自适应放疗在鼻咽癌调强放疗中的应用研究

发布时间：2019-06-30 22:57

【摘要】：目的：探讨自适应放疗(adaptive radiation therapy, ART)在鼻咽癌患者(nasopharyngeal carcinoma, NPC)调强放疗(intensity-modulated radiation therapy, IMRT)过程中对靶区和危及器官剂量的影响。方法：前瞻性分析11例鼻咽癌调强放疗患者,放疗至5次、15次时重新获取新的定位CT图像(CT1、CT2),制定新的放疗计划(replanl、replan2),并用于后续治疗,即自适应放疗。将原始计划(plan0)传递到新CT图像上生成计划(plan1、plan2),通过勾画系统中的工作流进行剂量叠加,合成计划plan0+replanl+replan2与plan0+planl+plan2,为自适应与非自适应放疗时的剂量分布情况,观察并比较两者靶区及危及器官剂量学差异。结果：与非白适应放疗比较,自适应放疗时靶区PTVnd、PTV1和PTV2的CI值上升,差异具有统计学意义,HI值变化不大。PTVnx中的V95中位值升高(P=0.013),PTVnd中的D95、D99、V100、V95和V93值分别升高2.16±2.52Gy、4.52±6.24Gy、5.47±7.27、2.6±3.5%和2.01±2.77%,PTVl的D95、V100值分别升高0.71±0.97Gy、0.56±0.65%、PTV2的D95、D99、V100、V95、V93值分别升高0.47±0.61 Gy、1.06±1.45 Gy、0.99±1.13%、0.50 ±0.61%和0.38±0.50%,以上差异均具有统计学意义。在危及器官中,经2次计划优化后,与非自适应放疗比较,自适应放疗中脑干、右侧颞叶Dmax分别下降2.34±2.63Gy和0.73±1.06Gy,右侧视神经Dmax中位值下降,声门、声门上Dmean分别降低3.95±3.99Gy和2.98±3.85Gy,左侧腮腺Dmean、V30分别下降1.36±1.90Gy和3.12±4.42%,皮肤V55下降0.85±1.20%,以上差异均具有统计学意义,其余OARs如眼球、晶体、视交叉、视神经、下颌骨、颞下颌关节、食管、口腔、耳蜗等剂量学改变均无统计学意义结论：鼻咽癌患者在放疗至5次、15次时进行自适应放疗,可以使靶区适形度和剂量覆盖得到改善,部分危及器官照射剂量下降,弥补了放疗过程中发生的剂量学变化。
[Abstract]:Objective: to investigate the effect of adaptive radiotherapy (adaptive radiation therapy, ART) on target area and endangered organ dose during (nasopharyngeal carcinoma, NPC) intensity modulation radiotherapy (intensity-modulated radiation therapy, IMRT) in patients with nasopharyngeal carcinoma (NPC). Methods: 11 patients with nasopharyngeal carcinoma undergoing intensity modulation radiotherapy were analyzed prospectively. new localized CT images (CT1,CT2) were obtained after radiotherapy for 5 times and 15 times, and a new radiotherapy plan (replanl,replan2) was made and used for follow-up treatment, that is, adaptive radiotherapy. The original plan (plan0) was transferred to the new CT image generation plan (plan1,plan2). By sketching the workflow in the system for dose superposition, the dose distribution of the synthetic plan plan0 replanl replan2 and plan0 planl plan2, for adaptive and non-adaptive radiotherapy was observed and compared, and the dosimetric differences between the target area and the endangered organ were observed and compared. Results: compared with non-white adaptive radiotherapy, the CI values of PTVnd,PTV1 and PTV2 in adaptive radiotherapy were significantly higher than those in non-white adaptive radiotherapy. The median value of V95 in PTVnx was higher than that in non-white adaptive radiotherapy (D95, D99, V100, V95 and V93 in P 鈮，

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