.3 '- Deoxy-3'-[~ (18) F] Fluoro Thymidine Nucleoside ([~ (18) F] Of Flt) The Preparation And Study

Positron emission tomography(PET), the so-called world's most advanced camera, is based on a NaI or BGO detector and imaging of positron-emitting radioisotopes which are introduced as a tracer into the regional tissue or organ of interest.With the aid of a computer visual images of a series of these distributions can be built into a picture of the functional status of the tissue or organ being imaged. This highly accurate imaging technique is already widely used for clinical diagnostics, dealing with heart diseases, brain disorders, tumors and so on.2-[¹⁸F]Fluoro-2-deoxy-D-glucose (FDG) as a tracer of glucose metabolism has been widely used with positron emission tomography (PET) for the diagnoses and treatment evaluations in oncology. However, high uptake of FDG in acute inflammatory reactions gives rise to false positive results in a considerable percentage of cases.Recently, a biologically stable radiofluorine labeled thymidine analog, [¹⁸F]3'-fluoro- 3'-deoxythymidine ([¹⁸F]FLT) has been developed as a candidate for cell proliferation imaging. It is an anti-virus compound and is captured by proliferating cells and stay inside the cells. The advantage of [¹⁸F]FLT compared to [¹⁸F]FDG is that it can distinguish cancer lesions from inflammations.Here, we choose 2,3'-anhydro-5'-O-(4,4'-dimethoxytrityl) thymidine (DMTThy) as labelling precursor and present a simplified and stable synthesis yielding of it. We also studied the process for the preparation of [¹⁸F]FLT from DMTThy and investigated the producing conditions of [¹⁸F]FLT with [¹⁸F]FDG autosynthesizer. Started with 800mCi ¹⁸F^-, within 35 minutes, the two-step process produced 140 mCi of [¹⁸F]FLT (Yield rate 21.8% , at the end of bombardment (EOB); 17.5% , at the end of synthesis (EOS)) suitable for injection.Finally, some animal experiments showd that [¹⁸F]FLT was highly uptaken by cancer lesions and low by normal tissues. And along with easy available synthesis and reliable labeling rate, [¹⁸F]FLT has shown preliminary promise for the in-vivo imaging of cellular proliferation.