摘要
目的探讨鼻咽癌调强放疗（IMRT）中靶区和正常器官变化规律。方法15例鼻咽癌初治患者接受全程IMRT，分别于计划设计前、治疗前、治疗25次时行3次CT扫描。第2、3次CT均和第1次CT行图像融合。3次CT图像的原发肿瘤（GTVnx）、GTVnx内气腔、腮腺、轮廓分别勾画，分析其变化规律。结果治疗计划完成时，有2例患者GTVnx增大。照射至25次时，GTVnx缩小0～10．39cm^3（即GTV内气腔容积）；腮腺体积缩小0．13～23．80 cm^3；腮腺缩小程度与原体积大小有一定的相关性；腮腺外界向内侧移动，内界位置变化不大。头部轮廓横径均有不同程度缩小。结论鼻咽癌患者在接受IMRT过程中，原发肿瘤体积、腮腺结构、位置、轮廓横径在一定程度发生变化，这可能会影响IMRT剂量分布，降低靶区、增加正常组织剂量，值得临床进一步研究。
Objective To study the changes in gross tumor volume（GTV） and normal organs during intensity modulated radiation therapy（IMRT）, and the probability of carrying out image-guided radiotherapy（IGRT） for nasopharyngeal carcinoma. Methods Fifteen patients with nasopharyngeal carcinoma were treated by IMRT. CT was acquired before the planning, start of treatment and at the twenty-fifth time during radiotherapy. All images were fused with the second,third CT pictures and the initial CT pictures. Both GTV and normal tissues were manually contoured on every axial slice to investigate the changes. Results Primary tumor volume increased in two cases after finishing plan. Up to the twenty-fifth time during radiotherapy, primary tumors and parotid glands in volume decreased by 0-10.39 cm^3 （ gas volume ） and 0. 13-23.80 cm^3; The shrunken degree correlated with the volume of the parotid glands before IMRT. The axial diameters of head decreased incoordinately. Condusions The primary tumor and normal tissue is changed during IMRT in nasopharyngeal carcinoma. The clinical consequences of these may be underdosage of tumor volume and/or overdosage of critical normal structures. Conclusively, the study is helpful in carrying out the second IMRT plan or IGRT for nasopharyngeal carcinoma.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2007年第2期81-85,共5页
Chinese Journal of Radiation Oncology
基金
中国医药卫生发展基金会资助项目（2006）
关键词
鼻咽肿瘤
放射疗法
调强放疗
图像引导放疗
Nasopharyngeal neoplasms/radiotherapy
Intensity modulated radiation therapy
Image-guided radiotherapy
