高能电子束不同吸收剂量测量方法的比较研究  

Comparison of the absorbed dose measurement methods for high-energy electron beams

作　　者：郭妍妍[1] 毕平[1] 李小东[1] 戴越[1] 

机构地区：[1]天津医科大学第二医院放疗科,300211

出　　处：《中华放射医学与防护杂志》2013年第3期314-317,共4页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的研究国际原子能机构（IAEA）第398号报告和第277号报告在电子线放射治疗剂量测定的差异。方法采用圆柱型电离室、平行板电离室以及在用户高能电子线射线质下经过交叉校准的平行板电离室，分别依据两个报告，对医科达Precise加速器6档电子线在水中的吸收剂量进行精确测量。结果用平行板电离室根据两个报告的测量规程测得的吸收剂量的差异为0．4％～2．3％，用圆柱型电离室测出的差异为0．6％～2．2％，用经过交叉校准的平行板电离室测出的结果是0．5％～2．0％。依据IAEATRS-398和TRS-277报告的方法测得的吸收剂量具有较好的-致性。结论IAEATRS-398号报告关于电子线的校准方法较TRS-277号报告更精确，更加适用于临床用户进行测量。Objective To study the difference in the measurement of the absorbed dose in water between the dosimetry protocols of IAEA TRS-398 and TRS-277 for high-energy electron beams. Methods The differences were compare in absorbed doses from 6 kinds of electron beams among the three methods of using cylindrical chamber ,plane-parallel chamber and cross-calibrated plane-parallel chamber which was calibrated in user＇ s high-energy electron beam according to IAEA TRS-398 and IAEA TRS-277. Results The difference in absorbed doses measured, following the two protocols, was 0.4% -2.3% for plane- parallel chamber, 0.6% -2.2% for cylindrical chamber,and 0. 5% -2. 0% for cross-calibrated chamber. The differences in measured absorbed doses between the two dosimetry protocols were slight. Conclusions The methods used to determine absorbed dose to water recommanded by IAEA TRS-398 for high-energy beams are more accurate and more suitable for clinical users to measure compared to the TRS-277.

关 键 词：放射治疗 剂量学 吸收剂量 电离室 

分 类 号：R[医药卫生]