左侧乳腺癌保乳术后放疗照射技术比较

发布时间：2018-05-19 05:57

本文选题：乳腺癌 + 四维CT　；参考：《清华大学》2015年硕士论文

【摘要】：容积旋转调强(VMAT)技术具有治疗时间短,靶区剂量适形度好,危及器官受照量小等优点,随着VMAT技术在乳腺癌中的应用,由于呼吸动度的原因,存在着肿瘤靶区漏照的问题。4D-CT可以采集患者各呼吸时相的图像,经过软件分析得出胸廓的动度阈值。将该阈值作为VMAT治疗计划中MLC外放的范围值,从而解决乳腺癌VMAT照射技术中所存在的靶区漏照问题。对左侧乳腺癌保乳术后患者三种照射技术进行剂量学比较。4D-CT定位扫描,获得10个呼吸时相的影像信息,分析后获得胸廓呼吸动度阈值。取呼气末影像勾画靶区和危及器官,在同一患者的影像中分别制作3D-CRT、4F-HIMRT、VMAT 3种治疗计划。PTV剂量50Gy。比较各计划之间靶区和危及器官的各项参数。同时比较3种计划平均治疗时间的差异。其中VMAT计划中,对MLC进行一定外放,解决呼吸运动引起的靶区漏照问题。利用4D-CT获得的呼吸时相数据,经过分析后得出呼吸动度阈值,做为外放的参考值。与切线野和调强计划相比,VMAT组明显提高了肿瘤靶区适形度和均匀性(P0.05)。VMAT组肺脏V20低于3D-CRT与IMRT组,V10、V5高于3D-CRT与IMRT组。VMAT组心脏V30,V40均低于3D-CRT与IMRT组。VMAT组对侧乳腺Dmax与Dmean高于3D-CRT与4F-HIMRT组。3D-CRT、4F-HIMRT、VMAT三种计划的治疗时间分别(110±5s)、(145±6s)、(105±6s)。与其它两种照射技术比较,VMAT改善了靶区的适形度和均匀性,降低了危及器官的受照剂量,减少了治疗时间。与此同时,危及器官的低剂量区域有所增加。
[Abstract]:Volume rotation intensity modulation (VMT) has the advantages of short treatment time, good dose conformability of target area, low exposure to organs, and so on. With the application of VMAT technique in breast cancer, respiratory motility is the reason. There is the problem of tumor target leakage. 4D-CT can collect the images of each breath phase of the patients, and get the threshold of thoracic motility by software analysis. The threshold is used as the range of MLC release in the VMAT treatment plan, so as to solve the problem of target leakage in VMAT irradiation for breast cancer. Dosimetric comparison of three irradiation techniques for patients with left breast cancer after breast conserving surgery was performed. The imaging information of 10 breathing phases was obtained and the threshold of thoracic respiratory motility was obtained. The target area and the dangerous organ were drawn from the end-expiratory image and the 3D-CRTX 4F-HIMRTT VMAT was made in the same patient. The dose of PTV was 50Gy. Compare the parameters of target area and organ hazard between plans. At the same time, the differences of average treatment time among the three plans were compared. In the VMAT program, MLC is given out to solve the problem of target area leakage caused by respiratory movement. Based on the respiratory phase data obtained by 4D-CT, the threshold of respiratory motility is obtained, which can be used as the reference value. Compared with tangent field and intensity modulation plan, VMAT group significantly increased the conformability and homogeneity of tumor target area. The lung V20 level in VMAT group was lower than that in 3D-CRT and IMRT group. V10 V5 was higher than that in 3D-CRT and IMRT group. V30 V40 in VMAT group was lower than that in 3D-CRT and IMRT group. VMAT group was higher than that in 3D-CRT and IMRT group. VMAT group in contralateral breast Dmax and Dmean was higher than that in 3D-CRT and IMRT group. The treatment time of 3D-CRT group and 4F-HIMRT group. 3D-CRT 4F-HIMRTT VMAT was 110 卤5s, 145 卤6s, 105 卤6s, respectively. Compared with the other two irradiation techniques, VMAT improved the conformability and uniformity of the target area, reduced the radiation dose of the endangered organs, and reduced the treatment time. At the same time, low-dose areas that endanger organs have increased.
【学位授予单位】：清华大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：R737.9

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