KDR and neoplasm: In vivo PET imaging in lung cancer xenografts (HCC4006 and A549 models) showed high tumor uptake (~9.5 ± 2.2 %ID/g at 48 h p.i. in HCC4006 and 2.2 ± 0.7 %ID/g in A549), correlating with VEGFR-2 expression levels.