| Abstract
Objective: Since DMSA (Dimercaptosuccinic Acid) is an important and more sensitive kit in the realm of renal
scintigraphy, in the course of this enormous study throughout five years, all quality control results from more than
500 Tc-99m radiolabeled DMSA kits and scans were studied to improve radiolabeling method through optimization
of all involving parameters.
Methods: Instant thin layer chromatography (ITLC) (support: ITLC-Silicic-acid (SA), solvent: n-Butanol
Saturated with 0.3N HCl) were used to calculate %radiochemical purity (%Tc-99m DMSA). Data from ITLC and
scans were investigated to obtain the optimized radiolabeling method so as to decrease background uptake
particularly liver uptake.
Results: Data suggested that if radiolabeling is performed under optimized involving parameters (Generator
used day 2, SA=(15-20 mCi)/ (1cc) radiochemical purity=99.5% (Al2O3<5 ppm), generator’s pH=4-4.5), the
% Tc-99m dimercaptosuccinic acid (DMSA) will be ≥ 90-95%. Moreover, more intricate scans with abnormal
biodistribution of radiotracer developed the expanded view on 99mTc-DMSA(III) renal scan impression with regard to
diseases that can affect the 99mTc-DMSA(III) biodistribution. During this investigation, it was concluded that almost
all diseases that influence liver and spleen including fatty liver, mononucleosis and similar illnesses could change
routine biodistribution of 99mTc-DMSA(III).
Conclusion: Finally, we suggested an optimized radiolabeling method 99mTc-DMSA(III) ≥ 90-95%) to reach a
precious imaging as more as we can decrease uncertainties about interpretation of Tc-99m DMSA scan considering
patient’s background to provide an effective diagnosis. |