In vivo PET/CT Imaging of Orthotopic Pancreatic Tumor

Example 10

In vivo PET/CT imaging was conducted in Balb/c mice. One week after the orthotropic implantation of 1×10⁶ luciferase-transfected KPCP cancer cells into the pancreas of Balb/c mice, the mice were used for PET imaging. Either the CNGRC-(⁶⁸Ga)NOTA-RGDyK heterodimer (“CNGRC” disclosed as SEQ ID NO: 1), (⁶⁸Ga)NOTA(CNGRC) (“CNGRC” disclosed as SEQ ID NO: 1), or (⁶⁸Ga)NOTA(RGDyK)] were injected into the bloodstream via tail vein injection. Blocking studies were conducted for the heterodimer studies by co-injecting 100× of CNGRC (SEQ ID NO: 1) and RGDyK. Small animal PET/CT was performed at 1 hour post injection of tracers (FIGS. 15A-15C). The heterodimer CNGRC-(⁶⁸Ga)NOTA-RGDyK (“CNGRC” disclosed as SEQ ID NO: 1) showed improved in in vivo performance (such as longer blood retention, better tumor/non-tumor ratios) (FIG. 15A). Uptakes of the RGD-NGR heterodimer in muscle, blood, liver, spleen, kidney, pancrease, and orthotopic tumor were 0.10% ID/g, 0.10% ID/g, 1.8% ID/g, 1.10% ID/g, 2.2% ID/g, 0.36% ID/g, and 1.4% ID/g, respectively.