Differentiation of histological subtypes in lung cancer with 18F-FDG-PET 3-point imaging and kinetic analysis

The purpose of this study was to evaluate differences in histological subtypes of lung cancer using (18)F-FDG-PET 3-point imaging and kinetic analysis. Subjects comprised 44 patients with histologically proven lung cancer (squamous cell carcinoma (SCC), n=18; well-differentiated adenocarcinoma (WDA), n=9; poorly/moderately differentiated adenocarcinoma (non-WDA), n=17) who underwent (18)F-FDG-PET/CT examinations at 1, 2 h and 3 h after injection of 185 MBq of (18)F-FDG, approximately. Mean standardized uptake value (SUV) in each lesion was measured at each time point and the increase rate of SUV (IR_SUV) was calculated. SUV and IR_SUV were compared among the 3 groups. In addition, to estimate differences in kinetic parameters for each group, kinetic analysis based on a 3-compartment model was performed. Our results showed SUV differed significantly at every time point among the 3 groups. IR_SUV between 2 and 3 h post-injection (IR_SUV (2-3)) differed significantly among the 3 groups, while both IR_SUV(1-3) and IR_SUV(1-2) were significantly higher in SCC than in WDA. In kinetic analyses, both K1 and k3 showed significant differences among the 3 groups, with highest values in SCC and lowest in WDA. In conclusion, (18)F-FDG-PET 3-point imaging and kinetic analysis enabled the differentiation of histological subtypes in lung cancer, arising from differences in glucose transporter density and enzymatic activity of hexokinase.