^125I粒子植入术后脊髓靶区勾画方法的研究  

Study on the method of drawing the target area of spinal cord after ^125I seed implantation

作　　者：王静 张萍 张坤 王义涛 董俊峰 杨健 WANG Jing;ZHANG Ping;ZHANG Kun;WANG Yitao;DONG Junfeng;YANG Jian(Precision Radiotherapy Center of Cangzhou People′s Hospital,Cangzhou 061000,China;不详)

机构地区：[1]沧州市人民医院精准放疗中心,河北沧州061000 [2]黄骅市开发区博爱医院,河北沧州062600

出　　处：《实用医学杂志》2020年第21期2971-2975,共5页The Journal of Practical Medicine

摘　　要：目的研究放射性^125I粒子植入术后正常脊髓组织的靶区勾画方法。方法选取5名健康体检者胸及腹部CT图像,层厚0.5 cm,载人计算机三维治疗计划系统(The 3D treatment planning system,TPS),在第12胸椎处逐层勾画分别模拟直径为4 cm、高3 cm(A组)、直径为5 cm、高4 cm(B组)和直径为6 cm、高5 cm(C组)距离脊髓1.0 cm的圆柱形肿瘤以及长4 cm、宽4 cm、高4 cm(D组)和长5 cm、宽5 cm、高5 cm(E组),以及长6 cm、宽6 cm、高6 cm(F组)距离脊髓1.0 cm,且肿瘤的高与脊髓平行。按照中间稀疏、周边密集的布源规则,处方剂量为135 Gy,行使术前计划。然后分别勾画GTV上下-1.0、-0.5、0.0、0.5、1.0、1.5、2、2.5、3.0 cm为正常脊髓组织靶区,然后计算正常脊髓组织所受到的平均剂量(Mean)、最大点剂量(Max)及D2c(c 2 cm3脊髓组织所接受的剂量)。结果肿瘤越大,相同处方剂量时,使用粒子数目越多,脊髓受量D2cc、最大点剂量、平均剂量越高。A、B、C、D、E、F组正常脊髓组织靶区勾画长度与其受到的最大点剂量无关,随着正常脊髓组织靶区勾画长度的增加脊髓受到的平均剂量逐渐减少,A、B、C、D、E、F组正常脊髓组织靶区勾画小于GTV层面时,D2cc随着正常脊髓组织靶区勾画长度缩短而减小,大于等于GTV层面时,D2cc不再随正常脊髓组织靶区勾画长度的增加而变化,且与肿瘤形状、肿瘤大小不相关,且脊髓勾画长度小于肿瘤靶区层面1.0 cm于其勾画长度大于等于肿瘤靶区层面相比差异有统计学意义(P<0.05)。结论放射性^125I粒子植入术后正常脊髓组织靶区勾画长度大于或等于GTV层面时,脊髓组织受量与肿瘤大小,肿瘤形状无关,为统一放射性^125I粒子植入术后正常脊髓组织靶区勾画的范围,推荐放射性^125I粒子植入术后正常脊髓组织靶区勾画长度为肿瘤靶区上下1.0 cm。Objective To study the target delineation method of normal spinal cord tissue after implantation of^125I radioactive particles.Methods The CT images of chest and abdomen of 5 healthy people were selected.The slice thickness was 0.5 cm,and the 3D treatment planning system was used.At the 12th thoracic vertebrae,the cylindrical tumors with the diameter of 4 cm,3 cm high(group A),5 cm in diameter and 4 cm in height(group B),6 cm in diameter and 5 cm in height(Group C)and 1.0 cm in length,width and height(Group D),5 cm in length,5 cm in width and 5 cm in height(Group E),and 6 cm in length,6 cm in width and 6 cm in height(Group F)and 1.0 cm in length,width and height were respectively depicted at the 12th thoracic vertebrae The tumor is a triangular pyramid.According to the rule of sparse in the middle and dense in the periphery,the prescription dose was 135 Gy,and the preoperative plan was carried out.Then the target areas of normal spinal cord tissue were delineated as-1.0,-0.5,0,0.5,1.0,1.5,2,2.5,3.0 cm,respectively.The mean,Max and D2cc of GTV were calculated.Results The particles used the dose of D2cc and the maximum point increases with the size of the tumor.In group A,B,C,D,E and F,the length of the target area which was delineated normal spinal cord tissue,was not related to the maximum dose received by the spinal cord.With the increase of the length of the target area of normal spinal cord tissue,the average dose received by the spinal cord decreased gradually.In group A,B,C,D,E and F,when the target area of normal spinal cord tissue was less than the GTV layer,the D2cc decreased with the reduction of the target area of normal spinal cord tissue,greater than or equal to the GTV layer In face time,D2cc did not change with the increase of target length in normal spinal cord,and was not related to tumor shape and size.There was a significant difference in the length of spinal cord sketch between the tumor target level and the tumor target level(P<0.05).Conclusion When the target area of normal spinal cord tissue

关 键 词：靶区勾画 脊髓 ^125I粒子 计算机三维治疗计划系统 

分 类 号：R730.5[医药卫生—肿瘤]