Sadremomtaz Alireza, Masoumi Mahboubeh
Physics Department, Faculty of Science, University of Guilan, Rasht, Iran.
Ann Nucl Med. 2019 Apr;33(4):252-264. doi: 10.1007/s12149-019-01329-w. Epub 2019 Jan 18.
Bone-seeking radiopharmaceuticals have the main role in the treatment of painful bone metastases. The aim of this study was to dosimetrically compare radiopharmaceuticals in use for bone pain palliation therapy and bone scan.
The MCNPX code was used to simulate the radiation transport in a vertebral phantom. Absorbed fractions were calculated for monoenergetic electrons, photons and alpha particles. S values were obtained for radionuclides P, P, Sr, Y, Tc, Sn, Sm, Ho, Er, Lu, Re, Re, Ra, Ra and their progenies for target regions including the active marrow and the bone endosteum.
The results demonstrated the dependence of dosimetric parameters on the source or target size, particle energy and location of the source. The electron emitters including P, Sn, Er and Lu and Ra as an α-emitter gave the lower absorbed dose to the active marrow. These radionuclides gave the highest values of the Relative Advantage Factor (RAF).
According to the results, P, Sn, Er, Lu and Ra have fewer side effects on the active marrow than other investigated radionuclides. Therefore, these radionuclides may be a better choice for use in palliative radiotherapy.
亲骨性放射性药物在疼痛性骨转移瘤的治疗中起主要作用。本研究的目的是对用于骨痛缓解治疗和骨扫描的放射性药物进行剂量学比较。
使用MCNPX代码模拟在椎体模型中的辐射传输。计算了单能电子、光子和α粒子的吸收分数。获得了放射性核素P、P、Sr、Y、Tc、Sn、Sm、Ho、Er、Lu、Re、Re、Ra、Ra及其子代在包括活性骨髓和骨内膜在内的靶区的S值。
结果表明剂量学参数取决于源或靶的大小、粒子能量和源的位置。包括P、Sn、Er和Lu的电子发射体以及作为α发射体的Ra对活性骨髓的吸收剂量较低。这些放射性核素的相对优势因子（RAF）值最高。
根据结果，P、Sn、Er、Lu和Ra对活性骨髓的副作用比其他研究的放射性核素少。因此，这些放射性核素可能是姑息性放疗中更好的选择。
