Collecting 48,000 CT Exams for the Lung Screening Study of the National Lung Screening Trial

Abstract

From 2002-2004, the Lung Screening Study (LSS) of the National Lung Screening Trial (NLST) enrolled 34,614 participants, aged 55-74 years, at increased risk for lung cancer due to heavy cigarette smoking. Participants, randomized to standard chest X-ray (CXR) or computed tomography (CT) arms at ten screening centers, received up to three imaging screens for lung cancer at annual intervals. Participant medical histories and radiologist-interpreted screening results were transmitted to the LSS coordinating center, while all images were retained at local screening centers. From 2005From -2007, all CT exams were uniformly de-identified and delivered to a central repository, the CT Image Library (CTIL), on external hard drives (94%) or CD/DVD (5.9%), or over a secure Internet connection (0.1%). Of 48,723 CT screens performed, only 176 (0.3%) were unavailable (lost, corrupted, compressed) while 48,547 (99.7%) were delivered to the CTIL. Described here is the experience organizing, implementing, and adapting the clinical-trial workflow surrounding the image retrieval, de-identification, delivery, and archiving of available LSS-NLST CT exams for the CTIL, together with the quality assurance procedures associated with those collection tasks. This collection of CT exams, obtained in a specific, well-defined participant population under a common protocol at evenly spaced intervals, and its attending demographic and clinical information, are now available to lung-disease investigators and developers of computer-aided-diagnosis algorithms. The approach to large scale, multi-center trial CT image collection detailed here may serve as a useful model, while the experience reported should be valuable in the planning and execution of future equivalent endeavors.

Lung cancer screening

“…The LSS confirmed LDCT's higher lung cancer detection rate compared with CXR: 1.8 vs 0.5% at baseline, and 2.4 vs 1.3% at the first year repeat. On the basis of the success of LSS, the National Cancer Institute, in collaboration with the American College of Radiology Imaging Network, launched the National Lung Screening Trial, which represents the largest randomised controlled trial comparing LDCT with CXR, with lung cancer mortality as the end point (Clark et al, 2008). More than 53 000 participants were enrolled from over 30 centres across the United States.…”

The Cancer Imaging Archive (TCIA): Maintaining and Operating a Public Information Repository

“…WUSTL has served as an imaging core in multi-center clinical trials, e.g., the Silent Cerebral Infarct Transfusion Trial (SITT) (∼1,000 patients; 1,552 examinations; 850,000 images) [17] and the CT Image Library for the Lung Screening Study of the National Lung Screening Trial (NLST) (17,309 patients with serial CT screens; 48,723 CT examinations; 12 million images) [18].…”

Long-term prognosis of patients with lung cancer detected on low-dose chest computed tomography screening

“…However, data for the prognosis of lung cancer cases identified on CT screening are limited [4][5][6] and the effect of this screening procedure on mortality remains inconclusive. While several randomized controlled trials are ongoing [7][8][9][10], results of previous analyses [11][12][13] have not supported an effect of CT-based screening in lowering lung cancer mortality. Recently, however, the National Lung Screening Trial (NLST), a randomized trial targeted for current and former heavy smokers, found a 20% reduction in lung cancer death among participants screened with low-dose helical CT compared to participants screened with chest X-ray [14].…”