CT scan procedure for lung cancer screening in asbestos-exposed workers.

In a meta-analysis by Ollier et al 1 on chest CT scan screening for lung cancer in asbestos-exposed workers in a recent issue of CHEST (June 2014), one source of heterogeneity was omitted: CT scan procedures. Among the seven studies included in the meta-analysis, slice thickness obtained with CT scans was heterogeneous. Not all CT scan procedures in the seven studies used thin slices. Most reported slice thicknesses were  5 mm. Th e exceptions described a 1-mm slice thickness but with reconstruction intervals of 10 mm, and another failed to report CT scan parameters ( Table 1 2 8 ). Th e importance of the article on lung cancer screening among smokers 9 was weakened by a protocol using a 10-mm slice thickness, previously described in the Early Lung Cancer Action Project (ELCAP). 10