The tumor localization of [64Cu]Cu-NOTA-trastuzumab Fab-PEG24-EGF bsRICs in these tumors with heterogeneous receptor expression was evaluated by PET and biodistribution studies and compared to tumors formed of SK-OV-3 cells or MDA-MB-468 cells that homogeneously express HER2 or EGFR, respectively. The gene discussed is EGFR; the disease is neoplasm.