Characterization of Fluoroscopy Radiation Dose Associated with the Administration of Y-90 Microspheres for Radioembolization Therapy
Presentations
MO-H345-IePD-F6-3 (Monday, 7/11/2022) 3:45 PM - 4:15 PM [Eastern Time (GMT-4)]
Exhibit Hall | Forum 6
Purpose: The administration of ⁹⁰Y-microspheres for radioembolization therapy of hepatic malignancies includes planning that involves an angiographic mapping and the injection of permanent ⁹⁰Y-microspheres as the carrier of the radiation to the hepatic arteries. Both are under fluoroscopy-guidance. In practice, we observe that ~4% of the administration procedures deliver >5Gy cumulative Reference Air Kerma (RAK), much higher than the overall incidence rate of ~0.4%. This study is to characterize the radiation dose of fluoroscopically-guided ⁹⁰Y-microspheres administration procedures and identify root causes resulting in a higher incidence rate.
Methods: 346 fluoroscopically-guided ⁹⁰Y-microspheres radioembolization procedures were retrospectively analyzed, including 162 mapping and 184 injection procedures, conducted between 05/2017 and 02/2022. The administered activity, patient body mass index (BMI), and RAK were retrieved. Clinical cases were categorized based on the type of procedures (mapping vs. injection), type of ⁹⁰Y-microspheres (SIR-Spheres vs. TheraSphere), and number of vials (1 vs. ≥2). Radiation doses between different types of procedures, ⁹⁰Y-microspheres, and number of vials as well as their correlation with BMI or administered activity were statistically compared.
Results: RAKs from 14 procedures (~4%) exceeded 5 Gy. Among them, 12 were mapping procedures. The mapping procedures with ≥2-vials showed a much higher incidence rate of 16.7% (5 of 30). RAK of mapping was significantly higher than RAK for injection (2601±1110.7 vs. 1025.0±229.1 mGy, p<0.01), and RAK for mapping with ≥2-vials was significantly higher than 1-vial (3535.3±453.5 vs. 2368.9±1232.9 mGy, p<0.01). There was no significant difference in RAK between procedures using SIR-Spheres or procedures using TheraSphere. No strong correlation was observed between RAK and administered activity or BMI.
Conclusion: Fluoroscopically-guided radioembolization mapping procedures, especially those requiring ≥2-vials likely deliver larger radiation dose (>5Gy) to patients compared to injection procedures. Further investigations are warranted to identify other possible root causes of the higher radiation dose beside the case complexity.
Keywords
Dose, Fluoroscopy, Intravascular Brachytherapy
Taxonomy
IM- Radiation Dose and Risk: General (Most Aspects)
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