Ex Vivo and In Vivo Tumor Accumulation, 18F-FDG and 64Cu-liposomes, cohort imaged 21 days after tumor implantation. Subgroup 1 did not undergo PET imaging as mice were sacrificed 0.5 hour after 18F-FDG injection. All values are reported as mean ± SEM (n = 8 tumors). Values are average %ID/cc, with total tumor %ID in parenthesis