局部晚期鼻咽癌诱导化疗后原发病灶靶区勾画的探讨  

Study on delineation of gross tumor volume （GTV） of primary locally advanced nasopharyngeal carcinoma after induction chemotherapy

作　　者：龚修云[1] 金风[1] 吴伟莉[1] 甘家应[1] 李媛媛[1] 龙金华[1] 陈潇潇[1] 王立敏[2] 

机构地区：[1]贵州省肿瘤医院贵州医科大学附属医院头颈肿瘤科,贵阳550004 [2]贵阳市第一人民医院科教科,550002

出　　处：《中华放射医学与防护杂志》2016年第2期116-120,共5页Chinese Journal of Radiological Medicine and Protection

基　　金：贵州省科技厅社发联合攻关项目，Key Project of Science and Technology Department of Guizhou Province

摘　　要：目的 探讨局部晚期鼻咽癌诱导化疗后原发病灶（GTVnx）靶区勾画.方法 选择2012-2013年收治的52例局部晚期鼻咽癌患者,诱导化疗2～3周期后行CT定位、标记及图像采集;同期采取相同体位行鼻咽部MRI平扫及增强扫描,采集T1W1增强图像;分别在CT图像及MRI图像进行GTVnx勾画;转移淋巴结、CTV1、CTV2及正常组织均在CT图像进行勾画;通过放疗计划系统进行MRI/CT图像GTVnx靶区融合;两套靶区给予相同处方剂量及正常组织限量,物理师进行调强放疗计划设计.比较不同图像下诱导化疗后GTVnx、各靶区照射体积及剂量、正常组织受量变化.结果 在局部晚期鼻咽癌诱导化疗后GTVnx勾画中,MRI图像勾画靶体积大于CT图像[（43.14±28.40）、（40.09±27.04）cm^3,t=3.791,P＜0.001];MRI图像勾画靶体积与诱导化疗前原发病灶体积差值[（27.90±11.86） cm^3]小于CT图像勾画体积差值[（30.64±11.86）cm^3]（t=3.948,P＜0.001）.两套计划原发病灶靶区照射体积比较,融合靶区计划（41.71±26.86）cm^3大于CT图像计划[（38.65±25.66）cm^3]（t=4.098,P＜0.001）,但靶区剂量及正常组织受量差异无统计学意义.结论 采用MRI图像进行局部晚期鼻咽癌诱导化疗后原发病灶靶区勾面、MRI/CT靶区图像融合进行放疗计划设计,增加原发灶靶区体积及照射体积,可能减少诱导化疗后放射治疗靶区勾画漏靶发生.Objective To investigate the delineation primary lesions of the gross tumor volume （GTVnx） in locally advanced nasopharyngeal carcinoma （LANC）.Methods During 2012-2013,52 patients with LANC treated with two-three cycles of induction chemotherapy accepted CT simulation and MRI scans in the same treatment position.All the images of CT and T1W1 sequence of MRI were collected and transmitted to the treatment planning system.The gross target volume （GTVnx） was delineated through CT and MRI images.Meanwhile,metastatic lymph nodes,CTV1,CTV2 and organs at risk（OAR） were delineated through CT images alone.The images from MRI and CT were then fused as MRI/CT fusion images by radiotherapy system,and the same prescription dose and limitation dose of OAR were given as CT images.The changes of GTV the radiation volume and dose,and dose coverage of normal organs from two different images were compared.Results The delineation volume in fused MRI/CT image [（43.14 ± 28.40 cm^3）] was larger than CT [（40.09± 27.04） cm^3] （t =3.791,P 〈 0.001）.And there was statistical difference between the two images in the GTV changes before and after IC,with MRI/ CT （27.90 ±11.86） and CT [（30.64 ±11.86） cm^3] （t =3.948,P 〈 0.001）,respectively.The radiation volume in MRI/CT fusion image [（41.71± 26.86） cm^3] was larger than CT [（38.65 ± 25.66） cm^3] （t =4.098,P 〈0.001）.But there were no statistical differences in target volume dose and dose coverage of normal organs between the two images.Conclusions The technique of MRI/CT fusion image can increase the radicalized GTV and may decrease the possibility of leaving out the target volume definition.

关 键 词：局部晚期鼻咽癌 诱导化疗 MRI/CT融合 靶区勾画 

分 类 号：R739.63[医药卫生—肿瘤]