DOTA-Tyr3-Octreotate:: Labeling with β-emitting radionuclides for the preparation of potential therapeutic radiopharmaceuticals

Radiolabeled somatostatin analogues, including octreotate have been used for targeted radiotherapy of neuroendocrine tumors such as lymphoma, breast cancer, small-cell lung cancer and melanoma. In this paper, studies on the optimization of the production of Lu-177, Ho-166 and Sm-153 radionuclides in Pakistan Atomic Research Reactor (PARR-I) and the investigations on the labeling of DOTA-Tyr-3 Octreotate with I-131, Lu-177, Ho-166 and Sm-153 have been reported. The labeled DOTA-Tyr3-Octreotate complexes were found to be stable in acetate/ascorbate buffer and saline at room temperature (18-22 degrees C). The biodistribution studies of Lu-177-DOTA-Tyr-3 Octreotate in rat model indicated that the critical organ for this complex was the pancreas and the excretion route was through kidney.