Fluorine F 18-FETrp

**Semantic type:** Pharmacologic Substance

**Definition:** A radioconjugate containing an analog of tryptophan, fluoroethyl-tryptophan (FETrp), labeled with the positron-emitting radioisotope fluorine F 18, with potential imaging applications upon positron emitting tomography (PET). Upon administration, fluorine F 18-FETrp is taken up by and accumulates in tumor cells. This may allow for the visualization of tumors upon PET. The immunosuppressive kynurenine pathway present in tumor cells leads to abnormal tryptophan metabolism and increased uptake of tryptophan by tumor cells.

**Synonyms:** - 1-(2-(FLUORO-18F)ETHYL)-L-TRYPTOPHAN - 1-(2-(Fluoro-18F)ethyl)-L-tryptophan - 1-(2-[18F]Fluoroethyl)-L-tryptophan - 1-L-[18F]FETrp - 18F-FETrp - L-Tryptophan, 1-(2-(fluoro-18F)ethyl)- - L-[18F]FETrp