Millar A M, Wilkinson A G, McAteer E, Best J J
Department of Radiopharmacy, Royal Infirmary, Edinburgh, UK.
Nucl Med Commun. 1990 Jun;11(6):405-12.
A kit for preparing technetium-99m mercaptoacetyltriglycine (99Tcm-MAG3), a new radiopharmaceutical for gamma camera renography, is available commercially. A drawback to the use of this kit is the recommended 1h expiry for 99Tcm-MAG3. This short expiry is a consequence of the possible growth of an impurity which undergoes hepatobiliary excretion and might interfere with renal imaging. Radiochemical purity of 99Tcm-MAG3 was measured by high performance liquid chromatography at 0, 1 and 6 h after preparation and was found to be consistently greater than 95. 99Tcm-MAG3 was shown to contain five impurities, one of which increased from 0.5% to 1% over 6 h. Dilution of 99Tcm-MAG3 eliminated this effect. A two-part clinical study was undertaken. For Part I, 99Tcm-MAG3 was prepared at 400 MBq/4 ml. For Part II, 99Tcm-MAG3 was prepared at 1 GBq/4 ml then subdivided and diluted to give single doses of 175 MBq/2.5 ml. In both parts, 10 patients were injected within 1 h after preparation and 10 were injected 5-6 h after preparation. From gamma camera images of the abdomen acquired 30 min after injection, the % injected 99Tcm in gall bladder and liver were calculated. In both parts, the % injected 99Tcm in gall-bladders and livers of the 1 h group were compared with those in the 5-6 h group and not found significantly different (p greater than 0.05). In conclusion, 99Tcm-MAG3 prepared according to the methods described, can be used up to 6 h after preparation.
一种用于制备锝-99m 巯基乙酰三甘氨酸（99Tcm-MAG3）的试剂盒已在市面上销售，99Tcm-MAG3 是一种用于γ相机肾造影的新型放射性药物。使用该试剂盒的一个缺点是建议 99Tcm-MAG3 的有效期为 1 小时。这种短有效期是由于可能产生一种经肝胆排泄的杂质，该杂质可能会干扰肾脏成像。在制备后 0、1 和 6 小时通过高效液相色谱法测量 99Tcm-MAG3 的放射化学纯度，发现其始终大于 95。结果表明 99Tcm-MAG3 含有五种杂质，其中一种在 6 小时内从 0.5%增加到 1%。99Tcm-MAG3 的稀释消除了这种影响。进行了一项分为两部分的临床研究。在第一部分中，以 400 MBq/4 ml 的剂量制备 99Tcm-MAG3。在第二部分中，以 1 GBq/4 ml 的剂量制备 99Tcm-MAG3，然后进行细分和稀释，以得到 175 MBq/2.5 ml 的单剂量。在两部分中，10 名患者在制备后 1 小时内注射，10 名患者在制备后 5 - 6 小时注射。从注射后 30 分钟采集的腹部γ相机图像中，计算胆囊和肝脏中注入的 99Tcm 的百分比。在两部分中，将 1 小时组胆囊和肝脏中注入的 99Tcm 的百分比与 5 - 6 小时组的进行比较，未发现显著差异（p 大于 0.05）。总之，按照所述方法制备的 99Tcm-MAG3 在制备后 6 小时内均可使用。
