18f-fes

What it is and how it works

18F-FES (16α-[18F]fluoro-17β-estradiol) is an oestradiol analogue that binds to oestrogen receptors. PET imaging shows the distribution and functional expression of oestrogen receptors in tumour lesions throughout the body.

Indications

PET imaging to detect oestrogen receptor-positive lesions as an adjunct to biopsy in patients with recurrent or metastatic breast cancer.

Dosage and administration (summary)

Dosing is individualised according to the imaging protocol and administered by nuclear medicine specialists as a single intravenous injection.

Contraindications

Hypersensitivity to the active substance or excipients.

Warnings and precautions

Drugs that bind oestrogen receptors, such as tamoxifen and fulvestrant, reduce tracer uptake and can cause false-negative results, so they should be withheld for an appropriate interval before imaging; uptake does not reliably assess HER2 or other receptors and does not replace biopsy. Radiation exposure should be minimised and patients encouraged to hydrate and void.

Pregnancy

Generally avoided in pregnancy unless essential, because of fetal radiation exposure.

Storage and supply

Store at room temperature in appropriate radiation shielding and use within the short shelf-life stated on the label.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.