Tracers / [18F]FET
[18F]FET
Also written as [18F]FET; [18F]fluoroethyltyrosine; [F-18]FET; [F-18]fluoroethyltyrosine; F-18 FET; F-18-FET; FET
- Radionuclide
- F-18 t½ 109.7 min
- Modality
- PET
- Production route
- Cyclotron liquid target
- Stage
- Clinical research
- Syntheses indexed
- 23
What it is
- Compound class
- Amino acid
- Target / mechanism
- System L amino-acid transport (LAT1) PMID 30519867 / DOI 10.1007/s00259-018-4207-9
- Clinical application
- Glioma grading and delineation; recurrence versus treatment change PMID 30519867 / DOI 10.1007/s00259-018-4207-9
- Theranostic pair
- —
Regulatory status
- FDA
- No Drugs@FDA / openFDA drug registry — no approved application found; search: https://www.accessdata.fda.gov/scripts/cder/daf/index.cfm?event=BasicSearch.process&searchTerm=fluoroethyltyrosine
- EMA (centralised)
- No EMA medicines register — no centrally authorised medicine containing fluoroethyl-tyrosine (18F); search: https://www.ema.europa.eu/en/medicines?search_api_fulltext=fluoroethyl-tyrosine
- Other approvals
- Not centrally authorised by EMA, but holds national marketing authorisations in EU/EEA member states (also approved in Switzerland). Example (official national register): France — IASOglio, fluoroethyl-L-tyrosine (18F), marketing authorisation active since 23/12/2015, holder Curium Austria GmbH.
- Brand names
- —
Clinical use
- Typical injected activity
- 185-200 MBq (fixed adult dose, glioma guideline) PMID 30519867 / DOI 10.1007/s00259-018-4207-9
- Uptake time
- Static: 20-min acquisition from 20 min post-injection; or 40-50 min dynamic acquisition from injection (glioma guideline) PMID 30519867 / DOI 10.1007/s00259-018-4207-9
Reported in the literature. Not a dosing recommendation.
Published syntheses
| Module | Cassette | Purification | Yield % | RCP % | Precursor / supplier | Source |
|---|---|---|---|---|---|---|
| ELIXYS FLEX/CHEM | — | HPLC | 35-55% yes | > 99% | — | 40980735 2025 Am J Nucl Med Mol Imaging Sofie ELIXYS — The radiochemical yield of [18F]FET was 35-55% and 30-55% decay corrected to start of synthesis (SOS) for Sofie ELIXYS and GE FASTlab 2, respectively. |
| FASTlab 2 | — | SPE | 30-55% yes | > 99% | — | 40980735 2025 Am J Nucl Med Mol Imaging GE FASTlab 2 — The radiochemical yield of [18F]FET was 35-55% and 30-55% decay corrected to start of synthesis (SOS) for Sofie ELIXYS and GE FASTlab 2, respectively. |
| AllinOne (AiO) Trasis | vendor cassette | HPLC | 49-52 no | >95% | O-(2-tosyloxyethyl)-N-trityl-L-tyrosine-tert-butyl ester (TET) | 40573166 2025 Pharmaceuticals (Basel) automated Trasis AllinOne module — achieved a non-corrected yield between 49% and 52% |
| AllinOne (AiO) Trasis | — | — | 46 ± 3% | — | N-Trt, O-tBu-protected tosylate precursor | 38747353 2024 Mol Pharm [18F]FET was prepared according to a known procedure41 in an AllInOne automated synthesis module (Trasis, Ans, Belgium) — which afforded the probe in activity yields of 46 ± 3% within 53 ± 1 min (calculated based on five representative radiosyntheses). |
| — | — | — | — | — | — | 31891883 2020 Nucl Med Biol |
| In-house / custom built in-house | custom manifold | HPLC | 55 ± 7% yes | >98% | (2S)-O-(2′-tosyloxyethyl)-N-trityl-tyrosine-tert-butyl ester (TET) ABX | 31893318 2019 EJNMMI Radiopharm Chem the synthesis was carried out in microvolume droplets manipulated on a disposable patterned silicon “chip” affixed to a heater — The microdroplet synthesis exhibited an overall decay-corrected radiochemical yield of 55 ± 7% (n = 4) after purification and formulation. |
| In-house / custom built in-house | custom manifold | HPLC | 54 ± 6% yes | — | (2S)-O-(2′-tosyloxyethyl)-N-trityl-tyrosine-tert-butyl ester (TET) ABX | 31893318 2019 EJNMMI Radiopharm Chem We also performed the synthesis using the automated droplet radiosynthesizer (i.e. with the passive transport microfluidic chips) and observed a crude decay-corrected RCY of 54 ± 6% (n = 5) — observed a crude decay-corrected RCY of 54 ± 6% (n = 5) |
| — | — | HPLC | — | >99.5% | N-trityl-O-(2-tosyloxyethyl)-L-tyrosine-tert-butyl ester | 31673030 2019 Sci Rep |
| — | — | — | 79 ± 0 % | — | — | 31891883 2020 Nucl Med Biol |
| — | — | HPLC | — | — | — | 29520821 2018 J Labelled Comp Radiopharm |
| — | — | — | 10.7 ± 4.7% (10 mg, n = 3) yes | >95% | TET precursor | 37408511 2023 J Labelled Comp Radiopharm automated (MX Tracerlab) module (n = 6) — The decay corrected average yield was 10.7 ± 4.7% (10 mg, n = 3) and 8.2 ± 2.6% (2 mg, n = 3) with automated chemistry module |
| — | — | — | 36.7 ± 7.3% (8-10 mg, n = 12) yes | >95% | TET precursor | 37408511 2023 J Labelled Comp Radiopharm semiautomated (FX2N Tracerlab) module (n = 19) — 36.7 ± 7.3% (8-10 mg, n = 12), 26.4 ± 3.1% (5-7 mg, n = 4), and 35.1 ± 3.8% (2-4 mg, n = 3) with semiautomated chemistry modules |
| — | — | — | 14 ± 2.2% | — | desmethyl labeling precursor and [18F]fluoroethyl tosylate | 33412382 2021 Appl Radiat Isot |
| — | — | — | — | — | — | 32877862 2020 Appl Radiat Isot |
| — | — | — | 20-25% yes | >99% | — | 31442794 2019 Appl Radiat Isot using our home-built automated multi-purpose 18F-radiosynthesis module — 20-25% radiochemical yield decay corrected to end of bombardment (EOB), based on H[18F]F |
| — | — | — | 25±5% no | more than 99% | — | 29275040 2018 Appl Radiat Isot commercially available fully automated GRP SCINTOMICS module — non-decay corrected yield 25±5% in about 55min |
| — | — | SPE | 24.6 ± 2% | >98% | Ni(II)-(S)-BPB-l-Tyr-O-CH2-CH2-OTs | 28570917 2017 Appl Radiat Isot |
| — | — | — | 41% | — | Resin-linker-vector (RLV) 8a,b | 23255371 2013 Chemistry |
| — | — | — | 70-90% | — | — | 21989864 2012 Nuklearmedizin |
| — | — | HPLC | 55±5% yes | >99% | O-(2-tosyloxyethyl)-N-trityl-L-tyrosine tert-butylester | 21718939 2011 Nucl Med Biol GE TracerLab FX(FN) synthesis module — 35±5% (n=22) yield non-decay-corrected (55±5% decay-corrected) |
| — | — | SPE | 41% yes | 97%-100% | L-tyrosine | 21718940 2011 Nucl Med Biol using a modified [(11)C]methionine module (Nuclear Interface) — The synthesis typically yielded 41% (21 experiments) of FET (d.c.) without an HPLC purification step. |
| — | — | SPE | 45% no | >99% | 2-bromoethyl triflate | 19804977 2009 Bioorg Med Chem |
| — | — | HPLC | 40-45% yes | — | Ni-(S)-BPB-(S)-Tyr-OCH2CH2X (X=OTs (3a)) | 18378460 2008 Bioorg Med Chem Overall synthesis time operated by Anatech RB 86 laboratory robot was 55min. — tosyl derivative 3a provided highest radiochemical yield (40-45%, corrected for radioactive decay) |
Precursor
- Common precursor
- O-(2-tosyloxyethyl)-N-trityl-L-tyrosine tert-butyl ester (TET), 2-step radiolabelling; alternative 2-step route: [18F]fluorination of ethylene glycol-1,2-ditosylate then fluoroethylation of L-tyrosine (disodium salt) PMID 40573166 / DOI 10.3390/ph18060769
- Suppliers seen in the literature
- —
- Cited suppliers in indexed syntheses
- ABX
- Typical final purification
- SPE
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Get in touchQuality control Pharmacopoeial monograph
- Ph. Eur. monograph
- 2466
- USP monograph
- not verified — the USP-NF monograph index is subscription-only and no public confirmation was found
How this set was arrived at. Cross-checked against Ph. Eur. general monograph 0125 (base set), EANM validation guideline (PMC7016057) and cGRPP guidance (PMC7881071). Draft X-marks consistent with the base set; tracer-specific analytical tests follow the specific monograph where one exists.
Tests listed by reference only. Monograph texts are copyrighted and are not reproduced here. How these are derived
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Get in touchNotes
Standard neuro-oncology tracer in Europe; national marketing authorisations in some EU states.