乳腺癌术后放疗乳腺切线野的CT模拟定位研究

CT-simulation based localization of tangential irradiation field on the breast after breast conserving surgery

目的:通过对乳腺癌保乳术后根治性放疗CT模拟乳腺切线野定位技术的研究及与传统X线模拟机定位的比较,阐述CT模拟乳腺切线野定位技术的特点,讨论其临床应用价值。方法:以60例早期乳腺癌保乳术后根治性放疗的病例为研究对象,进行CT模拟乳腺切线野的定位,首先用头颈垫,进行体位固定,并做体表标记,然后用飞利浦CT模拟定位机进行定位,确定切线野等中心,最后做等中心体表标记。再用传统X线模拟机进行定位并作比较分析。结果:CT模拟乳腺癌保乳术后根治性放疗乳腺切线野的定位技术比较传统X线模拟机的定位,能观察所有的射束重叠的解剖学信息,能观察是否将靶区精确覆盖,从而提高布野和防护的精确性,有利于关键结构重要器官的保护,并缩短了定位时间,患者感觉更加舒适耐受,减少了医患压力,提高了工作效率和资源的利用率。结论:CT模拟技术的应用使得乳腺癌保乳术后根治性放疗乳腺切线野的定位更加精确,模拟计划设计及剂量计算更加准确,并支持调强、加速部分乳腺照射及野中野等乳腺癌保乳术后根治性放疗新技术的临床应用,是提高放疗准确性和治疗效果的必要前提。

Objective： Comparing CT- simulation and X - ray conventional technique of tangential irradiation, we investigate the characteristic of CT- simulation technique of tangential irradiation so as to apply the value in clinic.Methods： Our forty objects are early breast cancer after breast conserving surgery , making CT- simulation, the body is fixed with head- and- neck pad, the skin is marked with lead - wires. Scanning the patient was used in sending image to the ACQSIM workstation. In this system, isocenter can be established. The couch with the lasers were moved to the programmed position. The isocenter is marked on the body surface. Then, we compare with conventional technique.Results： Comparing with technique of conventional tangential irradiation, CT- simulation observe conveniently target, whether or not it! is covred exactly and anatomical that information of all overlapping ray, CT- simulation can safeguard important organs and key struc- ture, it can reduce operating time and resourceful usefulrate. Conclusions： It is very significant that clinical application of CT- simulation. It can imporve accurate of simulation planning and dose count. It can support clinical application of intensity modulated radiation therapy, accelerated partial breast irradiation and field- in-field technique etc. It is influence accurate and quality of treatment.