McCarthy D W, Shefer R E, Klinkowstein R E, Bass L A, Margeneau W H, Cutler C S, Anderson C J, Welch M J
Edward Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO 63110, USA.
Nucl Med Biol. 1997 Jan;24(1):35-43. doi: 10.1016/s0969-8051(96)00157-6.
Copper-64 (T 1/2 = 12.7 h) is an intermediate-lived positron-emitting radionuclide that is a useful radiotracer for positron emission tomography (PET) as well as a promising radiotherapy agent for the treatment for cancer. Currently, copper-64 suitable for biomedical studies is produced in the fast neutron flux trap (irradiation of zinc with fast neutrons) at the Missouri University Research Reactor. Access to the fast neutron flux trap is only possible on a weekly basis, making the availability of this tracer very limited. In order to significantly increase the availability of this intermediate-lived radiotracer, we have investigated and developed a method for the efficient production of high specific activity Cu-64 using a small biomedical cyclotron. It has been suggested that it may be possible to produce Cu-64 on a small biomedical cyclotron utilizing the 64Ni(p,n)64Cu nuclear reaction. We have irradiated both natural nickel and enriched (95% and 98%) Ni-64 plated on gold disks. Nickel has been electroplated successfully at thicknesses of approximately 20-300 mm and bombarded with proton currents of 15-45 microA. A special water-cooled target had been designed to facilitate the irradiations on a biomedical cyclotron up to 60 microA. We have shown that it is possible to separate Cu-64 from Ni-64 and other reaction byproducts rapidly and efficiently by using ion exchange chromatography. Production runs using 19-55 mg of 95% enriched Ni-64 have yielded 150-600 mCi of Cu-64 (2.3-5.0 mCi/microAh) with specific activities of 94-310 mci/microgram Cu. The cyclotron produced Cu-64 had been used to radiolabel PTSM [pyruvaldehyde bis-(N4-methylthiosemicarbazone), used to quantify myocardial, cerebral, renal, and tumor blood flow], MAb 1A3 [monoclonal antibody MAb to colon cancer], and octreotide. A recycling technique for the costly Ni-64 target material has been developed. This technique allows the nickel eluted off the column to be recovered and reused in the electroplating of new targets with an overall efficiency of greater than 90%.
铜 - 64（半衰期(T_{1/2}=12.7)小时）是一种半衰期适中的正电子发射放射性核素，它是正电子发射断层扫描（PET）中一种有用的放射性示踪剂，也是一种有前景的癌症治疗放疗剂。目前，适用于生物医学研究的铜 - 64是在密苏里大学研究反应堆的快中子通量阱（用快中子辐照锌）中生产的。只有每周才能使用快中子通量阱，这使得这种示踪剂的可得性非常有限。为了显著提高这种半衰期适中的放射性示踪剂的可得性，我们研究并开发了一种使用小型生物医学回旋加速器高效生产高比活度铜 - 64的方法。有人提出，利用(^{64}Ni(p,n)^{64}Cu)核反应，有可能在小型生物医学回旋加速器上生产铜 - 64。我们用质子束轰击了镀在金盘上的天然镍和富集度为95%和98%的(^{64}Ni)。镍已成功电镀到约20 - 300微米的厚度，并以15 - 45微安的质子流进行轰击。设计了一种特殊的水冷靶，以便在生物医学回旋加速器上进行高达60微安的辐照。我们已经表明，通过离子交换色谱法可以快速有效地从镍 - 64和其他反应副产物中分离出铜 - 64。使用19 - 55毫克95%富集度的(^{64}Ni)进行生产运行，可产生150 - 600毫居里的铜 - 64（2.3 - 5.0毫居里/微安·小时），比活度为94 - 310毫居里/微克铜。回旋加速器生产的铜 - 64已用于标记PTSM[丙酮醛双 - （(N^4) - 甲基硫代半卡巴腙），用于量化心肌、脑、肾和肿瘤的血流]、单克隆抗体1A3[结肠癌单克隆抗体MAb]和奥曲肽。已经开发出一种用于昂贵的(^{64}Ni)靶材料的回收技术。该技术可回收从柱上洗脱的镍，并重新用于电镀新靶，总效率大于90%。
