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Hypothesis: We hypothesise that the validated HUNT Lung Cancer Risk Model would perform better than the NLST (USA) and the NELSON (Dutch-Belgian) criteria in the Danish Lung Cancer Screening Trial (DLCST)., Methods: The DLCST measured only five out of the seven variables included in validated HUNT Lung Cancer Model. Therefore a 'Reduced' model was retrained in the Norwegian HUNT2-cohort using the same statistical methodology as in the original HUNT model but based only on age, pack years, smoking intensity, quit time and body mass index (BMI), adjusted for sex. The model was applied on the DLCST-cohort and contrasted against the NLST and NELSON criteria., Results: Among the 4051 smokers in the DLCST with 10 years follow-up, median age was 57.6, BMI 24.75, pack years 33.8, cigarettes per day 20 and most were current smokers. For the same number of individuals selected for screening, the performance of the 'Reduced' HUNT was increased in all metrics compared with both the NLST and the NELSON criteria. In addition, to achieve the same sensitivity, one would need to screen fewer people by the 'Reduced' HUNT model versus using either the NLST or the NELSON criteria (709 vs 918, p=1.02e-11 and 1317 vs 1668, p=2.2e-16, respectively)., Conclusions: The 'Reduced' HUNT model is superior in predicting lung cancer to both the NLST and NELSON criteria in a cost-effective way. This study supports the use of the HUNT Lung Cancer Model for selection based on risk ranking rather than age, pack year and quit time cut-off values. When we know how to rank personal risk, it will be up to the medical community and lawmakers to decide which risk threshold will be set for screening., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2019. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.)

Background: We present the final results of the effect of lung cancer screening with low-dose CT on the smoking habits of participants in a 5-year screening trial., Methods: The Danish Lung Cancer Screening Trial (DLCST) was a 5-year screening trial that enrolled 4104 subjects; 2052 were randomised to annual low-dose CT (CT group) and 2052 received no intervention (control group). Participants were current and ex-smokers (≥4 weeks abstinence from smoking) with a tobacco consumption of ≥20 pack years. Smoking habits were determined annually. Missing values for smoking status at the final screening round were handled using two different models., Results: There were no statistically significant differences in annual smoking status between the CT group and control group. Overall the ex-smoker rates (CT + control group) significantly increased from 24% (baseline) to 37% at year 5 of screening (p<0.001). The annual point prevalence quit rate increased from 11% to 24% during the five screening rounds; the ex-smokers' relapse rate remained stable, around 11%, across the same period., Conclusions: Screening with low-dose CT had no extra effect on smoking status compared with the control group, but overall the screening programme probably promoted smoking cessation., Clinical Trial Registration: The DLCST is registered in Clinical Trials.gov Protocol Registration System (identification no. NCT00496977)., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.)

Introduction: Contamination, defined as screening in the control arm, may dilute the statistical power of randomised screening trials. We investigated the rate of contamination in DLCST during 4 years of annual CT screening., Methods: DLCST is a randomised trial involving 4104 healthy current and ex smokers. 2052 subjects were randomised to annual low dose chest CT scans (CT group) and 2052 were given no intervention (control group). The study is performed in collaboration with the NELSON trial (Nederlands Leuvens Screening Onderzoek) and mortality data will be pooled at the end. We defined contamination as off study CT scan received for lung cancer screening purposes. Annually during the screening period, the participants were asked whether they had received a CT scan and if so the purpose. The causes were divided into the following categories: 'Off study screening for lung cancer', 'Investigation of lung symptoms', 'Investigation of incidental finding on chest radiograph', 'Participation in other scientific trial involving chest CT', and finally 'Chest CT for other reasons'., Results: Response rates were high in both groups: 86.1% (control group), 93.6% (CT group) p<0.001., Control Group: 199 out of 7065 answers (2.8%) indicating acquisition of a chest CT during 4 years of the trial. Three answers fulfilled the definition of contamination, while 8 received chest CT due to involvement in other scientific trials. 126 reported CT scans as part of investigation for other diseases, while 10 and 52 went through investigations for abnormal chest radiograph and lung symptoms, respectively. CT group: Significantly lower number of answers (n=134) indicated acquisition of an off study chest CT. None had received off study lung cancer screening. Three were involved in other scientific trials, while 17 and 115 went through investigation of lung symptoms and chest CT for other reasons, respectively., Conclusion: Although the frequency of off study chest CT was significantly higher in the control group, it was relatively small in both randomisation groups, and thus contamination seems to be modest and acceptable in the DLCST. Clinical Trial no.: Clinical Trials.gov Protocol Registration System (identification no. NCT00496977)., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background: Lung cancer is the most common cause of cancer-related death worldwide and therefore there has been a growing demand for low-dose computed tomography (LDCT) protocols. Purpose: To investigate and evaluate the dose and image quality of patients undergoing lung cancer screening (LCS) using LDCT in Norway. Materials and Methods: Retrospective dosimetry data, volumetric CT dose index (CTDIvol) and dose-length product (DLP), from 70 average-size and 70 large-size patients who underwent LDCT scan for LCS were included in the survey. Effective dose and size-specific dose were calculated for each examination and were compared with the American Association of Physicists in Medicine (AAPM) requirement. For a quantitative image quality analysis, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) were determined for different regions in the chest with two iterative reconstruction techniques, iDose and Iterative Model Reconstruction. Differences in dose and image quality between average-size and large-size patients were evaluated by Independent sample t test, and Wilcoxon signed rank test within the same patient group. Results: The independent sample t test revealed significant differences (p <.05) in dose values between average-size and large-size patients. Mean CTDIvol and DLP for average-size patients were 2.8 mGy and 115 mGy.cm, respectively, with appropriate increment for the large-size patients. Image quality (image noise, SNR, and CNR) did not significantly differ between patient groups when images were reconstructed with a model based iterative reconstruction algorithm. Conclusion: The screening protocol assessed in this study resulted in CTDIvol values that were compliant with AAPM recommendation. No significant differences in objective image quality were found between patient groups. [ABSTRACT FROM AUTHOR]

Introduction:We review the current knowledge of CT screening for lung cancer and present an expert-based, joint protocol for the proper implementation of screening in the Nordic countries. Materials and methods:Experts representing all the Nordic countries performed literature review and concensus for a joint protocol for lung cancer screening. Results and discussion:Areas of concern and caution are presented and discussed. We suggest to perform CT screening pilot studies in the Nordic countries in order to gain experience and develop specific and safe protocols for the implementation of such a program. [ABSTRACT FROM PUBLISHER]

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 randomized 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.clinicaltrials.gov (NCT00496977). [ABSTRACT FROM AUTHOR]