医用加速器碳纤维治疗床延长板结合部对放疗剂量的影响

发布时间：2018-01-05 17:11

本文关键词：医用加速器碳纤维治疗床延长板结合部对放疗剂量的影响　出处：《放射学实践》2016年07期 　论文类型：期刊论文

【摘要】：目的:探讨加速器碳纤维治疗床结合部对调强放疗剂量的影响。方法:利用二维平板电离室矩阵,测量6MV X射线穿射过碳纤维治疗床延长板结合部和避开结合部后的剂量。分析不同机架角度下治疗床结合部对X射线剂量的影响。比较实例放疗计划穿射与避开结合部的治疗计划的验证通过率。结果:二维矩阵电离室实测结果显示,射野处于110°~180°机架角范围,穿射结合部位后射线会产生较大衰减,结合部衰减范围集中在延长板分界向床头方向3cm,床尾方向11cm的范围。116°~180°机架角,部分测量点剂量偏差值超过10%。145°机架角时测量点最大偏差值达24.2%。10例实例测量VMAT治疗计划中,射野穿透结合部的Gamma通过率较避开结合部显著降低(t=4.349,P=0.002)。结论:加速器碳纤维治疗床延长板结合部可显著降低放疗剂量。在放射治疗摆位应尽可能避免治疗射野穿射碳纤维治疗床结合部,无法避免时,应将其产生的射线衰减考虑在治疗计划的设计中。
[Abstract]:Objective: to investigate the effect of carbon fiber accelerator on the dose of intensity modulated radiotherapy. Methods: the two-dimensional plate ionization chamber matrix was used. Measurement 6 MV. The dose of X ray penetrating through the lamellar joint of carbon fiber treatment bed and avoiding the joint part. The effect of the treatment bed joint part on the X ray dose under different frame angles was analyzed. A comparison of the radiation planning and avoiding the joint part was made in the case of radiotherapy. Results:. The measured results of two-dimensional matrix ionization chamber show that. The beam field is in the angle range of 110 掳and 180 掳, and the radiation attenuation will occur after penetrating the joint, and the attenuation range of the joint is concentrated in extending the boundary of the plate to the head of the bed by 3 cm. The range of 11cm at the end of the bed. 116 掳/ 180 掳frame angle. The maximum deviation value of the measuring point was 24.2when the dose deviation value of some measuring points exceeded 10. 145 掳frame angle. 10 examples were used to measure the VMAT treatment plan. The passing rate of Gamma in the penetrating junctions was significantly lower than that in avoiding the junctions. Conclusion: the irradiation dose can be significantly reduced by lengthening the lamellar joint of the accelerator carbon fiber therapy bed, and the treatment field penetrating carbon fiber should be avoided as far as possible in the radiotherapy placement. When unavoidable, the radiation attenuation should be taken into account in the design of the treatment plan.
【作者单位】：华中科技大学同济医学院附属同济医院肿瘤中心;
【分类号】：R730.55
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