Synthesis of [18F]-L-DOPA radiopharmaceutical on a modified GE TracerLAB Fx F-E platform

18F-labelling innovations and their potential for clinical application

“…0.5 mg) amounts, as shown for labelled fatty acids, amino acids, or sugars. Given the gaseous fluorination reagent [ 18 F]F2 for labelling, two-step syntheses for 2-[ 18 F]fluoro-2-deoxy-D-glucose ([ 18 F]FDG), in the beginning of its production [18,19], and for 6-[ 18 F]FDOPA (first step 18 F-labelling, second step deprotection) could be easily established in an automatic synthesis device with one reactor [20], which is now commercially available [21,22]. This has been achieved despite the need of hazardous elemental fluorine and, in the case of 6-[ 18 F]FDOPA, of corrosive acids (HCl, HBr, HI) for the hydrolysis were challenges for the stability of valves and tubing within the synthesis device.…”

“…Earlier, those electrophilic 18 F-fluorination reactions were performed in Freon ® (CClF3) as solvent, but this is now commercially unavailable due to its environmental problem of ozone depletion. However, several studies have shown that CDCl3 could replace CClF3 without significant loss of RCY [22][23][24].…”

Nucleophilic Synthesis of 6-l-[18F]FDOPA. Is Copper-Mediated Radiofluorination the Answer?

“…Presently, the synthesis of 6- l -[ 18 F]FDOPA for clinical applications is conducted chiefly via an electrophilic regioselective 18 F-fluorodemetallation [ 21 ] of commercially-available organotin precursors using gaseous [ 18 F]F 2 ( Scheme 1 ). Despite the apparent simplicity and adaptability to modern automated synthetic modules [ 22 , 23 , 24 ] the electrophilic approach is known to have several limitations, such as difficulty in handling of radionuclide in a gas form (as [ 18 F]F 2 ), low productivity of the cyclotron targets and unavoidable addition of [ 19 F]F 2 carrier gas leading to decrease of molar activity (A m ) of the radiotracers produced [ 25 ]. Even though the molar radioactivity does not appear to be of a critical importance for clinical application of 6- l -[ 18 F]FDOPA, it is still desirable for obtaining high quality PET images [ 26 ] and ensuring absence of adverse reactions in patients [ 27 ].…”