摘要
目的 比较旋转调强技术与常规固定野调强技术在鼻咽癌计划中对靶区及危及器官剂量学差异.方法 选取10例同步加量放疗鼻咽癌患者,通过瓦里安Eclipse 8.6计划系统分别制定旋转调强放疗（IMAT）计划和固定野调强放疗（IMRT）计划,运用剂量体积直方图评价两种计划的靶区（PTV、PTV1、PTV2）及危及器官剂量参数、机器跳数（MU）和治疗时间（T）.结果 IMAT和IMRT计划的PTV、PTV1、PTV2适形指数均不同,分别为0.71和0.75（Z=-2.32,P＜0.05）、0.54和0.59（Z=-2.56,P＜0.05）、0.71和0.78（Z=-2.52,P＜0.05）;均匀指数均相似,分别为10.5和11.2（Z=-0.84,P＞0.05）、13.1和17.1（Z=-1.68,P＞0.05）、14.1和13.3（Z=-1.01,P＞0.05）.IMAT和IMRT计划的脑干平均剂量相似,分别为（3512.8±406.2）cGy和（3384.3±361.3）cGy（Z=-1.82,P＞0.05）,最大剂量也相似,分别为（5528.1±192.9）cGy和（5727.5±356.3）cGy（Z=-1.12,P＞0.05）;脊髓最大剂量不同,分别为（4186.1±8 8.7）cGy和（4390.2±74.9）cGy（Z=-2.38,P＜0.05）.两种计划中双侧腮腺平均剂量、腮腺33%体积受照剂量（D33）、D50、D60均相似（P值均＞0.05）,正常组织[定义为全身（body）减去PTV,即B-P]受照500 cGy体积占总B-P体积百分比（V5）、V10均也相似（P值均＞0.05）,但V15、V20、V25、V30、V35、V40、V45、V50均不同（P值均＜0.05）.两种计划的MU不同,MUIMRT=1308±213,MUIMAT=606±96（Z=-2.52,P＜0.05）.结论 IMAT计划靶区剂量覆盖与IMRT计划相当,适形度好于IMRT计划;危及器官受照剂量相当,B-P受照剂量明显降低;可减少机器跳数和治疗时间.
Objective To compare the dosimetric differences of target volume and organ at risk between intensity-modulated arc therapy （IMAT） and simultaneously integrated boost intensity-modulated radiotherapy （SIB-IMRT） in nasopharyngeal carcinoma. Methods IMAT and SIB-IMRT treatment plans of 10 nasopharyngeal carcinoma cases were generated by Varian Eclipse ver8. 6 treatment planning system. The dosimetric parameters of target volume and organ at risk （OAR）, the monitor units （MU） and treatment time were compared between IMAT and SIB-IMRT treatment plan. Results The conformal index （ CI ） of PTV, PTV1, PTV2 of IMAT and SIB-IMRT were 0. 71 and 0. 75 （ Z = - 2. 32, P ＜ 0. 05 ）, 0. 54 and 0. 59 （Z= -2.56,P＜0.05）, 0.71 and 0.78（Z= -2.52,P＜0.05）, respectively. the homogenous index （HI） of PTV, PTV1, PTV2 of IMAT and SIB-IMRT were 10.5 and 11.2（Z= -0. 84,P＞0.05）,13. 1 and 17. 1（Z= -1.68,P＞0.05） and 14. 1 and 13.3（Z= -1. 01,P＞0.05） respectively;the brain-stem mean does were 3512. 8 cGy ± 406. 2 cGy and 3384. 3 cGy ± 361.3 cGy （ Z= - 1.82, P ＞ 0. 05 ）; the brain-stem maximum dose were 5528. 1cGy ± 192. 9 cGy and 5727. 5 cGy ± 356. 3 cGy （ Z = - 1.12, P ＞ 0. 05 ）; the maximum dose of spinal-cord were were 4186. 1cGy ± 88.7 cGy and 4390. 2 cGy ± 74. 9 cGy （ Z =-2. 38 ,P ＜ 0. 05 ）. There were no significant differences between parotid dose and normal tissue （ P ＞0. 05. ） MU were 606 ± 96 and 1308 ± 213 for IMAT and SIB-IMRT （ Z= - 2. 52, P ＜ 0. 05 ）. Conclusions The IMAT plan showed a better conformal index than SIB-IMRT plan, with the same dosimetric parameters of the target volume and OAR. The IMAT plan could reduce normal tissues dose, monitor units and treatment time in the treatment of nasopharyngeal carcinoma.
出处
《中华放射肿瘤学杂志》
CSCD
北大核心
2010年第6期486-490,共5页
Chinese Journal of Radiation Oncology
关键词
鼻咽肿瘤/放射疗法
放射疗法
调强
放射疗法
旋转调强
放射疗法
同步加量
剂量学
Nasopharyngeal neoplasms/radiotherapy
Radiotherapy, intensity-modulated
Radiotherapy, intensity-modulated arc
Radiotherapy,simultaneously integrated boost
Dosimetry
