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: OBJECTIVES Guideline -specified curative therapies for a clinical stage I non-small cell lung cancer ( NSCLC ) are either lobectomy or Stereotactic Ablative Radiotherapy ( SABR ) . As outcomes of prospect i ve r and omized clinical trials comparing these modalities are unavailable , we performed a propensity-score matched analysis to create two similar groups in order to compare clinical outcomes . METHODS We selected 577 patients , 96 VATS or open lobectomy were treated at Erasmus University Medical Center Rotterdam and 481 SABR patients were treated at VU University Medical Center Amsterdam with clinical stage I NSCLC . RESULTS Matching of patients according to propensity score result ed in a cohort that consisted of 73 patients in the surgery group and of 73 patients in the SABR group . Median follow-up in the surgery and SABR group was 49 months and 28 months , respectively . Overall survival of patients who underwent surgery was 95 % and 80 % at 12 and 60 months , respectively . For the SABR group this was 94 % at 12 months and 53 % at 60 months . No statistical significant difference ( p=0.089 ) in survival was found between these groups . CONCLUSIONS In this study we found no significant differences in overall survival in propensity matched patients diagnosed with stage I NSCLC treated either surgically or with SABR . After 3 years there seems to be a trend toward improved survival in patients who were treated surgically Abstract Introduction . Stereotactic body radiation therapy ( SBRT ) for early stage non-small cell lung cancer ( NSCLC ) is now an accepted and patient friendly treatment , but still controversy exists about its comparability to conventional radiation therapy ( RT ) . The purpose of this single-institutional report is to describe survival outcome for medically inoperable patients with early stage NSCLC treated with SBRT compared with high dose conventional RT . Material and methods . From August 2005 to June 2012 , 100 medically inoperable patients were treated with SBRT at Odense University Hospital . The thoracic RT consisted of 3 fractions ( F ) of 15–22 Gy delivered in nine days . For comparison a group of 32 medically inoperable patients treated with conventional RT with 80 Gy/35–40  F ( 5 F/week ) in the period of July 1998 to August 2011 were analyzed . All tumors had histological or cytological proven NSCLC T1 - 2N0M0 . Results . The median overall survival was 36.1 months versus 24.4 months for SBRT and conventional RT , respectively ( p = 0.015 ) . Local failure-free survival rates at one year were in SBRT group 93 % versus 89 % in the conventional RT group and at five years 69 % versus 66 % , SBRT and conventional RT respectively ( p = 0.99 ) . On multivariate analysis , female gender and performance status of 0–1 and SBRT predicted improved prognosis . Conclusion . In a cohort of patients with NSCLC there was a significant difference in overall survival  favoring SBRT . Performance status of 0–1 , female gender and SBRT predicted improved prognosis . However , staging procedure , confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes . However , SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients BACKGROUND Video-assisted thoracoscopic surgery ( VATS ) lobectomy and stereotactic ablative radiotherapy ( SABR ) are both used for early-stage non-small-cell lung cancer . We carried out a propensity score-matched analysis to compare locoregional control ( LRC ) . PATIENTS AND METHODS  VATS lobectomy data from six hospitals were retrospectively accessed ; SABR data were obtained from a single institution data base . Patients were matched using propensity scores based on cTNM stage , age , gender , Charlson comorbidity score , lung function and performance score . Eighty-six VATS and 527 SABR patients were matched blinded to outcome ( 1:1 ratio , caliper distance 0.025 ) . Locoregional failure was defined as recurrence in/adjacent to the planning target volume/surgical margins , ipsilateral hilum or mediastinum . Recurrences were either biopsy-confirmed or had to be PET-positive and review ed by a tumor board . RESULTS The matched cohort consisted of 64 SABR and 64 VATS patients with the median follow-up of 30 and 16 months , respectively . Post-SABR LRC rates were superior at 1 and 3 years ( 96.8 % and 93.3 % versus 86.9 % and 82.6 % , respectively , P = 0.04 ) . Distant recurrences and overall survival ( OS ) were not significantly different . CONCLUSION This retrospective analysis found a superior LRC after SABR compared with VATS lobectomy , but OS did not differ . Our findings support the need to compare both treatments in a r and omized , controlled trial Abstract Elderly patients with early stage non-small cell lung cancer ( NSCLC ) who undergo surgical resection  are at a high risk of treatment-related complications . Stereotactic body radiation therapy ( SBRT ) is considered an alternative treatment option with a favorable safety profile . Given that prospect i ve comparative data on SBRT and surgical treatments are limited , we compared the 2 treatments for early stage NSCLC in the elderly . We retrospectively collected information from the data base at our geriatric institution on patients with clinical stage IA/B NSCLC who were treated with surgery or SBRT .  The patients were matched using a propensity score based on gender , age , T stage , tumor location , pulmonary function ( forced expiratory volume in 1 second [FEV1]% and FEV1 ) , Charlson comorbidity score , and World Health Organization performance score . We compared locoregional control rate , recurrence-free survival ( RFS ) , overall survival ( OS ) , and cancer-specific survival ( CSS ) between the 2 treatment cohorts before and after propensity score matching . A total of 106 patients underwent surgery , and 74 received SBRT . Surgical patients were significantly younger ( 72.6 ± 7.9 vs 82.6 ± 4.1 years , P = 0.000 ) , with a significantly higher rate of adenocarcinoma ( P = 0.000 ) , better Eastern Cooperative Oncology Group performance scores ( P = 0.039 ) , and better pulmonary function test results ( P = 0.034 for predicted FEV1 and P = 0.032 for FEV1 ) . In an unmatched comparison , there were significant differences in locoregional control ( P = 0.0012 ) and RFS ( P < 0.001 ) . The 5-year OS was 69 % in patients who underwent surgery and 44.6 % in patients who underwent SBRT ( P = 0.0007 ) . The 5-year CSS was 73.9 % in the surgery group and 57.5 % in the SBRT group ( P = 0.0029 ) . Thirty-five inoperable or marginally operable surgical patients and 35 patients who underwent SBRT were matched to their outcomes in a blinded manner ( 1:1 ratio , caliper distance = 0.25 ) . In this matched comparison , the follow-up period of this subgroup ranged from 4.2 to 138.1 months , with a median of 58.7 months . Surgery was associated with significantly better locoregional control ( P = 0.0191 ) and RFS ( P = 0.0178 ) , whereas no significant differences were found in OS ( 5-year OS , 67.8 % for surgery vs 47.4 % for SBRT , P = 0.07 ) or CSS ( 67.8 % for surgery vs 58.2 % for SBRT , P = 0.1816).This retrospective analysis found superior locoregional control rates and RFS after surgery compared with SBRT , but there were no differences in OS or CSS .  SBRT is an alternative treatment option to surgery in elderly NSCLC patients who can not tolerate surgical resection because of medical comorbidities . Our findings support the need to compare the 2 treatments in r and omized controlled trials BACKGROUND Patients who present with early stage non-small cell lung cancer and are poor c and i date s for lobar resection may be offered sublobar resection ( commonly wedge ) or stereotactic body radiotherapy ( SBRT ) . However , comparing the relative effectiveness of these techniques is difficult because of differences in patient selection . We performed a propensity-matched analysis to compare the different treatment modalities . We compared the overall recurrence , overall survival , disease-free survival , and recurrence-free survival between treatment groups . METHODS A prospect ively collected data base was review ed for patients who underwent a wedge resection , a wedge plus brachytherapy , or SBRT for clinical stage IA non-small cell lung cancer from 2001 to 2012 . Patients who underwent SBRT were further assessed to confirm operability . Univariate and Cox regression multivariate analysis were performed for predictors of a composite end point of recurrence and mortality . RESULTS There were 164 patients identified , from which 99 were matched by age , sex , and histology . There were 61 women ( 62 % ) and 38 men ( 38 % ) with a median age of 73 years . Thirty-eight patients underwent a wedge resection only , 38 patients underwent a wedge with brachytherapy , and 23 patients had SBRT . Median follow-up was 35 months . Overall recurrence ( local and distant ) was significantly higher after SBRT ( wedge , 9 % ; SBRT , 30 % ; p = 0.016 ) . Although recurrence-free 3 -year survival was significantly better after wedge resection ( 88 % versus 72 % ; p = 0.001 ) , there was no difference between the two groups in disease-free 3-year survival ( 77 % versus 59 % ; p = 0.066 ) . Multivariate regression analysis identified male sex and SBRT as significant predictors for mortality and recurrence . CONCLUSIONS Patients with clinical stage IA non-small cell lung cancer treated by SBRT appear to have higher overall disease recurrence than those treated by wedge resection . However , there was no significant difference in disease-free survival . A r and omized trial is needed to define the role of SBRT in the potentially operable patient Background The results of R and omized Controlled Trials ( RCTs ) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio . These do not constitute the sufficient statistics required for meta- analysis or cost-effectiveness analysis , and their use in secondary analyses requires strong assumptions that may not have been adequately tested . In order to enhance the quality of secondary data analyses , we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated . Methods We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations , using where available information on number of events and numbers at risk . The reproducibility and accuracy of survival probabilities , median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics ( survival probabilities , medians and hazard ratios ) with statistics based on repeated reconstructions by multiple observers . Results The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics . Accuracy was excellent for survival probabilities and medians , for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported . Conclusion The algorithm is a reliable tool for meta- analysis and cost-effectiveness analyses of RCTs reporting time-to-event data . It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves Background The treatment schedules for stereotactic body radiotherapy ( SBRT ) for lung cancer vary from institution to institution . Several reports have indicated that stage IB patients had worse outcomes than stage IA patients when the same dose was used . We evaluated the clinical outcomes of SBRT for stage I non-small cell lung cancer ( NSCLC ) treated with different doses depending on tumor diameter . Methods Between February 2004 and November 2008 , 124 patients with stage I NSCLC underwent SBRT .  Total doses of 44 , 48 , and 52 Gy were administered for tumors with a longest diameter of less than 1.5 cm , 1.5 - 3 cm , and larger than 3 cm , respectively . All doses were given in 4 fractions . Results For all 124 patients , overall survival was 71 % , cause-specific survival was 87 % , progression-free survival was 60 % , and local control was 80 % , at 3 years . The 3-year overall survival was 79 % for 85 stage IA patients treated with 48 Gy and 56 % for 37 stage IB patients treated with 52 Gy ( p = 0.05 ) . At 3 years , cause-specific survival was 91 % for the former group and 79 % for the latter ( p = 0.18 ) , and progression-free survival was 62 % versus 54 % ( p = 0.30 ) . The 3-year local control rate was 81 % versus 74 % ( p = 0.35 ) . The cumulative incidence of grade 2 or 3 radiation pneumonitis was 11 
    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: OBJECTIVES Guideline -specified curative therapies for a clinical stage I non-small cell lung cancer ( NSCLC ) are either lobectomy or Stereotactic Ablative Radiotherapy ( SABR ) . As outcomes of prospect i ve r and omized clinical trials comparing these modalities are unavailable , we performed a propensity-score matched analysis to create two similar groups in order to compare clinical outcomes . METHODS We selected 577 patients , 96 VATS or open lobectomy were treated at Erasmus University Medical Center Rotterdam and 481 SABR patients were treated at VU University Medical Center Amsterdam with clinical stage I NSCLC . RESULTS Matching of patients according to propensity score result ed in a cohort that consisted of 73 patients in the surgery group and of 73 patients in the SABR group . Median follow-up in the surgery and SABR group was 49 months and 28 months , respectively . Overall survival of patients who underwent surgery was 95 % and 80 % at 12 and 60 months , respectively . For the SABR group this was 94 % at 12 months and 53 % at 60 months . No statistical significant difference ( p=0.089 ) in survival was found between these groups . CONCLUSIONS In this study we found no significant differences in overall survival in propensity matched patients diagnosed with stage I NSCLC treated either surgically or with SABR . After 3 years there seems to be a trend toward improved survival in patients who were treated surgically Abstract Introduction . Stereotactic body radiation therapy ( SBRT ) for early stage non-small cell lung cancer ( NSCLC ) is now an accepted and patient friendly treatment , but still controversy exists about its comparability to conventional radiation therapy ( RT ) . The purpose of this single-institutional report is to describe survival outcome for medically inoperable patients with early stage NSCLC treated with SBRT compared with high dose conventional RT . Material and methods . From August 2005 to June 2012 , 100 medically inoperable patients were treated with SBRT at Odense University Hospital . The thoracic RT consisted of 3 fractions ( F ) of 15–22 Gy delivered in nine days . For comparison a group of 32 medically inoperable patients treated with conventional RT with 80 Gy/35–40  F ( 5 F/week ) in the period of July 1998 to August 2011 were analyzed . All tumors had histological or cytological proven NSCLC T1 - 2N0M0 . Results . The median overall survival was 36.1 months versus 24.4 months for SBRT and conventional RT , respectively ( p = 0.015 ) . Local failure-free survival rates at one year were in SBRT group 93 % versus 89 % in the conventional RT group and at five years 69 % versus 66 % , SBRT and conventional RT respectively ( p = 0.99 ) . On multivariate analysis , female gender and performance status of 0–1 and SBRT predicted improved prognosis . Conclusion . In a cohort of patients with NSCLC there was a significant difference in overall survival  favoring SBRT . Performance status of 0–1 , female gender and SBRT predicted improved prognosis . However , staging procedure , confirmation procedure of recurrence and technical improvements of radiation treatment is likely to influence outcomes . However , SBRT seems to be as efficient as conventional RT and is a more convenient treatment for the patients BACKGROUND Video-assisted thoracoscopic surgery ( VATS ) lobectomy and stereotactic ablative radiotherapy ( SABR ) are both used for early-stage non-small-cell lung cancer . We carried out a propensity score-matched analysis to compare locoregional control ( LRC ) . PATIENTS AND METHODS  VATS lobectomy data from six hospitals were retrospectively accessed ; SABR data were obtained from a single institution data base . Patients were matched using propensity scores based on cTNM stage , age , gender , Charlson comorbidity score , lung function and performance score . Eighty-six VATS and 527 SABR patients were matched blinded to outcome ( 1:1 ratio , caliper distance 0.025 ) . Locoregional failure was defined as recurrence in/adjacent to the planning target volume/surgical margins , ipsilateral hilum or mediastinum . Recurrences were either biopsy-confirmed or had to be PET-positive and review ed by a tumor board . RESULTS The matched cohort consisted of 64 SABR and 64 VATS patients with the median follow-up of 30 and 16 months , respectively . Post-SABR LRC rates were superior at 1 and 3 years ( 96.8 % and 93.3 % versus 86.9 % and 82.6 % , respectively , P = 0.04 ) . Distant recurrences and overall survival ( OS ) were not significantly different . CONCLUSION This retrospective analysis found a superior LRC after SABR compared with VATS lobectomy , but OS did not differ . Our findings support the need to compare both treatments in a r and omized , controlled trial Abstract Elderly patients with early stage non-small cell lung cancer ( NSCLC ) who undergo surgical resection  are at a high risk of treatment-related complications . Stereotactic body radiation therapy ( SBRT ) is considered an alternative treatment option with a favorable safety profile . Given that prospect i ve comparative data on SBRT and surgical treatments are limited , we compared the 2 treatments for early stage NSCLC in the elderly . We retrospectively collected information from the data base at our geriatric institution on patients with clinical stage IA/B NSCLC who were treated with surgery or SBRT .  The patients were matched using a propensity score based on gender , age , T stage , tumor location , pulmonary function ( forced expiratory volume in 1 second [FEV1]% and FEV1 ) , Charlson comorbidity score , and World Health Organization performance score . We compared locoregional control rate , recurrence-free survival ( RFS ) , overall survival ( OS ) , and cancer-specific survival ( CSS ) between the 2 treatment cohorts before and after propensity score matching . A total of 106 patients underwent surgery , and 74 received SBRT . Surgical patients were significantly younger ( 72.6 ± 7.9 vs 82.6 ± 4.1 years , P = 0.000 ) , with a significantly higher rate of adenocarcinoma ( P = 0.000 ) , better Eastern Cooperative Oncology Group performance scores ( P = 0.039 ) , and better pulmonary function test results ( P = 0.034 for predicted FEV1 and P = 0.032 for FEV1 ) . In an unmatched comparison , there were significant differences in locoregional control ( P = 0.0012 ) and RFS ( P < 0.001 ) . The 5-year OS was 69 % in patients who underwent surgery and 44.6 % in patients who underwent SBRT ( P = 0.0007 ) . The 5-year CSS was 73.9 % in the surgery group and 57.5 % in the SBRT group ( P = 0.0029 ) . Thirty-five inoperable or marginally operable surgical patients and 35 patients who underwent SBRT were matched to their outcomes in a blinded manner ( 1:1 ratio , caliper distance = 0.25 ) . In this matched comparison , the follow-up period of this subgroup ranged from 4.2 to 138.1 months , with a median of 58.7 months . Surgery was associated with significantly better locoregional control ( P = 0.0191 ) and RFS ( P = 0.0178 ) , whereas no significant differences were found in OS ( 5-year OS , 67.8 % for surgery vs 47.4 % for SBRT , P = 0.07 ) or CSS ( 67.8 % for surgery vs 58.2 % for SBRT , P = 0.1816).This retrospective analysis found superior locoregional control rates and RFS after surgery compared with SBRT , but there were no differences in OS or CSS .  SBRT is an alternative treatment option to surgery in elderly NSCLC patients who can not tolerate surgical resection because of medical comorbidities . Our findings support the need to compare the 2 treatments in r and omized controlled trials BACKGROUND Patients who present with early stage non-small cell lung cancer and are poor c and i date s for lobar resection may be offered sublobar resection ( commonly wedge ) or stereotactic body radiotherapy ( SBRT ) . However , comparing the relative effectiveness of these techniques is difficult because of differences in patient selection . We performed a propensity-matched analysis to compare the different treatment modalities . We compared the overall recurrence , overall survival , disease-free survival , and recurrence-free survival between treatment groups . METHODS A prospect ively collected data base was review ed for patients who underwent a wedge resection , a wedge plus brachytherapy , or SBRT for clinical stage IA non-small cell lung cancer from 2001 to 2012 . Patients who underwent SBRT were further assessed to confirm operability . Univariate and Cox regression multivariate analysis were performed for predictors of a composite end point of recurrence and mortality . RESULTS There were 164 patients identified , from which 99 were matched by age , sex , and histology . There were 61 women ( 62 % ) and 38 men ( 38 % ) with a median age of 73 years . Thirty-eight patients underwent a wedge resection only , 38 patients underwent a wedge with brachytherapy , and 23 patients had SBRT . Median follow-up was 35 months . Overall recurrence ( local and distant ) was significantly higher after SBRT ( wedge , 9 % ; SBRT , 30 % ; p = 0.016 ) . Although recurrence-free 3 -year survival was significantly better after wedge resection ( 88 % versus 72 % ; p = 0.001 ) , there was no difference between the two groups in disease-free 3-year survival ( 77 % versus 59 % ; p = 0.066 ) . Multivariate regression analysis identified male sex and SBRT as significant predictors for mortality and recurrence . CONCLUSIONS Patients with clinical stage IA non-small cell lung cancer treated by SBRT appear to have higher overall disease recurrence than those treated by wedge resection . However , there was no significant difference in disease-free survival . A r and omized trial is needed to define the role of SBRT in the potentially operable patient Background The results of R and omized Controlled Trials ( RCTs ) on time-to-event outcomes that are usually reported are median time to events and Cox Hazard Ratio . These do not constitute the sufficient statistics required for meta- analysis or cost-effectiveness analysis , and their use in secondary analyses requires strong assumptions that may not have been adequately tested . In order to enhance the quality of secondary data analyses , we propose a method which derives from the published Kaplan Meier survival curves a close approximation to the original individual patient time-to-event data from which they were generated . Methods We develop an algorithm that maps from digitised curves back to KM data by finding numerical solutions to the inverted KM equations , using where available information on number of events and numbers at risk . The reproducibility and accuracy of survival probabilities , median survival times and hazard ratios based on reconstructed KM data was assessed by comparing published statistics ( survival probabilities , medians and hazard ratios ) with statistics based on repeated reconstructions by multiple observers . Results The validation exercise established there was no material systematic error and that there was a high degree of reproducibility for all statistics . Accuracy was excellent for survival probabilities and medians , for hazard ratios reasonable accuracy can only be obtained if at least numbers at risk or total number of events are reported . Conclusion The algorithm is a reliable tool for meta- analysis and cost-effectiveness analyses of RCTs reporting time-to-event data . It is recommended that all RCTs should report information on numbers at risk and total number of events alongside KM curves Background The treatment schedules for stereotactic body radiotherapy ( SBRT ) for lung cancer vary from institution to institution . Several reports have indicated that stage IB patients had worse outcomes than stage IA patients when the same dose was used . We evaluated the clinical outcomes of SBRT for stage I non-small cell lung cancer ( NSCLC ) treated with different doses depending on tumor diameter . Methods Between February 2004 and November 2008 , 124 patients with stage I NSCLC underwent SBRT .  Total doses of 44 , 48 , and 52 Gy were administered for tumors with a longest diameter of less than 1.5 cm , 1.5 - 3 cm , and larger than 3 cm , respectively . All doses were given in 4 fractions . Results For all 124 patients , overall survival was 71 % , cause-specific survival was 87 % , progression-free survival was 60 % , and local control was 80 % , at 3 years . The 3-year overall survival was 79 % for 85 stage IA patients treated with 48 Gy and 56 % for 37 stage IB patients treated with 52 Gy ( p = 0.05 ) . At 3 years , cause-specific survival was 91 % for the former group and 79 % for the latter ( p = 0.18 ) , and progression-free survival was 62 % versus 54 % ( p = 0.30 ) . The 3-year local control rate was 81 % versus 74 % ( p = 0.35 ) . The cumulative incidence of grade 2 or 3 radiation pneumonitis was 11 
    Output:
    