摘要
背景与目的:鼻咽癌放疗中佩戴个体化口腔支架可以保护口腔黏膜和舌,具有临床应用价值,本研究旨在探讨鼻咽癌放疗中个体化口腔支架在口腔中的位置重复性,明确其在放疗中应用的可行性。方法:选择17例初治鼻咽癌患者制作个体化口腔支架,并在口腔支架内埋入3个直径为2mm的铅点,患者戴口腔支架作面罩固定和CT扫描,放疗前及放疗中每周在常规模拟机下拍摄正侧位X线片,根据X线片计算和比较铅点在左右、前后和头脚方向的位移。在放疗40Gy时,戴原面罩并按照原来的位置标记点复查CT扫描,计算并比较两套CT图像间3个铅点和3个选择的骨性结构几何中心的位移有无差异。结果:得到240张X线片,铅点在左右、前后、头脚方向上的位移分别为(0.69±0.54)mm、(0.49±0.62)mm、(0.56±0.57)mm,三维矢量位移为(1.20±0.77)mm(0～4.98mm)。三维方法显示3个铅点几何中心在左右、前后、头脚方向的位移分别为(0.75±0.68)mm、(1.25±1.12)mm、(1.06±0.77)mm,三维矢量位移为(2.15±0.90)mm(1～4.24mm)。用ANOVA方法比较3个铅点和3个骨性结构几何中心在左右、前后、头脚方向上的位移及三维矢量位移,结果差异均无统计学意义(P>0.05)。结论:鼻咽癌放疗中口腔支架在口腔中的位置重复性较好,可以和骨性结构之间形成一种固定的关系,其在鼻咽癌放疗中应用是可行的。
Background and Objective： Individual oral stent used in nasopharyngeal carcinoma （NPC） patients during radiotherapy can spare the oral mucosa and tongue. This study was to analyze the placement repeatability and feasibility of individual oral stent used in radiotherapy of NPC. Methods： Individual oral stents were made for 17 naive NPC patients, and three lead markers of 2.0 mm diameter were embedded in each oral stent. The patients wearing individual oral stent were immobilized by thermoplast mask and unerwent CT scan. Before and every week during radiotherapy, orthogonal （antero-posterior and lateral） X-ray films were taken in conventional simulator, respectively. Displacements of leader markers in medio-lateral （M-L）,antero-posterior （A-P） and cranio-caudal （C-C） directions were respectively calculated and compared on each patient＇s X- ray films. At the dose of 40 Gy, a repeated CT scan was done with the same thermoplast mask and positioning markers. The displacements of coordinating gravity center of three lead markers and three selected bony structures between two sets of CT images for each patient were calculated and compared by ANOVA. Results： A total of 240 X-ray films were taken. The displacements of lead markers were （0.69±0.54）mm in M-L direction, （0.49±0.62） mm in A-P direction, and （0.56±0.57）mm in C-C direction, and the overall vector displacement was （1.2±0.77）mm （range, 0-4.98 mm）. In three-dimensional method, the displacements of co-ordinating gravity center of three lead markers were （0.75±0.68）mm in M-L direction, （1.25±1.12）mm in A-P direction, and （1.06±0.77）mm in C-C direction, and the overall vector displacement was （2.15±0.90）mm （range, 1-4.24 mm）. The displacements between gravity center of three lead markers and three bony structures had no significant difference in M-L, A-P, and C-C directions （P〉0.05）. The overall vector displacements also had no significant difference （P=0.083）. Conclusion. The placement repeatability of individual oral dental stent in the mouth is very good during radiotherapy of NPC, and dental stent has a fixed position relationship with bony structures.
出处
《癌症》
SCIE
CAS
CSCD
北大核心
2009年第10期1103-1107,共5页
Chinese Journal of Cancer
基金
广东省科技计划项目(No.2007B031505001)~~
关键词
口腔支架
鼻咽肿瘤
位置重复性
摆位误差
dental stent, nasopharyngeal neoplasm, placementrepeatability, set-up uncertainty
