Radioiodinated MIBG has shown considerable promise as an imaging agent for cardiac and oncologic applications, and also as a targeted radiotherapeutic for treating patients with neuroendocrine tumors. This radiolabeled agent, synthesized at a no-carrier-added level, has demonstrated advantages over the carrier-added preparation in preliminary clinical studies. Earlier we developed a silicon precursor from which both radioiodinated MIBG and the α-particle-emitting 211At analog [211At]MABG could be synthesized at a no-carrier-added level. In order to increase the practicality of this approach, we have developed a synthesis of a tin precursor in two steps from a readily available starting material. This tin precursor, N, N′-bis(tert-butyloxycarbonyl)-3-(trimethylstannyl)benzylguanidine (Bis-Boc MTMSBG) was evaluated for the synthesis of n.c.a. [*I]MIBG and [211At]MABG via halodestannylation. The radiochemical yields were 83 ± 9% (n=7), 30 ± 21% (n=2), 77 ± 2% (n=2), and 66 ± 7% (n=4) for labeling with 131I, 124I, 125I, and 211At, respectively. Copyright © 2007 John Wiley & Sons, Ltd.
放射性
碘化 MIBG 作为心脏和肿瘤成像剂,以及作为治疗神经内分泌肿瘤患者的靶向放射治疗药物,已显示出相当大的前景。在初步临床研究中,这种以无载体添加
水平合成的放射性标记制剂已显示出优于载体添加制剂的优势。早些时候,我们开发了一种
硅前体,用它可以在不添加载体的情况下合成放射性
碘化 MIBG 和发射 α 粒子的 211At 类似物 [211At]MABG。为了提高这种方法的实用性,我们开发了一种利用现成的起始材料分两步合成
锡前体的方法。我们对这种
锡前体--N, N′-双(叔丁氧羰基)-3-(
三甲基锡)苄基
胍(Bis-Boc
MTMSBG)进行了评估,以通过卤代烷酰化法合成 n.c.a. [*I]MIBG 和 [211At]MABG。用 131I、124I、125I 和 211At 标记的放射
化学收率分别为 83 ± 9% (n=7)、30 ± 21% (n=2)、77 ± 2% (n=2) 和 66 ± 7% (n=4)。Copyright © 2007 John Wiley & Sons, Ltd. All Rights Reserved.