Development of 68Ga ethyl cysteinate dimer for PET studies

In this work development of 68 Ga-ethyl cysteinate dimer ( 68 Ga-ECD) a 68 Ga tracer for possible cerebral blood flow based on 99m Tc ECD homolog is reported. 68 Ga-ECD was prepared using generator-based 68 GaCl 3 and ECD at optimized conditions. Quality control, stability, partition co-efficient and the biodistribution of the tracer (by tissue counting and PET/CT in rats) was studied. Significant metabolism of the lipophilic tracer into water soluble metabolite(s) led to urinary excretion of the tracer, un-comparable to that of homologous 99m Tc-compound. Cardiac uptake of the complex suggests formation of a possible lipophil cationic complex and/or metabolite.