正电子放射性药物生产条件和影响因素的探讨

Conditions for and factors influencing the production of positron-emitting radiopharmaceutical

目的探讨正电子核素及其放射性药物生产的影响因素和生产条件。方法利用18O（p,n）18F和16O（p,α）13N核反应在PETtrace回旋加速器中生产18F负离子和13N-NOx-,以亲核取代反应法合成18F-FDG;采用戴氏合金（Devarda’s alloy）还原法制备13N-NH3·H2O。同时观察靶水纯度及丰度、轰击时间及质子束流大小等因素对放射性药物生产的影响。结果靶水电阻率<10MΩ·cm时,18F-FDG和13N-NH3·H2O的产率分别低于9.5％和38.2％;18O-H2O的丰度>50％,18F-FDG的产率>20％。束流强度在5-35μA时,18F负离子和13N-NO的产额随束流增大而增加;在0-20min的轰击时间内,13N-NOx-的产额平均以1.2GBq/min的幅度增加,轰击30min以上,其增加幅度仅为0.1GBq/min;轰击时间在60min内,18F负离子的产额平均以1.1GBq/min的幅度增加,轰击120 <min后,其增加幅度<0.68GBq/min。结论靶水纯度和质子束流大小是影响正电子放射性药物产率的主要因素。当靶水电阻率>15MΩ·cm时,以正电子核素的一个半衰期时间,用25-35μA的质子束流持续轰击,其·18F负离子和13N-NOx-的产额以及18F-FDG和13N-NH3·H2O的产率较高。

Objective To investigate the conditions for producing positron-emitting radionuclides and radiopharmaceutical synthesis and determine the factors influencing their production. Methods [18F]fluorine anion and 'N-NOx- were producted by 18O (p, n)18F and 'O (p, α)13N nuclear reaction in PETtrace Cyclotron, respectively. The 2-deoxy-2-[18F]-fluoro-D-glucose (18F-FDG) was synthesized by direct nucleophilic exchange on 4- (4-methylpiperidinyl) pyridinium resin. The 13N-NOX- in target water was reduced by Devard's alloy to prepare 13N-ammoina. At the same time, the effect of the abundance and purity of target water, the irradition time, and the proton beam current on the productions of positron-emitting radionuclides and radiopharmaceutical were observed. Results While the resistivity of water was less than 10 MΩ·cm, the yields of 18F-FDG and l3N-ammoina were less than 9.5μ and 38.2μ, respectively. The yield of 18F-FDG was more than 20μ by using high abundance of 18O-water above 50μ. When proton beam current were between 5μA and 35 μA, the yields of [18F]fluorine anion and 13N-NOX- were increased with the increment of the proton beam current. During irradition, the yield of 13N-NOX- increased at a rate of 1.2 GBq/min in 20 min, but the yield of 13N-NOX- was only 0.1 GBq/min after 30 min. Furthermore, the yield of [l8F]fluorine anion increased at a rate of 1.1 GBq/min in 60 min, and was less than 0.68 GBq/min after 120 min. Concolutions The purity of the target water and the proton beam current are the principal factors affecting the production of the positron emitting radionuclides and the synthesis of radiopharmaceutical. When the resistivity of target water was above 15 MΩ·cm and the irradition time was one half-life of the positron-emitting nuclides, the higher yields of [18F]fluorine anion and 13N-NOX- and radiopharmaceutical can obtained by using 25μA -35μA proton beam current bombarding the 18O- and 16O-water respectively.