Validation of a new protocol for ¹⁸F-FDG infusion using an automatic combined dispenser and injector system

In nuclear medicine, radiopharmaceuticals are usually administered in unit doses partitioned from multi-dose vials. The partitioning typically takes place in a radiopharmacy, depending on local practice. Automatic, as opposed to manual, partitioning and administration should reduce radiation exposure of the personnel involved, improve the accuracy of the administration and mitigate contamination. This study set out to verify and validate the (18)F-fluorodeoxyglucose (FDG) administration procedure performed using Intego (MEDRAD, Inc., Warrendale, PA, USA), a combined dispenser and injector system. We considered maintenance of sterility and the system's potential to improve, with respect to the manual procedure, the accuracy of net administered (18)F-FDG radioactivity in patients and the radiation protection of operators.

A media-fill procedure was used to assess whether sterility is maintained during use of the Intego system. Simulating a typical working day's setup and use of the system, we investigated the accuracy of the net administered (18)F-FDG activity obtained with Intego versus the manual dose delivery system. We also measured personnel radiation exposure during use of Intego and during manual administration and recorded and compared environmental doses in the two conditions.

The radiopharmaceutical remained sterile in all the tests performed. The accuracy of the net (18)F-FDG activity delivered to the patients was found to be within 3 % points, as required by European Association of Nuclear Medicine (EANM) guidelines on (18)F-FDG imaging procedures. With Intego, the residual radioactivity in the tubing was 0.20 MBq, corresponding to approximately 0.07 % of the mean activity delivered. With manual injection, the residual radioactivity in the syringe averaged 7.37 MBq, corresponding to a mean error of 2.9 % in the delivered dose. During the injection step of the positron emission tomography (PET) procedure, whole-body and extremity radiation exposures were significantly reduced with Intego by 38 and by 94 %, respectively, compared to the levels associated with manual administration (p < 0.05).

Integoaccurately partitions and administers sterile doses of (18)F-FDG from multi-dose vials. Compared with standard manual (18)F-FDG administration, the new procedure with an automatic dispensing and injection system greatly reduces the extremity dose to the operator involved in the administration of the radiopharmaceutical.