18F-SF12051

**18F-SF12051** is a novel radioligand developed for positron emission tomography (PET) imaging of the **18-kDa translocator protein (TSPO)**. This radiotracer functions as a **TSPO modulator**, binding to the protein found on mitochondrial membranes, which is associated with inflammation in the brain. By visualizing TSPO during PET scans, 18F-SF12051 has the potential to aid in the diagnosis and understanding of various inflammatory conditions affecting the brain. The radiotracer was initially developed by the National Institute of Mental Health and showed promising results in preclinical studies in mice and rhesus monkeys, demonstrating high brain uptake and specific TSPO binding. Its structure is similar to [11C]ER-176 but is labeled with fluorine-18 (18F), offering the advantage of a longer half-life compared to carbon-11 (11C), making it more practical for clinical use by allowing transportation. A Phase 1 clinical trial (NCT05564429) was initiated in February 2023 to assess its ability to image TSPO in healthy human subjects but was subsequently terminated. As of May 2025, the development of 18F-SF12051 appears to be discontinued.

Other names

[18F]SF12051