Rasouli Fatemeh S, Bakhshandeh Hasan, Salehkoutahi S Mohsen
Department of Physics, K.N. Toosi University of Technology, P.O. Box 15875-4416, Tehran, Iran.
EJNMMI Phys. 2020 Dec 3;7(1):71. doi: 10.1186/s40658-020-00341-8.
Due to the sensitivity of this tissue, and the potential for metastasis of its cancer as well, finding accurate methods to be employed for the treatment of esophagus tumors is of especial interest for the researchers. The present study deals with a Monte Carlo simulation of Cf neutron brachytherapy for treating these tumors using MCNPX (Version 2.6.0) code. The widely accepted AAPM TG-43 protocol has been used to benchmark the simulated source and to examine the accuracy of the modeling. The MIRD human phantom has been used for dose evaluation in the mentioned tumor and in the surrounding normal tissues as well. To decrease the dose delivered to the healthy tissue, using appropriate shields has been proposed. Through dosimetric calculations for several candidates, Pt-Ir 10% with a thickness of 1 cm has been selected as the optimized shield. The depth-dose results as well as the isodose curves corresponding to the presence of the shielded Cf neutron source in the center of the simulated tumor offer this source as an appropriate candidate to be used for the treatment of the esophagus tumors and sparing normal tissues. For a suggested clinical condition of positioning the source inside the esophagus, the damage to the first depth in spine can be avoided by managing the treatment time.
由于这种组织的敏感性以及其癌症转移的可能性，寻找用于治疗食管肿瘤的准确方法对研究人员来说尤为重要。本研究使用MCNPX（2.6.0版）代码对 Cf 中子近距离治疗这些肿瘤进行蒙特卡罗模拟。广泛接受的AAPM TG - 43协议已用于对模拟源进行基准测试并检验建模的准确性。MIRD人体模型也已用于上述肿瘤及其周围正常组织的剂量评估。为了减少输送到健康组织的剂量，已提出使用适当的屏蔽。通过对几种候选材料的剂量学计算，选择了厚度为1厘米的10%铂铱作为优化屏蔽。对应于模拟肿瘤中心有屏蔽的 Cf 中子源的深度剂量结果以及等剂量曲线表明，该源是用于治疗食管肿瘤并保护正常组织的合适候选者。对于将源置于食管内的建议临床情况，通过控制治疗时间可以避免对脊柱第一深度的损伤。
