局部晚期鼻咽癌调强放疗解剖体积变化及其对剂量分布的影响

发布时间：2019-07-13 15:22

【摘要】：目的探讨局部晚期鼻咽癌调强放疗(IMRT)的解剖体积改变及其对剂量分布变化的影响,并评估IMRT再次计划的必要性。方法选择11例接受IMRT的局部晚期鼻咽癌患者,所有患者均接受同步放化疗。利用疗程中的重新定位CT图像,重新勾画靶区和危及器官,把基于初次定位CT图像的初始IMRT计划移植到重新定位CT图像上,重新计算并形成新计划,经统计后评估靶区和危及器官的体积变化及剂量分布相对初始计划的差异。结果与治疗前相比,放疗中期GTVnx、GTVnd、CTV1的初始体积分别平均缩小27.0%、48.0%和19.1%,差异有统计学意义(P0.05)。左、右腮腺的平均体积分别下降11.9%和13.7%,差异有统计学意义(P0.05)。GTVnx的Dmean、D95和D5分别增加0.48%、0.42%、0.45%,GTVnd的Dmean、D95和D5分别增加1.05%、0.95%、0.65%,CTV1的Dmean、D95和D5分别下降3.77%、6.62%、1.18%,但差异均无统计学意义(P0.05)。左、右侧腮腺的Dmean平均升高了3.9 Gy(19.06%)和3.4 Gy(18.99%),差异有统计学意义(P0.05);V30平均升高了29.13%和19.26%,差异有统计学意义(P0.05);D50平均升高了2.7 Gy(23.58%)和2.7 Gy(19.49%),但差异无统计学意义(P0.05)。结论鼻咽癌IMRT过程中靶区和腮腺的体积均明显缩小,而GTVnx、GTVnd和CTV1各剂量学参数值变化不大,除左、右腮腺受照剂量增加明显外,对于鼻咽部的其他危及器官,脊髓、脑干、左、右下颌骨、晶体等的剂量改变并无明显差异。
[Abstract]:Objective to investigate the anatomical volume of (IMRT) in local advanced nasopharyngeal carcinoma (NPC) and its effect on dose distribution, and to evaluate the necessity of IMRT replanning. Methods 11 patients with locally advanced nasopharyngeal carcinoma (NPC) receiving IMRT were selected and all patients received synchronous radiotherapy and chemotherapy. Using the repositioning CT image in the course of treatment, the target area and endangered organs were resketched, the initial IMRT plan based on the initial positioning CT image was transferred to the repositioned CT image, and the new plan was recalculated and formed. The volume changes of the target area and the endangered organs and the difference of dose distribution relative to the initial plan were evaluated after statistics. Results compared with before treatment, the initial volume of GTVnx,GTVnd,CTV1 in the middle stage of radiotherapy decreased by 27.0%, 40.0% and 19.1%, respectively, the difference was statistically significant (P 0.05). The average volume of left and right parotids decreased by 11.9% and 13.7%, respectively (P 0.05). Dmean,D95 and D5 of GTVnx increased by 0.48%, 0.42%, 0.45%, Dmean,D95 and D5 of GTVND increased by 1.05%, 0.95%, 0.65%, Dmean,D95 and D5 of CTV1 decreased by 3.77%, 6.62%, 1.18%, respectively, but the difference was not statistically significant (P 0.05). The Dmean of left and right parotids increased by 3.9 Gy (19.06%) and 3.4 Gy (18.99%), V30 increased by 29.13% and 19.26%, the difference was statistically significant (P 0.05), D50 increased by 2.7 Gy (23.58%) and 2.7 Gy (19.49%), but the difference was not statistically significant (P 0.05). Conclusion the volume of target area and parotid gland in nasopharyngeal carcinoma during IMRT was significantly reduced, but the values of GTVnx,GTVnd and CTV1 did not change significantly. There was no significant difference in the dose changes of other endangered organs, spinal cord, brainstem, left, right mandibular and lens except for the increase of irradiation dose of left and right parotid gland.
【作者单位】：广州医科大学附属肿瘤医院放疗中心;
【基金】：广州市医药卫生科技项目(编号:20131A011165) 广州医学院科学研究项目(编号:2012A16)
【分类号】：R739.63

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