Synthesis and Quality Control of 68Ga-PSMA PET/CT Tracer used in Prostate Cancer Imaging and Comparison with 18F-Fluorocholine as a Reference Point

The clinical usefulness of choline-based PET/CT tracers (11C-Choline and 18F-Fluorocholine) in prostate cancer recurrence imaging is well established. However, choline uptake is not increased in a considerable number of patients. In 2012 was proposed the new prostate-specific PET radio ligand PSMA 68Ga-labeled, with superior sensibility and specificity than choline-based tracers. This work has as aim to describe the procedures for labeling PSMA ligands and its quality control procedures as a medicinal product and its comparison with 18F-fluorocholine synthesis and quality control procedures. Both the manual and automated synthesis methods for 68Ga-PSMA were taken into account and set of a quality control methods based mainly on chromatographic and spectrometric methods used to determine chemical, radiochemical and radionuclide purity. PSMA synthesis time, dose of radiation to operators and quality control protocols were compared to choline. Finally, some images of PET performed with 18F-Fluorocholine and 68Ga-PSMA in the same patients were showed.