FOLH1 and neoplasm: More importantly, the PET results from [<sup>43</sup>Sc]Sc-PSMA-617 PET were highly correlated with the therapeutic response from [<sup>47</sup>Sc]Sc-PSMA-617, showing that <sup>43</sup>Sc PET data can predict therapeutic outcomes in individual animals from <sup>47</sup>Sc agents, even in animals sharing a genetic background and implanted with tumors from the same cell line.<h4>Conclusions</h4>Two chemically identical, PSMA-targeting radioscandium pharmaceuticals demonstrated <i>in vivo</i> stability, specificity and retention in PSMA+ tumor models.