Comparison of Positron Emission Tomography Using 2-[18F]-fluoro-2-deoxy-D-glucose and 3-deoxy-3-[18F]-fluorothymidine in Lung Cancer Imaging

Background: The detection of solitary pulmonary nodules (SPNs) that may potentially develop into a malignant lesion is essential for early clinical interventions. However, grading classification based on computed tomography (CT) imaging results remains a significant challenge. The 2-[ 18 F]-fluoro-2-deoxy-D-glucose ( 18 F-FDG) positron emission tomography (PET)/CT imaging produces both false-positive and false-negative findings for the diagnosis of SPNs. In this study, we compared 18 F-FDG and 3-deoxy-3-[ 18 F]-fluorothymidine ( 18 F-FLT) in lung cancer PET/CT imaging. Methods: The binding ratios of the two tracers to A549 lung cancer cells were calculated. The mouse lung cancer model was established ( n = 12), and micro-PET/CT analysis using the two tracers was performed. Images using the two tracers were collected from 55 lung cancer patients with SPNs. The correlation among the cell-tracer binding ratios, standardized uptake values (SUVs), and Ki-67 proliferation marker expression were investigated. Results: The cell-tracer binding ratio for the A549 cells using the 18 F-FDG was greater than the ratio using 18 F-FLT ( P 18 F-FLT binding ratio ( r = 0.824, P 18 F-FDG imaging in xenografts was higher than that of 18 F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of 18 F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of 18 F-FLT for lung cancer were 71%, 79%, and 76%, respectively. There was an obvious positive correlation between the lung cancer Ki-67 expression and the mean maximum SUV of 18 F-FDG and 18 F-FLT ( r = 0.658, P r = 0.724, P Conclusions: The 18 F-FDG uptake ratio is higher than that of 18 F-FLT in A549 cells at the cellular level. 18 F-FLT imaging might be superior for the quantitative diagnosis of lung tumor tissue and could distinguish lung cancer nodules from other SPNs.