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The prostate-specific membrane antigen (PSMA) represents an ideal biomarker for molecular imaging. Various PSMA-targeted radioligands are available for prostate cancer imaging. In this study, labelling of PSMA I&T with 68 Ga as well as validation of the radiochemical purity of the synthesis product by reverse phase radio HPLC method are intended. Since the standard procedure for the quality control (QC) was not available, definition of chemical and radiochemical purity of 68 Ga-PSMA I&T was carried out according to Q2 (R1) ICH guideline. The standard QC tests were analyzed with Scintomics 8100 radio-HPLC system equipped with a radioactivity detector. The method was evaluated in terms of linearity, precision and accuracy, LOQ, robustness parameters and specificity. To assess the radiochemical and chemical purity of 68 Ga-2 PSMA I&T, the developed method was validated to apply safely to patients. An excellent linearity was found between 1 μg/mL and 30 μg/mL, with a limit of detection and limit of quantitation of 0.286 μg/mL and 0.866 μg/mL, respectively for 68 Ga-PSMA I&T. The recovery was 96.8 ± 3.8%. The quality control of the final product was performed many times with validated radio-HPLC method found comply with ICH requirements, thus demonstrating the accuracy and robustness of the method for routine clinical practice.

: Gallium-68 is an ideal research and hospital-based PET radioisotope. The uptake mechanism of Gallium citrate is a combination of specific and non-specific processes, for example, vasodilatation, increased vascular permeability, plasma transferrin binding and lactoferrin and siderophores. In this study, by applying the 68Ge/68Ga generator product, a simple technique for the synthesis and quality control of 68Ga-citrate was introduced and was followed by preliminary animal studies. The synthesis of 68Ga-citrate was performed with a cationic method using the Scintomics automated synthesis system (Scintomics GmbH GRP module 4V). Since the standard procedure for quality control (QC) was not available, the definition of chemical and radiochemical purity of 68Ga-citrate was carried out according to the ICH Q2(R1) guideline. The standard QC tests were analysed with Scintomics 8100 radio-HPLC system equipped with a radioactivity detector. In this study, a New Zealand rabbit weighing 2520 g was used for PET/CT images. 68Ga-citrate synthesis was performed by a cationic method without using organic solvents. The labelling efficiency was found to be >98%. The HPLC method used to assess the radiochemical purity of 68Ga -citrate was validated as rapid, accurate and reproducible enough to apply it to patients safely. The physiological distribution of 68Ga-citrate was investigated in a healthy rabbit. The blood pool, liver, spleen, kidneys and growth plates were the most common sites of 68Ga-citrate involvement.

This study was designed to evaluate the accuracy of detecting pulmonary embolism (PE) using the Technegas SPECT/CT combined with 68Ga PET/CT in a rabbit model. One hour after artificial PE (n = 6) and sham (n = 6) models were created, Technegas SPECT/CT ventilation and 68Ga-MAA PET/CT perfusion scan (V/Q scan) were performed. Ventilation imaging was performed first on all cases. Technegas SPECT/CT and 68Ga-MAA PET/CT images were evaluated by a nuclear medicine physician who recorded the presence, number, and location of PE on a per-lobe basis. The sensitivity, specificity, and accuracy of Technegas SPECT/CT and 68Ga-MAA PET/CT for detecting PE were calculated using a histopathological evaluation as a reference standard. A total of 60 lung lobes were evaluated in 12 rabbits, and PE was detected in 20 lobes in V/Q scans and histopathological analysis. The overall sensitivity, specificity, and accuracy were 100%, 100%, and 100%, respectively, for both the Technegas SPECT/CT and 68Ga-MAA PET/CT V/Q scans. Technegas/68Ga-MAA V/Q scans have good sensitivity, specificity, and accuracy in the detection of PE in this animal model study.

Background/aim Especially suitable for PET due to its nuclear physical and radiochemical properties, the positron emitter Gallium-68 (68Ga) occurs by electron capture from Germanium-68 (68Ge). In such a radionuclide generator, the germanium is bound to an insoluble, inert column matrix and forms a secular radioactive balance with 68Ga obtained in the hour. As a result of the limited radiochemical selectivity of the elution process, the eluate obtained is basically contaminated with the main nuclide traces, so that the eluate becomes a mixture of 68Ga and 68Ge radionuclides. Also, the generator eluate contains a number to metal cations that reduce specific radioactivity and can compete with 68Ga. The presence of toxic metal that can be found in the eluate carries the risks of contamination at every step from the production of generators to radiopharmaceutical production. Materials and method In our study, by collecting the eluate of the 68Ge/68Ga generators used with different identities in different centers in Turkey, we report comparative analysis of metal contamination in the generator eluate. The eluates of 68Ge/68Ga generators to five different identities were collected. Eluates were analyzed by inductively coupled plasma–mass spectrometry. Results and Conclusion As a result, each generator contains metallic impurities different from its certificate.

In this study, quality control parameters such as radiochemical yield, radiochemical purity, and in vitro stability of gallium (68Ga)‐prostate‐specific membrane antigen‐11 ([68Ga]Ga‐PSMA11) radiopharmaceutical obtained in a research laboratory with three different synthesis algorithms were evaluated and compared. Gallium (68Ga) chloride precursor to be used in labeling in all three methods was obtained by using ITG brand 68Ge/68Ga generator. The first method for the [68Ga]Ga‐PSMA11 radiopharmaceutical was performed with the automated synthesis module, which is widely used in clinical practice. Its radiochemical yield, quality assurance, and stability met expectations. Radiolabeling success, suitability of quality control parameters, and in vitro stability of [68Ga]Ga‐PSMA11 radiopharmaceutical performed with ANMI kit were examined. The final product showed success in 68Ga‐complexation kinetics. All quality control criteria performed met the expectation for clinical applications. Direct cold labeling of PSMA11 ligand with sodium bicarbonate buffer was examined. Results were similar to the ANMI kit. Considering that all three methods are successful in radiochemical labeling, labeling with NaHCO3 buffer shows the labeling preference when we choose the cheap, practical, and easy labeling option.