摘要
目的:研究非小细胞肺癌(NSCLC)放疗中靶区体积变化及相应修改放疗计划对肺脏受照射量的影响。方法:将40例NSCLC患者,初次定位和复位CT根据椎骨进行匹配。在初次CT上复制并勾画复位CT靶区体积,外扩相同边界后,根据定位与复位靶区分别按原放疗计划相同的照射野和剂量分配重新运算。分析定位与复位靶区体积差异及相关肺脏剂量容积参数变化。结果:40例患者计划修改前照射次数为(21.0±6.2)次,修改计划后GTV缩小了(26.3±37.9)%,且GTV变化与计划修改前照射次数呈正相关,r=0.434,P=0.005。初次计划与复位计划拟合后患侧肺和双侧肺平均肺受量(MLD)分别下降了(4.1±11.0)%和(3.9±9.6)%,P值分别为0.01和0.02。与定位时比较,照射次数≤20次复位者,GTV缩小了(19.0±33.0)%,患侧肺和双肺MLD分别下降了(17.5±46.4)%和(19.4±48.0)%;照射20次后复位者,GTV缩小了(40.9±36.6)%,患侧肺和双肺MLD分别下降了(58.0±46.4)%和(55.8±42.5)%,照射20次前后复位GTV及MLD变化程度的差异有统计学意义。结论:NSCLC在放疗中原发肿瘤体积发生了显著褪缩,通过放疗中修改放疗计划能够显著降低肺受量。
OBJECTIVE：To study the change of target volume during 3-dimentional conformal radiotherapy（3D CRT） for non-small cell lung cancer（NSCLC）and the inference of treatment plan changing for lung dosimetry.METHODS：Forty NSCLC patients treated with 3D-CRT scaned by planning CT repeatly and treatment plan changed no less than one time.The first and the second set of CT images were matched by vertebrae in Pinnacle3 treatment system,then GTVs of the second CT scans were contoured on the first CT scans.The same margins extended for GTVs of one patient,and the second treatment plans were designed just as the first one＇s irradiation beams and dose distribution according to the second GTVs.The difference of GTVs between the first and the second planning CT and related dosimetric parameters were analyzed.RESULTS：Totally patients with（21.0±6.2） irradiation fractions before treatment plan changing were included,when GTVs shrinkaged（26.3±37.9）%,and the change of GTVs were pasitive correlated with irradiation fractions befor treatment plan changing（r=0.434,P=0.005）.Mean lung dose（MLD） of ipilateral and bilateral pulmonary descented（4.1±11.0）% and（3.9±9.6）%,which was assessed combined with the primary and the changed treatment plans.Compared to primary CT,GTVs with irradiation fraction≤20 shrinkaged（19.0±33.0）%,ipilateral and bilateral pulmonary MLD descented（17.5±46.4）% and（19.4±48.0）%.Worthwhile GTVs with irradiation fraction 20 shrinkaged（40.9±36.6）%,ipilateral and bilateral pulmonary MLD descented（58.0±46.4）% and（55.8±42.5）%.CONCLUSION：Primary tumor volume of NSCLC retracted extinctly during radiotherapy,and MLD can be descented more extinctly with treatment replanning after 20 fractions.
出处
《中华肿瘤防治杂志》
CAS
2010年第22期1852-1854,共3页
Chinese Journal of Cancer Prevention and Treatment
关键词
癌
非小细胞肺/放射疗法
三维适形放疗
放疗计划修改
回顾性研究
carcinoma
non-small cell lung/radiotherapy
three-dimentional-conformal radiotherapy
treatment planning change
retrospective studies
