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 252Cf 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 252Cf 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.

中文翻译：

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²⁵² Cf治疗人体模型食管肿瘤的模拟研究

由于该组织的敏感性以及其癌转移的潜力，因此寻找精确的方法来治疗食道肿瘤对研究人员尤为重要。本研究涉及使用MCNPX（版本2.6.0）代码对252Cf中子近距离放射治疗这些肿瘤的Monte Carlo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查建模的准确性。MIRD人模型已用于上述肿瘤以及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，已经提出使用适当的防护罩。通过对几种候选物的剂量计算，已选择厚度为1 cm的10％Pt-Ir作为最佳屏蔽。深度剂量结果以及与在模拟肿瘤中心存在252Cf屏蔽中子源相对应的等剂量线曲线，提供了该源作为用于治疗食道肿瘤和保留正常组织的合适候选者。对于将食源定位在食道内的建议临床状况，可以通过管理治疗时间来避免对脊柱第一深度的损害。