SIR-Spheres Activity Measurements Reveal Systematic Miscalibration

The Journal of Nuclear Medicine

article

Stephen A. Graves¹  Molly Martin¹  Ashok Tiwari¹  Michael Merrick¹  John Sunderland¹ 

[1] Department of Radiology, University of Iowa;Department of Biomedical Engineering, University of Iowa;Department of Radiation Oncology, University of Iowa;Department of Physics, University of Iowa

关键词: TARE;    radioembolization;    radiopharmaceutical therapy;   

DOI  :  10.2967/jnumed.121.262650

学科分类：医学（综合）

来源: Society of Nuclear Medicine

【 摘 要 】

The purpose of this work was to perform an independent and National Institute of Standards and Technology–traceable activity measurement of 90Y SIR-Spheres (Sirtex). γ-spectroscopic measurements of the 90Y internal pair production decay mode were made using a high-purity germanium detector. Methods: Measured annihilation radiation detection rates were corrected for radioactive decay during acquisition, dead time, source attenuation, and source geometry effects. Detection efficiency was determined by 2 independent and National Institute of Standards and Technology–traceable methods. Results: Measured SIR-Spheres vials (n = 5) contained more activity than specified by the manufacturer calibration; on average, the ratio of measured activity to calibrated was 1.233 ± 0.030. Activity measurements made using 2 distinct efficiency calibration methods agreed within 1%. Conclusion: The primary SIR-Spheres activity calibration appears to be a significant underestimate of true activity.

【 授权许可】

CC BY