Evaluation of 99mTc-labeled amino acids as radiopharmaceuticals. III. 99mTc complexes of ligands related to ethylenediamine-N,N-diacetic acid for tumor visualization.

Abstract

Seventeen 99mTc-labeled ligands were evaluated as tumor scanning agents by preparing sequential scintigrams of mice bearing intramuscularly transplanted Ehrlich tumor. The ligands were labeled by the SnCl2 method and were administered intravenously to the mice. The ligands studied were ethylenediamine-N, N-diacetic acid (u-EDDA) and structurally related compounds. 99mTc complexes of u-EDDA, ethylenediamine-N, N'-diacetic acid, N-hydroxyethyliminodiacetic acid, and propylene-1, 3-diamine-N, N-diacetic acid achieved clear visualization of Ehrlich tumors. The image of the tumor was less clearly visualized with the complexes of iminodiacetic acid, N-methyliminodiacetic acid, nitrilotriacetic acid, ethylenediamine-N, N, N, ', N'-tetraacetic acid, N-hydroxyethylethylenediamine-N, N, ', N'-triacetic acid, hydrazine-N, N-diacetic acid, and 3-oxopiperazine-1-acetic acid.