human
***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: Objective : To compare the results of percutaneous local ablative therapy ( PLAT ) with surgical resection in the treatment of solitary and small hepatocellular carcinoma ( HCC ) . Summary Background Data : PLAT is effective in small HCC . Whether it is as effective as surgical resection in the long-term survivals remains unknown . Methods : We conducted a prospect i ve r and omized trial on 180 patients with a solitary HCC ≦5 cm to receive either PLAT or surgical resection .  The patients were regularly followed up after treatment with physical examination , blood , and radiologic tests . Results : Of the 90 patients who were r and omized to PLAT , only 71 received PLAT because 19 withdrew their consent . Of the 90 patients who were r and omized to surgical resection , a single Couinaud liver segment resection was carried out in 69 patients , 2 segments in 16 patients , and 3 or more segments in 3 patients . Ethanol injection was given during open surgery in 2 patients . Only 1 patient died after surgical resection within the same hospital admission . Posttreatment complications were more often and severe after surgery than PLAT . The 1- , 2- , 3- , and 4-year overall survival rates  after PLAT and surgery were 95.8 % , 82.1 % , 71.4 % , 67.9 % and 93.3 % , 82.3 % , 73.4 % , 64.0 % , respectively . The corresponding disease-free survival rates were 85.9 % , 69.3 % , 64.1 % , 46.4 % and 86.6 % , 76.8 % , 69 % , 51.6 % , respectively . Statistically , there was no difference between these 2 treatments . Conclusion : PLAT was as effective as surgical resection in the treatment of solitary and small HCC . PLAT had the advantage over surgical resection in being less invasive Abstract Background : Resection combined with radiofrequency ablation ( RFA ) is a novel approach in patients who are otherwise unresectable . The objective of this study was to investigate the safety and efficacy of hepatic resection combined with RFA . Methods : Patients with multifocal hepatic malignancies were treated with surgical resection combined with RFA . All patients were followed prospect ively to assess complications , treatment response , and recurrence . Results : Seven hundred thirty seven tumors in 172 patients were treated ( 124 with colorectal metastases ; 48 with noncolorectal metastases ) .  RFA was used to treat 350 tumors . Combined modality treatment was well tolerated with low operative times and minimal blood loss . The postoperative complication rate was 19.8 % with a mortality rate of 2.3 % . At a median follow-up of 21.3 months , tumors had recurred in 98 patients ( 56.9 % ) . Failure at the RFA site was uncommon ( 2.3 % ) . A combined total number of tumors treated with resection and RFA > 10 was associated with a faster time to recurrence ( P = .02 ) . The median actuarial survival time was 45.5 months . Patients with noncolorectal metastases and those with less operative blood loss had an improved survival ( P = .03 and P = .04 , respectively ) , whereas radiofrequency ablating a lesion > 3 cm adversely impacted survival ( HR = 1.85 , P = .04 ) . Conclusions : Resection combined with RFA provides a surgical option to a group of patients with liver metastases who traditionally are unresectable , and may increase long-term survival Abstract Background : Radiofrequency ablation ( RFA ) is increasingly used for the local destruction of unresectable hepatic malignancies . There is little information on its optimal approach or potential complications . Methods : Since late 1997 , we have undertaken 91 RFA procedures to ablate 231 unresectable primary or metastatic liver tumors in 84 patients .  RFA was performed via celiotomy ( n=39 ) , laparoscopy ( n=27 ) , or a percutaneous approach ( n=25 ) . Patients were followed with spiral computed tomographic ( CT ) scans at 1 to 2 weeks postprocedure and then every 3 months for 2 years . Results : Intraoperative ultrasound ( IOUS ) detected intrahepatic disease not evident on the preoperative scans of 25 of 66 patients ( 38 % ) undergoing RFA via celiotomy or laparoscopy . In 38 of 84 patients ( 45 % ) , RFA was combined with resection or cryosurgical ablation ( CSA ) , or both . RFA was used to treat an average of 2.8 lesions per patient , and the median size of treated lesions was 2 cm ( range , 0.3–9 cm ) . The average hospital stay was 3.6 days overall ( 1.8 days for percutaneous and laparoscopic cases ) . Ten patients underwent a second RFA procedure ( sequential ablations ) and , in one case , a third RFA procedure for large ( one patient ) , progressive ( seven patients ) , and /or recurrent ( three patients ) lesions . Seven ( 8 % ) patients had complications : one skin burn ; one postoperative hemorrhage ; two simple hepatic abscesses ; one hepatic abscess associated with diaphragmatic heat necrosis following sequential percutaneous ablations of a large lesion ; one postoperative myocardial infa rct ion ; and one liver failure . There were three deaths , one ( 1 % ) of which was directly related to the RFA procedure . Three of the complications , including one RFA-related death , occurred after percutaneous RFA . At a median follow-up of 9 months ( range , 1–27 months ) , 15 patients ( 18 % ) had recurrences at an RFA site , and 36 patients ( 43 % ) remained clinical ly free of disease . Conclusions : Celiotomy or laparoscopic approaches are preferred for RFA because they allow IOUS , which may demonstrate occult hepatic disease . Operative RFA also allows concomitant resection , CSA , or placement of a hepatic artery infusion pump , and isolation of the liver from adjacent organs . Percutaneous RFA should be reserved for patients at high risk for anesthesia , those with recurrent or progressive lesions , and those with smaller lesions sufficiently isolated from adjacent organs . Complications may be minimized when these approaches are applied selectively BACKGROUND Radiofrequency ablation ( RFA ) has been used to treat hepatocellular carcinoma ( HCC ) and liver metastases for more than 10 years with promising early outcomes . Preliminary results comparing percutaneous and surgical approaches have shown no difference in short-term outcomes . In this study , the longer-term outcomes were presented . METHODS Patients with liver malignancies treated by RFA were prospect ively studied from 2003 to 2011 .  Post-ablation assessment by  computed tomography ( CT ) scan and serum biochemistry was performed at regular intervals . Recurrence rates and long-term survival were analysed . RESULTS A total of 233 patients with liver malignancies ( 75.5 % HCC and 24.5 % liver metastases ) were analysed . Three RFA approaches were used ( percutaneous 58.4 % , laparoscopic 9.4 % and open 32.2 % ) . The median follow-up time was 29 months . Complete ablation was achieved in 83.7 % , with no difference between the two approaches . More wound and chest complications were observed in the surgical group . Intra-hepatic recurrences were observed in 69.5 % ; extra-hepatic recurrences were detected in 22.3 % , with no difference between the two groups . There was no statistical difference between the two approaches in overall 1- , 3- and 5-year survival . CONCLUSION An extended period of follow-up in patients with liver malignancies showed that RFA is an effective treatment . No difference was demonstrated between the percutaneous and surgical approach , in terms of recurrence and survival INTRODUCTION A probe emitting radiofrequency ( RF ) waves is able to destroy tumour tissue by thermal ablation . The purpose of this study was to undertake a prospect i ve estimation of the benefit of RF thermoablation of liver tumours during hepatic and extrahepatic resections aim ed at obtaining an R0 status in patients in whom disease is notoriously considered unresectable . METHOD Twenty-one patients underwent surgery between January 1997 and September 1999 . In 17 cases , RF was associated with a hepatectomy and in nine of these cases with resection of extrahepatic lesions . In two cases , extensive resection of extrahepatic lesions was associated with RF to treat liver metastases , and in two cases RF was ultimately performed alone . The mean number of liver metastases was 6.2+/-4.3 ( range 1 - 15 ) per patient . A total of 32 lesions were treated with RF . The mean size of the 33 RF-thermoablated tumours was 13.6+/-9.7 mm ( range 5 - 52 mm ) , and in all but one case , a Pringle manoeuvre was performed during the RF procedure . RESULTS A probable R0-resection was obtained in 18 cases . No operative deaths or any RF-related complications occurred . If we exclude the case in which it was clearly impossible to destroy liver metastases intraoperatively , only one local recurrence occurred ( 3 % ) among the 32 thermoablated lesions after a mean follow-up of 17.3 months . The 2-year overall and disease-free survival rates for this initially unresectable population were 94.7 % and 22 % , respectively . CONCLUSION Intraoperative use of RF to destroy unresectable liver tumours increases the rate of curative resections . Future progress in RF technology and adequate vascular clamping during RF should increase this rate BACKGROUND ALPPS induces rapid liver hypertrophy after stage‐1 operation , enabling safe , extended resections ( stage‐2 ) after a short period . Recent studies have suggested that partial transection at stage‐1 might be associated with a better safety profile . The aim of this study was to assess the amount of liver parenchyma that needs to be divided to achieve sufficient liver hypertrophy in ALPPS . METHODS In a bi‐institutional , prospect i ve cohort study , nonfibrotic patients who underwent ALPPS with complete ( n = 22 ) or partial ( n = 23 ) transection for colorectal liver metastases were analyzed and compared with an external ALPPS cohort ( n = 23 ) . A radiologic tool was developed to quantify the amount of parenchymal transection . Liver hypertrophy and clinical outcome were compared between both techniques . The relationship of partial transection and hypertrophy was investigated further in an experimental murine model of partial ALPPS . RESULT The median amount of parenchymal transection in partial ALPPS was 61 % ( range , 34–86 % ) . The radiologic method correlated poorly with the intraoperative surgeon 's estimation ( rS = 0.258 ) . Liver hypertrophy was equivalent for the partial ALPPS , ALPPS , and external ALPPS cohort ( 64 % vs 60 % vs. 64 % ) . Experimental data demonstrated that partial transection of at least 50 % induced comparable hypertrophy ( 137 % vs 156 % ) and hepatocyte proliferation compared to complete transection . CONCLUSION The study provides clinical and experimental evidence that partial liver partition of at least 50 % seems to be equally effective in triggering volume hypertrophy as observed with complete transection and can be re recommended as less invasive alternative to ALPPS AIMS Radiofrequency ablation is gaining popularity as the interventional therapy of choice for unresectable hepatic malignancies . However , little attention has been paid to the importance of operator experience in this therapy . This study aims to evaluate the results of RFA treatment dependent on operator experience and learning curve . PATIENTS AND METHODS Between 2/2000 and 11/2004 we have undertaken 116 RFA procedures to ablate 404 unresectable primary or metastatic liver tumours in 84 patients . The clinical data of all patients were recorded prospect ively and treatment results of the first 42 patients ( group I ) and the second 42 patients ( group II ) were compared . All patients were treated by the same surgeon or interventional radiologist . RESULTS RFA was performed percutaneously in 44 procedures ( group I n = 35 , group II n = 9 ) , via laparotomy in 64 procedures ( group I n = 27 , group II n = 37 ) and via laparoscopy in eight procedures ( group I n = 1 , group II n = 7 ) . The complication rate was comparable in both groups with 7.9 % in group I and 7.5 % in group II . Group II had a higher complete ablation rate ( 96.2 vs 93.7 % ) than group I. One- and two-year survival rates of 92 and 89 % in group II were significantly higher than in group I with 69 and 46 % ( p = 0.015 ) . CONCLUSION By the experience conditional optimization of indication and performance by a specialized RFA team the results could be improved significantly . The data on h and speak for a considerable learning curve in the RFA and demonstrate the importance of the experience of the therapist for the outcome of the patients 
    Output:
    
agent
***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: Objective : To compare the results of percutaneous local ablative therapy ( PLAT ) with surgical resection in the treatment of solitary and small hepatocellular carcinoma ( HCC ) . Summary Background Data : PLAT is effective in small HCC . Whether it is as effective as surgical resection in the long-term survivals remains unknown . Methods : We conducted a prospect i ve r and omized trial on 180 patients with a solitary HCC ≦5 cm to receive either PLAT or surgical resection .  The patients were regularly followed up after treatment with physical examination , blood , and radiologic tests . Results : Of the 90 patients who were r and omized to PLAT , only 71 received PLAT because 19 withdrew their consent . Of the 90 patients who were r and omized to surgical resection , a single Couinaud liver segment resection was carried out in 69 patients , 2 segments in 16 patients , and 3 or more segments in 3 patients . Ethanol injection was given during open surgery in 2 patients . Only 1 patient died after surgical resection within the same hospital admission . Posttreatment complications were more often and severe after surgery than PLAT . The 1- , 2- , 3- , and 4-year overall survival rates  after PLAT and surgery were 95.8 % , 82.1 % , 71.4 % , 67.9 % and 93.3 % , 82.3 % , 73.4 % , 64.0 % , respectively . The corresponding disease-free survival rates were 85.9 % , 69.3 % , 64.1 % , 46.4 % and 86.6 % , 76.8 % , 69 % , 51.6 % , respectively . Statistically , there was no difference between these 2 treatments . Conclusion : PLAT was as effective as surgical resection in the treatment of solitary and small HCC . PLAT had the advantage over surgical resection in being less invasive Abstract Background : Resection combined with radiofrequency ablation ( RFA ) is a novel approach in patients who are otherwise unresectable . The objective of this study was to investigate the safety and efficacy of hepatic resection combined with RFA . Methods : Patients with multifocal hepatic malignancies were treated with surgical resection combined with RFA . All patients were followed prospect ively to assess complications , treatment response , and recurrence . Results : Seven hundred thirty seven tumors in 172 patients were treated ( 124 with colorectal metastases ; 48 with noncolorectal metastases ) .  RFA was used to treat 350 tumors . Combined modality treatment was well tolerated with low operative times and minimal blood loss . The postoperative complication rate was 19.8 % with a mortality rate of 2.3 % . At a median follow-up of 21.3 months , tumors had recurred in 98 patients ( 56.9 % ) . Failure at the RFA site was uncommon ( 2.3 % ) . A combined total number of tumors treated with resection and RFA > 10 was associated with a faster time to recurrence ( P = .02 ) . The median actuarial survival time was 45.5 months . Patients with noncolorectal metastases and those with less operative blood loss had an improved survival ( P = .03 and P = .04 , respectively ) , whereas radiofrequency ablating a lesion > 3 cm adversely impacted survival ( HR = 1.85 , P = .04 ) . Conclusions : Resection combined with RFA provides a surgical option to a group of patients with liver metastases who traditionally are unresectable , and may increase long-term survival Abstract Background : Radiofrequency ablation ( RFA ) is increasingly used for the local destruction of unresectable hepatic malignancies . There is little information on its optimal approach or potential complications . Methods : Since late 1997 , we have undertaken 91 RFA procedures to ablate 231 unresectable primary or metastatic liver tumors in 84 patients .  RFA was performed via celiotomy ( n=39 ) , laparoscopy ( n=27 ) , or a percutaneous approach ( n=25 ) . Patients were followed with spiral computed tomographic ( CT ) scans at 1 to 2 weeks postprocedure and then every 3 months for 2 years . Results : Intraoperative ultrasound ( IOUS ) detected intrahepatic disease not evident on the preoperative scans of 25 of 66 patients ( 38 % ) undergoing RFA via celiotomy or laparoscopy . In 38 of 84 patients ( 45 % ) , RFA was combined with resection or cryosurgical ablation ( CSA ) , or both . RFA was used to treat an average of 2.8 lesions per patient , and the median size of treated lesions was 2 cm ( range , 0.3–9 cm ) . The average hospital stay was 3.6 days overall ( 1.8 days for percutaneous and laparoscopic cases ) . Ten patients underwent a second RFA procedure ( sequential ablations ) and , in one case , a third RFA procedure for large ( one patient ) , progressive ( seven patients ) , and /or recurrent ( three patients ) lesions . Seven ( 8 % ) patients had complications : one skin burn ; one postoperative hemorrhage ; two simple hepatic abscesses ; one hepatic abscess associated with diaphragmatic heat necrosis following sequential percutaneous ablations of a large lesion ; one postoperative myocardial infa rct ion ; and one liver failure . There were three deaths , one ( 1 % ) of which was directly related to the RFA procedure . Three of the complications , including one RFA-related death , occurred after percutaneous RFA . At a median follow-up of 9 months ( range , 1–27 months ) , 15 patients ( 18 % ) had recurrences at an RFA site , and 36 patients ( 43 % ) remained clinical ly free of disease . Conclusions : Celiotomy or laparoscopic approaches are preferred for RFA because they allow IOUS , which may demonstrate occult hepatic disease . Operative RFA also allows concomitant resection , CSA , or placement of a hepatic artery infusion pump , and isolation of the liver from adjacent organs . Percutaneous RFA should be reserved for patients at high risk for anesthesia , those with recurrent or progressive lesions , and those with smaller lesions sufficiently isolated from adjacent organs . Complications may be minimized when these approaches are applied selectively BACKGROUND Radiofrequency ablation ( RFA ) has been used to treat hepatocellular carcinoma ( HCC ) and liver metastases for more than 10 years with promising early outcomes . Preliminary results comparing percutaneous and surgical approaches have shown no difference in short-term outcomes . In this study , the longer-term outcomes were presented . METHODS Patients with liver malignancies treated by RFA were prospect ively studied from 2003 to 2011 .  Post-ablation assessment by  computed tomography ( CT ) scan and serum biochemistry was performed at regular intervals . Recurrence rates and long-term survival were analysed . RESULTS A total of 233 patients with liver malignancies ( 75.5 % HCC and 24.5 % liver metastases ) were analysed . Three RFA approaches were used ( percutaneous 58.4 % , laparoscopic 9.4 % and open 32.2 % ) . The median follow-up time was 29 months . Complete ablation was achieved in 83.7 % , with no difference between the two approaches . More wound and chest complications were observed in the surgical group . Intra-hepatic recurrences were observed in 69.5 % ; extra-hepatic recurrences were detected in 22.3 % , with no difference between the two groups . There was no statistical difference between the two approaches in overall 1- , 3- and 5-year survival . CONCLUSION An extended period of follow-up in patients with liver malignancies showed that RFA is an effective treatment . No difference was demonstrated between the percutaneous and surgical approach , in terms of recurrence and survival INTRODUCTION A probe emitting radiofrequency ( RF ) waves is able to destroy tumour tissue by thermal ablation . The purpose of this study was to undertake a prospect i ve estimation of the benefit of RF thermoablation of liver tumours during hepatic and extrahepatic resections aim ed at obtaining an R0 status in patients in whom disease is notoriously considered unresectable . METHOD Twenty-one patients underwent surgery between January 1997 and September 1999 . In 17 cases , RF was associated with a hepatectomy and in nine of these cases with resection of extrahepatic lesions . In two cases , extensive resection of extrahepatic lesions was associated with RF to treat liver metastases , and in two cases RF was ultimately performed alone . The mean number of liver metastases was 6.2+/-4.3 ( range 1 - 15 ) per patient . A total of 32 lesions were treated with RF . The mean size of the 33 RF-thermoablated tumours was 13.6+/-9.7 mm ( range 5 - 52 mm ) , and in all but one case , a Pringle manoeuvre was performed during the RF procedure . RESULTS A probable R0-resection was obtained in 18 cases . No operative deaths or any RF-related complications occurred . If we exclude the case in which it was clearly impossible to destroy liver metastases intraoperatively , only one local recurrence occurred ( 3 % ) among the 32 thermoablated lesions after a mean follow-up of 17.3 months . The 2-year overall and disease-free survival rates for this initially unresectable population were 94.7 % and 22 % , respectively . CONCLUSION Intraoperative use of RF to destroy unresectable liver tumours increases the rate of curative resections . Future progress in RF technology and adequate vascular clamping during RF should increase this rate BACKGROUND ALPPS induces rapid liver hypertrophy after stage‐1 operation , enabling safe , extended resections ( stage‐2 ) after a short period . Recent studies have suggested that partial transection at stage‐1 might be associated with a better safety profile . The aim of this study was to assess the amount of liver parenchyma that needs to be divided to achieve sufficient liver hypertrophy in ALPPS . METHODS In a bi‐institutional , prospect i ve cohort study , nonfibrotic patients who underwent ALPPS with complete ( n = 22 ) or partial ( n = 23 ) transection for colorectal liver metastases were analyzed and compared with an external ALPPS cohort ( n = 23 ) . A radiologic tool was developed to quantify the amount of parenchymal transection . Liver hypertrophy and clinical outcome were compared between both techniques . The relationship of partial transection and hypertrophy was investigated further in an experimental murine model of partial ALPPS . RESULT The median amount of parenchymal transection in partial ALPPS was 61 % ( range , 34–86 % ) . The radiologic method correlated poorly with the intraoperative surgeon 's estimation ( rS = 0.258 ) . Liver hypertrophy was equivalent for the partial ALPPS , ALPPS , and external ALPPS cohort ( 64 % vs 60 % vs. 64 % ) . Experimental data demonstrated that partial transection of at least 50 % induced comparable hypertrophy ( 137 % vs 156 % ) and hepatocyte proliferation compared to complete transection . CONCLUSION The study provides clinical and experimental evidence that partial liver partition of at least 50 % seems to be equally effective in triggering volume hypertrophy as observed with complete transection and can be re recommended as less invasive alternative to ALPPS AIMS Radiofrequency ablation is gaining popularity as the interventional therapy of choice for unresectable hepatic malignancies . However , little attention has been paid to the importance of operator experience in this therapy . This study aims to evaluate the results of RFA treatment dependent on operator experience and learning curve . PATIENTS AND METHODS Between 2/2000 and 11/2004 we have undertaken 116 RFA procedures to ablate 404 unresectable primary or metastatic liver tumours in 84 patients . The clinical data of all patients were recorded prospect ively and treatment results of the first 42 patients ( group I ) and the second 42 patients ( group II ) were compared . All patients were treated by the same surgeon or interventional radiologist . RESULTS RFA was performed percutaneously in 44 procedures ( group I n = 35 , group II n = 9 ) , via laparotomy in 64 procedures ( group I n = 27 , group II n = 37 ) and via laparoscopy in eight procedures ( group I n = 1 , group II n = 7 ) . The complication rate was comparable in both groups with 7.9 % in group I and 7.5 % in group II . Group II had a higher complete ablation rate ( 96.2 vs 93.7 % ) than group I. One- and two-year survival rates of 92 and 89 % in group II were significantly higher than in group I with 69 and 46 % ( p = 0.015 ) . CONCLUSION By the experience conditional optimization of indication and performance by a specialized RFA team the results could be improved significantly . The data on h and speak for a considerable learning curve in the RFA and demonstrate the importance of the experience of the therapist for the outcome of the patients 
    Output:
    