Nuclear Engineering Department, Universidade Federal do Rio de Janeiro, Horácio Macedo Ave., 2030, Block G, Technology Center, University City, Fundão Island, 21941-914, Rio de Janeiro, RJ, Brazil.
Nuclear Engineering Department, Universidade Federal do Rio de Janeiro, Horácio Macedo Ave., 2030, Block G, Technology Center, University City, Fundão Island, 21941-914, Rio de Janeiro, RJ, Brazil.
Appl Radiat Isot. 2022 Nov;189:110387. doi: 10.1016/j.apradiso.2022.110387. Epub 2022 Aug 2.
Radium-223 dichloride (RaCl2), approved by FDA (Food and Drug Administration) in 2013 and in Brazil by ANVISA (Agência Nacional de Vigilância Sanitária) in 2016, offers a new therapeutic option for bone metastases from castration-resistant prostate cancer (CRPC). The advantages of radionuclide therapy for bone metastases include the simultaneous treatment of multiple lesions at the same time. The activity prescription is based on the patient's body weight, disregarding the absorbed dose limit of 2 Gy in the organ at risk: bone marrow. This study focuses on Internal Dosimetry for RaCl2 therapy aiming to apply biokinetic models described in the literature to estimate absorbed doses in the organs of interests, especially for the bone marrow. For this purpose, the present paper compares and validates the GATE Monte Carlo simulation with the Radioactive Decay Module (RDM) and calculates a set of S-values for Radium-223 radionuclide using male and female XCAT computational models. Moreover, a comparison of S-values for Radium-223 for three male computational models with different anatomies is also evaluated, Male (standard), Pat1 (lower body weight) and Pat2 (highest body weight). A comprehensive set of S-values was calculated for the Male model, 30 source-regions and 47 target-regions, and for Female model, 30 source-regions and 42 target-regions for Radium-223 and its decay scheme: Radon-219, Polonium-215, Lead-211, Bismuth- 211, Polonium-211 and Thallium-207. The new set of S-values will facilitate absorbed dose calculations for Radium-223 therapy. In addition, Absorbed Dose Evaluation for RaCl2 therapy was estimated for three different biodistributions described in the literature within three male computational models. For all biodistributions, the Pat2 phantom has a greatest absorbed dose within the red marrow, when compared with Male and Pat1.
镭-223 二氯化物（RaCl2）于 2013 年获得美国食品和药物管理局（FDA）批准，2016 年获得巴西国家卫生监督局（ANVISA）批准，为去势抵抗性前列腺癌（CRPC）的骨转移提供了一种新的治疗选择。放射性核素治疗骨转移的优点包括同时治疗多个病变。活性处方基于患者的体重，而不考虑风险器官（骨髓）中 2Gy 的吸收剂量限制。本研究专注于 RaCl2 治疗的内部剂量学，旨在应用文献中描述的生物动力学模型来估计感兴趣器官的吸收剂量，特别是骨髓。为此，本文比较和验证了 GATE 蒙特卡罗模拟与放射性衰变模块（RDM），并使用男性和女性 XCAT 计算模型计算了一组镭-223 放射性核素的 S 值。此外，还评估了三种不同解剖结构的男性计算模型的镭-223 的 S 值的比较，分别是男性（标准）、Pat1（体重较低）和 Pat2（体重最高）。为男性模型计算了一组全面的 S 值，有 30 个源区和 47 个靶区，为女性模型计算了 30 个源区和 42 个靶区，用于镭-223 及其衰变方案：氡-219、钋-215、铅-211、铋-211、钋-211 和铊-207。新的 S 值集将为镭-223 治疗的吸收剂量计算提供便利。此外，还在三个男性计算模型中对文献中描述的三种不同生物分布情况进行了 RaCl2 治疗的吸收剂量评估。对于所有的生物分布，Pat2 模型的红骨髓吸收剂量最大，而与男性和 Pat1 模型相比。
