DEVELOPMENT OF A 191-OS:191M-IR RADIONUCLIDE GENERATOR

直到最近，191OS-191M/Ir发电机的发展一直是 基于对不同组合的系统评估 离子交换材料和洗脱液，同时保持相同的化学形式 Os-191的母体。虽然已经实现了渐进的改进 通过这种方法，迄今为止，这些改进并不是戏剧性的 足以方便放射性核素191M/Ir的常规临床使用 心血管造影术。然而，我们最近已经证明了这一点 发电机性能的更大改进可以通过 使用不同化学形式的Os-191母体。通过使用 我们研制了一种新的有机试剂--二元酸--Os(VI)络合物的发生器 191M/iR的产量是191M/iR的2-3倍，是191O的十分之一 更早的设计。此外，这些是第一批191O-191M/Ir发电机 可以与生理上相容的洗脱剂一起使用。这些 然而，发电机仍然具有相对较低的191M/Ir产量(30%毫升)和 由于Os的光解，产率随时间降低。 很复杂。 该项目的目标是开发一种新的191OS-191M/IR 具有较高(和恒定)191m/ir产额的发电机，保持了 低~(191)Os突破的特性和生理相容 二元酸发生器的洗脱液。这个目标一定会实现的 通过对一系列新的氧化程度较低的臭氧络合物的评价 国家(II，III)比在以前的任何设计中使用的 191OS-191M/Ir发电机。在这些较低的氧化态中的Os络合物 在~(191)Os的β衰变后，将直接导致稳定的Ir络合物 这可能会在高收益的情况下被洗脱。这种方法避免了固有的 ~(191)OS-191M/Ir产生器在较高功率下的使用限制 (IV，VI)氧化态，不提供直接通向难以捉摸的Ir的途径 复杂，同时融合了我们早期的结果 研究表明发电机性能的改善可能是 通过更合适地选择Os-191母体络合物来实现。

The development of the 191Os-191m/Ir generator has, until recently, been based on the systematic evaluation of different combinations of ion-exchange material and eluent while retaining the same chemical form of the osmium-191 parent. While incremental improvements have been realized through this approach, these improvements have not, to date, been dramatic enough to facilitate routine clinical use of 191m/Ir for radionuclide angiocardiography. We have recently demonstrated, however, that much greater improvements in generator performance can be achieved through the use of a different chemical form of the osmium-191 parent. Through the use of dicarboxylic acid complexes of osmium(VI) we have developed generators with 2-3 times higher 191m/Ir yield and one-tenth the 191Os breakthrough of earlier designs. In addition, these are the first 191Os-191m/Ir generators that may be used with a physiologically compatible eluent. These generators still, however, have relatively low 191m/Ir yield (30% mL) and the yield decreases with time as a result of photolysis of the osmium complex. The goal of this project is the development of a new 191Os-191m/Ir generator with higher (and constant) 191m/Ir yield that retains the properties of low 191Os breakthrough and a physiologically compatible eluent of the dicarboxylic acid generators. This goal will be achieved through evaluation of a new series of osmium complexes in lower oxidation states (II, III) than those used in any of the previous designs of the 191Os-191m/Ir generator. Osmium complexes in these lower oxidation states will, after beta decay of 191Os, lead directly to stable iridium complexes that may be eluted in high yield. This approach avoids one of the inherent limitations of 191Os-191m/Ir generators using osmium complexes in higher (IV, VI) oxidation states that offer no direct path to an elutable iridium complex and, at the same time, incorporates the results of our earlier studies showing the improvements in generator performance that may be realized through more appropriate choice of the osmium-191 parent complex.