胃癌术后不同IMRT布野方式对剂量分布的影响  

Dosimetric comparison of IMRT plans with different beam directions for postoperative patients with gastric cancer

作　　者：卢晓光[1] 刘细友[1] 郑言宏 黄章玲 邱红[1] 

机构地区：[1]华中科技大学同济医学院附属同济医院肿瘤科,湖北武汉430030

出　　处：《中国医学物理学杂志》2016年第7期664-667,673,共5页Chinese Journal of Medical Physics

摘　　要：目的:研究比较胃癌术后放射治疗中两种不同布野方式的静态调强放射治疗(IMRT)计划在靶区剂量分布和正常组织受量等方面的差别,提出更优化的IMRT计划布野方式。方法:选取20例胃癌术后放疗患者,勾画靶区后,分别采用射野方向为0°、30°、60°、90°、330°(方案Ⅰ)和0°、45°、90°、195°、320°(方案Ⅱ)两种布野方式,在同等参数条件下制定逆向调强计划,比较计划的靶区适形度(CI)和均匀性(HI)、脊髓的最大剂量(D_(max))和平均剂量(D_(mean))、正常肝组织V30和D_(mean)以及双肾的V_5、V_(15)、V_(20)和D_(mean)。结果:研究表明方案Ⅰ计划的脊髓D_(max)和D_(mean)、肝脏V_(30)、左肾V_5,V_(15),V_(20)和D_(mean)以及右肾V_(15),V_(20)均优于方案Ⅱ计划(P<0.05)。靶区CI和HI、肝脏D_(mean)以及右肾V_5和D_(mean)在两种计划方案中的差异无统计学意义(P>0.05)。结论:胃癌术后IMRT计划按照0°、30°、60°、90°、330°(方案Ⅰ)布野能在保证靶区剂量的同时更有效减少正常组织受量,在临床值得推荐采用。Objective To optimize the beam directions of intensity-modulated radiotherapy（IMRT） for postoperative patients with gastric cancer by comparing the dose differences of target volumes and normal tissue between different treatment plans. Methods Twenty postoperative patients with gastric cancer were selected. After the target volume delineation, IMRT plans with different beam directions of 0°, 30°, 60°, 90°, 330°（PlanⅠ） and 0°, 45°, 90°, 195°, 320°（PlanⅡ） were designed.The conformal index and homogeneity index of planning target volume, the D_（max）and D_（mean）of spinal cord, the dose volume V_（30） and D_（mean）of normal liver tissue, the V_5, V_（15）, V_（20） and D_（mean）of kidneys were compared between two plans. Results The D_（max） and D_（mean）of spinal cord, the V_（30） of liver tissue, the V_5, V_（15）, V_（20） and D_（mean）of the left kidney and the V_（15）, V_（20） of the right kidney in the Plan Ⅰ were better than those in Plan Ⅱ（P0.05）. No significant differences were found between two plans in the conformal index, homogeneity index of planning target volume, the D_（mean）of liver tissue, the V_5 and D_（mean）of the right kidney（P0.05）. Conclusion Plan Ⅰ for postoperative patients with gastric cancer is worthy of clinical application for it can effectively reduce the dose of normal tissue and ensure the dose of target volumes.

关 键 词：胃癌 术后 调强放射治疗 射野方向 剂量 

分 类 号：R735.2[医药卫生—肿瘤] R730.55[医药卫生—临床医学]