Combined use of thin-section CT and 18F-FDG PET/CT for characterization of solitary pulmonary nodules

REN Yunyan; LI Youcai; WU Hubing; WANG Quanshi; HAN Yanjiang; ZHOU Wenlan; LI Hongsheng; WANG Zhen; MOHAMMED Shah Alam

doi:10.3969/j.issn.1673-4254.2017.03.01

Abstract：Objective To investigate whether fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) combined with thin-section CT improves the diagnostic performance for solitary pulmonary nodules (SPNs).Methods A total of 267 patients underwent examinations with 18F-FDG PET/CT and thin-section CT for evaluating the SPNs with undetermined nature,which was further confirmed by pathological examination or clinical follow-up.The performance of two diagnostic criteria based on findings in PET/CT alone (Criterion 1) and in PET/CT combined with thin-section CT (Criterion 2) were compared.Results Thin-section CT provided greater diagnostic information for SPNs in 84.2％ of the patients.Compared with Criterion 1,the diagnosis based on Criterion 2 significantly increased the diagnostic sensitivity (80.4％ vs 91％,P＜0.01) and accuracy (76.4％ vs 87.2％,P＜0.01) for lung cancer.The lesion size and the CT features including lobulation,air bronchogram,and feeding vessel,but not SUVmax,were all helpful for characterizing non-solid SPNs.Thin-section CT rectified diagnostic errors in 50％ (20/40) of the cancerous lesions,which had been diagnosed as benign by PET due to their low metabolism.For non-solid SPNs,Criterion 2 showed a significantly higher diagnostic sensitivity than Criterion 1 (90.0％ vs 40.0％,P=0.000) but their diagnostic specificity were comparable (75.2％ vs 58.3％,P=0.667).For solid nodules,the use of thin-section CT resulted in no significant improvement in the diagnostic performance (P＞0.05).Conclusion The combination of PET/CT and thin-section CT creates a synergistic effect for the characterization of SPNs,especially non-solid nodules.