Technetium-99m MAG3 kit formulation: preliminary results in normal volunteers and patients with renal failure

Previous studies have shown that [99mTc]mercaptoacetyltriglycine (MAG3) purified by high performance liquid chromatography (HPLC) is a very promising new renal imaging agent which has characteristics very similar to [131I]orthoiodohippurate. An easily prepared kit formulation has been developed and evaluated in ten normal volunteers and three patients on hemodialysis. The average radiochemical purity was 96.6%. There were no adverse reactions. In the volunteers, the relative uptake +/- 1 s.d. was 49.1% +/- 2.6% for the right kidney and 50.9% +/- 2.6% or the left kidney. Urine activity was 71.4% +/- 6.4% of the injected dose at 30 min and 94.4% +/- 2.2% at 180 min. The 60-min plasma clearance was 340.0 +/- 79.0 ml/min and the volume of distribution was 5.15 +/- 1.1I. Approximately 0.5% of the injected dose was present in the gallbladder at 30-60 min postinjection. Gut activity was not present 30-60 min postinjection but reached 1% of the injected dose by 3 hr. In the hemodialysis patients, approximately 1% of the injected dose was present in the gallbladder and 0.5% in the gut at 30-60 min; gut activity increased to approximately 5% at 3 hr. In summary, results using the kit formulation compare favorably to previously published data using the HPLC purified material. Based on these preliminary results, the kit formulation is expected to have widespread clinical utility.