局部中晚期鼻咽癌IMRT二次扫描的临床研究

发布时间：2018-10-12 06:23

【摘要】：目的：研究局部中晚期鼻咽癌IMRT二次扫描在保护正常组织、提高靶区剂量及近期疗效方面的优势。实验方法： 1.对比实验组病例第一次扫描和第二次扫描BODY、GTVnx、 GTVnd、PGTVnx、PGTVnd、PTV1的体积及脊髓距GTVnx、GTVnd的最短距离,脑干距GTVnx的最短距离,以及双侧晶体距GTVnx的最短距离的改变。并对比对照组与实验组第一次扫描GTVnx、 GTVnd、PGTVnx、PGTVnd、PTV1的体积,了解两组间靶区体积有无差异。实验组、对照组靶区勾画均由同一影像科教授和同一肿瘤科教授确认。 2.收集实验组运用第二次扫描计划继续放疗后脊髓、脑干、双侧晶体及PGTVnx、PGTVnd、PTV1的剂量分布,并以PGTVnx224cGy/f、PGTVnd212cGy/f、PTV1185cGy/f作为其相应的理论剂量,得出PGTVnx、PGTVnd、PTV1相应的V100%、V110%、V95%、V93%的相对体积数值。并收集若以第一次扫描方案继续放疗上述指标的数值。分析前后两次扫描高危器官及靶区的剂量分布。 3.对比实验组及对照组病人脊髓、脑干、双侧晶体及PGTVnx、 PGTVnd、PTV1的平均剂量有无差异。 4.在放疗结束3-6月后复查鼻咽及颈部MRI,评估近期疗效。实验结果： 1.用Wilcoxon符号秩检验对比第一、二次扫描BODY、GTVnx、 GTVnd、PGTVnx、PGTVnd、PTV1相应的体积、脊髓距GTVnd的最短距离,脑干距GTVnx的最短距离,以及双侧晶体距GTVnx的最短距离,P0.05,差异有统计学意义。脊髓距GTVnx的最短距离及对照组PGTVnx、PGTVnd、PTV1的体积差异无统计学意义。 2.对比第二次扫描后放疗计划脊髓、脑干、左右晶体所受剂量及PGTVnx、PGTVnd、PTV1的平均剂量及按一次性计划放疗完成的相应剂量,除右侧晶体及脊髓外,第二次扫描危及器官的剂量均较第一次扫描低,靶区剂量均较第一次扫描高,但是仅左侧晶体的剂量差异有统计学意义,PGTVnx、PGTVnd、PTV1的V100%、V110%、V95%、V93%两组对比中,PGTVnd V100%第二次扫描后计划明显比第一次扫描后计划高,P0.05。其余各项两次扫描后计划无明显差异。 3.对比两组病例脊髓、脑干、左右晶体及PGTVnx、PGTVnd、 PTV1的平均剂量,除左侧晶体及PGTVnx外,实验组危及器官平均剂量均低于对照组,靶区剂量均高于对照组,其中,实验组PTV1的剂量较对照组明显提高,P0.05。 4.实验组CR率为41.38%,对照组CR率为31.03%。CR率提高了11.35%。实验结论：对肿瘤体积较大的局部中晚期鼻咽癌,有必要行二次扫描制定放疗计划使其提高靶区剂量,保护危及器官,从而提高患者的CR率。
[Abstract]:Objective: to study the advantages of secondary IMRT scan in protecting normal tissue, increasing target dose and short term curative effect of local advanced nasopharyngeal carcinoma (NPC). Experimental method: 1. The volume of BODY,GTVnx, GTVnd,PGTVnx,PGTVnd,PTV1, the shortest distance from spinal cord to GTVnx,GTVnd, the shortest distance from brainstem to GTVnx, and the shortest distance from bilateral lens to GTVnx were compared. The volume of GTVnx, GTVnd,PGTVnx,PGTVnd,PTV1 was compared between the control group and the experimental group. In the experimental group and the control group, the target area drawing was confirmed by the same imaging professor and the same oncology professor. The dose distributions of spinal cord, brain stem, bilateral lens and PGTVnx,PGTVnd,PTV1 were collected by the second scanning plan, and the relative volume value of V 100 V 110 and V 95 V 93% was obtained by using PGTVnx224cGy/f,PGTVnd212cGy/f,PTV1185cGy/f as its corresponding theoretical dose. The values of the above indexes were collected if the first scan was continued. The dose distribution of high risk organs and target area was analyzed before and after twice scanning. The average dose of spinal cord, brain stem, bilateral lens and PGTVnx, PGTVnd,PTV1 were compared between experimental group and control group. 4. Nasopharyngeal and cervical MRI, were reviewed 3-6 months after radiotherapy to evaluate the short-term efficacy. Experimental results: 1. The relative volume of the first and second scanning BODY,GTVnx, GTVnd,PGTVnx,PGTVnd,PTV1, the shortest distance from the spinal cord to GTVnd, the shortest distance from the brainstem to GTVnx, and the shortest distance from bilateral crystals to GTVnx were compared by Wilcoxon sign rank test (P0.05). There was no significant difference between the shortest distance from spinal cord to GTVnx and the volume of PGTVnx,PGTVnd,PTV1 from control group. 2. The dose of spinal cord, brain stem, left and right lens and the average dose of PGTVnx,PGTVnd,PTV1 and the corresponding dose of radiotherapy according to one time plan were compared after the second scan, except for the right crystal and spinal cord. The dose of the second scan was lower than that of the first scan, and the dose of the target area was higher than that of the first scan. However, there was significant difference in the dose of the left crystal only. In the two groups of PGTVnx,PGTVnd,PTV1 V100 and V11010 and V95 / 93%, the plan of PGTVnd V100% after the second scan was significantly higher than that after the first scan (P0.05). There was no significant difference between the other two scans. 3. The average dose of spinal cord, brain stem, left and right lens and PGTVnx,PGTVnd, PTV1 were compared between the two groups. Except for left lens and PGTVnx, the average dose of endangered organs in the experimental group was lower than that in the control group, and the dose in the target area was higher than that in the control group. The dose of PTV1 in the experimental group was significantly higher than that in the control group (P0.05.4). The CR rate in the experimental group was 41.38, and the 31.03%.CR rate in the control group was increased by 11.35%. Conclusion: it is necessary to make radiotherapy plan for locally advanced nasopharyngeal carcinoma with large tumor volume so as to increase the dose of target area and protect the organ so as to improve the CR rate of patients.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：R739.63

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