Assessment of Residual [^99mTc]Tc-Tetrofosmin Activity in Routine Nuclear Medicine Practice at Hospital Kuala Lumpur

Myocardial perfusion imaging using the radiopharmaceutical [^99mTc]Tc-tetrofosmin plays a crucial role in diagnosing cardiac conditions. However, variations in the residual activity of [^99mTc]Tc-tetrofosmin in plastic syringes after administration may impact imaging quality and patient safety. This study aimed to evaluate the residual activity of [^99mTc]Tc-tetrofosmin in plastic syringes after administration during routine nuclear medicine procedures at Hospital Kuala Lumpur, assessing compliance with department protocols and variability among different syringe brands. <b>Methods:</b> A single-center prospective observational study was conducted using stratified quota sampling, encompassing 396 samples across 3 syringe brands (SJ, BD, and Ciringe). Residual activity was measured immediately after administration, and statistical analysis was performed to compare brands and assess compliance with the department dosage protocol range of 333-555 MBq. <b>Results:</b> All injected activities aligned with the department protocol dose, with a mean effective activity of 451.23 ± 30.73 MBq and a mean residual activity of 12.63% ± 4.73%. However, variability in residual activity was observed among syringe brands. BD exhibited the highest mean residual activity (16.45%), significantly differing from SJ (9.95%) and Ciringe (11.50%) (<i>P</i> < 0.001). <b>Conclusion:</b> Rigorous syringe selection is crucial in myocardial perfusion imaging procedures to minimize residual activity and ensure compliance with dosimetry standards, emphasizing the importance of integrating pharmacy practices into nuclear medicine protocols. Standardized protocols and quality assurance measures are essential to optimize imaging outcomes and prioritize patient safety. These findings highlight the importance of ongoing monitoring and interdisciplinary collaboration to navigate residual activity management effectively in routine nuclear medicine practice.