Background: Residual activity in dispensing syringes is a problem that has been sporadically reported with various radiopharmaceuticals. Studies with [99mTc]Tc-tetrofosmin are non-consistent so far. The aim was to quantify the residual activity of [99mTc]Tc-tetrofosmin in different syringes in a clinical setting and to assess its impact on the clinical imaging procedure.
Methods: The residual activity of [99mTc]Tc-tetrofosmin was measured in 3 types of syringes: 3-part lubricated and non-lubricated syringes and 2-part syringe (n ≥ 30 for each syringe). The residual activity was located and quantified using a CzT SPECT camera and radio-counting then was correlated with different clinical parameters and processed by multiple linear regression analysis.
Results: Residual activity was different in all syringe types but lubricated syringes showed significantly higher levels with a mean ± SD of 26.12 ± 10.21% (P < .001). For these syringes, the residual activity was mainly located on the lubricated body. They also have a positive and significant impact on the standardized counting duration of patients' acquisitions.
Conclusion: Lubricated syringes with high residual activity should be avoided as they increase the risk of prolonging patient acquisition time and potentially increasing the risk of poor image quality.
Keywords: Myocardial perfusion imaging; adsorption; radiopharmaceuticals; syringes; tetrofosmin.
© 2022. The Author(s) under exclusive licence to American Society of Nuclear Cardiology.