EGF and neoplasm: These [64Cu]Cu-NOTA-trastuzumab Fab-PEG24-EGF bsRICs imaged s.c. HER2-negative/EGFR-positive MDA-MB-468, HER2-positive/EGFR-positive MDA-MB-231/H2N, or HER2-positive/EGFR-negative SK-OV-3 tumors in non-obese diabetic severe combined immunodeficiency (NOD-SCID) mice at 24 or 48 h p.i. An important finding was that the PEG24 linker prolonged the residence time in the blood compared to bsRICs without a PEG24 linker, which may contribute to higher tumor uptake of bsRICs compared to monospecific [64Cu]Cu-NOTA-trastuzumab Fab or [64Cu]Cu-NOTA-EGF.