背景:本研究的目的是开发并证明一种可行的方法,该方法使用中等通量反应器生产具有可接受比活性的(169)Er,并根据基于汞池阴极的电化学途径从(169)Yb中纯化,以放射性核素纯形式利用(169)Er,这对其治疗用途至关重要。
方法:通过在〜8×10(13)n.cm(-2)的热中子通量下对同位素富集((168)Er中的98.2%)目标进行中子轰击,在反应堆中产生了169。s(-1)为21d。彻底优化辐照参数,包括中子通量,进行了辐照时间和靶冷却时间。研究了不同实验参数对从(169)Er中定量去除(169)Yb的影响,优化并基于结果;采用了两个循环的电化学分离程序。通过使用羟基磷灰石(HA)颗粒和1,4,7,10-四氮杂环十二烷-1,4,7,10-四氨基亚甲基膦酸(DOTMP)进行放射性标记研究,确定了纯化(169)Er在放射滑膜切除术和骨痛缓解中的适用性,分别。
结果:在〜8×10(13)n.cm(-2)的通量下,对10mg同位素富集((168)Er中的98.2%)目标进行热中子辐照。s(-1)21d,然后对(169)Yb杂质进行两步电化学分离,得到〜3.7GBq(100mCi)的(169)Er,比活性为〜370MBq/mg(10mCi/mg)和放射性核素纯度>99.99%。通过执行几个生产批次,充分证明了这种方法的可靠性,其中每个批次的性能保持一致。在使用HA颗粒和DOTMP的放射性标记研究中证明了纯化的(169)Er的实用性,其中两种放射性标记产物都以高放射性标记产率(>99%)获得。
结论:批量生产和纯化(169)Er的可行策略,适用于治疗应用,已经开发和证明。
BACKGROUND: The aim of the present study was to develop and demonstrate a viable method for the reactor production of (169)Er with acceptable specific activity using moderate flux reactor and its purification from (169)Yb following electrochemical pathway based on mercury-pool cathode to avail (169)Er in radionuclidically pure form essential for its therapeutic use.
METHODS: Erbium-169 was produced in reactor by neutron bombardment of isotopically enriched (98.2% in (168)Er) erbium target at a thermal neutron flux of ~8×10(13) n.cm(-2).s(-1) for 21 d. A thorough optimization of irradiation parameters including neutron flux, irradiation time and target cooling time was carried out. The influence of different experimental parameters for the quantitative removal (169)Yb from (169)Er was investigated, optimized and based on the results; a two-cycle electrochemical separation procedure was adopted. The suitablility of purified (169)Er for application in radiation synovectomy and bone pain palliation was ascertained by carrying out radiolabeling studies with hydroxypaptite (HA) particles and 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraaminomethylene phosphonic acid (DOTMP), respectively.
RESULTS: Thermal neutron irradiation of 10mg of isotopically enriched (98.2% in (168)Er) erbium target at a flux of ~8×10(13) n.cm(-2).s(-1) for 21 d followed by a two-step electrochemical separation of (169)Yb impurity yielded ~3.7GBq (100mCi) of (169)Er with a specific activity of ~370MBq/mg (10mCi/mg) and radionuclidic purity of >99.99%. The reliability of this approach was amply demonstrated by performing several production batches, where the performance of each batch remained consistent. The utility of the purified (169)Er was demonstrated in the radiolabeling studies with HA particles and DOTMP, wherein both the radiolabeled products were obtained with high radiolabeling yield (>99%).
CONCLUSIONS: A viable strategy for the batch production and purification of (169)Er, suitable for therapeutic applications, has been developed and demonstrated.