A radioconjugate containing a derivative of the androgen testosterone (FMDHT) and labeled with the radioisotope fluorine F 18, with potential use as an imaging agent for positron emission tomography (PET). Upon administration, fluorine F 18 FMDHT binds to the androgen receptor (AR). Upon PET imaging, AR-expressing prostate tumor cells can be imaged and assessed. Check for active clinical trials using this agent. (NCI Thesaurus)