四种不同体外照射在宫颈癌根治性放疗中的剂量学比较

发布时间：2018-02-06 03:18

本文关键词： 宫颈癌根治性放疗剂量学　出处：《中南大学》2014年硕士论文　论文类型：学位论文

【摘要】：目的：比较常规放疗、3D-CRT、IMRT及IMAT四种治疗计划在未手术宫颈癌根治性放疗中的剂量学差异及优劣。方法：收集14例宫颈癌患者,经过严格的膀胱训练后,在充盈膀胱和排空直肠状态下行定位CT及MRI扫描获取影像学资料,并传送至TPS工作站进行数字影像重建后,由同一医疗组勾画靶区和危及器官,予以PTV46Gy/23次,并由同一物理师设计完成常规放疗、3D-CRT、IMRT、IMAT四种治疗计划,观察其平面剂量分布图和剂量体积直方图(Dose Volume Histogram,DVH),计算并比较4种治疗计划在满足处方剂量要求的等剂量曲线分布及PTV的最大剂量(Dmax)、最小剂量(Dmin)、平均剂量(Dmean)、适形指数(Comformal Index, CI)、均匀性指数(Homogeneity Index, HI)和危及器官(直肠、膀胱、肠管、双侧股骨头)的受照体积和剂量。结果： 1.比较四种不同体外照射在横断面、矢状面、冠状面的平面剂量分布图,结果显示IMRT和IMAT较其他两种治疗计划在PTV46Gy时更贴近靶区,减少了直肠和膀胱受照体积,而常规放疗和3D-CRT中直肠和膀胱几乎全部在靶区内；常规放疗时双侧股骨头的部分区域受46Gy的照射,而其余三种治疗计划几乎全部避免了46Gy的照射。 2.四种不同体外照射中,常规放疗Dmax (4877.34±69.2cGy)、 Dmin (2030.54±492.11cGy)、Dmean(4595.25±115.74cGy)与另外三种体外照射3D-CRT(5036.21±31.55cGy、3816.52±192.04cGy、4809.47±20.82cGy)、IMRT(5065.02±53.84cGy、3817.43±356.17cGy、4769.66±29.14cGy)、IMAT(4971.65±117.63cGy、4415.29±213.15cGY、4754.07±72.37cGy)比较差异均有统计学意义(P值0.0001；而IMAT与3D-CRT、IMRT比较差异亦有统计学意义(P值0.0001)；后二者之间比较差异无统计学意义(P0.05)。 3.IMRT、IMAT的C1分别为0.64±0.1、0.65±0.17,明显优于常规放疗(0.1±0.06)、3D-CRT(0.32±0.06),P值0.0001。 4.HI在四种不同照射计划之间比较差异无统计学意义(P=0.233)。 5.常规放疗的危及器宫受量明显高于其他三种治疗计划,差异比较均有统计学意义(P0.05),尤其在V46、V40、V35时差异明显；而IMRT、IMAT的危及器官保护要优于3D-CRT(P0.05), IMRT与IMAT两者比较除V25以外均无显著差异(P0.05)。 6.比较IMRT和IMAT机器跳数差异有统计学意义(1488.86MUvs625.64MU,P0.001)。结论： 1.对未手术宫颈癌根治性放疗的四种不同体外照射计划比较的结果显示IMRT和IMAT在剂量学、靶区适形度、对危及器官的保护均明显优于常规放疗和3D-CRT,说明IMRT、IMAT较常规放疗和3D-CRT具有明显的优势,可临床应用于宫颈癌根治性放疗。 2. IMAT与IMRT在靶区适形度、均匀性以及对危及器官的保护相当,但IMAT的跳数明显小于IMRT,能明显缩短治疗时间。
[Abstract]:Objective: to compare the dosimetric differences and advantages of conventional radiotherapy with 3D-CRTIMRT and IMAT in radical radiotherapy for unoperated cervical cancer. Methods: 14 cases of cervical cancer were collected. After strict bladder training, CT and MRI scans were performed under filling bladder and emptying rectum to obtain imaging data. After transferring to TPS workstation for digital image reconstruction, the same medical group drew the target area and endangered organs, gave PTV46Gy/23 times, and designed by the same physicist to complete the routine radiotherapy. The planar dose distribution and dose volume histogram (Dose Volume Histogramma DVHs) of 3D-CRT / IMRT / IMAT were observed. Four treatment plans were calculated and compared in the distribution of isodose curve to meet the prescribed dose requirements, and the maximum dose of PTV, the minimum dose of Dmina, and the average dose of Dmean) were calculated and compared. Conformal Index, CIN, homogeneity Index, HIX, and endangering organs (rectum, bladder, intestine). The volume and dose of exposure to the bilateral femoral head. Results: 1. To compare the plane dose distribution of four kinds of external irradiation in cross section, sagittal plane and coronal plane. The results showed that IMRT and IMAT were closer to the target area during PTV46Gy than the other two treatment plans, and reduced the exposure volume of rectum and bladder. In conventional radiotherapy and 3D-CRT, the rectum and bladder were almost all in the target area. Part of the bilateral femoral head was exposed to 46Gy during conventional radiotherapy, while the other three treatment plans almost avoided 46Gy irradiation. 2.In four different kinds of irradiation in vitro, conventional radiotherapy for Dmax was 4877.34 卤69.2 cGy and Dmin was 2030.54 卤492.11cGy). Dmean(4595.25 卤115.74cGy) and the other three kinds of in vitro irradiation 3D-CRT 5036.21 卤31.55cGy. 3816.52 卤192.04cGy 4809.47 卤20.82cGy IMRTT 5065.02 卤53.84cGy. 3817.43 卤356.17cGy 4769.66 卤29.14cGy IMATA 4971.65 卤117.63cGy. 4415.29 卤213.15cGYT 4754.07 卤72.37cGy (P = 0.0001); The difference between IMAT and 3D-CRT IMRT was statistically significant (P = 0.0001). There was no significant difference between the latter two groups (P 0.05). 3. The C1 of IMAT was 0.64 卤0.1 卤0.17, which was significantly better than that of conventional radiotherapy (0.1 卤0.06). 3D-CRT = 0.32 卤0.06 (P = 0.0001). 4. There was no significant difference in HI between the four different radiation plans. 5. The quantity of pernicious uterus received by conventional radiotherapy was significantly higher than that of the other three treatment plans, and the difference was statistically significant (P 0.05), especially at V46 / V40 / V35. The organ protection of IMAT was better than that of 3D-CRT (P 0.05). There was no significant difference between IMRT and IMAT except V25. 6.Compared with IMRT and IMAT, the difference of hops was statistically significant (1488.86 MUVs 625.64 MUP 0.001). Conclusion: 1. The results of comparison of four different external irradiation plans for radical radiotherapy for unoperated cervical cancer showed that IMRT and IMAT were in dosimetry and target conformability. The protection of endangered organs was obviously superior to that of conventional radiotherapy and 3D-CRT, which indicated that IMAT had obvious advantages over conventional radiotherapy and 3D-CRT. It can be used clinically in radical radiotherapy for cervical cancer. 2.The conformability, homogeneity and protection of IMAT and IMRT in target area were similar, but the hops of IMAT were obviously smaller than that of IMRT, and the treatment time could be shortened obviously.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R737.33

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