Dos and Don'ts that are Issued through Radiolabeling Process of DMSA (Dimercaptosuccinic Acid) by 99mTco4- as 99mTc-DMSA(III), the Gold Standard Radiopharmaceutical for Renal Cortical Scintigraphy

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 on99mTc-DMSA(III) renal scan impression with regard to diseases that can affect the99mTc-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 of99mTc-DMSA(III). Conclusion: Finally, we suggested an optimized radiolabeling method99mTc-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.