone , PEI-RFA enables to induce comparable coagulated necrosis with smaller energy requirement , and that PEI-RFA is likely to be less invasive than RFA alone irrespective of inducing enhanced coagulated necrosis . Thus , simple prior injection of ethanol may make RFA treatment more effective and less invasive for the treatment of patients with HCC Abstract Objective To evaluate the efficacy and safety of combined radiofrequency ablation ( RFA ) and ethanol injection with a multipronged needle in the treatment of medium ( 3.1–5.0 cm ) and large ( 5.1–7.0 cm ) hepatocellular carcinoma ( HCC ) . Methods A total of 65 patients with 67 HCC nodules were enrolled in this prospect i ve study . All of them received the treatment of combined RFA and multipronged ethanol injection percutaneously . Results The average volume of injected ethanol was 14.4 ± 4.1 ml ( range , 9–30 ml ) . The average number of RFA electrode insertions was 1.7 ± 0.8 ( range , 1–4 ) . The rate of initial local complete response ( CR ) was 94.0 % ( 63/67 ) . After additional treatment , technical success was achieved in all HCC nodules . There were no treatment-related deaths , and major complications were observed in 3 ( 4.6 % ) patients . After a mean follow-up of 20.0 ± 7.6 months , local tumour progression was observed in 10 ( 10/67 , 14.9 % ) tumours , whereas distant recurrence developed in 32 ( 32/65 , 49.2 % ) patients . The 1-year and 2-year survival rates were 93.1 % and 88.1 % , respectively . Conclusion The combination of RFA and multipronged ethanol injection in the treatment of medium and large HCC is safe and effective with a high rate of local tumour control . Key Points• Combined radiofrequency ablation and multipronged ethanol injection is a new therapeutic strategy • Treatment is safe and effective for medium and large hepatocellular carcinoma (HCC)• A multipronged needle allows for a homogeneous ethanol BACKGROUND & AIMS The aim of this study was to compare the clinical outcome of percutaneous radiofrequency ( RF ) ablation , conventional percutaneous ethanol injection ( PEI ) , and higher-dose PEI in treating hepatocellular carcinoma ( HCC ) 4 cm or less . METHODS A total of 157 patients with 186 HCCs 4 cm or less were r and omly assigned to 3 groups ( 52 patients in the conventional PEI group , 53 in the higher-dose PEI group , and 52 in the RF group ) . Clinical outcomes in terms of complete tumor necrosis , overall survival , local tumor progression , additional new tumors , and cancer-free survival were compared across 3 groups . RESULTS The rate of complete tumor necrosis was 88 % in the conventional PEI group , 92 % in the higher-dose PEI group , and 96 % in the RF group . Significantly fewer sessions were required to achieve complete tumor necrosis in the RF group than in the other 2 groups ( P < .01 ) . The local tumor progression rate was lowest in the RF group ( vs the conventional PEI group , P = .012 ; vs the higher-dose PEI group , P = .037 ) . The overall survival rate was highest in the RF group ( vs the conventional PEI group , P = .014 ; vs the higher-dose PEI group , P = .023 ) . The cancer-free survival rate was highest in the RF group ( vs the conventional PEI group , P = .019 ; vs the higher-dose PEI group , P = .024 ) . Multivariate analysis determined that tumor size , tumor differentiation , and the method of treatment ( RF vs both methods of PEI ) were significant factors in relation 
    Output:
    
Compared with PEI , RFA was associated with significant improvement in overall survival ( OS ) rate at 1 , 2 , 3 and 4 years , cancer-free survival ( CFS ) rate at 1 , 2 and 3 years and complete tumour necrosis .
RFA was associated with a significant reduction in the local recurrence rate at 1 , 2 and 3 years .
However , RFA was also associated with a higher total risk of complications .
Compared with RFA alone , combined RFA-PEI was associated with a significant improvement in the OS rate at 1.5 , 2 and 3 years and a significant reduction in the local recurrence rate .
However , combined RFA-PEI was also associated with a higher risk of fever .
Conclusion : The combination of RFA and PEI appears to be the optimal treatment strategy when considering combined RFA-PEI or either RFA or PEI alone .
Combined RFA-PEI significantly improves OS and reduces the risk of local recurrence without increasing major complications .