Specific tumor uptake of peptide radiopharmaceuticals depends on tumor binding affinity and their radiochemical purity. Several important parameters that influence the ^99mTc‐labeling and consequently the radiochemical purity of 6‐hydrazinonicotinamide (HYNIC)‐conjugated peptide are radionuclide activity, the amount of peptide, the amount of coligands, and the amount of reducing agents (stannous ion). In this review article, we have attempted studying these parameters in the HYNIC‐conjugated peptides (somatostatin, cholecystokinin/gastrin, bombesin, and RGD analogs) from a new perspective to obtain most used and optimized radio‐stoichiometric relationships. One of the most important results in this review is that for ^99mTc‐labeling of HYNIC‐conjugated peptides, it is better to consider the most calculated mole ratio between technetium‐99m and the peptide (mole ratio of technetium‐99m to the peptide 1:200–400). The statistical results also show that among these ^99mTc‐labeled peptides, the most used and favorable coligand is tricine/EDDA with two to one (2:1) mole ratio. These optimized radio‐stoichiometric relationships, favorable coligand mole ratio, and applicable radiolabeling points can greatly improve the labeling process of the HYNIC‐conjugated peptides, by reducing trial and error, increasing specific activity, and saving materials.

中文翻译：

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从新角度研究 6-肼基烟酰胺偶联肽的 99mTc 标记条件：术语放射化学计量学简介

肽放射性药物的特定肿瘤吸收取决于肿瘤结合亲和力及其放射化学纯度。影响^99m Tc 标记并因此影响 6-肼基烟酰胺 (HYNIC) 偶联肽的放射化学纯度的几个重要参数是放射性核素活性、肽的量、配体的量和还原剂（亚锡离子）的量。在这篇综述文章中，我们尝试从新的角度研究 HYNIC 偶联肽（生长抑素、缩胆囊素/胃泌素、铃蟾肽和 RGD 类似物）中的这些参数，以获得最常用和最优化的放射化学计量关系。本次审查中最重要的结果之一是对于^99mHYNIC 偶联肽的 Tc 标记，最好考虑锝-99m 与肽之间最计算的摩尔比（锝99m 与肽的摩尔比为 1:200-400）。统计结果还表明，在这些^99m Tc 标记的肽中，最常用和最有利的多配体是三碱/EDDA，摩尔比为二比一 (2:1)。这些优化的放射性化学计量关系、有利的配体摩尔比和适用的放射性标记点可以通过减少试验和错误、增加比活性和节省材料，大大改善 HYNIC 偶联肽的标记过程。