Ultra low dose CT screen-detected non-malignant incidental findings in the Western Australian Asbestos Review Programme.
Computed tomography (CT)-based studies of asbestos-exposed individuals report a high prevalence of lung cancer, but the utility of low dose CT (LDCT) to screen asbestos-exposed populations is not established. We aimed to describe the prevalence of indeterminate pulmonary nodules and incidental findings on chest LDCT of asbestos-exposed subjects in Western Australia.



A total of 906 subjects from the Western Australian Asbestos Review Programme underwent LDCT of the chest as part of regular annual review. An indeterminate (solid) nodule was defined as >50 mm3and part-solid/non-solid nodules >5 mm. The presence of asbestos-related diseases was recorded with a standardized report.



Subjects were mostly (81%) men with a median age of 70 years. Fifty-eight (6.5%) participants were current smokers, 511 (56.4%) ex-smokers and 325 (36.4%) never-smokers. One hundred and four indeterminate nodules were detected in 77 subjects (8.5%); of these, eight cases had confirmed lung cancer (0.88%). Eighty-seven subjects (9.6%) had incidental findings that required further investigation, 42 (4.6%) from lower airways inflammation. The majority of nodules were solid, 4-6 mm and more common with age. Five hundred and eighty (64%) subjects had pleural plaques, and 364 (40.2%) had evidence of interstitial lung disease.



The prevalence of LDCT-detected indeterminate lung nodules in 906 individuals with significant asbestos exposure was 8.5%, lower than many other CT studies. Clinically important incidental findings were found in 9.4%, predominantly related to lower respiratory tract inflammation. LDCT appears to effectively describe asbestos-related diseases and is likely to be an acceptable modality to monitor asbestos-exposed individuals.
Department of Diagnostic Imaging, Royal Perth Hospital, Perth, Western Australia, Australia.
Conor P
CP
Murray
Department of Diagnostic Imaging, Royal Perth Hospital, Perth, Western Australia, Australia.
Patrick M
PM
Wong
Department of Diagnostic Imaging, Royal Perth Hospital, Perth, Western Australia, Australia.
Joelin
J
Teh
School of Population Health, University of Western Australia, Perth, Western Australia, Australia.|Telethon Kids Institute, University of Western Australia, Subiaco, Western Australia, Australia.
Nick
N
de Klerk
Telethon Kids Institute, University of Western Australia, Subiaco, Western Australia, Australia.
Tim
0000-0003-3727-5131
T
Rosenow
School of Public Health, Curtin University, Perth, Western Australia, Australia.
Helman
H
Alfonso
School of Public Health, Curtin University, Perth, Western Australia, Australia.
Alison
A
Reid
School of Population Health, University of Western Australia, Perth, Western Australia, Australia.
Peter
P
Franklin
School of Population Health, University of Western Australia, Perth, Western Australia, Australia.|Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.|School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia.
A W Bill
AW
Musk
Department of Respiratory Medicine, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia. fraser.brims@uwa.edu.au.|School of Medicine and Pharmacology, University of Western Australia, Perth, Western Australia, Australia. fraser.brims@uwa.edu.au.|Institute for Respiratory Health, Perth, Western Australia, Australia. fraser.brims@uwa.edu.au.
Fraser J H
FJ
Brims
D000368:Aged; D001194:Asbestos / Q000009:adverse effects / Q000032:analysis; D005260:Female; D006801:Humans; D033162:Incidental Findings; D019570:Inhalation Exposure / Q000009:adverse effects / Q000032:analysis / Q000517:prevention & control; D017563:Lung Diseases, Interstitial / Q000453:epidemiology*; D008175:Lung Neoplasms / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010995:Pleural Diseases / Q000453:epidemiology*; D015995:Prevalence; D011314:Preventive Health Services / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods; D014904:Western Australia / Q000453:epidemiology
D001194:Asbestos
asbestos; multidetector computed tomography; pleural diseases; pulmonary nodule