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-[18F]-fluoro-2-deoxy-D-glucose (18F-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 18F-FDG and 3-deoxy-3-[18F]-fluorothymidine (18F-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 18F-FDG was greater than the ratio using 18F-FLT (P < 0.05). The Ki-67 expression showed a significant positive correlation with the 18F-FLT binding ratio (r = 0.824, P< 0.01). The tumor-to-nontumor uptake ratio of 18F-FDG imaging in xenografts was higher than that of 18F-FLT imaging. The diagnostic sensitivity, specificity, and the accuracy of 18F-FDG for lung cancer were 89%, 67%, and 73%, respectively. Moreover, the diagnostic sensitivity, specificity, and the accuracy of 18F-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 18F-FDG and 18F-FLT (r = 0.658, P< 0.05 and r = 0.724, P< 0.01, respectively). CONCLUSIONS: The 18F-FDG uptake ratio is higher than that of 18F-FLT in A549 cells at the cellular level. 18F-FLT imaging might be superior for the quantitative diagnosis of lung tumor tissue and could distinguish lung cancer nodules from other SPNs.

Analysis of Myocardial (18)F-FDG Uptake by PET/CT in the Patients with Different Dialectically Classified Coronary Heart Diseases (CHD).

To quantify myocardial glucose metabolism by (18)F-FDG PET/CT in patients that have coronary heart disease (CHD) according to traditional Chinese medicine classification. Ninety patients with CHD were enrolled and were categorized into three groups. All patients underwent PET-CT examination for (18)F-FDG uptake quantification. In group A, the radioactive signals were weak in multiple segments in 27 cases (90 %). One case had no visualization and two had normal visualization (mean SUV = 4 ± 0.6). In group B, the radioactive signals were in some local areas in eight cases (26.7 %). Twenty cases had an overall increase in signal density (SUV ≥ 8) (66.7 %). One case had no visualization, and one case had normal visualization (mean SUV 4 ± 0.6). In group C, 23 cases had no visual or a weak visual (SUV ≤ 2 ± 0.3) (76.7 %). Seven cases had segmental weak signals or signal defects. Different types of CHD demonstrate different metabolisms of myocardium glucose. It is necessary to dialectically classify CHD and apply differential treatment.