[en] A synthetic procedure for the routine preparation of [¹⁸F] N-3-fluoropropyl-2-β-carbomethoxy-3-β-(4' methylphenyl) nortropane (¹⁸F FPCMT) has been developed. The synthesis is based on alkylation of nortropane with ¹⁸F labeled fluoropropyl tosylate. Purification of the final product was achieved by a preparative HPLC procedure using Alltech Econosil column. Separation of the desired compound was achieved and the product was clean. The radiochemical yield (without decay correction) is 4 to 5%, calculated at the end of the synthesis based on the total amount of fluorine recovered from the target. Radiochemical purity was in the range of 98 to 99%

[en] A synthetic procedure for the routine preparation of 6-[¹⁸F] fluorodopamine has been developed. The synthesis is based on electrophilic fluorination of a 6-mercurated dopamine precursor. Fluorodemercuration of the dopamine precursor using [¹⁸F] acetylhypofluorite and hydrolysis by a mixture of acetic anhydride and HI gave the desired radiopharmaceutical with a radiochemical yield of 13.7 ± 0.7% calculated at the end of synthesis based on five synthetic preparations (without decay correction) and also based on the amount of total [¹⁸F]F₂ recovered from the target. Radiochemical purity as well as chemical purity were >98%. In order to maintain good sterility and pyrogenicity, the synthetic unit is made up of mostly sterile disposable components that are readily available. The routine operations of the synthetic unit are carried out in a closed hot cell, using a Master Slave Manipulator arm. Since no manual handling of radioactivity is involved, the operation of the synthetic unit is radiation safe and the radiation exposure to the operator is minimized. (Author)

[en] A simple procedural change for the synthesis of [¹⁸F]FDG has been used to recover [¹⁸O]water by direct distillation. The [¹⁸O]water thus recovered is reusable to produce [¹⁸F]fluoride without further purification. The recovery of [¹⁸O]water is reliable and our results are based on over 300 routine FDG preparations. The [¹⁸F]fluoride present in the target water is converted to potassium fluoride during the distillation and will be available for further reaction to complete the synthesis of FDG. The same procedure can be used to recover [¹⁸O]water in similar situations where [¹⁸F]fluoride is converted to potassium fluoride and in turn used to react with kryptofix for labelling other precursors. (author)

[en] A procedure for the routine preparation of [¹⁸F]FP-CIT has been developed. Purification of the final product was achieved by preparative HPLC using phenethyl column without decomposition or epimerization. [¹⁸F] labeled-N-fluoropropyl-2β-carbomethoxy-3β-(4-iodophenyl)nortropane was prepared and PET imaging was performed on human subjects. A high uptake into striatal regions was observed. HPLC plasma analysis using [¹⁸F]FP-CIT indicated the presence of only one metabolite. By directly comparing the behavior of these three radiotracers ([¹⁸F]DOPA, [¹²³I]FP-CIT, and [¹⁸F]FP-CIT) in the same subjects, we can enhance our understanding of the dopaminergic system as well as the relative potential of these techniques in a clinical research setting

[en] A self contained, Master Slave Manipulator operated and largely disposable apparatus for the large scale production of [¹⁸F]FDG using nucleophilic fluorination methodology has been developed. The synthetic unit consists of readily available sterile disposable components and is easy to assemble. Operation of the synthetic unit is carried out in a hot cell under a closed system to minimize radiation exposure to personnel. Recovery of [¹⁸O]water by direct distillation from the reaction vial makes the system even more attractive. Normal production runs yield 25-150 mCi of [¹⁸F]FDG. Since no manual handling of radioactivity is involved, a scaled up production is feasible by this procedure. We have avoided the use of any permanent electrical liquid transfer devices in our system, thereby eliminating the possibility of pyrogen build up. An in-house radiopharmaceutical program to check the sterility and apyrogenicity of the short-lived radiopharmaceuticals is an added convenience at our institution. (author)

[en] A synthetic procedure for the preparation of [¹⁸F]FPCBT, an imaging agent for the dopamine transporter (DAT), has been developed. The radiosynthesis was carried out in a two step procedure. Even though the yield was low, we were able to prepare 20 to 30mCi of the product, which was enough for two or three studies. The radiochemical purity was greater than 96%. The in vivo properties of this radiotracer were evaluated using baboon and it showed highest uptake in the striatum. The studies also revealed that the maximum uptake was reached within 7 to 10 minutes post injection. Plasma metabolite analysis indicated that there is only one metabolite and it is less lipophilic than the parent compound. [¹⁸F]FPCBT displayed good brain uptake and its high target to non target ratio indicate that it is a potential candidate for DAT imaging