TY - JOUR T1 - <sup>225</sup>Ac-PSMA-617 for PSMA-Targeted α-Radiation Therapy of Metastatic Castration-Resistant Prostate Cancer JF - Journal of Nuclear Medicine JO - J Nucl Med SP - 1941 LP - 1944 DO - 10.2967/jnumed.116.178673 VL - 57 IS - 12 AU - Clemens Kratochwil AU - Frank Bruchertseifer AU - Frederik L. Giesel AU - Mirjam Weis AU - Frederik A. Verburg AU - Felix Mottaghy AU - Klaus Kopka AU - Christos Apostolidis AU - Uwe Haberkorn AU - Alfred Morgenstern Y1 - 2016/12/01 UR - http://jnm.snmjournals.org/content/57/12/1941.abstract N2 - Prostate-specific membrane antigen (PSMA) is a promising target in prostate cancer. Recently, we started the first-in-human treatment with an α-radionuclide–labeled PSMA ligand. Although the case series is still ongoing, we here report in advance about two patients in highly challenging clinical situations who showed a complete response to 225Ac-PSMA-617 therapy. Methods: 68Ga-PSMA-11 PET/CT validated the presence of the PSMA-positive tumor phenotype. A 100-kBq activity of 225Ac-PSMA-617 per kilogram of body weight was administered bimonthly. Prostate-specific antigen response and hematologic toxicity were measured at least every 4 wk. Restaging was performed with 68Ga-PSMA-11 PET/CT. Results: Both patients experienced a prostate-specific antigen decline to below the measurable level and showed a complete response on imaging. No relevant hematologic toxicity was observed. Xerostomia was the only mentionable clinical side effect. Conclusion: Targeted α-therapy with 225Ac-PSMA-617, although still experimental, obviously has strong potential to significantly benefit advanced-stage prostate cancer patients. ER -