摘要
目的对加速器小野的剂量学特性进行研究,以指导调强放疗在临床上的应用。方法计算西门子primusM加速器小野条件下的总散射因子并比较相对剂量分布的测量和计算结果。结果在小野测试中,当治疗计划系统计算精度优于0.2 cm时,>2 cm×2 cm射野的总散射因子的计算值误差<3%,所有射野的计算与测量的相对剂量分布均较为吻合,但<2 cm×2 cm的射野在边缘低剂量区有一定的偏差。结论对于治疗计划系统计算的小射野剂量分布的误差在调强计划设计上应加以考虑,多叶准直器的到位精度对小射野剂量影响不容忽视。
Objective To investigate the dosimetric characteristics of small segment dimensions, so as to instruct the clinical application in intensity modulated radiation therapy（IMRT）. Methods Using the Siemens primusM accelerator, we compare the results of measurement and calculation about total scatter factors and relative dose distributions in small segments. Results In the small segment dimensions testing, when the calculation precision of TPS was under 0.2 cm, deviations of calculated total scatter factors was within 3% for fields collimated up to 2 cm × 2 cm, calculated relative dose distributions in all fields agree well with measured ones, but there were some deviations for the fields down to 2 cm×2 cm in low dose region. Conclusion The error of TPS calculated dose distributions for small fields must be taken into account, in addition, MLC leaf positional accuracy is important for the small fields, so QA/QC for static MLCs can＇t be ignored.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2007年第6期469-472,共4页
Chinese Journal of Radiation Oncology
关键词
调强放射疗法
小野
剂量学
Intensity modulated radiation therapy
Small segment dimensions
Dosimetry
