FLT

18F-FLT (18F-fluorothymidine, 3’-deoxy-3’-18F-fluorothymidine, Alovudine (18F) injection)

Fluorothymidine is an analogue of the nucleoside thymidine (deoxythymidine) FLT is transported from the blood into cells by active transport. In the cell, FLT is a substrate for thymidine kinase 1 (TK1) and is phosphorylated but is not incorporated into DNA.

The assumption is that the concentration of FLT nucleotides in cells is proportional to TK1 activity and therefore to cellular proliferation. 

Monitoring of cellular proliferation through PET is a tool to monitor the response to anticancer treatment.

The principal tests for 18F-FLT are:

Test

Technic/instrument

Appearance

Visual

Radionuclidic Identity

Gamma-ray spectroscopy with Multichannel analyser

Radionuclidic Identity

Half-life determination with a dose calibrator

pH

pH-meter or pH strips with reading through a reflexion photometer

Chemical purity (Alovudine and related substances)     

Gradient HPLC with UV detector

Impurtiy kryptofix  (aminopolyether)

Spot test

Residual solvents

Gas chromatography

Bacterial endotoxins (LAL)

Endosafe Portable Test System (PTS)

Radiochemical purity

Radio-HPLC

Radiochemical purity

Radio-TLC

Radiochemical identity

Radio-HPLC

Osmolality

Osmometer

Radionuclidic purity

Gamma-ray spectroscopy  with  Multichannel analyser

Sterility

Compendial method

Radioactivity

Dose calibrator