Tc-99m-2GAM: A tracer for renal imaging

We propose a renal imaging agent, the Tc-99m complex of the bidentate-N,S chelate N-(mercaptoacetyl)glycine (Tc-99m-2GAM), with the imaging characteristics of Tc-99m-DMSA but a faster kidney uptake; chemical evidence supports the formulation of Tc-99m-2GAM as [Tc-V(O)(GAM)(2)](-). After biodistribution and toxicity studies in animals, Tc-99m-2GAM was evaluated in five normal volunteers. Tc-99m-2GAM is rapidly cleared from the blood t(1/2), = 9 min) and 50% of the ID is excreted in the urine in the first 2 h. Dynamic data show a rapid renal uptake that increases up to 1 h with no significant wash-out between 1 and 8 h. The uptake in each kidney ranges from 11.3% to 20.7% ID. Low, stable liver uptake is observed. No significant activity is detected in other organs. We showed no differences between Tc-99m-2GAM and Tc-99m-DMSA compared in three patients with unilateral kidney disease, We conclude that Tc-99m-2GAM has good practical and dosimetric features for renal imaging. Copyright (C) 1996 Elsevier Science Inc.