Abstract
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Objectives: Yttrium 90 (Y-90) radioembolization is a growing method of therapy for patients with metastatic and primary liver neoplasm. Current dose delivery methods do not enable real-time feedback as to whether the dose from the sterile vial was completely administered to the patient during the infusion procedure. This work shows results and initial use of a modular detector system to enable near real-time feedback of Y-90 dose administration during radioembolization procedures.
Methods: A modular detector system was used to record radioactivity at locations throughout the dose administration kit. One detector was placed near the sterile vial while the other was placed at approximately 2.54 cm from the dose administration tubing near the exit port of the delivery system. Data from the detector system began recording just prior to the beginning of the Y-90 dose infusion. Data collection continued through the completion of three saline flush injections which is the standard procedure for the specific Y-90 spheres delivered in these initial tests. Data from the detectors were downloaded and viewed on a local system. Data were plotted as a function of counts/s vs. time to generate a time activity curve for analysis. Time activity curves generated from the detectors were compared to determine the total dose exiting the delivery system and to estimate how much of the dose is delivered on the first injection compared to subsequent saline flushes.
Results: Data indicate that the system sensitivity is such that it is capable of measuring the change in activity as the Yttrium dose is administered to the patient. Peaks occur at the three time intervals that correspond to the initial infusion and the subsequent saline flushes with the latter flushes all showing significant reductions in measured activity. The attached figure shows the time activity curve with the scaling of the Y-axis clipped to show all three peaks during the infusion.
Conclusion: This work shows initial results that a modular detector system may be useful in the monitoring and assessment of yttrium dose deliveries in radioembolization procedures. This type of system may provide improved feedback to clinicians and staff regarding therapeutic dose delivery and may enable more rapid intervention in the event of a dose misadministration or other related event. Research Support: All funding for this study was provided by the Molecular Imaging and Translational Research Program departmental funds. $$graphic_43A5118A-17E5-42B0-BADD-9ECBB8E61603$$