Definition

A radioconjugate composed of a human prostate specific membrane antigen (PSMA)-targeting ligand, P3, labeled with the radioisotope gallium Ga 68, with potential use as a tracer for PSMA-expressing tumors during positron emission tomography (PET). Upon intravenous administration of gallium Ga 68 P3, the P3 moiety targets and binds to PSMA-expressing tumor cells. Upon binding, PSMA-expressing tumor cells can be detected during PET imaging. PSMA, a tumor-associated antigen (TAA) and type II transmembrane protein, is expressed on the membrane of prostatic epithelial cells and overexpressed on prostate tumor cells as well as a variety of other solid tumors.