Diagnostic value of solitary pulmonary nodules using (99)Tcm-3P4-RGD2 scintigraphy

Objective To investigate the value of 99Tcm-HYNIC-(poly-(ethylene glycol),PEG) 4-E (PEG4-c(RGDfK))2 (99Tcm-3P4-RGD2) SPECT imaging in the diagnosis of SPN by visual and semiquantitative analysis.Methods Twenty-one patients (13 men,8 women; age range 37-77 (58±11) years)with SPN observed on CT were analyzed prospectively.All patients underwent SPECT imaging after administration of 99Tcm-3P4-RGD2 with a dose of (939 ± 118) MBq.The gold standard was based on the histopathological diagnosis of the surgical samples from all recruited patients.The diagnostic performance of CT,SPECT visual and semiquantitative analysis was compared and analyzed with ROC curves.Immunohistochemistry was performed in part of the samples to obtain the information of integrin αvβ3 expression.Informed consent was obtained from all patients.Application of a new radiopharmaceutical was permitted and approved by the local independent Ethics Committee and the Institutional Review Board of the China-Japan Union Hospital.One-way analysis of variance,two-sample t test were used with SPSS 13.0.Results Among the 21 SPN patients,15 cases (71％) were diagnosed as malignant,and the other 6 (29％) were benign.T/NT ratio in malignant SPN was higher than that in benign SPN (1.87 ± 0.39 vs 1.41 ± 0.65),but with no statistical significance (t =2.01,P ＞ 0.05).The sensitivities for CT,SPECT visual and semiquantitative analysis were 80％ (12/15),100％ (15/15) and 100％ (15/15) respectively,and the specificity were all 4/6.The AUC was 0.811 (95％ CI 58％-95％) for CT,0.833 (95％ CI 61％-96％) for SPECT and 0.844 (95％ CI 62％-96％) for T/NT ratios,which showed no statistical significance (F =0.83,P ＞0.05).Immunohistochemistry confirmed αvβ3 expression in both the malignant and benign nodules which had uptake of 99Tcm-3P4-RGD2 in SPECT imaging.Conclusion SPECT visual and semiquantitative analysis with 99Tcm-3P4-RGD2 appears to have high sensitivity and consistency in diagnosis of SPN. Key words: Lung neoplasms ;  Technetium;  Arg-Gly-Asp;  Tomography, emission-computed,single-photon;  Tomography, X-ray computed