Abstract
3094
Background: Partial extravasation of PET intravenous dose administration undermines image quality, accuracy of SUV calculation and other quantitation, and unnecessary local radiation to tissue. The Lucerno Dynamics LARA device is a simple, non-invasive way to characterise partial dose extravasation. Standard imaging protocols with the arms extended above the head mean visual identification of partial extravasation is uncommon. Data from the device use in the US supports the published rate of 15% of partially extravasated doses following manual administration of 18F-FDG. The NRC in the USA, with respect to radiopharmaceutical administration, have determined that “extravasation frequently occurs ⋯⋯⋯ it is virtually impossible to avoid ⋯⋯.. does not consider extravasation to be misadministration⋯” and thus avoid reporting and accountability requirements of misadministration. The aims of this project were to provide an Australian context to PET extravasation rates using autoinjector administration and a variety of radiopharmaceuticals.
Methods: Patients referred for 18F FDG, 68Ga DOTATATE and 68Ga PSMA PET/CT studies in a single department with 1 PET/CT were monitored from injection through uptake period with the device. Image data sets were assessed for evidence of extravasation following administration via the KARL100 autoinjector and Rad-inject pump system; facilitating immediate impact on clinical decision making. Detailed analysis of the entire cohort was undertaken retrospectively.
Results: 4 (1.1%) extravasations were noted in 296 patients. This low rate likely reflects line preparation, infusion rate, and flush volume associated with use of automated dose injectors (compared to manual injection). The device did identify other anomalies at injection (8%); most notably one case of leaking apparatus that saw some of the patient dose leak prior to injection and 22 cases of delayed kinetics associated with venous retention.
Conclusions: Use of an autoinjector technique demonstrates that very low levels of extravasation are possible. Potentially eliminating extravasation for PET studies is possible and every effort to achieve this reduction is essential to enhance image quality, improve SUV accuracy/reliability, and minimize unintentional radiation exposure to patient tissue. The recognition of extravasated doses as misadministration with associated investigation and reporting requirements of ARPANSA in Australia may also be a factor in reducing rates. Funding This project was funded by an ANSTO/ANZSNM Research Grant. 1 Figure 1: Annotated TACs for normal (A), minimal extravasation without resolution (B), significant extravasation without resolution (C), and venous retention with resolution (D). 2