61Cu-ATSM

61Cu-ATSM is a radiopharmaceutical agent used in positron emission tomography (PET) imaging to identify and delineate hypoxic regions within tumors. It consists of the radioisotope copper-61 (61Cu) chelated by the lipophilic ligand diacetyl-bis(N4-methylthiosemicarbazone) (ATSM). The complex is neutral and membrane-permeable, allowing it to diffuse freely into cells. In the presence of oxygen (normoxia), the copper(II) center is reduced to copper(I) but can be re-oxidized and washed out of the cell. However, in hypoxic environments, the reduced copper(I) species remains trapped intracellularly, leading to selective accumulation in hypoxic tissue. This imaging capability is critical for identifying radioresistant tumor zones, predicting treatment outcomes, and guiding biologically targeted radiation therapy in various cancers, including sinonasal tumors, cervical cancer, and lung cancer.

Other names

Copper (61Cu) diacetyl-bis(N4-methylthiosemicarbazone)61Cu-labeled ATSMCopper-61 diacetyl-bis(N4-methylthiosemicarbazone)