Objective:
To investigate the clinical significance of low-dose CT (LDCT) in coal mine workers with relatively long working years.
Methods:
A total of 907 coal mine workers with ≥20 working years were enrolled, among whom there were 863 male and 44 female workers with a mean age of 49.5 years. Digital radiography (DR) was performed for these workers in 2013, and LDCT was performed for three consecutive years from 2014 to 2016.
Results:
A total of 32 workers were found to have lung nodules by DR in 2013, while in 2014, 269 workers were found to have non-calcified lung nodules by LDCT, and there was a significant difference in the number of workers with lung nodules (χ2=233.73, P<0.005) . There was also a significant difference in the detection rate of nodules between the workers with different working years of dust exposure (χ2=6.648, P=0.00) . The male workers had a significantly higher detection rate of nodules than the female workers (χ2=5.690, P=0.017) . There was no significant difference in the number of nodules between workers with different types of work (χ2=16.985, P=0.05) . There were 443 lung nodules in total, among which 71.56% were solid nodules and 55.75% had a size of ≤4mm; malignant nodules were confirmed by surgery in 6 (0.66%) of the 907 workers after baseline LDCT. LDCT reexamination in 2015 and 2016 found new nodules in 8 workers and enlarged nodules in 3 workers, and there was no significant change in the number of nodules with a size of ≤4 mm.
Conclusions
It is necessary to perform high-risk population screening for coal mine workers by LDCT. The follow-up strategies for nodules with a size of ≤4mm are the same as those for negative results; annual reexamination is recommended for nodules with a size of >4-8 mm, and clinical treatment should be considered for nodules with a size of >8 mm.