Zinn K R, Chaudhuri T R, Cheng T P, Morris J S, Meyer W A
University of Missouri Research Reactor, Columbia 65211.
Cancer. 1994 Feb 1;73(3 Suppl):774-8. doi: 10.1002/1097-0142(19940201)73:3+<774::aid-cncr2820731305>3.0.co;2-l.
Positron emission tomography offers advantages for radioimmunodiagnosis of cancer but requires radionuclides of appropriate half-life that have high specific activity and high radio-purity. This work was designed to develop a viable method to produce and purify 64Cu, which has high specific activity, for positron emission tomography.
64Cu was produced at the University of Missouri Research Reactor by the nuclear reaction, 64Zn(n,p)64Cu. Highly pure zinc metal (99.9999%) was irradiated in a specially designed boron nitrite lined container, which minimized thermal neutron reactions during irradiation. A new two-step procedure was developed to chemically separate the no-carrier-added 64Cu from the zinc metal target.
64Cu recovery for 24 runs averaged 0.393 (+/- 0.007) mCi per milligram of zinc irradiated. The boron-lined irradiation container reduced unwanted zinc radionuclides 14.3-fold. Zinc radionuclides and non-radioactive zinc were separated successfully from the 64Cu. The new separation technique was fast (2 hours total time) and highly efficient for removing the zinc. The zinc separation factor for this technique averaged 8.5 x 10(-8), indicating less than 0.0000085% of the zinc remained after separation. Thus far, the highest 64Cu specific activity at end of irradiation was 683 Ci/mg Cu, with an average of 512 Ci/mg Cu for the last six analyzed runs.
The boron-lined irradiation container has sufficient capacity for 75-fold larger-sized zinc targets (up to 45 g). The new separation technique was excellent for separating 64Cu, which appears to be a radionuclide with great potential for positron emission tomography.
正电子发射断层扫描在癌症的放射免疫诊断中具有优势，但需要具有高比活度和高放射性纯度的合适半衰期的放射性核素。本研究旨在开发一种可行的方法来生产和纯化用于正电子发射断层扫描的具有高比活度的64Cu。
在密苏里大学研究反应堆中通过核反应64Zn(n,p)64Cu生产64Cu。将高纯度锌金属（99.9999%）在一个特殊设计的衬有亚硝酸硼的容器中进行辐照，该容器可使辐照期间的热中子反应降至最低。开发了一种新的两步法，以从锌金属靶中化学分离无载体添加的64Cu。
24次运行的64Cu回收率平均为每毫克辐照锌0.393（±0.007）毫居里。衬硼的辐照容器将不需要的锌放射性核素减少了14.3倍。锌放射性核素和非放射性锌成功地与64Cu分离。新的分离技术速度快（总时间2小时），并且在去除锌方面效率很高。该技术的锌分离系数平均为8.5×10(-8)，表明分离后残留的锌不到0.0000085%。到目前为止，辐照结束时64Cu的最高比活度为683居里/毫克铜，最近六次分析运行的平均值为512居里/毫克铜。
衬硼的辐照容器对于大75倍尺寸的锌靶（高达45克）具有足够的容量。新的分离技术在分离64Cu方面表现出色，64Cu似乎是一种在正电子发射断层扫描中具有巨大潜力的放射性核素。
