Buserelin Was successively labeled with [In-111]-Indium chloride after residuation with DTPA-dianhydride. Radio-chromatography showed an overall radiochemical purity of >90% (RTLC) and > 95% (HPLC) at optimized conditions after labeling (specific activity: 400-450GBq/M). The serum stability of the tracer was determined LIP to 24 h. The biodistribution of the tracer was determined in normal rats showing significant breast and ovaries uptakes 60 min post injection. MCF-7 cell binding of the tracer was > 98%. A significant testes uptake was demonstrated in normal male Kits using SPECT studies.