Delayed Nephrotoxicity After 225Ac-PSMA-617 Radioligand Therapy

177Lu-PSMA-617 radioligand therapy (RLT) has evolved as a suitable alternative to existing therapeutic options in patients with metastatic castration-resistant prostate cancer. With the emergence of α-emitters such as 225Ac, the efficacy of PSMA-RLT has further improved. Xerostomia and myelosuppression are common early treatment-emergent adverse events in patients receiving this therapy; however, data on long-term toxicity are relatively scarce. In this report, we describe a 76-year-old man with metastatic castration-resistant prostate cancer, who after having an initial excellent response to 2 cycles of 225Ac-PSMA-617 RLT, developed delayed nephrotoxicity in the form of tubulointerstitial nephritis.