GRPR and neoplasm: In agreement with the in vitro data, [64Cu]Cu-NOTA-PEG2-RM26 showed a tendency to higher uptake in the tumor (p = 0.7) and GRPR-expressing tissues (pancreas, small intestine, and stomach) at 3 h p.i. in comparison with [64Cu]Cu-NODAGA-PEG2-RM26.