不同宽度多叶准直器叶片对食管癌调强放射治疗的剂量学影响
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摘要
目的:探讨不同宽度多叶准直器(MLC)叶片对食管癌调强放射治疗(IMRT)的剂量学影响,为食管癌IMRT提供更加合理的参考。方法:选取40例食管癌调强病例,采用瓦里安Eclipse13.5治疗计划系统设计放射治疗计划。在MLC的中间区域以及边缘区域进行IMRT优化设计,分别对靶区的基本参数以及危及器官的受量进行比较,分析出两组计划的差异;利用剂量体积直方图比较靶区、肺、心脏和脊髓照射剂量和体积。结果:选择在MLC的中间区域进行优化,靶区的D_(mean)更高,且均匀性以及适形性更优,心脏受量更高,心脏MLC中间区域的D_(mean)和V_(30)值均低于MLC边缘区域,其差异有统计学意义(t=-3.531,t=-3.551;P<0.05);双肺MLC中间区域的D_(mean)、V_5、V_(10)、V_(20)及V_(30)略高于MLC边缘区域,其差异有统计学意义(t=4.773,t=6.282,t=0.047,t=4.536,t=2.075;P<0.05),脊髓剂量MLC中间区域的D_(max)值要高于MLC边缘区域,其差异有统计学意义(t=-5.980,P<0.05)。结论:在肺部、脊髓以及心脏等危及器官都能达到剂量限值的基础上,应尽量选择MLC的中间区域进行优化,使其获得良好的靶区剂量分布,提高肿瘤的控制率。
Objective: To investigate dosimetry effects of vane with different width of multi-leaf collimator(MLC) on intensity modulated radiation therapy(IMRT) of esophageal carcinoma so as to provide more reasonable references for IMRT of esophageal carcinoma. Methods: 40 patients with esophageal carcinoma were selected, and the radiotherapy plan was designed with the Varian Eclipse13.5 treatment plan system. IMRT was optimized in the intermediate and marginal areas of MLC. The basic parameters of target area and the received dose of organs at risk(OAR) were respectively compared, and the differences of them between the two plans were further analyzed. Dose volume histogram was used to compare the dose and volume of radiation in target area, lung, heart and spinal cord. Results: The intermediate area of MLC was chosen to implement optimization, and D_(mean) of target area was higher, and its homogeneity and conformal were better, and heart injectivity was higher, and both the D_(mean) and V_(30) value of intermediate area of MLC were significantly lower those of marginal area of MLC(t=-3.531, t=-3.551, P<0.05). Besides, the D_(mean), V_5, V_(10), V_(20) and V_(30) of intermediate area of MLC of double lungs were significantly higher than those of marginal area of MLC of double lungs(t=4.773, t=6.282, t=0.047, t=4.536, t=2.075, P<0.05). And the D_(max) value of intermediate area of MLC of spinal cord also was significantly higher that of marginal area of MLC of spinal cord(t=-5.980, P<0.05). Conclusion: On the basis that the lungs, the spinal cord, the heart and other OARs can meet the dose limits, the intermediate area of MLC should be chosen to implement optimization as far as possible so as to get a better target dose distribution and increase the control rate of the tumor.
Objective: To investigate dosimetry effects of vane with different width of multi-leaf collimator(MLC) on intensity modulated radiation therapy(IMRT) of esophageal carcinoma so as to provide more reasonable references for IMRT of esophageal carcinoma. Methods: 40 patients with esophageal carcinoma were selected, and the radiotherapy plan was designed with the Varian Eclipse13.5 treatment plan system. IMRT was optimized in the intermediate and marginal areas of MLC. The basic parameters of target area and the received dose of organs at risk(OAR) were respectively compared, and the differences of them between the two plans were further analyzed. Dose volume histogram was used to compare the dose and volume of radiation in target area, lung, heart and spinal cord. Results: The intermediate area of MLC was chosen to implement optimization, and D_(mean) of target area was higher, and its homogeneity and conformal were better, and heart injectivity was higher, and both the D_(mean) and V_(30) value of intermediate area of MLC were significantly lower those of marginal area of MLC(t=-3.531, t=-3.551, P<0.05). Besides, the D_(mean), V_5, V_(10), V_(20) and V_(30) of intermediate area of MLC of double lungs were significantly higher than those of marginal area of MLC of double lungs(t=4.773, t=6.282, t=0.047, t=4.536, t=2.075, P<0.05). And the D_(max) value of intermediate area of MLC of spinal cord also was significantly higher that of marginal area of MLC of spinal cord(t=-5.980, P<0.05). Conclusion: On the basis that the lungs, the spinal cord, the heart and other OARs can meet the dose limits, the intermediate area of MLC should be chosen to implement optimization as far as possible so as to get a better target dose distribution and increase the control rate of the tumor.
引文
[1]陈进琥,尹勇,刘同海,等.颈段食管癌固定野调强与旋转调强放疗计划比较研究[J].中华放射肿瘤学杂志,2010,19(5):429-435.
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[7]范廷勇,李建彬,于金明,等.MLC叶片宽度对IMRT计划的影响[J].中华肿瘤防治杂志,2005,12(8):611-613.
[8]张富利,刘清智,王雅棣.基于配置不同类型MLC叶片加速器的宫颈癌术后调强放疗计划评估[J].中国医学物理学杂志,2013,30(5):4383-4386.
[9]杨超凤,杨海明,邓烨,等.多叶准直器叶片宽度对鼻咽癌调强计划剂量学的影响[J].医疗装备,2015,28(14):41-42.
[10]叶柳清,洪文松,李桢,等.不同MLC叶片宽度对肺癌调强放疗剂量学的影响[J].临床肿瘤学杂志,2017,22(11):1035-1037.
[11]李军,张西志,张先稳,等.Varian医用直线加速器DMLC物理参数的测量与验证[J].北京生物医学工程,2015(5):509-513.
[12]李军,张西志,张先稳,等.医科达Synergy-S加速器多叶准直器剂量学研究[J].中国医学装备,2018,15(4):39-42.
[2]李军,张西志,花威,等.胸段食管癌VMAT计划的剂量学验证研究[J].中华放射肿瘤学杂志,2014,23(3):259-261.
[3]Van Benthuysen L,Hales L,Podgorsak M.Volumetric modulated arc therapy vs IMRT for the treatment of distal esophageal cancer[J].Med Dosim,2011,36(5):404-409.
[4]Yin Y,Chen J,Xing L,et al.Applications of IMATin cervical esophageal cancer radiotherapy:Acomparison with fixed field IMRT in dosimetry and implementation[J].J Appl Clin Med Phys,2011,12(2):48-57.
[5]乔延伟.肿瘤精确放疗技术发展及应用现状[J].中国医疗设备,2014,29(7):73-76.
[6]柏朋刚,李奇欣,陈开强,等.COMPASS系统在鼻咽癌容积旋转调强剂量验证中的应用[J].中华放射医学与防护杂志,2012,32(3):304-307.
[7]范廷勇,李建彬,于金明,等.MLC叶片宽度对IMRT计划的影响[J].中华肿瘤防治杂志,2005,12(8):611-613.
[8]张富利,刘清智,王雅棣.基于配置不同类型MLC叶片加速器的宫颈癌术后调强放疗计划评估[J].中国医学物理学杂志,2013,30(5):4383-4386.
[9]杨超凤,杨海明,邓烨,等.多叶准直器叶片宽度对鼻咽癌调强计划剂量学的影响[J].医疗装备,2015,28(14):41-42.
[10]叶柳清,洪文松,李桢,等.不同MLC叶片宽度对肺癌调强放疗剂量学的影响[J].临床肿瘤学杂志,2017,22(11):1035-1037.
[11]李军,张西志,张先稳,等.Varian医用直线加速器DMLC物理参数的测量与验证[J].北京生物医学工程,2015(5):509-513.
[12]李军,张西志,张先稳,等.医科达Synergy-S加速器多叶准直器剂量学研究[J].中国医学装备,2018,15(4):39-42.