Feasibility study of ²²⁵Ac-PSMA-CY313 dosimetry in mCRPC patients using SPECT.

ABSTRACT:

Purpose

Actinium-225 (²²⁵Ac)-labeled prostate-specific membrane antigen (PSMA) radiopharmaceuticals represent a promising therapeutic approach for metastatic castration-resistant prostate cancer (mCRPC), yet clinical implementation remains limited by the absence of accurate dosimetric assessment methods. The complex decay chain and non-imaging alpha emissions of ²²⁵Ac pose substantial challenges for quantitative imaging. We aimed to evaluate the feasibility of quantitative single photon emission computed tomography (SPECT)-based dosimetry for ²²⁵Ac-PSMA-CY313 therapy by exploiting gamma emissions from daughter radionuclides francium-221 (²²¹Fr) and bismuth-213 (²¹³Bi).

Methods

Four mCRPC patients received 185.8 ± 11.7 µCi ²²⁵Ac-PSMA-CY313 and underwent multi-timepoint SPECT/

SUBMITTER: Zhang H 

PROVIDER: S-EPMC12858698 | biostudies-literature | 2025 Dec

REPOSITORIES: biostudies-literature