Purpose: In recent years, radionuclides like ¹⁷⁷Lu have been considered promising material for the creation of therapeutic radiopharmaceuticals. With the therapeutic use of radiopharmaceuticals, the absorbed doses per tumor may exceed 10 Gy. It is extremely important that doses absorbed by healthy organs and tissues do not exceed the threshold for the incidence of deterministic effects.

Materials and methods: The potential use of the radionuclide lutetium-177 for the palliative treatment of pain in bone metastases is analyzed. The radionuclide ¹⁷⁷Lu is a beta-emitting nuclide with a maximal energy of 0.49 MeV and a half-life of 6.6 days (161 h). Two therapeutic agents were considered: methylene diphosphonate (MDP) and ethylenediamine tetramethylene phosphonic acid (EDTMP). Both drugs contain phosphorus compounds in their composition, which ensures high tropism in bone tissue. For both drugs, biokinetic models of ¹⁷⁷Lu’s behavior in the human body are created. A number of studies have shown that the radiochemical stability of these drugs is about 99%: these calculations took into account the presence of a free ¹⁷⁷Lu radionuclide in each solution. The absorbed doses in organs and tissues when using the radiopharmaceuticals ¹⁷⁷Lu-MDP and ¹⁷⁷Lu-EDTMP, as well as the currently used drugs ¹⁵³Sm-EDTMP and ⁸⁹SrCl₂, are compared. In order to assess the risk of the patient’s exposure to a radiopharmaceutical, the absorbed doses are calculated for each organ where the radioactive label is mainly deposited: the kidneys, red bone marrow, liver and bone surface.

Results: The intensity of dose accumulation when using different drugs on the pathological focus is different. The drug ¹⁷⁷Lu-MDP is faster than other drugs when it comes to the full realization of the expected dose; therefore, a therapeutic effect is achieved faster when it is used. The slowest absorbed dose accumulates when strontium chloride is used. To compare the effectiveness of preparations based on the ¹⁷⁷Lu radionuclide, an analysis of the radiopharmaceuticals currently used for the palliative therapy of bone metastases (⁸⁹SrCl₂ and ¹⁵³Sm-EDTMP) was performed. For ⁸⁹Sr, the most vulnerable organs are the kidneys, red bone marrow and liver, while for ¹⁵³Sm-EDTMP, red marrow bone is most vulnerable. For radiopharmaceuticals based on the ¹⁷⁷Lu radionuclide, the most vulnerable organs are the kidneys, liver and red bone marrow. This proves the effectiveness of the ¹⁷⁷Lu-MDP and ¹⁷⁷Lu-EDTMP radiopharmaceuticals.

Conclusions: According to the results of the calculations, ¹⁷⁷Lu-EDTMP and ¹⁷⁷Lu-MDP demonstrate the best results for the palliative therapy of bone metastases.

目的：近年来，像¹⁷⁷ Lu这样的放射性核素被认为是用于创建治疗性放射性药物的有前途的材料。随着放射性药物的治疗用途，每个肿瘤的吸收剂量可能超过10 Gy。健康器官和组织吸收的剂量不要超过确定性作用发生的阈值，这一点极为重要。

材料和方法：分析了放射性核素lut 177在姑息治疗骨转移瘤中的潜在用途。放射性核素¹⁷⁷ Lu是发射β的核素，最大能量为0.49 MeV，半衰期为6.6天（161小时）。考虑了两种治疗剂：二膦酸二甲酯（MDP）和乙二胺四亚甲基膦酸（EDTMP）。两种药物的成分中都含有磷化合物，可确保骨骼组织中的高向性。对于这两种药物，都创建了¹⁷⁷ Lu在人体中行为的生物动力学模型。大量研究表明，这些药物的放射化学稳定性约为99％：这些计算考虑了游离¹⁷⁷的存在。鲁放射性核素在每种溶液中。比较了使用放射性药物¹⁷⁷ Lu-MDP和¹⁷⁷ Lu-EDTMP以及当前使用的药物¹⁵³ Sm-EDTMP和⁸⁹ SrCl ₂在器官和组织中的吸收剂量。为了评估患者暴露于放射性药物的风险，针对主要沉积放射性标记的每个器官（肾脏，红色骨髓，肝脏和骨表面）计算吸收剂量。

结果：在病理焦点上使用不同药物时剂量累积的强度不同。药物¹⁷⁷路-MDP比其他药物更快，当涉及到完全实现预期的剂量; 因此，使用时可以更快地达到治疗效果。当使用氯化锶时，最慢的吸收剂量会累积。为了比较基于¹⁷⁷ Lu放射性核素的制剂的有效性，对目前用于姑息性骨转移治疗的放射性药物（⁸⁹ SrCl ₂和¹⁵³ Sm-EDTMP）进行了分析。对于⁸⁹ Sr，最脆弱的器官是肾脏，红骨髓和肝脏，而对于¹⁵³ Sm-EDTMP，最脆弱的是红骨髓。对于基于¹⁷⁷ Lu放射性核素的放射性药物，最脆弱的器官是肾脏，肝脏和红色骨髓。这证明了¹⁷⁷ Lu-MDP和¹⁷⁷ Lu-EDTMP放射性药物的有效性。

结论：根据计算结果，¹⁷⁷ Lu-EDTMP和¹⁷⁷ Lu-MDP证明了姑息性骨转移治疗的最佳结果。