177Lu-radiopharmaceuticals can contain the metastable impurity [177mLu]lutetium with a physical half-life of 160.4 days, in varying concentrations depending on the route of production of the radionuclidic precursor [177Lu]lutetium. Due to the long half-life of [177mLu]lutetium, difficulties with waste disposal or sterility testing could arise. Here, we analyzed several 177Lu-samples of different origins and suppliers regarding their 177mLu-concentration. All samples tested showed a 177mLu-concentration in the range that was stated on the certificate of analysis from the supplier which is in accordance with the European Pharmacopoeia. Although all 177mLu-concentrations were in accordance with the European Pharmacopoeia, we need to take into account the respective national legislation regarding radioactivity release limits. With regard to the German legislation, several probes for sterility testing in external laboratories could not be released for transport due to the concentration of [177mLu]lutetium. Moreover, waste water tanks should specifically be monitored for 177mLu-concentration, when e.g. Lutathera® is administered in the clinic.

中文翻译：

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评估内部生产的 177Lu 放射性药物和市售 Lutathera® 中的 177mLu 浓度

177Lu-放射性药物可含有亚稳态杂质[177mL]镥，其物理半衰期为160.4天，其浓度取决于放射性核素前体[177Lu]镥的生产途径。由于[177mL]镥的半衰期较长，可能会出现废物处理或无菌测试的困难。在这里，我们分析了几个不同来源和供应商的 177Lu 样品的 177mLu 浓度。所有测试样品的浓度均为 177mLu，在供应商分析证书上规定的范围内，符合欧洲药典。尽管所有 177mLu 浓度均符合欧洲药典，但我们需要考虑有关放射性释放限制的相应国家立法。根据德国立法，由于[177mL]镥浓度，外部实验室用于无菌检测的几种探针不能放行运输。此外，当在诊所使用 Lutathera® 时，应特别监测废水箱的 177mLu 浓度。