Operational and clinical evaluation of (Mo-99)/(Tc-99m)-TCM-autosolex generator at hospital radiopharmacy center

Shortage of high specific activity (HSA) Mo-99 used in producing Mo-99/Tc-99m alumina column generator for obtaining clinical grade sodium pertechnetate (Tc-99m) provided the necessary impetus to develop a closed, shelf-shielded, computer-interfaced autosolex generator for producing Tc-99m from low specific activity (LSA) Mo-99-based methyl ethyl ketone (MEK) solvent extraction technology. This study is aimed to evaluate the operational and clinical efficacy of autosolex generator at hospital radiopharmacy center. The evaluation is carried out by labeling different TCKs (cold kit of Tc-99m radiopharmaceutical) with Tc-99m and subsequently using the agents in routine scintigraphic imaging. Separation is based on difference in relative conductivity of two phases while MEK solvent extraction technology is used. Labeling, quality control, and scintigraphic imaging were performed as per standard procedures. Operational efficacy was evaluated by extracting Tc-99m from autosolex using three different batch size of LSA Mo-99 (200 (n = 7), 500 (n = 16), and 750 mCi (n = 3)) with extraction yield of 80% ± 5% (n = 96). All batches radiochemical purity (RCP) >98%, pH: 6.5, Mo-99 breakthrough <0.010%, Mo and Al concentration <10 µg/ml, and MEK levels <0.1%. All batches complies sterility and EL <5 EU/ml. All extracted Tc-99m batches labeled with Hynic-Toc, HSA-NC, methoxy isobutyl isonitrile, ubiquicidin, TRODAT along with other TCKs. RCP for all these Tc-99m-labeled radiopharmaceuticals (Tc-99m-Rps) were >95% (n = 146) except >90% for Tc-99m-TRODAT. All these labeled Tc-99m-Rps used for routine scintigraphic imaging in 355 patients. Good signal to noise ratio with proper clearance observed in all patients. Clinical grade Tc-99m could be successfully sourced from autosolex and be efficiently used in labeling of various TCKs. Clinically interpretable scintigraphic images obtained with Tc-99m-Rps prove the operational and clinical efficacy of Tc-99m from the generator for use in hospital radiopharmacy settings. (author)