Abstract
2722a
Objectives It has been demonstrated that [18F] Fluor-L-dopa is a significant specific neurological and tumoral tracer since the first electrophilic synthesis pathway was reported by Dr Jorge Barrio at UCLA(1) in 1979. The electrophilic process, however has limited the use of FDOPA to a few PET services due to its low activity and the gas target complexities. Several nucleophilic pathways for FDOPA were sought, as was once done with FDG after its successful nucleophilic synthesis in 1986, when it got spread globally (2) Coenen- Hamacher and col. However, until now, all the reported electrophilic syntheses have been complex and low activity was obtained.
Methods We have been studying and developing several nucleophilic pathways published by Emer, but although its radiochemical yield at the first step of labelling was high, the next steps turned out to be difficult to implement, specially the hydrolysis. Lemaire et al. designed a promising nucleophilic process, which may result in obtaining larger amounts of FDOPA so that it can be spread globally, too. The radiochemistry automation experts from Trasis, who in the mid nineties created the famous “Coincidence” module (also called Tracerlab) lately developed a maximal refinement module called “AllinOne”.
Results We present our experience with more than 30 production runs for a clinical trial, following the procedure by Lemaire et al. using the AllinOne module from Trasis. Some minor adjustments were made. The product has a radiochemical purity > 99 %, an enantiomeric purity > 97% and complies with the other standard quality control tests. The overall synthesis showed an average uncorrected yield of 33±3%, and a new methodology reaches >40%. This method will be a breakthrough for the clinical use of this radiopharmaceutical, such as the FDG nucleophilic synthesis was in 1986. Recently the possibility to localize the Hyperinsulinoma with FDOPA in children allows the resection of the tumor cells with no damage to the remaining pancreas. This will be a very important tool in the future to save the life of children with this disease. We are planning a clinical trial in order to evaluate cardiac innervation with FDOPA, due to the fact that the DOPA is a precursor of norepinephrine and epinephrine.
Conclusions CONCLUSION: This new nucleophilic route of synthesis of F-DOPA will give us the possibility of the clinical utilization of this molecule due to the high production levels that can be obtained. We think that it would be possible to develop new clinical applications with this radioharmaceutical owing to its high clinical potential. The existence of a European marketing authorization for this molecule has facilitated its registration by the Argentinean Sanitary Authorities.