NPY and breast neoplasm: Small-animal PET studies with [Pra4([18F]FGlc),F7,P34]NPY (10) on MCF-7 breast tumor-bearing nude mice in direct comparison with a scrambled low-affinity peptide (11, Figure 1) revealed specific uptake of 10 in the MCF-7 tumor with increasing tumor-to-blood ratio from 1.2 to 2.4, a tumor retention of 76 % (45−90 min p.i.)and decreased kidney uptake compared to DOTA analogues of this peptide.