Métayé Thierry, Rosenberg Thierry, Guilhot Joëlle, Bouin-Pineau Marie-Hélène, Perdrisot Rémy
Department of Nuclear Medicine and Radiopharmacy, University Hospital, Poitiers, France.
J Nucl Med Technol. 2012 Sep;40(3):187-93. doi: 10.2967/jnmt.111.101246. Epub 2012 Aug 7.
A high radiochemical purity (RCP) is recommended for radiopharmaceutical compounds used in the clinical practice of nuclear medicine. However, some preparations of (99m)Tc-sestamibi contain excess impurities (>6%). To understand the origin of these impurities, we investigated the effect of sodium nitrate on the RCP of sestamibi preparations by testing eluates from 3 commercially available (99m)Tc generators.
The sestamibi kits (Stamicis) were reconstituted with (99m)Tc eluate from nitrate-containing wet-column (NCWC), nitrate-free wet-column (NFWC), and nitrate-free dry-column (NFDC) generators. Sodium nitrate was 0.05 mg/mL in eluates from the NCWC generators. The RCP was determined using aluminum oxide sheets as the stationary phase and absolute ethanol as the mobile phase. Succimer, tetrofosmin, oxidronate, exametazine, albumin nanocolloid, and soluble albumin were also tested for their RCP values with eluates from the 3 different (99m)Tc generators.
The RCP assessment of (99m)Tc-sestamibi was performed on 127 Stamicis preparations. Significantly lower RCP values were found for Stamicis kits prepared with the NCWC generator than for Stamicis prepared with the NFWC (P < 0.0001) and NFDC (P < 0.0001) generators. The number of Stamicis preparations with an RCP under 94% was greater with the NCWC generator (32 of 53 kits) than with the NFDC (2 of 51 kits) or NFWC (0 of 23 kits) generator. Furthermore, the addition of a 0.05 mg/mL concentration of nitrate in NFWC generator eluates significantly decreased the RCP of the Stamicis preparation. In the absence of nitrate in (99m)Tc eluate, no difference was observed between the RCP values of Stamicis kits prepared with the NFWC and NFDC generators. The (99m)Tc impurities generated by nitrates did not modify the quality of myocardial imaging (normal heart-to-lung ratio, 2.2), probably because these impurities are not in the heart field of view. No other tested (99m)Tc-radiopharmaceutical interfered with nitrates.
We recommend using nitrate-free generator eluates in (99m)Tc-sestamibi preparations to improve the product quality and prevent unnecessary exposure of the patient to radiation.
在核医学临床实践中使用的放射性药物化合物推荐具有高放射化学纯度（RCP）。然而，一些（99m）Tc-司他美比制剂含有过量杂质（>6%）。为了解这些杂质的来源，我们通过测试来自3种市售（99m）Tc发生器的洗脱液，研究了硝酸钠对司他美比制剂RCP的影响。
用来自含硝酸盐湿柱（NCWC）、无硝酸盐湿柱（NFWC）和无硝酸盐干柱（NFDC）发生器的（99m）Tc洗脱液重构司他美比试剂盒（Stamicis）。NCWC发生器洗脱液中硝酸钠的浓度为0.05mg/mL。以氧化铝薄板为固定相、无水乙醇为流动相测定RCP。还用来自3种不同（99m）Tc发生器的洗脱液测试了二巯基丁二酸、替曲膦、奥曲膦、依沙美嗪、白蛋白纳米胶体和可溶性白蛋白的RCP值。
对127份Stamicis制剂进行了（99m）Tc-司他美比的RCP评估。发现用NCWC发生器制备的Stamicis试剂盒的RCP值显著低于用NFWC（P<0.0001）和NFDC（P<0.0001）发生器制备的Stamicis试剂盒。RCP低于94%的Stamicis制剂数量，NCWC发生器（53份试剂盒中的32份）多于NFDC（51份试剂盒中的2份）或NFWC（23份试剂盒中的0份）发生器。此外，在NFWC发生器洗脱液中添加0.05mg/mL浓度的硝酸盐会显著降低Stamicis制剂的RCP。在（99m）Tc洗脱液中不存在硝酸盐的情况下，用NFWC和NFDC发生器制备的Stamicis试剂盒的RCP值之间未观察到差异。硝酸盐产生的（99m）Tc杂质未改变心肌显像质量（正常心/肺比值为2.2），可能是因为这些杂质不在心脏视野内。没有其他测试的（99m）Tc放射性药物受硝酸盐干扰。
我们建议在（99m）Tc-司他美比制剂中使用无硝酸盐的发生器洗脱液，以提高产品质量并防止患者不必要地暴露于辐射。
