上颌窦癌3D-CRT与IMRT剂量学对比分析研究

发布时间：2018-03-07 19:05

本文选题：上颌窦癌　切入点：调强放疗　出处：《苏州大学》2014年硕士论文　论文类型：学位论文

【摘要】：目的通过比较未行手术治疗的上颌窦癌三维适形放疗（3D-CRT）与调强放疗（IMRT）靶区剂量分布的均匀性、适形性、靶区剂量情况，以及各危及器官受照体积、剂量情况，评价调强放疗较三维适形放疗的剂量学优势。方法选取2010年~2012年在苏州大学附属第一医院放疗科就诊的并经病理证实的上颌窦癌患者5例。将这5例患者治疗前的CT定位扫描图像资料导入3D-TPS工作站。根据患者MRI所显示出来的病灶图像，在CT横断面上勾画出靶区和危及器官。分别对每个病例分别作出3D-CRT计划以及5野、7野、9野的IMRT计划。评价指标为：PTV靶体积的适形指数(CI)、均匀指数(HI)、V95、D95、Dmax、Dmin和Dmean；危及器官(包括脑干、视交叉、垂体、视神经、眼球和晶体)的Dmax和Dmean等。比较这些指标在3D-CRT和各组IMRT之间的差异。结果 1．靶区：各组IMRT与3D-CRT相比前者显著提高了PTV-G的Dmax、V95%和CI值（P0.05）以及PTV-C的Dmax、Dmin和CI值（P0.05）。与3D-CRT相比，各组IMRT显著降低了PTV-C的V95%（P0.05）。而在PTV-G和PTV-C的靶区均匀指数（HI）方面，3D-CRT与各组IMRT相比较都未表现出统计学差异（P值分别为0.596和0.103）。此外，各组IMRT间比较，IMRT-5F的PTV-C靶区适形度较IMRT-7F和IMRT-9F要差，有统计学差异（P0.05），靶区其他的观察指标在各组IMRT计划之间无明显差别(P0.05)。九野调强放疗的靶区适形度相对七野而言并没有增加；综合考虑IMRT-7F有更好的增益比。 2．危及器官：在脑干、视交叉、垂体和视神经的保护方面，各组IMRT均优于3D-CRT (P0.05)。IMRT-7F与3D-CRT相比，脑干的Dmean降低了约32.25%；视交叉的Dmax和Dmean分别降低了7.66%和20.92%；垂体的Dmax和Dmean分别降低了17.19%和34.10%；同侧视神经的Dmax和Dmean分别降低了约5.19%和15.53%；对侧视神经的Dmax和Dmean分别降低了约7.20%和12.80%。而眼和晶体的各观察指标均为各组IMRT计划大于3D-CRT（P0.05）。所有的危及器官，，除脑干Dmean值IMRT-7F小于IMRT-5F和IMRT-9F外（P0.05），其他指标在各组IMRT计划中均无明显差别(P0.05)。结论 1.3D-CRT和IMRT均能较好地满足靶区剂量覆盖、均匀性和适形性的要求，但在危及器官保护方面，IMRT明显优于3D-CRT，其中IMRT-7F的增益比较高。 2．增加IMRT照射野的数目(从5野到9野)并不能明显提高靶区的覆盖率、均匀性和适形性，亦不能明显降低危及器官的受量。
[Abstract]:Purpose. By comparing the dose distribution in the target area of maxillary sinus carcinoma without surgical treatment (3D-CRT) and IMRTT, the dose distribution of the target area, the radiation volume and dose of each organ at risk, were compared. To evaluate the dosimetric advantages of IMRT over 3 D conformal radiotherapy. Method. From 2010 to 2012, 5 patients with maxillary sinus cancer confirmed by pathology were selected from the radiotherapy Department of the first affiliated Hospital of Suzhou University. The CT scanning images of the 5 patients before treatment were imported into 3D-TPS workstation. The image of the lesion displayed by MRI, The target area and the organ at risk were delineated on the CT cross section. The 3D-CRT plan and the IMRT plan of 5 field and 7 field and 9 field were performed respectively for each case. The evaluation indexes were the conformal index of the target volume of 1: PTV, the homogeneity index, the uniform index, the V95 D95DmaxDmin and the Dmean. the organs (including brain stem) were endangered. Dmax and Dmean of optic chiasma, pituitary, optic nerve, eyeball and lens were compared between 3D-CRT and IMRT. Results. 1. Target area: compared with 3D-CRT, the IMRT of each group significantly increased the Dmaxus V95% and CI value (P0.05) of PTV-G, and the Dmaxn Dmin and CI value of PTV-C (P0.05), compared with 3D-CRT, compared with 3D-CRT, the target area of each group was significantly higher than that of 3D-CRT. IMRT in each group significantly decreased the V95g of PTV-C, but the 3D-CRT of PTV-G and PTV-C showed no significant difference compared with IMRT of each group (P = 0.596 and P = 0.103). In addition, the conformability of PTV-C in IMRT group was lower than that in IMRT-7F and IMRT-9F. There was no significant difference in other observation indexes of target area between the IMRT plan of each group (P 0.05). The conformal degree of target area of NIMRT was not increased compared with that of seven fields, and IMRT-7F had a better gain ratio. 2. Endangering organs: in the protection of brain stem, optic chiasma, pituitary and optic nerve, IMRT in each group was superior to 3D-CRT in P0.05, IMRT-7F and 3D-CRT. Dmean of brainstem decreased about 32.25%; Dmax and Dmean of optic chiasma decreased 7.66% and 20.92; Dmax and Dmean of pituitary decreased 17.19% and 34.10 respectively; Dmax and Dmean of ipsilateral optic nerve decreased about 5.19% and 15.53, respectively; Dmax and Dmean of contralateral optic nerve decreased respectively. About 7.20% and 12.80.All the observation indexes of the eye and lens were that the IMRT plan of each group was greater than 3D-CRTP0.050.All the organs were endangered. Except that the IMRT-7F of brainstem Dmean was lower than that of IMRT-5F and IMRT-9F, there was no significant difference in other indexes in IMRT planning. Conclusion. 1.3D-CRT and IMRT can meet the requirements of target dose coverage, uniformity and conformability, but IMRT is better than 3D-CRT in endangering organ protection, among which the gain of IMRT-7F is higher. 2. Increasing the number of IMRT irradiation fields (from 5 to 9 fields) could not significantly improve the coverage, uniformity and conformability of the target area, nor could it significantly reduce the amount of organ damage.
【学位授予单位】：苏州大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R739.8

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