[68Ga]Ga-13.1b

[68Ga]Ga-13.1b is an experimental radiopharmaceutical agent developed for the diagnostic imaging of prostate cancer. It belongs to a series of DOTA-conjugated ligands designed to target Prostate-Specific Membrane Antigen (PSMA), also known as glutamate carboxypeptidase II (GCPII), which is significantly overexpressed in prostate adenocarcinoma. The molecule consists of a PSMA-binding motif linked to a DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) chelator, which complexly binds the positron-emitting radioisotope Gallium-68 (68Ga). In preclinical evaluations, this series of conjugates demonstrated high binding affinity and internalization in PSMA-positive cell lines (such as LNCaP). While its sibling conjugate [68Ga]Ga-13.1c was highlighted for superior kidney-to-tumor ratios, [68Ga]Ga-13.1b represents a specific structural variant within this optimization effort aimed at improving the sensitivity and specificity of PET/CT imaging in prostate cancer patients.