***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: Background : In  lung cancer CT screening  , participants often have an indeterminate screening result at baseline requiring a follow-up CT . In subjects with either an indeterminate or a negative result after screening , we investigated whether health-related quality of life ( HRQoL ) changed over time and differed between groups in the short term . Methods : A total of 733 participants in the NELSON trial received four question naires : T0 , before r and omisation ; T1 , 1 week before the baseline screening ; T2 , 1 day after the screening ; and T3 , 2 months after the screening results but before the 3-month follow-up CT .  HRQoL was measured as generic HRQoL ( the 12-item Short Form , SF-12 ; the EuroQol question naire , EQ-5D ) , anxiety ( the Spielberger State-Trait Anxiety Inventory , STAI-6 ) , and lung-cancer-specific distress ( the Impact of Event Scale , IES ) . For analyses , repeated- measures analysis of variance was used , adjusted for covariates . Results : Response to each question naire was 88 % or higher . Scores on SF-12 , EQ-5D , and STAI-6 showed no clinical ly relevant changes over time . At T3 , IES scores that were clinical ly relevant increased after an indeterminate result , whereas these scores showed a significant decrease after a negative result . At T3 , differences in IES scores between the two baseline result groups were both significant and clinical ly relevant ( P<0.01 ) . Conclusion : This longitudinal study among participants of a lung cancer screening programme showed that in the short term recipients of an indeterminate result experienced increased lung-cancer-specific distress , whereas the HRQoL changes after a negative baseline screening result may be interpreted as a relief Background Lung cancer screening using low-dose CT ( LDCT ) was shown to reduce lung cancer mortality by 20 % in the National Lung Screening Trial . Methods The pilot UK Lung Cancer Screening ( UKLS ) is a r and omised controlled trial of LDCT screening for lung cancer versus usual care . A population -based question naire was used to identify high-risk individuals . CT screen-detected nodules were managed by a pre-specified protocol . Cost effectiveness was modelled with reference to the National Lung Cancer Screening Trial mortality reduction . Results 247 354 individuals aged 50–75 years were approached ; 30.7 % expressed an interest , 8729 ( 11.5 % ) were eligible and 4055 were r and omised , 2028 into the CT arm ( 1994 underwent a CT ) . Forty-two participants ( 2.1 % ) had confirmed lung cancer , 34 ( 1.7 % ) at baseline and 8 ( 0.4 % ) at the 12-month scan . 28/42 ( 66.7 % ) had stage I disease , 36/42 ( 85.7 % ) had stage I or II disease . 35/42 ( 83.3 % ) had surgical resection . 536 subjects had nodules greater than 50 mm3 or 5 mm diameter and 41/536 were found to have lung cancer . One further cancer was detected by follow-up of nodules between 15 and 50 mm3 at 12 months . The baseline estimate for the incremental cost-effectiveness ratio of once-only CT screening , under the UKLS protocol , was £ 8466 per quality adjusted life year gained ( CI £ 5542 to £ 12 569 ) . Conclusions The UKLS pilot trial demonstrated that it is possible to detect lung cancer at an early stage and deliver potentially curative treatment in over 80 % of cases . Health economic analysis suggests that the intervention would be cost effective — this needs to be confirmed using data on observed lung cancer mortality reduction . Trial registration IS RCT N 78513845 OBJECTIVES This study attempts to quantify the difference in loss of quality -adjusted life expectancy ( QALE ) for patients with operable and inoperable non-small-cell lung cancer ( NSCLC ) . PATIENTS AND METHODS A cohort consisting of 1652 pathologically verified NSCLC patients with performance status 0 - 1 was monitored for 7 years ( 2005 - 2011 ) to obtain the survival function . This was further extrapolated to lifetime , based on the survival ratios between patients and age- and sex-matched referents simulated from the life tables of the National Vital Statistics of Taiwan . Between 2011 and 2012 , EuroQol 5-dimension question naires were used to prospect ively measure the quality -of-life ( QoL ) of a 518 consecutive , cross-sectional sub sample . We adjusted the lifetime survival function by the utility values of QoL for the cancer cohort to obtain the QALE , while that for the age and sex-matched referents were adjusted to the values collected from the 2009 National Health Interview Survey , and the difference between them was the loss-of-QALE . RESULTS The QALE for patients with operable and inoperable NSCLC were 11.66±0.18 and 1.43±0.05 quality -adjusted life year ( QALY ) , with the corresponding loss-of-QALE of 5.25±0.18 and 14.24±0.05 QALY , respectively . The lifetime utility difference for patients with operable and inoperable NSCLC was 9.00±0.18 QALY , after adjustment for QoL and lead-time bias . CONCLUSION The utility gained from surgical operation for operable lung cancer is substantial , even after adjustment for lead-time bias . Future studies should compare screening programs with treatment strategies when carrying out cost-utility assessment s to improve patients ' values RATIONALE As of April 2015 , participants in the Danish Lung Cancer Screening Trial had been followed for at least 5 years since their last screening . OBJECTIVES Mortality , causes of death , and lung cancer findings are reported to explore the effect of computed tomography ( CT ) screening . METHODS A total of 4,104 participants aged 50 - 70 years at the time of inclusion and with a minimum 20 pack-years of smoking were r and omized to have five annual low-dose CT scans ( study group ) or no screening ( control group ) . MEASUREMENTS AND MAIN RESULTS Follow-up information regarding date and cause of death , lung cancer diagnosis , cancer stage , and histology was obtained from national registries . No differences between the two groups in lung cancer mortality ( hazard ratio , 1.03 ; 95 % confidence interval , 0.66 - 1.6 ; P = 0.888 ) or all-cause mortality ( hazard ratio , 1.02 ; 95 % confidence interval , 0.82 - 1.27 ; P = 0.867 ) were observed . More cancers were found in the screening group than in the no-screening group ( 100 vs. 53 , respectively ; P < 0.001 ) , particularly adenocarcinomas ( 58 vs. 18 , respectively ; P < 0.001 ) . More early-stage cancers ( stages I and II , 54 vs. 10 , respectively ; P < 0.001 ) and stage IIIa cancers ( 15 vs. 3 , respectively ; P = 0.009 ) were found in the screening group than in the control group . Stage IV cancers were nonsignificantly more frequent in the control group than in the screening group ( 32 vs. 23 , respectively ; P = 0.278 ) . For the highest-stage cancers ( T4N3M1 , 21 vs. 8 , respectively ; P = 0.025 ) , this difference was statistically significant , indicating an absolute stage shift . Older participants , those with chronic obstructive pulmonary disease , and those with more than 35 pack-years of smoking had a significantly increased risk of death due to lung cancer , with nonsignificantly fewer deaths in the screening group . CONCLUSIONS No statistically significant effects of CT screening on lung cancer mortality were found , but the results of post hoc high-risk subgroup analyses showed nonsignificant trends that seem to be in good agreement with the results of the National Lung Screening Trial . Clinical trial registered with www . clinical trials.gov ( NCT00496977 ) BACKGROUND Low-dose CT screening is recommended for individuals at high risk of developing lung cancer . However , CT screening does not detect all lung cancers : some might be missed at screening , and others can develop in the interval between screens . The NELSON trial is a r and omised trial to assess the effect of screening with increasing screening intervals on lung cancer mortality . In this prespecified analysis , we aim ed to assess screening test performance , and the epidemiological , radiological , and clinical characteristics of interval cancers in NELSON trial participants assigned to the screening group . METHODS Eligible participants in the NELSON trial were those aged 50 - 75 years , who had smoked 15 or more cigarettes per day for more than 25 years or ten or more cigarettes for more than 30 years , and were still smoking or had quit less than 10 years ago . We included all participants assigned to the screening group who had attended at least one round of screening . Screening test results were based on volumetry using a two-step approach . Initially , screening test results were classified as negative , indeterminate , or positive based on nodule presence and volume . Subsequently , participants with an initial indeterminate result underwent follow-up screening to classify their final screening test result as negative or positive , based on nodule volume doubling time . We obtained information about all lung cancer diagnoses made during the first three rounds of screening , plus an additional 2 years of follow-up from the national cancer registry . We determined epidemiological , radiological , participant , and tumour characteristics by reassessing medical files , screening CTs , and clinical CTs . The NELSON trial is registered at www.trialregister.nl , number IS RCT N63545820 . FINDINGS 15,822 participants were enrolled in the NELSON trial , of whom 7915 were assigned to low-dose CT screening  with increasing interval between screens , and 7907 to no screening .  We included 7155 participants in our study , with median follow-up of 8·16 years ( IQR 7·56 - 8·56 ) . 187 ( 3 % ) of 7155 screened participants were diagnosed with 196 screen-detected lung cancers , and another 34 ( < 1 % ; 19 [ 56 % ] in the first year after screening , and 15 [ 44 % ] in the second year after screening ) were diagnosed with 35 interval cancers . For the three screening rounds combined , with a 2-year follow-up , sensitivity was 84·6 % ( 95 % CI 79·6 - 89·2 ) , specificity was 98·6 % ( 95 % CI 98·5 - 98·8 ) , positive predictive value was 40·4 % ( 95 % CI 35·9 - 44·7 ) , and negative predictive value was 99·8 % ( 95 % CI 99·8 - 99·9 ) . Retrospective assessment of the last screening CT and clinical CT in 34 patients with interval cancer showed that interval cancers were not visible in 12 ( 35 % ) cases . In the remaining cases , cancers were visible when retrospectively assessed , but were not diagnosed because of radiological detection and interpretation errors ( 17 [ 50 % ] ) , misclassification by the protocol ( two [ 6 % ] ) , participant non-compliance ( two [ 6 % ] ) , and non-adherence to protocol ( one [ 3 % ] ) . Compared with screen-detected cancers , interval cancers were diagnosed at more advanced stages ( 29 [ 83 % ] of 35 interval cancers vs 44 [ 22 % ] of 196 screen-detected cancers diagnosed in stage III or IV ; p<0·0001 ) , were more often small-cell carcinomas ( seven [ 20 % ] vs eight [ 4 % ] ; p=0·003 ) and less often adenocarcinomas ( nine [ 26 % ] vs 102 [ 52 % ] ; p=0·005 ) . INTERPRETATION Lung cancer screening in the NELSON trial yielded high specificity and sensitivity , with only a small number of interval cancers . The results of this study could be used to improve screening algorithms , and reduce the number of missed cancers . FUNDING Zorgonderzoek Nederl and Medische Wetenschappen and Koningin Wilhelmina Fonds OBJECTIVES To determine the diagnostic accuracy of lung nodule detection in thoracic CT using 2 reduced dose protocol s comparing 3 available CT reconstruction algorithms ( filtered back projection-FBP , adaptive statistical reconstruction-ASIR and model-based iterative reconstruction-MBIR ) in a western population . MATERIAL S AND METHODS A prospect i ve single-center study recruited 98 patients with written consent .  St and ard dose ( STD ) thoracic CT followed by 2 reduced-dose protocol s using automatic tube current modulation ( RD1 ) and fixed tube current ( RD2 ) were performed and reconstructed with FBP , ASIR and MBIR with subsequent diagnostic accuracy analysis for nodule detection . RESULTS 108 solid nodules , 47 subsolid nodules and 89 purely calcified nodules were analyzed . RD1 was superior to RD2 for assessment of solid nodules ≤4 mm , and subsolid nodules ≤5 mm ( p<0.05 ) . Deterioration of RD2 is correlated to patient 's body mass index and 
    Output:
    
The findings also showed that LDCT screening demonstrated a non-statistically significant increase in all-cause mortality .
The results showed that LDCT was ranked as the best screening strategy in terms of lung cancer mortality reduction .
CXR had a 99.7 % probability of being the worst intervention and usual care was ranked second .
Cost-effectiveness - screening programmes are predicted to be more effective than no screening , reduce lung cancer mortality and result in more lung cancer diagnoses .
Screening programmes also increase costs .
LDCT screening may be clinical ly effective in reducing lung cancer mortality , but there is considerable uncertainty .
There is evidence that a single round of screening could be considered cost-effective at conventional thresholds , but there is significant uncertainty about the effect on costs and the magnitude of benefits .