Therefore, the objective of this study was to perform integrated dosimetry, quantify the therapeutic index (TI), and establish dose-response relationships for the tumor control and organ toxicity of <sup>225</sup>Ac-PSMA-617 in a PSMA-positive xenograft model.<h4>Methods</h4>In male nude mice bearing C4-2 xenografts, a dosimetry group (n = 32) received 5 kBq <sup>225</sup>Ac-PSMA-617 for multi-time-point biodistribution. This evidence concerns the gene FOLH1 and neoplasm.