Abstract：
Cardiac blood pool imaging is currently performed almost exclusively with 99mTc-based compounds and SPECT/CT imaging. Using a generator-based PET radioisotope has a few advantages, including not needing nuclear reactors to produce it, obtaining better resolution in humans, and potentially reducing the radiation dose to the patient. When the shortlived radioisotope 68Ga is used, it can be applied repeatedly on the same day-for example, for the detection of bleeding. Our objective was to prepare and evaluate a long-circulating polymer functionalized with gallium for its biodistribution, toxicity, and dosimetric properties. A 500 kDa hyperbranched polyglycerol was conjugated to the chelator NOTA and radiolabeled rapidly at room temperature with 68Ga. It was then injected intravenously into a rat, and gated imaging allowed us to easily observe wall motion and cardiac contractility, confirming the suitability of this radiopharmaceutical for cardiac blood pool imaging. Internal radiation dose calculations showed that the radiation doses that patients would receive from the PET agent would be 2.5× lower than those from the 99mTc agent. A complete 14-day toxicology study in rats concluded that there were no gross pathology findings, changes in body or organ weights, or histopathological events. This radioactive-metal-functionalized polymer might be a suitable non-toxic agent to advance for clinical application.
摘要：
心脏血池成像目前几乎完全使用基于99mTc的化合物和SPECT/CT成像进行。使用基于发生器的PET放射性同位素具有一些优点，包括不需要核反应堆来生产它，在人类中获得更好的分辨率，并有可能减少对患者的辐射剂量。当使用短寿命放射性同位素68Ga时，它可以在同一天重复应用-例如，用于检测出血。我们的目标是制备和评估一种用镓功能化的长循环聚合物，用于其生物分布，毒性,和剂量测定属性。将500kDa超支化聚甘油与螯合剂NOTA缀合,并在室温下用68Ga快速放射性标记。然后静脉注射到老鼠体内,门控成像使我们能够轻松观察壁运动和心脏收缩力，确认该放射性药物用于心脏血池成像的适用性。内部辐射剂量计算表明，患者从PET剂接受的辐射剂量比99mTc剂的辐射剂量低2.5倍。对大鼠进行的为期14天的完整毒理学研究得出的结论是，没有大体的病理学发现，身体或器官重量的变化，或组织病理学事件。这种放射性金属官能化的聚合物可能是一种适合于临床应用的无毒试剂。
