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目的:探讨国内外不同辐射防护标准对质子治疗机房屏蔽设计的影响。方法:以一个多室质子中心机房为例，分别根据美国国家辐射防护与测量委员会(NCRP)151号报告、新加坡辐射防护法案、英国ACoP指南以及国家标准GBZ/T 201.5-2015规定的辐射防护限值，得到相应的屏蔽方案。比较各个机房间隔墙和机房与控制室间隔墙厚度，在保持各个机房设计尺寸不变的前提下，从机房有效使用面积、建设成本等方面讨论上述4种屏蔽方案的差异性。结果:由NCRP 151号报告计算得到的各机房墙体(A～F)厚度最薄，由国家标准计算得到的墙体厚度最厚，其中两个旋转治疗室间隔墙厚度增加了1倍以上，总的治疗室使用面积减少17.69%，总建筑材料成本增加44万元。结论:通过比较不同屏蔽标准对质子治疗机房设计的影响，发现与其他国际法规或标准相比，我国现行的质子机房辐射屏蔽标准远高于其他国家，这会显著增加机房的屏蔽墙厚度，对国内的质子治疗技术的发展及将来升级到超高剂量率治疗模式都有一定影响。建议参考质子治疗技术相对成熟的国家标准和经验，适当放宽瞬时剂量率限值条件，增加更能反映现实治疗工况的时间平均剂量率(time averaged dose rate，TADR)限值条件，以更好地实现机房屏蔽设计的最优化原则。“,”Objective:To explore the impacts of different foreign and domestic radiation shielding standards on the shielding design of proton therapy treatment rooms.Methods:A multi-room proton therapy center was taken as an example. Different shielding schemes were determined for the center according to different radiation shielding limits stipulated in NCRP Report No.151, the Singapore Radiation Protection Act, the UK Approved Code of Practice and Guidance, and the national standard in China GBZ/T 201.5-2015. Afterwards, the thickness of the walls between two adjacent treatment rooms and the walls between the control room and its adjacent treatment room were compared. Meanwhile, the differences among the four radiation shielding schemes were discussed in terms of effective usable areas and the construction cost of concrete on the premise that each room′s design size remains the same in these four schemes.Results:The calculation result revealed that the concrete shielding walls (A-F) of the treatment rooms determined according to NCRP Report No.151 were the thinnest. In contrast, the walls of the treatment rooms determined according to GBZ/T 201.5-2015 were the thickest, among which the wall between the two adjacent gantry rooms was more than doubled in thickness. As a result , the total usable area of the four treatment rooms decreased by 17.69%, and the total construction cost increased by 440 thousand yuan.Conclusions:Compared with other regulations and standards listed in this paper, the current national standard in China is the strictest in terms of radiation shielding criteria. This will notably increase the shielding wall thickness and will have certain impacts on the development of domestic proton therapy technology and the possible upgrade to ultra-high dose rate treatment mode in the future. Therefore, it is recommended that the threshold of the instantaneous dose rate (IDR) should be appropriate improved and the limit of the time-averaged dose rate (TADR) that can better reflect actual treatment conditions be added by referring to the standards and experience of countries with mature proton therapy technologies. In this way, the shielding for proton therapy treatment rooms can be designed optimally.