PLAUR and neoplasm: At 1 h p.i., some non-specific tumor accumulation of R3b23-GEM-[99mTc]Tc(CO)3-IRDye800CW was still present, but the difference between the bimodal labeled uPAR and R3b23 sdAb became more evident at 4 h p.i. with tumor values of respectively 0.51 ± 0.07%ID/cc and 0.33 ± 0.01%ID/cc (p*<0.05), based on quantitative analysis of SPECT/CT images (Figures 4C, E).