A diagnostic radioimmunoconjugate comprised of the recombinant humanized monoclonal antibody trastuzumab conjugated with the positron-emitting radioisotope copper Cu 64. Copper Cu 64 trastuzumab binds to the extracellular domain of human epidermal growth factor receptor 2 (HER2), allowing the detection of HER2 distribution using positron emission tomography (PET). Check for active clinical trials using this agent. (NCI Thesaurus)