MVCT引导下宫颈癌调强放疗中子宫移动的外放距离及子宫退缩的研究

发布时间：2018-02-15 11:46

本文关键词： 器官运动外放边界退缩 MVCT 宫颈癌　出处：《北京协和医学院》2014年博士论文　论文类型：学位论文

【摘要】：背景与目的：IMRT应用到宫颈癌的外照射中降低了周围正常组织的剂量,但对放疗的准确性提出了更高的要求。子宫的器官移动成为宫颈癌放疗中一个不容忽视的问题,如果外放距离过小,子宫移动后超出了PTV范围,意味着靶器官治疗的不充分,外放距离过大,尽管能将子宫的活动范围都包含,会导致危机器官受照体积的增多,肠道、膀胱等正常组织副反应的加重。本研究的目的是在MVCT图像引导下测定子宫移动的外放距离,同时研究子宫的退缩及膀胱、直肠体积变化与子宫活动度的关系。材料与方法：9名宫颈癌患者接受调强放疗,每天治疗前扫描MVCT,得到共245次MVCT图像。勾画子宫、直肠、膀胱,取并集得到每名患者子宫的活动范围。S、I、A、P、L、R六个方向在子宫移动上的外放距离取决于子宫活动范围边界到每一个子宫边界的距离,并将其与子宫的退缩、膀胱的体积变化、直肠的体积变化相关联。结果：S、I、A、P、L、R六个方向在子宫移动上的外放距离为0.54、0.44、1.56、1.18、0.83、0.82,单位为cm。放疗后子宫体积平均退缩大于30%,主要以S方向运动为主(p0.001),第19次治疗后出现显著变化(p=0.013)。膀胱与直肠的体积变化与子宫的移动显著相关,前者主要影响S方向(p0.001),后者主要影响P方向(p=0.0011。结论：子宫移动上的外放距离的结果可靠,但用不同公式求得两组CTV-PTV的外放距离差别较大,不能直接用于临床,有必要进行前瞻性研究来测算系统误差。建议第19次治疗完后重新定位。在临床治疗中,膀胱体积改变大于100cc,直肠体积改变大于10cc时,值得警惕。
[Abstract]:Background and objective: the application of IMRT to the external irradiation of cervical cancer reduces the dose of normal tissue around the cervix, but puts forward higher requirements for the accuracy of radiotherapy. The organ movement of the uterus becomes a problem that can not be ignored in the radiotherapy of cervical cancer. If the outfall distance is too small and the uterus moves beyond the PTV range, it means that the target organ is not being treated adequately, and the outpouring distance is too large, even though the range of activity of the uterus can be included, which can lead to an increase in the exposed volume of the organ in crisis, the intestinal tract. The purpose of this study was to determine the distance of uterine movement under the guidance of MVCT images, and to study the relationship between uterine retraction, bladder and rectum volume changes and uterine activity. Materials and methods Twenty five MVCT images were obtained from 9 patients with cervical cancer undergoing intensity modulated radiotherapy. The range of uterine activity in each patient's uterus was determined by the distance of uterine movement in the six directions. The distance between the range of uterine activity and the boundary of each uterus was determined by the distance from the range of uterine activity to the boundary of each uterus, and the volume of the bladder was changed by the withdrawal of the uterus, the volume of the bladder, and the volume of the bladder. Rectal volume changes are associated. Results the extravasation distance of the six directions in the uterine movement was 0.54 / 0.44 / 1.180.83 / 0.82. The mean volume of uterus after radiotherapy was greater than 30%, mainly in the direction of S (p 0.001). There was a significant change (p0.013) in bladder and rectum after the 19th treatment. There was a significant correlation between the changes of the volume and the movement of the uterus. The former mainly affects S direction p 0.001 and the latter mainly affects P direction P 0. 0011. Conclusion: the results of the extravasation distance on uterine movement are reliable, but the two groups of CTV-PTV can not be directly used in clinic because of the difference between the two groups. It is necessary to carry out a prospective study to measure the systematic error. It is recommended to reposition after the 19th treatment. In clinical treatment, the change of bladder volume is greater than 100 ccand the rectal volume is greater than 10 cc.
【学位授予单位】：北京协和医学院
【学位级别】：博士
【学位授予年份】：2014
【分类号】：R730.55;R737.33

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