Objective To investigate the feasibility and security of the boost plan as a method of field sizes reduction after the initial irradiation for local advanced non - small-cell lung cancer through the evaluation of dose distributions .Methods 1 3 8 patients with lung cancer were divided into two groups ,the observed group and the control group .Both the observed group and the control group accepted 3 DCRT (6 0 Gy/2 Gy ) .In the initial radiotherapy plan the two teams both accepted the same 3 DCRT (4 0 Gy/2 Gy) And 2 0 Gy was used for the boost radiotherapy plan of the observed group .In the other group ,there was 6 0 Gy to the primary tumor and involved nodal regions using a single plan .Results (1 )The median conformity index of the boost plan was 2 .0 ,lower than 2 .2 in the initial plan (20 Gy) .The median heterogeneity index were 1 .1 and 1^2 .The V5 (P=0 .8 2 0 ) ,V1 0 ( P=0 .7 0 3 ) ,V2 0 ( P=0 .1 4 9 )and the spine cord volumes irradiated (maximal dose)( P=0 .0 6 3 ) did not decreased significantly using the boost plan .The mean lung dose( P=0 .0 4 8 ) was reduced significantly in the boost plan compared with the initial plan (2 0 Gy ) .The volume of gross tumor volume ( P=0.0 1 3 )and planning target volume(P=0 .039 )in the boost plan was significantly shrinked .(2 )The one - and two -year survival rate ,the one- and two-year local recurrence rate for the observed group and the control group were 89 .5% and 73 .7% (P=0 .209 ) ,15 .8% and 10 .5% (P=0 .631 ) ,81 .2% and 87 .5% (P=0 .782 ) ,57 .1%and 62 .5% (P=0 .833 ) .The median disease free survival were 12 .5 months compared with 11 .9 months(P=0 .8 4 6 ) .The one - and two -year distant metastase rate for the observed group and the control group were 2 2.2% and 4 4 .4% ( P=0 .1 5 7 ) ,6 1 .5% and 6 8 .8% ( P=0 .6 8 4 ) .(3 )T he radiation pneumonitisis probability was 5 .2% ,was significantly lower than 31 .6% in the control group(P=0 .036 ) .Conclusions The application of boost plan is not bad and fitting to patients with local advanced non - small-cell lung cancer .%目的：评价缩野推量计划在局部晚期非小细胞肺癌缩野放疗中的安全性和实用性。方法收集2009年1月至2012年12月局部晚期非小细胞肺癌患者138例作为研究对象，分为缩野推量计划组（观察组）与单一计划组（对照组）。78例患者因为肿瘤体积较大或肿瘤部位特殊接受缩野推量计划，其中60例因为二程计划延长疗程及经济原因拒绝二程。两组均接受60 Gy／2 Gy的三维适形放疗计划。其中观察组一程剂量40 Gy ，缩野推量20 Gy ；对照组按一程计划照射60 Gy ，通过分析剂量－体积直方图（DV H图）及剂量分布图对两组患者的变异度与适形度、不同剂量时的肺照射体积、脊髓平均受照射剂（MLD）及生存率、复发转移率进行评价。结果（1）缩野推量计划中位适形指数是2．0，低于一程计划（20Gy）的2．2；实验组与对照组的变异指数分别为1．1与1．2；两组的V5，V10，V20 脊髓最大剂量受照体积相比无显著差异。缩野推量计划的肺平均受量（mean lung dose ，MLD）（ P＝0．048）明显低于一程计划（20 Gy ）。缩野推量计划的GTV（P＝0．013）及PTV（P＝0．039）明显缩小。（2）观察组与对照组的1年与2年生存率、局部复发率分别为89．5％与73．7％（P＝0．209） ，15．798％与10．5％（P＝0．631）；81．2％与87．5％（P＝ 0．782）。观察组与对照组中位无病生存期分别为12．5与11．9个月（P＝0．846）。观察组与对照组1年、2年远处转移率分别为22．2％与44．4％（P＝0．157），61．5％与68．8％（P＝0．684）。结论缩野推量计划对于肿块较大的局部晚期非小细胞肺癌治疗安全、有效。
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