Imaging proliferation of 18 F-FLT PET/CT correlated with the expression of microvessel density of tumour tissue in non-small-cell lung cancer

Purpose The aim of this study was to analyse the correlation between 18 F-labelled 3′-deoxy-3′-fluorothymidine ( 18 F-FLT) PET/CT proliferation images and tumour angiogenesis as reflected by intratumoral microvessel density (MVD) in non-small-cell lung cancer (NSCLC) to provide a noninvasive method to predict the response to antiangiogenic therapy. Methods A total of 68 patients with proven or suspected NSCLC underwent FLT PET/CT scans followed by surgery. PET/CT images were compared with pathology. Tumour proliferation was evaluated in terms of a Ki-67 labelling index (Ki-67 LI). MVD was determined using an anti-CD31 mAb (CD31-MVD), anti-CD34 mAb (CD34-MVD) and an anti-CD105 mAb (CD105-MVD) for each resected tumour. Results Tumour FLT maximum standardized uptake values (SUVmax) were significantly correlated with the Ki-67 LI and CD105-MVD ( r = 0.550 and 0.633, P = 0.000 and 0.000, respectively), but were only marginally correlated with the CD31-MVD and CD34-MVD ( r = 0.228 and 0.235, P = 0.062 and 0.054, respectively). The FLT PET false-negative patients had a longer median survival time than the FLT PET true-positive patients (log rank test, P = 0.012). The patients with a lower CD105-MVD had a longer median survival time than those with a higher CD105-MVD ( P = 0.046), while patients with a lower CD31-MVD and CD34-MVD did not have a longer median survival time than those with a higher value ( P = 0.438 and 0.187, respectively). Conclusion FLT PET/CT imaging correlated with tumour angiogenesis as reflected by CD105-MVD and prognosis, and may be helpful in assessing antiangiogenic therapy of NSCLC.