Analysis of blood clearance and labeled metabolites for the estrogen receptor tracer [F-18]-16 alpha-fluorestradiol (FES)
Analysis of blood clearance and labeled metabolites for the estrogen receptor tracer [F-18]-16 alpha-fluorestradiol (FES)
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DOI：
10.1016/s0969-8051(97)00002-4
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发表时间：
1997-05-01
影响因子：
3.1
通讯作者：
Eary, JF
中科院分区：
文献类型：
--
作者：
Mankoff, DA;Tewson, TJ;Eary, JF
[F-18] 16 α -氟雌二醇（FES）已被证明是乳腺肿瘤中雌激素受体含量的示踪剂；然而，由于示踪剂在体内的快速代谢，FES图像的定量分析变得复杂。为了优化FES PET成像研究，并为乳腺肿瘤中FES摄取的定量分析提供输入函数，我们研究了15例乳腺癌患者FES的清除和代谢。进行了FES清除率、蛋白质结合和代谢物产生以及确定标记代谢物身份的有限测定。这些研究表明，FES能迅速从血液中清除并代谢；在20分钟时，只有20%的循环放射性是未代谢的FES，其中大部分是蛋白质结合的。血液或尿液中可检测到的代谢物是偶联产物，主要是葡萄糖醛酸盐和FES的硫酸盐，它们通过肾脏排泄，其速度与它们进入循环的速度相当。注射后20分钟，血液中的放射性水平保持相当稳定。我们的研究结果是人类代谢物的第一份报告，与之前FES代谢的动物研究非常一致。这些研究表明，由于FES清除迅速，代谢物背景几乎不变，因此在注射后20至30分钟开始成像可能提供含雌激素组织的良好可视化。在量化FES摄取时，需要考虑标记的代谢物。(C) 1997爱思唯尔科学有限公司
[F-18] 16 alpha-Fluoroestradiol (FES) has been shown to be a tracer of estrogen receptor content in breast tumors; however, quantitative analysis of FES images is complicated by the rapid metabolism of the tracer in vivo. To optimize FES PET imaging studies and to provide an input function for the quantitative analysis of the tracer FES uptake in breast tumors, we studied the clearance and metabolism of FES in 15 breast cancer patients. FES clearance, protein binding, and metabolite production and limited assays to determine the identity of labeled metabolites were performed. These studies show that FES was rapidly cleared from the blood and metabolized; at 20 min only 20% of the circulating radioactivity was unmetabolized FES, and much of this was protein bound. The detectable metabolites in either blood or urine are conjugation products, largely the glucuronide and the sulfate of FES, and these are excreted through the kidneys at a rate comparable to their introduction into the circulation. After 20 min postinjection the blood levels of radioactivity remain fairly constant. Our results, the first report on human metabolites, are in close agreement with previous animal studies of FES metabolism. These studies show that because FES clearance is rapid and metabolite background is nearly constant, imaging starting at 20 to 30 min after injection may provide good visualization of estrogen-containing tissues. Labeled metabolites need to be accounted for in quantifying FES uptake. (C) 1997 Elsevier Science Inc.