碘-124的生产、标记及在肿瘤PET分子影像的应用

¹²⁴I是一种半衰期较长的正电子核素（T_1/2=4.2 d），由于其生产工艺要求较高、复杂的衰变纲图以及辐射出的超高能量γ射线，在过去很长一段时间里限制了其临床应用。如今，随着回旋加速器生产核素技术的进步及正电子发射型计算机断层显像（PET）技术在肿瘤及药物药代动力学等研究中应用不断拓展，使得¹²⁴I核素标记的化合物成为具有应用价值的核医学PET分子探针。本文主要对¹²⁴I正电子核素的核性质、生产方式、常规标记方法以及在PET分子影像方面的临床应用进行阐述。

Production of Iodine-124 and Its Application in PET Molecular Imaging

Iodine-124 (¹²⁴I) is an isotope for positron as well as unique chemical properties and convenient half life of 4.2 days. Its modes of decay are 74.4% electron captureand 25.6% positron emission. Until recently,¹²⁴I is not considered to be an attractive isotope for medical application owing to its complex radioactive decay scheme and the high-energy gamma rays.¹²⁴I can be made by numerous nuclear reactions via a cyclotron. The most common starting material is¹²⁴Te and¹²⁴I that can decay to¹²⁴Te.¹²⁴I as sodium iodine form can be used to image the thyroid and corresponding tumor using positron emission tomography (PET) directly. The¹²⁴I nuclide can be chemically bonded to a pharmaceutical to form a positron-emitting radiopharmaceutical. Radioiodination of¹²⁴I can be efficiency attached to small molecular, peptide or antibody within radiochemistry labs. Nowadays, due to the increasing application of PET in medical oncology, pharmacokinetics and drug metabolism,¹²⁴I-labeled radiopharmaceuticals are now becoming one of the most useful tools for PET imaging.¹²⁴I-labeled monoclonal antibodies (mAbs) are being used for clinical immuno-PET. Among them,¹²⁴I-cG250 accurately identifies clear-cell renal carcinoma attracting clinical attentions. Based on those progress, this review outlined the physical property, production and application of¹²⁴I in PET molecular imaging.