Effect of Residual Volume in a Three-way Stopper and a Syringe on Actual Dose of Radiopharmaceuticals: Effect of Different Three-way Stoppers and Washing

Abstract

The purpose of this study were to evaluate the residual volume of radiopharmaceuticals in the three-way stopper and syringe used during radiopharmaceutical administration and the effect of washing. The three-way stoppers were a top injector tube, a top three-way stopper, and a Nipro three-way stopper with a needle. Sodium pertechnetate [ 99m Tc] injection ( 99m TcO 4 −) was used to compare the residual volume of radiopharmaceuticals in the three-way stopper and syringe without and with washing. Clinically, 137 patients who underwent cerebral blood flow scintigraphy, dopamine transporter scintigraphy, and bone scintigraphy were included. N-isopropyl-p-[ 123 I]iodoamphetamine ( 123 I-IMP), 123 I-N-ω-fluoropropyl-2β-carboxymethoxy-3β-(4-iodophenyl)nortropane ( 123 I-FP-CIT), and 99m Tc-methylene diphosphonate ( 99m Tc-MDP) were used to compare the residual volume of radiopharmaceuticals in the three-way stopper and syringe without and with washing. The residual volume depended on the type of three-way stopper and radiopharmaceutical used. The residual volume could be reduced by washing, but the effect depended on the type of three-way stopper and radiopharmaceutical used. The residual volume of radiopharmaceuticals in three-way stoppers and syringes can be determined and subtracted to achieve more accurate dose control.