Abstract
Smokers and subjects with chronic obstructive pulmonary disease (COPD) have neutrophilic inflammation in peripheral airways. Activated neutrophils are known accumulate 18F-fluorodeoxyglucose (18FDG). The aim of this study was to examine if inflammation in the lung in smokers can be detected with 18FDG and combined positron emission tomography/computed tomography (PET/CT).
We recruited 22 current smokers and 23 never-smokers among subjects referred for diagnosis or staging of cancer with and 18FDG and PET/CT. Subjects with focal abnormalities in 18FDG lung uptake or CT were excluded. Other exclusion criteria were diabetes and suspicion of infection or interstitial lung disease. The right lung was segmented in the CT image and lung density measured. 18FDG uptake was measured in standardised uptake values in the corresponding volume and corrected for lung density.
There were no significant differences in lung uptake of 18FDG or lung density between smokers and never-smokers (0.49 ± 0.11 vs. 0.49 ± 0.10 and -772 ± 56 HU vs. -750 ± 50 HU, respectively). When corrected for lung density, lung uptake of 18FDG was nine per cent higher in current smokers than in never-smokers (2.00 ± 0.21 vs. 1.84 ± 0.20, p<0.05).Increased uptake of 18FDG in lung tissue in current smokers relative to never-smokers probably indicates inflammation in peripheral airways. Measurements of 18FDG uptake in the lung may be useful for studies of the pathophysiology of airways disease in COPD and the relation between airway and systemic inflammation.
- © 2012 ERS
