Diagnostic Performance of Ultra-Low-Dose Computed Tomography for Detecting Asbestos-Related Pleuropulmonary Diseases: Prospective Study in a Screening Setting

Abstract

ObjectiveTo evaluate the diagnostic performance of Ultra-Low-Dose Chest CT (ULD CT) for the detection of any asbestos-related lesions (primary endpoint) and specific asbestos-related abnormalities, i.e. non-calcified and calcified pleural plaques, diffuse pleural thickening, asbestosis and significant lung nodules (secondary endpoints).Material and Methods55 male patients (55.7±8.1 years old) with occupational asbestos exposure for at least 15 years and where CT screening was indicated were prospectively included. They all underwent a standard unenhanced chest CT (120kV, automated tube current modulation), considered as the reference, and an ULD CT (135kV, 10mA), both with iterative reconstruction.Two chest radiologists independently and blindly read the examinations, following a detailed protocol. Sensitivity, specificity, positive predictive value, negative predictive value, accuracy and error rate of ULD CT were calculated using the exact method of Pearson with a confidence interval of 95%.ResultsRadiation dose was 17.9±1.2mGy.cm (0.25mSv) for the ULD-CT versus 288.8 ±151mGy.cm (4mSv); p <2.2e-16.Prevalence of abnormalities was 20%. The ULD CT’s diagnostic performance in joint reading was high for the primary endpoint (sensitivity = 90.9%, specificity = 100%, positive predictive value = 100%, negative predictive value = 97.8%), high for lung nodules, diffuse pleural thickening and calcified pleural plaques (sensitivity, specificity, PPV and NPV = 100%) and fair for asbestosis (sensitivity = 75%, specificity = 100%, PPV = 00%, NPV = 98.1%).Intra-reader accuracy between the ULD CT and the reference CT for the primary endpoint was 98% for the senior and 100% for the junior radiologist. Inter-reader agreement for the primary endpoint was almost perfect (Cohen’s Kappa of 0.81).ConclusionULD CT in the screening of asbestos exposure related diseases has 90.9% sensitivity and 100% specificity, and could therefore be proposed as a first line examination.

ACR Appropriateness Criteria® Occupational Lung Diseases

“…Although no studies have implemented a population-based CT screening and surveillance program specifically for occupational lung disease to examine morbidity or mortality benefit, several recent studies have used reduced-dose CT to demonstrate adequate detection of parenchymal changes in at-risk workers. In a prospective study of 55 patients with a 15-year asbestos exposure history, screening ultra-low-dose chest CT was compared with standard acquisition chest CT, demonstrating 91% sensitivity and 100% specificity for asbestos-associated primary endpoint findings [12]. Retrospective studies utilizing lung cancer screening examinations have also revealed potential benefit.…”

“…Despite well-known risks and mitigation efforts, occupational lung diseases such as the pneumoconioses continue to arise for a variety of reasons [4][5][6][7][8][9][10][11]. Medical imaging continues to play a critical role in the diagnosis and management of occupational lung disease, with increasing use of chest CT, particularly at reduced dose [12][13][14]. Various biomarkers in conjunction with medical imaging are proving to further refine assessment [15][16][17][18][19][20].…”

Impact of Morphotype on Image Quality and Diagnostic Performance of Ultra-Low-Dose Chest CT

“…All 170 patients from 3 prior prospective studies performed in Strasbourg University Hospital and carried out on the same second-generation 320-row scanner (Aquillion One Vision Edition, Toshiba, Japan), were retrospectively included. The first study [ 18 ] included 55 patients from July 2013 to May 2014 with an occupational exposure to asbestos of at least 15 years, referred for screening of asbestos-related pleuro-pulmonary lesions. The second study [ 19 ] (April 2014 to September 2014) and the third study [ 20 ] (April 2015 to September 2015) included 51 and 64 patients, respectively, that were referred for a clinically indicated unenhanced chest CT.…”

“…All examinations were performed in successive end-inspiratory apneas, arms raised above the head. The 55 patients from the first study were acquired in prone position, to avoid gravity-dependent posterior parenchymal abnormalities—as recommended when screening for asbestos-related diseases [ 18 ]. The 115 patients from the two following studies were acquired in supine position.…”

Added benefits of early detection of other diseases on low-dose CT screening

“…Beyond these diseases, the LDCT provides information on other diseases of the lungs, mediastinum, breasts, bones, and upper abdomen, which may be better treated when identified early. The current vision of LDCT screening provides a comprehensive "health check" of the lungs, heart, and other organs visualized on the LDCT, particularly as LDCT radiation doses are almost as low as chest radiography (14)(15)(16)(17). LDCT findings and follow-up recommendations have been developed over the past 20 years of LDCT screening since the initial publication on LDCT screening and long-term follow-up (18)(19)(20).…”