医用加速器X-射线射野剂量分布的蒙特卡罗模拟与实验测量  

Monte Carlo simulation and experimental measurement of X-ray fields' dose distribution for medical accelerator

作　　者：蔡国鑫[1,2] 王学涛[2] 杨耕[2] 招什武 朱远湖 周凌宏[1] 

机构地区：[1]南方医科大学生物医学工程学院,广州510515 [2]广东省中医院,广州510120

出　　处：《辐射研究与辐射工艺学报》2015年第2期13-17,共5页Journal of Radiation Research and Radiation Processing

基　　金：广东省医学科研基金项目(A2014274)资助

摘　　要：用电离室测量及蒙特卡罗方法计算水模体中瓦里安6 MV X-射线射野的百分深度剂量和射野离轴比,对测量和计算结果进行比较和分析。结果表明:10 cm×10 cm射野百分深度剂量在0-20 cm深度范围内,按2 mm/2%标准,?≤1的通过率为96.47%,按3 mm/3%标准,?≤1的通过率为99.23%;射野离轴比按2 mm/2%标准,?≤1的通过率为97.56%,按3 mm/3%标准,?≤1的通过率为99.42%;10 cm×10 cm射野深度剂量中的电子线份额为5.3%,40 cm×40 cm射野深度剂量中的电子线份额为15.2%。通过电离室测量和蒙特卡罗计算的方法能够确定X-射线射野的剂量分布特性。The beam dose distribution is compared with those obtained from Monte Carlo（MC） simulation and measurement to investigate dosimetry characteristics for X-ray fields. The beam data, including percentage depth dose（PDD） and off axis ratio（OAR）, were acquired by measurement and MC calculation in water phantom for Varian 6 MV X-ray fields. The results were compared and analyzed. The match result, for PDD of the field of 10 cm × 10 cm, has shown 96.47% agreement for γ ≤1 with 2% delta dose and 2 mm DTA for calculated and measured dose distribution at the depth of 0 to 20 cm, and 99.23% for γ ≤1 with 3% delta dose and 3 mm DTA. The match result of OAR has shown 97.56% agreement for γ ≤1 with 2% delta dose and 2 mm DTA for calculated and measured dose distribution, and 99.42% for γ ≤1 with 3% delta dose and 3mm DTA. Electron dose is 5.3% of depth dose for 10 cm × 10 cm, and 15.2% for 40 cm × 40 cm. Dose distribution can determined through the measurement and calculation in fields.

关 键 词：剂量分布 蒙特卡罗模拟 实验测量 

分 类 号：TL72[核科学技术—辐射防护及环境保护]