Eggert Laura A, Dick Michael D, Mahoney Douglas W, Olson Joseph P, Werner Gregory L, Hung Joseph C
Division of Nuclear Medicine, Department of Radiology, Mayo Clinic, Rochester, Minnesota 55905-0001, USA.
J Nucl Med Technol. 2010 Jun;38(2):81-4. doi: 10.2967/jnmt.109.070573. Epub 2010 May 18.
The standard radiochemical purity (RCP) testing method for (99m)Tc-tetrofosmin as described in the package insert requires extensive time (20-30 min) and considerable skill to achieve accurate results. Additionally, the instant thin-layer chromatography strip impregnated with silica gel (2x20 cm) used in the standard method will not be commercially available in the future. The purpose of this study was to evaluate whether a method developed by our laboratory for RCP testing of (99m)Tc-sestamibi could also be used as an alternative method for the RCP assay of (99m)Tc-tetrofosmin.
The alternative RCP testing system consisted of a precut paper strip (1x8.5 cm) from solvent saturation pads (Pall Corp.) as the stationary phase, with 1:1 chloroform:tetrahydrofuran used as the mobile phase. To validate the reliability of the alternative method, RCP values from 17 kit preparations were compared with the 2 methods. Kits were reconstituted according to the package insert instructions, and 4 additions of (99m)Tc-sodium pertechnetate were purposely added to create trials with RCP values below the accepted limit of 90% purity.
Two hundred four trials (100 of which were replicated) were run from the 17 kit preparations. Sixty-four (31%) of the 204 trials were below 90% purity based on the standard method. The overall agreement between the standard and alternative methods was 94% (192/204). The sensitivity of the alternative method for unacceptable RCP limits was 86% (55/64), and the specificity for acceptable RCP values was 98% (137/140). The agreement between the replicated trials of the alternative method was 99% (99/100), and for the standard method it was 92% (92/100).
The standard method proved to be a much slower method and requires much more precision and attention. The alternative method is much faster, is easier, requires less attention to the solvent-development process, and can be used for RCP testing of both (99m)Tc-tetrofosmin and (99m)Tc-sestamibi. Furthermore, the stationary phase is much more readily available, is not moisture-sensitive, and is less susceptible to operator technique. Our method is accurate in determining the RCP value of (99m)Tc-tetrofosmin and is a better RCP testing method for (99m)Tc-tetrofosmin.
药品说明书中描述的（99m）锝-替曲膦标准放射化学纯度（RCP）检测方法需要较长时间（20 - 30分钟）且需要相当的技巧才能获得准确结果。此外，标准方法中使用的浸渍硅胶的即时薄层色谱条（2×20厘米）未来将不再有商业供应。本研究的目的是评估我们实验室开发的一种用于（99m）锝-司他比RCP检测的方法是否也可作为（99m）锝-替曲膦RCP测定的替代方法。
替代RCP检测系统由来自溶剂饱和垫（颇尔公司）的预切纸条（1×8.5厘米）作为固定相，以氯仿：四氢呋喃1:1作为流动相。为验证替代方法的可靠性，将17个试剂盒制剂的RCP值用这两种方法进行比较。试剂盒按照药品说明书的说明进行复溶，并特意添加4次（99m）高锝酸钠以创建RCP值低于90%纯度可接受限度的试验。
从17个试剂盒制剂中进行了204次试验（其中100次为重复试验）。根据标准方法，204次试验中有64次（31%）纯度低于90%。标准方法与替代方法的总体一致性为94%（192/204）。替代方法对不可接受RCP限度的灵敏度为86%（55/64），对可接受RCP值的特异性为98%（137/140）。替代方法重复试验之间的一致性为99%（99/100），标准方法为92%（92/100）。
标准方法被证明是一种慢得多的方法，需要更高的精度和更多关注。替代方法更快、更简便，对溶剂展开过程的关注更少，可用于（99m）锝-替曲膦和（99m）锝-司他比的RCP检测。此外，固定相更容易获得，对水分不敏感，且受操作人员技术影响较小。我们的方法在测定（99m）锝-替曲膦的RCP值方面准确，是一种更好的（99m）锝-替曲膦RCP检测方法。
