title: Adherence of Tc-99 Sestamibi to Plastic Syringes Could Complicate Efforts in Dose Reduction in MPI SPECT.
abstract: BACKGROUND
  Multiple disposable syringe designs are available both with and without silicone lubricant. Tc99m sestamibi variably adheres to certain syringe designs. In practice, this increases pre-injection activity to ensure constant acceptable image quality in the setting of high adherence.
  
  
  METHODS
  The residual activity following 35 Tc99m MDP injections was used as a proxy for the dead-space residual activity. This was compared to Tc99m sestamibi injections in the same syringe in 107 injections, a syringe without lubricant in 35 injections, and a syringe without lubricant or rubber gasket in 16 injections. The syringe with lubricated barrel was disassembled and each part separately assayed to see which part demonstrated the most adherence.
  
  
  RESULTS
  The standard design demonstrated a mean adherence of 26% (SD 7.0%). This was significantly more than the 6% (SD 3.7%) demonstrated with MDP. The two designs without silicone lubricant demonstrated mean adherence of 7.2% (SD 2.3%) and 6.4% (SD 2.3%). Disassembly of the three part syringe showed the greatest adherence to the rubber gasket.
  
  
  CONCLUSIONS
  QC procedures determining adherence in the administration syringe are warranted for any change in syringe design or manufacturer. If adherence is present, conversion to non-lubricated plastic syringes with lower and more predictable retention of Tc99m sestamibi enables more precise titration of prescribed activities and reduction of overall patient absorbed doses.
authors: Diagnostic Radiology, The University of Vermont Medical Center, Burlington, VT, USA. sean.reynolds@vtmednet.org.
authors: Sean N
authors: SN
authors: Reynolds
authors: Nuclear Medicine and Diagnostic Radiology, The University of Vermont Medical Center, Burlington, VT, USA.
authors: Janusz
authors: J
authors: Kikut
mesh_terms: D000268:Adhesiveness; D006801:Humans; D055414:Myocardial Perfusion Imaging; D011829:Radiation Dosage; D013594:Syringes; D017256:Technetium Tc 99m Sestamibi; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D017256:Technetium Tc 99m Sestamibi
keywords: Technetium-99m; image quality; myocardial perfusion imaging: SPECT; radiopharmaceuticals; sestamibi