Graduate School of Biomedical Sciences, The University of Texas at Houston, Houston, TX 77030, USA.
Phys Med Biol. 2010 Dec 7;55(23):6975-85. doi: 10.1088/0031-9155/55/23/S01. Epub 2010 Nov 12.
Stray neutrons generated in passively scattered proton therapy are of concern because they increase the risk that a patient will develop a second cancer. Several investigations characterized stray neutrons in proton therapy using experimental measurements and Monte Carlo simulations, but capabilities of analytical methods to predict neutron exposures are less well developed. The goal of this study was to develop a new analytical model to calculate neutron ambient dose equivalent in air and equivalent dose in phantom based on Monte Carlo modeling of a passively scattered proton therapy unit. The accuracy of the new analytical model is superior to a previous analytical model and comparable to the accuracy of typical Monte Carlo simulations and measurements. Predictions from the new analytical model agreed reasonably well with corresponding values predicted by a Monte Carlo code using an anthropomorphic phantom.
散裂质子治疗中产生的散裂中子令人担忧，因为它们增加了患者发生第二种癌症的风险。一些研究使用实验测量和蒙特卡罗模拟对质子治疗中的散裂中子进行了描述，但分析方法预测中子暴露的能力还不够完善。本研究的目的是开发一种新的分析模型，以基于被动散射质子治疗设备的蒙特卡罗建模来计算空气中的中子环境剂量当量和体模中的当量剂量。新分析模型的准确性优于先前的分析模型，并且与典型的蒙特卡罗模拟和测量的准确性相当。新分析模型的预测值与使用人体模型的蒙特卡罗代码的相应预测值相当吻合。
