Clinical Application Of ¹⁸F-FDG And ¹⁸F-FLT In Diagnosis Of Lung Cancer

ObjectiveIn order to enhance the diagnostic efficiency of lung cancer,PET/CT imaging of ¹⁸F-FLT,a tracer that reflects proliferation,was used to complement ¹⁸F-FDG. To investigate the applicational value of the tracer ¹⁸F-FLT in diagnosing lung cancer,and then to search for a fast,accurate and scientific diagnostic proposal for lung cancer,we compared the sensibility,specificity and accuracy of ¹⁸F-FDG, ¹⁸F-FLT PET/CT and the dual-tracer imaging.Materials and MethodsThirty-eight cases undergoing dual-tracer imaging of ¹⁸F-FDG and ¹⁸F-FLT were collected by us in a randomized,standardized and prospective trial.The imagings were read in a blind collective way.Histological diagnosis or clinical findings in a long term follow-up served as the standard of truth.Then the diagnostic efficiency of all the detectings were analyzed and compared.After the tumor resection through the surgery,the tumor proliferating fos-related antigen Ki-67 index was detected through immunohistochemistry and then the associativity between the tumor proliferation and the two tracers were compared.Results1,The sensitivity,specificity and accuracy of ¹⁸F-FDG-PET/CT was 84.6% (22/26),66.7%(8/12) and 78.9%(30/38).2,The sensitivity,specificity and accuracy of ¹⁸F-FLT PET/CT was 69.2% (18/26),91.7%(11/12) and 76.3%(29/38).3,The sensitivity,specificity and accuracy of dual-tracer imaging was 96.2% (25/26),100%(12/12) and 97.4%(37/38).Dual-tracer PET/CT was proved to be the best proposal to diagnose pulmonary nodules comparing with single tracer,for it is more sensitive than ¹⁸F-FLT(P<0.05),more specific than ¹⁸F-FDG(P<0.05) and more accurate than any tracer.Dual-tracer PET/CT improved the diagnostic sensitivity from 69.2%-84.6%to 96.2%,and specificity from 66.7%-91.7%to 100%,and accuracy from 76.3%-78.9%to 97.4%in comparison with the single tracer imaging.The best separation of malignancies and benign lung tumors was achieved when FLT/FDG SUV ratio 0.4-0.9 was used as the threshold.4,The detection rate for the dual-tracer imaging to detect metastatic lymph nodes was 75%(3/4),and the diagnose accordance rate was 87.5% (35/40).5,The maximal standardized uptake value(SUVmax) of both tracers was correlated with Ki-67,and the contiguous coefficient of ¹⁸F-FLT was higher than ¹⁸F-FDG(0.81 and 0.67,P<0.01).ConclusionThe combination of ¹⁸F-FDG and ¹⁸F-FLT PET/CT imagings may overcome limitations of the single imaging and produce a complementary effect.Comparing between the two single imaging,we found that the dual-tracer imaging can improve the diagnostic efficiency obviously and create active influences clinically.