Collider Accelerator Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
Collider Accelerator Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
Nucl Med Biol. 2021 Jan;92:184-201. doi: 10.1016/j.nucmedbio.2020.03.004. Epub 2020 Apr 13.
Molecular imaging is a non-invasive process that enables the visualization, characterization, and quantitation of biological processes at the molecular and cellular level. With the emergence of theragnostic agents to diagnose and treat disease for personalized medicine there is a growing need for matched pairs of isotopes. Matched pairs offer the unique opportunity to obtain patient specific information from SPECT or PET diagnostic studies to quantitate in vivo function or receptor density to inform and tailor therapeutic treatment. There are several isotopes of arsenic that have emissions suitable for either or both diagnostic imaging and radiotherapy. Their half-lives are long enough to pair them with peptides and antibodies which take longer to reach maximum uptake to facilitate improved patient pharmacokinetics and dosimetry then can be obtained with shorter lived radionuclides. Arsenic-72 even offers availability from a generator that can be shipped to remote sites and thus enhances availability. Arsenic has a long history as a diagnostic agent, but until recently has suffered from limited availability, lack of suitable chelators, and concerns about toxicity have inhibited its use in nuclear medicine. However, new production methods and novel chelators are coming online and the use of radioarsenic in the pico and nanomolar scale is well below the limits associated with toxicity. This manuscript will review the production routes, separation chemistry, radiolabeling techniques and in vitro/in vivo studies of three medically relevant isotopes of arsenic (arsenic-74, arsenic-72, and arsenic-77).
分子成像是非侵入性的过程，能够在分子和细胞水平可视化、描述和定量生物过程。随着治疗诊断试剂的出现，为了实现个性化医疗，对匹配的同位素的需求也在不断增长。匹配对提供了一个独特的机会，可以从 SPECT 或 PET 诊断研究中获取患者特异性信息，以定量体内功能或受体密度，从而为治疗提供信息并进行个性化调整。有几种砷同位素的发射适合诊断成像和放射治疗。它们的半衰期足够长，可以与肽和抗体配对，这些物质需要更长的时间才能达到最大摄取量，从而改善患者的药代动力学和剂量学，而半衰期较短的放射性核素则无法做到这一点。砷-72 甚至可以从可以运送到偏远地区的发生器中获得，从而提高了可用性。砷作为诊断剂已有很长的历史，但直到最近，由于可用性有限、缺乏合适的螯合剂以及对毒性的担忧，限制了其在核医学中的应用。然而，新的生产方法和新型螯合剂正在出现，放射性砷在皮克和纳摩尔级的使用远远低于与毒性相关的限制。本文将综述三种医学相关的砷同位素（砷-74、砷-72 和砷-77）的生产途径、分离化学、放射性标记技术以及体外/体内研究。
