低能光子线术中放射治疗系统的剂量学特性分析和潜在临床应用
发布时间：2018-08-02 10:22
【摘要】：目的 INTRABEAM系统是一款使用低能X射线的术中放射治疗(intra-operative radiotherapy,IORT)专用设备,其低能X射线特性平板和针形施用器相关剂量学研究较少。本研究测试低能光子线术中放射治疗系统,分析低能X射线源和球形、平板、针形三种施用器的剂量学特点并对其潜在临床应用进行初步探讨。方法采用专用水箱、平行板电离室和静电计等测量仪器,测量X射线源在不同管电压/管电流下的剂量特性,以及3种施用器的深度剂量率、各向同性、剂量重复性,并与系统数据进行比对。结果40和50kV X射线的深度剂量率测量值与系统数据偏差分别为(-1.56±1.29)%和(-2.16±1.36)%,不同管电流下的深度剂量率测量值与理论值偏差为-2.3%~1.7%。不同施用器的剂量梯度不同,直径越小,表面剂量越高,剂量梯度越大。施用器的转换系数随施用器种类、大小和测量深度而变化;不同直径球形施用器转换系数测量值与系统值偏差均值为-2.6%~2.4%,针形施用器转换系数偏差均值为-3.8%。重复测量结果表明,X射线源和3种施用器的深度剂量率、各向同性的重复性较好。结论低能X射线源在不同管电压/管电流下的测量值与系统数据一致性较好,其剂量分布随施用器的种类、大小和测量深度变化较大,临床应用时应充分考虑。
[Abstract]:Objective INTRABEAM system is a special equipment for intra-operative radiotherapytherapy (IORT) using low energy X ray. The dosimetry of low energy X ray characteristic plate and needle applicator is less. In this study, the low energy photon line intraoperative radiotherapy system was tested, and the dosimetric characteristics of the low energy X-ray source and three applicators, spherical, flat and needle, were analyzed and their potential clinical applications were discussed. Methods the dose characteristics of X-ray sources under different tube voltages / tube currents were measured with special water tank, parallel plate ionization chamber and electrometer, and the depth dose rate, isotropy and dose repeatability of the three applicators were measured. And compared with the system data. Results the depth dose rate measurements of 40 and 50kV X-rays were (-1.56 卤1.29)% and (-2.16 卤1.36)%, respectively. The deviation between the depth dose rate measurements at different tube currents and the theoretical values was -2.3% and 1.7%, respectively. The dose gradient of different applicators is different, the smaller the diameter, the higher the surface dose and the larger the dose gradient. The conversion coefficient of the applicator varies with the type, size and depth of the applicator, and the mean deviation between the measured value of the conversion coefficient and the system value of the spherical applicator with different diameters is -2.6 and 2.4, and the mean deviation of the conversion coefficient of the needle applicator is -3.8. The results of repeated measurement showed that the depth dose rate and isotropic repeatability of X-ray source and three applicators were good. Conclusion the measured values of low energy X-ray sources under different tube voltages / tube currents are in good agreement with the system data, and the dose distribution varies greatly with the type, size and depth of the applicator, which should be fully considered in clinical application.
【作者单位】： 中山大学附属第一医院放射治疗科;
【分类号】：R730.55
，
本文编号：2159122
[Abstract]:Objective INTRABEAM system is a special equipment for intra-operative radiotherapytherapy (IORT) using low energy X ray. The dosimetry of low energy X ray characteristic plate and needle applicator is less. In this study, the low energy photon line intraoperative radiotherapy system was tested, and the dosimetric characteristics of the low energy X-ray source and three applicators, spherical, flat and needle, were analyzed and their potential clinical applications were discussed. Methods the dose characteristics of X-ray sources under different tube voltages / tube currents were measured with special water tank, parallel plate ionization chamber and electrometer, and the depth dose rate, isotropy and dose repeatability of the three applicators were measured. And compared with the system data. Results the depth dose rate measurements of 40 and 50kV X-rays were (-1.56 卤1.29)% and (-2.16 卤1.36)%, respectively. The deviation between the depth dose rate measurements at different tube currents and the theoretical values was -2.3% and 1.7%, respectively. The dose gradient of different applicators is different, the smaller the diameter, the higher the surface dose and the larger the dose gradient. The conversion coefficient of the applicator varies with the type, size and depth of the applicator, and the mean deviation between the measured value of the conversion coefficient and the system value of the spherical applicator with different diameters is -2.6 and 2.4, and the mean deviation of the conversion coefficient of the needle applicator is -3.8. The results of repeated measurement showed that the depth dose rate and isotropic repeatability of X-ray source and three applicators were good. Conclusion the measured values of low energy X-ray sources under different tube voltages / tube currents are in good agreement with the system data, and the dose distribution varies greatly with the type, size and depth of the applicator, which should be fully considered in clinical application.
【作者单位】： 中山大学附属第一医院放射治疗科;
【分类号】：R730.55
，
本文编号：2159122
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