Abstract:
Prostate-specific membrane antigen (PSMA), a type II glycoprotein, is highly
expressed in almost all prostate cancers. By playing such a universal role in the disease,
PSMA provides a target for diagnostic imaging of prostate cancer using positron emission
tomography/computed tomography (PET/CT). The PSMA-targeting ligand Glu-NH-CONH-
Lys-(Ahx)-HBED-CC (DKFZ-PSMA-11) has superior imaging properties and allows
for highly-specific complexation of the generator-based radioisotope Gallium-68 (68Ga).
However, only module-based radiolabeling procedures are currently available. This study
intended to develop a single vial kit solution to radiolabel buffered DKFZ-PSMA-11 with 68Ga. A 68Ge/68Ga-generator was utilized to yield 68GaCl3 and major aspects of the kit
development were assessed, such as radiolabeling performance, quality assurance, and
stability. The final product was injected into patients with prostate cancer for PET/CT imaging
and the kit performance was evaluated on the basis of the expected biodistribution, lesion
detection, and dose optimization. Kits containing 5 nmol DKFZ-PSMA-11 showed rapid,
quantitative 68Ga-complexation and all quality measurements met the release criteria
for human application. The increased precursor content did not compromise the ability of
68Ga-DKFZ-PSMA-11 PET/CT to detect primary prostate cancer and its advanced lymphaticand
metastatic lesions. The 68Ga-DKFZ-PSMA-11 kit is a robust, ready-to-use diagnostic
agent in prostate cancer with high diagnostic performance.
