基于蒙特卡洛方法和数字体模的质子治疗设施屏蔽优化设计

目的:评估采用蒙特卡洛（MC）模拟方法和中国科学技术大学数字人体模型（USTC体模）在质子治疗设施中的辐射屏蔽优化设计。方法:使用MC模拟方法和USTC体模计算数字体模处于不同位置时在不同部位的当量剂量率（EDR），对安徽省合肥市离子医学中心（HIMC）的新型质子治疗设施的屏蔽设计进行评估，并将其与采用经验公式计算得出的EDR进行比较。结果:使用铁靶时，经验公式计算得出的EDR值比MC模拟方法得到的结果偏高27.6倍；使用水靶时，经验公式计算结果较MC模拟结果高36.6倍，说明使用经验公式进行屏蔽计算将使得剂量被高估，从而导致成本增加，不符合辐射防护最优化原则。结论:利用USTC体模对质子治疗设施进行基于MC模拟的屏蔽计算可以得到更加准确和优化的结果。

Shielding optimization of proton therapy facilities based on Monte Carlo simulations and voxelized human phantoms

Objective To evaluate the shielding optimization of proton therapy facilities by using Monte Carlo (MC) methods and voxelized computational USTC human phantoms(USTC phantoms). Methods The shielding design of a new proton therapy facility in Hefei Ion Medical Center (HIMC) was evaluated through the calculation of the Equivalent Dose Rate (EDR) in different parts of voxelized phantoms at different positions by using MC simulations and USTC phantoms, and the EDR was then compared with the EDR calculated through empirical formulas. Results When iron was used as target。EDR calculated by empirical formulas were 27.6 times higher than that by MC simulations, and when water was used as target, EDR calculated by empirical formulas were 36.6times higher than that by MC simulations. Thus, the dose was overestimated to some degree inempirical formulas, resulting in excessive shielding costs, which does not meet the principle of radiation protection optimization. Conclusion The calculation by using MC simulations and the USTC phantoms can be more accurate and optimized in the shielding evaluation of proton therapy facilities.