[Necessity of radiopharmaceutical control and vigilance]

A recent problem with radiopharmaceutics in Val-de-Grâce hospital proves the necessity of a control. Using of the 99mTc (Hydroxy-methylene diphosphonate [HMDP] skeletal image we got a kidney scintigraphic images instead of the expected skeleted. The investigation of the occurrences has rapidly shown no possible confusion: At the day of failed examination, only 99mTc microspheres (target: Lung), methoxy-isobutyl-isonitrile, MIBI (target: heart) and 99mTc Phytate (target: Reticulo-Endothelial System) were used. Radioactivity control of 99mTc generator was conformable and labelled efficiency of the whole of HMDP assays were satisfying. This test is only an approach of radiochemical purity and was not adequate here. The renal image had suggested a chelate use. Accordingly, we have realized the Pharmacopoeia identification of DTPA with dimethyl-glyoxime-Ni, HMDP standards, DTPA (diethylene-triamino pentacetate), and HMDP residues from the vials used on the incident's day. It has been shown that residues of HMDP contain, like DTPA, but not like HMDP standards, a nickel chelating system. This proves a substitution of compound unknown to medical users.