Figure 4.

I-124 Imaging of 33-NIS-Infected Tumor Cells In Vivo

CF33-hNIS is tropic for tumor cells, and CF33-hNIS-infected tumor cells take up I-124 and are thus imageable using PET/CT. HCT116 and HT29-derived flank xenografts were implanted in nude mice using 3 × 10⁶ cells per tumor. When tumor volume reached a predetermined 150 mm³, mice received intratumoral (i.t.) injections of PBS, CF33-FLuc, or CF33-hNIS at a dose of 10⁴ PFU. (A) Comparisons of PET/CT images on day 7 across treatment and control groups 2 h following i.v. injection of 200 μCi of I-124. (B) images of a single mouse over time. Note I-124 uptake in right-sided tumor on day 22 despite injection of only left-sided tumor. NIS, sodium iodide symporter; PFU, plaque-forming units.