A multicenter clinical trial on the diagnostic value of dual-tracer PET/CT in pulmonary lesions using 3′-deoxy-3′-18F-fluorothymidine and 18F-FDG

Some new radiotracers might add useful information and improve diagnostic confidence of F-18-FDG imaging in tumors. A multicenter clinical trial was designed to investigate the diagnostic performance of dual-tracer (F-18-FDG and 3'-deoxy3'-F-18-fluorothymidine [F-18-FLT]) PET/CT in pulmonary nodules. Methods: Fifty-five patients underwent dual-tracer imaging in 6 imaging centers using the same models of equipment and standardized protocols. The images were interpreted by a collective group of readers who were unaware of the clinical data. The diagnostic performance using either tracer alone or dual-tracers together, with or without CT, was compared. The histological diagnosis or clinical findings in a 12-mo follow-up period served as the standard of truth. Results: In 16 patients with malignant tumor, 16 with tuberculosis, and 23 with other benign lesions, the sensitivity and specificity of F-18-FDG and F-18-FLT were 87.5% and 58.97% and 68.75% and 76.92%, respectively. The combination of dual-tracer PET/CT improved the sensitivity and specificity up to 100% and 89.74%. The 3 subgroups of patients could be best separated when the F-18-FLT/F-18-FDG standardized uptake value ratio of 0.4-0.90 was used as the threshold. Conclusion: By reflecting different biologic features, the dualtracer PET/CT using F-18-FDG and F-18-FLT favorably affected the diagnosis of lung nodules.