Transferability of a two-strip method for the quality control of technetium-99m mercaptoacetyltriglycine ([Tc-99m]Tc-MAG3)

Objectives Technetium-99m mercapto-acetyl-triglycine ([Tc-99m]Tc-MAG3) is a radiopharmaceutical diagnostic agent used in nuclear medicine intended for the exploration of nephrological and urological disorders. Patient safety and reliability of this imaging procedure especially depend on the radiochemical purity (RCP) of the [Tc-99m]Tc-MAG3 preparation. Recently, the Summary of Product Characteristics (SPC) of NephroMAG, a kit dedicated to [Tc-99m]Tc-MAG3 preparation, proposed a two-strip thin layer chromatography (TLC) based quality control (QC) method. Also, Straub et al recently proposed another TLC based QC method. We sought to evaluate the transferability of these QC methods in our hospital radiopharmacy and compared them to our currently employed TLC method and radio-HPLC (high-pressure liquid chromatography) to select the most appropriate in the context of hospital radiopharmacy. Methods Ten consecutive [Tc-99m]Tc-MAG3 preparations were controlled using: HPLC combined with a radiodetector (radio-HPLC), a single strip TLC method (method 1) in current use in our centre, a two-strip TLC method described in the SPC (method SPC) and a two-strip TLC method (method 2) described by Straub et al. Quantitative results for the four tested QC methods were measured and compared in terms of RCP (%), sodium pertechnetate ([Tc-99m]TcO4 (-)) (%) and duration of analysis (min). Results RCP was significantly different between method SPC and radio-HPLC (p<0.001) and method 2 (p<0.001). Also, the percentage of [Tc-99m]TcO4 (-) was statistically different between the radio-HPLC and the method SPC (p<0.001), but not with the method 1 and method 2 group (p>0.05). The duration of analysis (min) was significantly different between the four QC procedures (p<0.001) with method 2 and method SPC being the quickest. Conclusions Our study showed it is possible to transfer and select a quick and reliable QC method for the preparation of NephroMAG kits in our centre. We therefore advise the widespread use of the method from Straub et al in hospital radiopharmacies.