Author: Stewart J. Becker, Andrew Genuit, Mariana Guerrero, Yannick P. Poirier 👨🔬
Affiliation: University of Maryland School of Medicine, Department of Radiation Oncology, University of Maryland School of Medicine 🌍
Purpose: To introduce an additional quality assurance step to prevent human error in vial mix-ups during Yttrium-90 (Y90) radioembolization by verifying the local assay at the time of delivery. We propose verifying the activity in the delivery vial using exposure rate measurements and comparing them against predictions based on historical exposure readings in the operating room.
Methods: A retrospective chart review was conducted on patients from January 2018 to December 2024 who received Y90 therapy with single vials: SirSpheres (n=98) or TheraSpheres (n=54). Data on procedure activity (mCi) and exposure rate (mR/h) before administration at a fixed geometry and distance from the vial were collected. Patients were divided based on the survey meter used (Victoreen or Ludlum Model #3). Results were graphed and analyzed.
Results: A linear relationship was found between source exposure rate and procedure activity in the delivery vial for both Y90 therapies (R²>0.9). No significant difference (P>0.2) was observed between the two measuring devices, regardless of the therapy used. Combined data analysis showed similar linear relationships for both therapies. However, a significant difference (P<0.05) was found between the equations for the two therapies. These equations can be used to determine expected exposure based on prescribed activity.
Conclusion: This study provides a method for a final quality assurance check in the operating room before Y90 delivery, independent of the survey meter used. This QA procedure can detect errors in assayed activity and vial mix-ups, helping to avoid medical errors and misadministration. It is particularly important when multiple patients and vials are treated on the same day, reducing the risk of vial mix-ups.