FOLH1 and neoplasm: In this study, we report the efficacy and safety of [225Ac]Ac-PSMA-617 augmented [177Lu]Lu-PSMA-617 RLT in 177Lu-naive mCRPC patients with poor prognosis, namely, the presence of visceral metastases, high total tumor burden with diffuse bone metastases or rapid PSA increase (DT < 2 months).