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

直到最近，191 Os-191 m/Ir发生器的开发一直是 根据对不同组合的系统评价， 离子交换材料和洗脱液，同时保留相同的化学形式， 锇-191母体 虽然已经实现了逐步改善， 通过这种方法，迄今为止，这些改进并不显著 足以促进放射性核素191 m/Ir的常规临床使用 心血管造影 然而，我们最近证明， 发电机性能的更大改进可以通过 使用不同化学形式的锇-191母体。 通过使用 二羧酸配合物的锇（VI），我们已经开发出发电机 191 m/Ir产额高出2-3倍，191 Os突破的十分之一， 早期的设计 此外，这些是第一批191 Os-191 m/Ir发生器 可以与生理相容的洗脱液一起使用。 这些 然而，发生器仍然具有相对低的191 m/Ir产率（30%mL）， 由于锇的光解，产率随时间而降低 复杂. 该项目的目标是开发新的191 Os-191 m/Ir 具有更高（和恒定）191 m/Ir产额的发电机， 低191 Os穿透和生理相容性的特性 二羧酸发生剂的洗脱液。 这一目标将得以实现 通过评价一系列新的锇配合物， （二）在以前的设计中， 191 Os-191 m/Ir发生器。 这些较低氧化态的锇络合物 在191 Os的β衰变后，将直接导致稳定的铱络合物 其可以高产率洗脱。 这种方法避免了一种固有的 使用锇络合物的191 Os-191 m/Ir发生器在较高温度下的局限性 (IV VI）不提供可洗脱铱的直接路径的氧化态 复杂，同时，结合了我们早期的结果 研究表明，发电机性能的改善可能是 通过更适当地选择锇-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.