Because of the longer half-life of 177Lu, which facilitates in vivo studies at later time points, 177Lu-PSMA-I&F was selected to determine the general biodistribution and clearance kinetics of PSMA-I&F–based ligands in non–tumor-bearing SCID mice at 1 and 6 h after injection (Table 2). Here, FOLH1 is linked to neoplasm.