Definition

A radioconjugate composed of the selective sigma-1 receptor (S1R) ligand FTC-146 labeled with the radionuclide fluorine F 18, with potential use as an imaging agent for S1R-expressing tumor cells upon positron emission tomography (PET)/computed tomography (CT). Upon administration, fluorine F 18 FTC-146 targets and selectively binds to S1R expressed on tumor cells. The S1R-expressing tumor cells can then be visualized using PET/CT. S1R, widely distributed in the central nervous system (CNS) and peripheral tissues, plays a key role in the modulation of ion channels and other neurotransmitter systems, and in restoring neuronal function. It is upregulated in inflammatory diseases and in a variety of cancers. 18F-FTC-146 shows excellent selectivity for the S1R over the sigma-2 receptor and vesicular acetylcholine transporter (VAChT).