Tailored Media-Fill Test Protocols Inspired by ⁶⁸Ga Kit-Based Radiopharmaceuticals

Gallium-68 radiolabeling is an increasingly common activity in radiopharmacy. Single vial cold kits to radiolabel DOTATOC and PSMA-11 with ⁶⁸Ga were developed, either for manual or automated preparation. Both approaches are very specific and require aseptic compounding skills, raising the need for dedicated training. The aim of this work was to design and implement an integrative media-fill test (MFT) protocol inspired by ⁶⁸Ga kit-based radiopharmaceuticals for operator qualification, suitable for both manual and automated preparation simulations. Three custom MFT protocols (two manual and one automated simulations) compatible with specific radiopharmacy equipment were designed for operator training. During MFT sessions, the microbiological quality of the working environment was monitored by surface and air sampling. The sensitivity of the tryptic soy broth (TSB) and the influence of the number of punctures performed in each vial on the units positivity were also studied. Four operators were evaluated and carried out in triplicate the three MFTs. None of the 336 incubated units showed turbidity, although 27.8% of surface samples and 11.1% of air samples were positive (1-4 CFU). Over 36 MFT sessions, 15 contaminations of the working area by TSB drops occurred. TSB sensitivity was estimated >3.12 UFC. Units positivity showed a probable relationship with the number of punctures in a vial and, more obviously, with the contamination level of the vial stopper. As a part of a general sterile compounding instruction, these MFT protocols may be useful tools for initial and continuing training of operators carrying out manual and automated ⁶⁸Ga radiolabeling.