全身皮肤电子线放疗中快速确定机架角度的方法-《中国医学物理学杂志》

文章信息/Info

Title:: A rapid method for gantry angle determination in total skin electron therapy

Author(s):: JI Weixing; ZHANG Yujie; LI Tingting; ZHANG Jianying; Department of Radiation Oncology, Zhongshan Hospital, Fudan University, Shanghai 200032, China

Keywords:: total skin electron therapy six-dual-field technique gantry angle

摘要:: 目的：为双机架角多野全身皮肤电子线放疗技术提供一种快速确定机架角度的方法。方法：引入一个与治疗时辐射场几何条件关联的新因子F，F与机架角度、准直器大小和源皮距相关。查阅以往相关文献，归纳总结出不同几何条件下因子F的规律，然后建立根据F快速推算机架角度的方法，再用两组试验验证该方法的有效性。结果：分析以往文献中的数据后发现，因子F的值稳定在一个固定值左右，F的平均值为0.79，标准差为0.05。新建立的快速计算方法可将机架角度搜索范围从一般方法推荐的15°缩小到5°左右。在两组试验中，最佳照射时的机架角度均能快速而准确地确定。结论：在双机架角多野全身皮肤电子线放疗技术中，因子F的引入和新的计算方法能够有效提高确定照射机架角度的效率。

Abstract:: Objective To provide a method for rapidly determining the gantry angle in six-dual-field total skin electron therapy. Methods A new factor F which was related to the geometric conditions of radiation field such as gantry angle, collimator size and source-skin-distance was introduced. According to the rules of F under different geometric conditions which were summarized by referring the previous literatures, a rapid method for gantry angle determination was proposed. The effectiveness of the method was verified by two groups of experiments. Results The analysis of the data from the previous literatures showed that F was stable at a fixed value, with mean value of 0.79 and standard deviation of 0.05. The proposed method narrowed the search range of gantry angle from the generally recommended 15° to about 5°. In the two groups of experiments, the optimal gantry angle could be determined quickly and accurately. Conclusion The introduction of F and the novel calculation method improve the efficiency for the determination of the gantry angle in six-dual-field total skin electron therapy.