Technetium(99mTc) Tetrofosmin

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. Methods: 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. Results: 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%) (P < 0.001). Conclusion: 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.

This study was approved by the Johns Hopkins Institutional Review Board and all patients signed written, informed consent. Enrolled patients were categorised into two cohorts, comprising a total of 11 subjects.Cohort A consisted of four patients with previously biopsied renal masses demonstrating ′oncocytic neoplasm′. Cohort B consisted of seven patients with cT1 renal masses scheduled to undergo resection.The exclusion criteria prohibited pregnant patients, those with a history of other malignancy with concern for renal metastasis, or those with any known allergy to technetium or tetrofosmin.Patients were asked to be nil per os for approx. 6 h prior to radiotracer injection.Patients were placed supine on the scanner table, 75 min after the i.v. injection of 925 37 MBq (25 1 mCi) of 99mTc-tetrofosmin.A Symbia 16-slice or Intevo 16-slice single-photon emission CT (SPECT)/CT gamma camera (Siemens Healthineers, Erlangen, Germany) were used for all imaging procedures.SPECT imaging was acquired in step and shoot mode, with 25 s per image, utilizing 3 degrees per step over 120 steps and a detector range of 180 degrees per detector.CT images were acquired at 110 kV and 200 mAs with dose care modulation enabled. Images were reconstructed using a 128 9 128-pixel matrix, and the imaging field was focused on the abdomen between the diaphragm and the tops of the iliac crests; 3-mm axial images were reconstructed for both SPECT and CT imaging.