Definition

A radioconjugate composed of an urea-based human prostate-specific membrane antigen (PSMA)-targeting ligand, conjugated to the gamma-emitting radioisotope technetium Tc 99m, with potential use as a tracer for PSMA-expressing tumors using single photon emission computed tomography/computed tomography (SPECT/CT). Upon intravenous administration of the technetium Tc 99m trofolastat, the trofolastat moiety targets and binds to PSMA-expressing tumor cells. Upon internalization, PSMA-expressing tumor cells can be detected during SPECT/CT imaging. PSMA, a tumor-associated antigen and type II transmembrane protein, is expressed on the membrane of prostatic epithelial cells and overexpressed on prostate tumor cells.