摘要
目的掌握螺旋断层放射治疗机房的辐射水平,制订合理可行的辐射屏蔽与防护设计方案,为TOMO装置临床应用的辐射安全提供保障。方法以某医院的1台Tomotherapy Hi-Art螺旋断层放射治疗装置为研究对象,依据设备的性能参数,参照NCRP No.151报告和GBZ/T 201.2等技术标准以及AAPM No.148中相应的质量控制细则,确定TOMO机房的屏蔽与安全防护设计规划,并评估其防护效果。结果 TOMO机房屏蔽方案为:东、西防护墙和室顶为95cm重晶石;南墙为70cm重晶石;迷路内外墙分别为(70～30)cm重晶石和(30～70)cm重晶石;防护门为8mm铅。机房外围辐射水平估算结果表明,南墙外设备夹层通道的辐射剂量率最高为8.89μGy/h,其次为机房地下电缆沟处(3.25μGy/h);防护门外最高为1.6μGy/h。推算出机房外围放射工作人员所受年剂量最高为0.27mSv,公众可能受到的最高剂量均不高于0.03mSv/a。结论 TOMO装置治疗机房可主要考虑对泄漏辐射的屏蔽设计,同时应根据装置实际的照射参数、工作负荷和治疗机房的场所条件进行相应的防护效果分析。
Objective To determine the radiation dose level outside of a helical tomotherapy room and formulate a reasonable protection designing project of the radiation treatment room, and to ensure that the project is worked out to provide radiation safety protection safeguard for the clinical application of TOMO facility. Methods A helical tomotherapy facility typed Tomotherapy Hi-Art of a hospital was studied as the object researched. According to performance parameters of the facility, relative technical standards such as NCRP report No. 151, GBZ/T 201.2 - 2011 and QC rules of the AAPM Task Group No. 148, the shielding and safety protection design of the tomotherapy room were confirmed. The protective effect of the room was appraised. Results The shielding design project was determined as follows： the eastern, western protective wall and ceiling of the tomotherapy room should be constructed with barites of 95 em thickness of barites, southern wall with 70 cm barites, inner wall and external wall of the maze should be constructed with 70 - 30 cm and 30 - 70 cm of barites respectively. In addition, a protective door with 8mmPb shielding should be set at the entrance of the room. All the radiation dose levels penetrating from the room wall were calculated, and it was shown that the maximum radiation dose rate in the facility interlayer alleyway outside wall was 8.89 μGy/h, and the cable channel under ground （ 3.25 μGy/h） ranked the second. The maximum value outside of the protective door reached 1.6 μGy/h. Based on the above data, the highest annual effective dose received by the radiation workers in the treatment place was 0. 27 mSv, and the relative public near the treatment room was not more than O. 03 mSv/a. Conclusion Leakage radiation should be primarily taken into consideration during radiation design for a helical tomotherapy room. Meanwhile, the relevant control protection effect of the treatment room also should be assessed in terms of the real irradiation parameters, the workload and room conditions.
出处
《首都公共卫生》
2012年第6期246-251,共6页
Capital Journal of Public Health
基金
北京市预防医学公益应用研究项目(2012-BJCDC-06)
关键词
螺旋断层放射治疗
屏蔽设计
辐射防护
辐射屏蔽
Helical tomotherapy
Shielding designing
Radiation shielding
Radiation protection
