多剂量水平鼻咽癌容积调强与动态调强放射治疗剂量比较及传输效能分析

发布时间：2018-06-10 19:38

本文选题：鼻咽癌 + 多剂量水平　；参考：《生物医学工程学杂志》2017年06期

【摘要】：本研究目的为系统地比较双弧容积旋转调强放射治疗(VMAT)与动态调强放射治疗(d-IMRT)两种技术方法在多剂量水平鼻咽癌(NPC)计划质量和传输效能上的异同,分析靶体积与计划质量差异的相关性。为20例2014年—2015年在本机构进行过4~5剂量水平全颈同步加量(SIB)调强放疗的NPC患者重新设计双弧VMAT计划,其逆向优化条件与设计IMRT计划时相同。然后对两组计划的靶区和危及器官(OAR)的剂量参数、传输效能进行了比较,用三维剂量验证系统进行了质量保证验证,分析肿瘤靶体积与计划质量差异的相关性。结果显示,双弧VMAT靶区的适形度指数(CI)优于d-IMRT(P0.05),未发现两者差异与靶体积明显相关(P0.05)。VMAT在靶区PTV1、PGTVnd和PTV3的剂量分布与d-IMRT相似或前者略好。VMAT降低了PTV2剂量,均匀指数(HI)变差。对脊髓、脑干等,VMAT有更好的保护作用,但会增加腮腺剂量。d-IMRT计划跳数为VMAT计划的3.32倍,出束时间为VMAT计划的2.19倍。在COMPASS?质量保证(QA)验证中,VMAT与IMRT计划的靶区γ(3 mm,3%)通过率均大于97%。本研究结果表明,VMAT和d-IMRT两种技术对多水平处方剂量NPC患者的治疗效果相差不大,VMAT能提高靶区的适形度,但使除颈部转移淋巴结外的颈部靶区剂量覆盖率和剂量分布变差。VMAT的QA优于d-IMRT,且VMAT在传输效率上也明显高于d-IMRT。
[Abstract]:The purpose of this study was to systematically compare the differences and similarities between the two techniques of dual arc volume rotational intensity modulated radiotherapy (VMATT) and dynamic intensity modulated radiotherapy (DIMRT) in planning quality and transmission efficiency of NPCs at multiple dose levels for nasopharyngeal carcinoma (NPC). The correlation between target volume and planned quality difference is analyzed. A double-arc VMAT plan was redesigned for 20 NPC patients who underwent 4 ~ 5 doses of SIB-IMRT from 2014 to 2015, and the conditions of reverse optimization were the same as those of IMRT. Then, the dose parameters and transmission efficiency of the target area and the OARs of the two groups were compared. The quality assurance verification was carried out by using the three-dimensional dose verification system, and the correlation between the tumor target volume and the planned quality difference was analyzed. The results showed that the conformability index (CI) of double arc VMAT was better than that of d-IMRTT. There was no significant correlation between the difference and the target volume. The dose distribution of PGnd and PTV3 in the target region was similar to that of d-IMRT or that the former decreased the dose of PTV2, and the variation of homogeneity index was lower than that of d-IMRT. VMAT in spinal cord, brain stem and so on had better protective effect, but increased the parotid gland dose. D-IMRT had 3.32 times of VMAT and 2.19 times of VMAT. At compass? The pass rates of VMAT and IMRT targets were higher than 97 mm / 3. The results showed that the effect of VMAT and d-IMRT on patients with NPC with multi-level prescription dose was not different. VMAT could improve the conformability of target area. However, the dose coverage and dose distribution of the cervical target area except cervical metastatic lymph nodes became worse. The QA of VMAT was superior to d-IMRTT, and the transmission efficiency of VMAT was significantly higher than that of d-IMRTT.
【作者单位】：南通大学附属医院肿瘤放疗科;南通大学医学院;
【分类号】：R730.55;R739.63

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