鼻咽癌IMRT中脑干外放距离对靶区和各危及器官剂量分布的影响分析

Analysis of the Effect of Brain Stem External Distance on Target Area and Organ Distribution in Nasopharyngeal Carcinoma IMRT

目的旨在找到较理想的脑干外放距离的参考范围,以提高放疗计划设计的精确度,为物理师提供方便。方法我们挑选了10例原发性鼻咽癌IMRT患者的资料信息,在各类参数相同的同一计划下进行调强逆向运算,分析脑干的不同外放距离所引起的靶区剂量和其它各危及器官剂量分布的变化情况。结果鼻咽癌IMRT放疗中综合权衡利弊,脑干外放距离为7野计划3~4mm,9野计划2~4mm是比较合适的。结论物理师可直接参考这个数值,在这个范围内根据病人的具体情况适当调整即可,操作更简便,更可靠。

Objective The purpose of this study was to find out the reference range of the external distance of brain stem,so as to improve the accuracy of the radiotherapy plan design and provide convenience for the physical therapist. Methods 10 patients with primary nasopharyngeal carcinoma（ IMRT） were selected in this paper. The strong reverse operation were carried out under the same program with the same parameters,and the target area dose caused by different external distances of the brainstem and other changes affecting the dose distribution in organs were analyzed. Results The 3 ~ 4mm 7 the wild field plan and the 2 ~ 4mm 9 the wild field plan were more appropriate by IMRT radiotherapy in nasopharyngeal carcinoma. Conclusion The physical therapist can refer to the value directly and adjust in this range according to the specific condition of the patient. The operation is simpler and more reliable.