[F-18]-Fluorothymidine Injection (“[F-18]-FLT”), when used with positron emission tomography (PET), is being developed as a non-invasive imaging biomarker for the in vivo assessment of cellular proliferation. Clinical studies suggest that [F-18]-FLT has potential as a tool for cancer staging and monitoring response to  treatment.

[F-18]-FLT is a radiolabeled analogue of thymidine, a nucleotide that is a component of DNA. [F-18]-FLT is transported across the plasma membrane by nucleoside transporters, followed by phosphorylation via thymidine kinase 1 (TK1) and intracellular retention as [F-18]-FLT monophosphate; unlike thymidine, there is little incorporation into DNA. Since rapid cellular proliferation is a hallmark of cancer, there is increased cellular demand for nucleotides, reflected by increased TK1 activity; this results in increased thymidine uptake which is the basis for [F-18]-FLT PET imaging.



Li Z, Yu Y, Zhang H et al. A meta-analysis comparing 18F-FLT PET with 18F-FDG PET for assessment of brain tumor recurrence. Nucl Med Commun. 2015; 36(7): 695-701. PMID: 25768337.


Li XF, Dai D, Song XY et al. Comparison of the diagnostic performance of 18F-fluorothymidine versus 18F-fluorodeoxyglucose positron emission tomography on pulmonary lesions: A meta analysis. Mol Clin Oncol. 2015; 3(1): 101-108.


Deng SM, Zhang W, Zhang B et al. Assessment of tumor response to chemotherapy in patients with breast cancer using 18F-FLT: a meta-analysis. Chin J Cancer Res. 2014; 26(5): 517-24.


Chalkidou A, Landau DB, Odell EW et al. Correlation between Ki-67 immunohistochemistry and 18F-Fluorothymidine uptake in patients with cancer: A systematic review and meta-analysis. Eur J Cancer. 2012; 48(18): 3499-3513.



These references are provided for informational purposes only and do not represent an endorsement for any particular clinical use. 

Investigational Product Use Only

The safety and efficacy of [F-18]-FLT Injection have not been fully established and it has not been approved by Health Canada as a commercial product for medicinal use. It is an investigational drug product and can only be used under an approved clinical trial application (CTA). Please contact the CPDC if you require further information.