Background and purpose: Integrin α

v

β

3

receptor plays an important role in promoting

sustaining and regulating the angiogenesis. It is overexpressed on neovascular endothelial ce

lls and tumor cells. RGD peptide specifically binds to integrin α

v

β

3

which could evaluate growth status and invasiveness of tumor. This study aimed to investigate the biodistribution in healthy KM mice and micro PET/CT imaging in U87MG tumor-bearing mice of

18

F-E[c(RGDfK)

2

]

. Methods:

18

F-E[c(RGDfK)2

]

was produced using an automated synthesis module via a simple one-step

18

F-labeling strategy of the precursor 4-NO

2

-3-TFMBz-E[c(RGDfK)

2

]

. The percentage activity of injection dose per gram of tissue (%ID/g) was calculated at 0.5

1

2

4 h post injection of the probe. Micro PET/CT images of U87MG tumor-bearing nude mice with or without

18

F-E[c(RGDfK)

2

]

blocking were acquired at each time point. Results: The labeling efficiency and radiochemical purity of

18

F-E[c(RGDfK)

2

]

were 10% and 98%

respectively.

18

F-E[c(RGDfK)

2

]

was excreted via renal route

with a high blood clearance. The other organs had backgroundlevel activity accumulation. At 1 h

the %ID/g of kidney

liver

intestine

muscle and blood was (1.02±0.16)%ID/g

(0.24±0.06)%ID/g

(0.35±0.03)%ID/g

(0.13±0.03)%ID/g and (0.11±0.03)%ID/g

18

F-E[c(RGDfK)

2

]

had initial high tumor uptake [(5.2±0.56)%ID/g

]

and good tumor-to-background contrast (5.36) at 1 h post injection. Tumor uptake for blocking group was lower than those without blocking

and T/M reduced to 1.57. Conclusion:

18

F-E[c(RGDfK)

2

]

appears a promising PET molecular imaging probe targeting integrin α

v

β

3

with high tumor uptake. It could be suitable for prognosis evaluation of integrin-positive tumor

selection of vascular targeting therapy and therapy effect monitoring.