摘要
目的比较应用不同外照射技术治疗鼻咽癌时后组颅神经的最大剂量和并发症发生概率,以指导鼻咽癌放疗计划的制定。方法应用三维治疗计划系统(TPS)在10例鼻咽癌患者的CT图像上分别设计3种常规外照射计划(A计划:先用面颈联合野加下颈切线野照射36Gy,再用面颈联合野缩野加下颈切线野照射14Gy;B计划:先面颈联合野加下颈切线野照射36Gy,再用耳前野加全颈切线野照射14Gy;C计划:应用耳前野加全颈切线野照射50Gy。3种计划最后都用耳前野加量照射至鼻咽72Gy),应用剂量体积直方图比较3种计划颈动脉鞘的最大剂量和正常组织并发症发生概率(NTCP)的区别。根据颈动脉鞘的NTCP来估计放射性后组颅神经损伤(RILCN)的发生概率。结果由TPS发现耳前野与全颈切线野在颌下重叠,形成高剂量区。A、B、C3种放疗计划颈动脉鞘最大剂量的均数向量分别为xA=(77.72,76.85)′、xB=(83.89,83.78)′和xC=(105.97,106.11)′,差别有统计学意义(F=55.003,P<0.01);3种计划NTCP的均数向量分别为xA=(36.4,35.0)′、xB=(52.2,49.6)′和xC=(94.8,95.0)′,差别也有统计学意义(F=36.901,P<0.01);而且3种计划的最大剂量和NTCP两两之间的差别均有统计学意义(P值均<0.01)。应用A计划时颈动脉鞘的最大剂量和NTCP最低,C计划的最高。结论使用耳前野加全颈切线野时,在颌下区的重叠会增加颈动脉鞘的最大照射剂量和NTCP,有可能增加鼻咽癌放疗后RILCN的发生概率。建议停用耳前野加全颈切线野的照射方式。
Objective To compare the maximum doses and complication probabilities of lower cranial nerve in different conventional external irradiation technique in treatment of patients with nasoparyngeal carcinoma, and to help design the radiotherapeutic planning. Methods To design respectively three conventional external irradiation treatment plans in nasopharyngeal carcinoma by using three-dimensional treatment planning system. A, initially using two lateral faciocervial portals plus inferior neck tangential portal to 36 Gy, followed by two contracted faciocervial portals plus inferior neck tangential portal to 50 Gy. B, initially using two lateral faciocervial portals plus inferior neck tangential portal to 36 Gy, followed by two pre-auricular portals plus whole neck tangential portal to 50 Gy. C, directly using two preauricular portals plus whole neck tangential portal to 50 Gy. All of the three plans end up by using two pre-auricular portals boosted to 72 Gy, then to compare the difference of their maximum doses and normal tissue complication probabilities（NTCP） of the carotid sheath through dose-volume histogram, and esti- mate the probability of developing radiation-induced lower cranial neuropathy（RILCN） according to the NTCP of carotid sheath. Results There was a high dose region on submandibular region because of the overlapping between pre-auricular portal and whole neck tangential portal in all planning system. The mean vectors of the maximum dose of carotid sheath in three different external irradiation techniques were x^-A=（77.72, 76.85）＇,x^-B=（83.89, 83.78）＇ and x^-C = （105. 97 ,106.11） ＇. The mean vectors of the NTCP of carotid sheath by using the three different techniques were x^-A = （36.4, 35.0）＇ ,x^-B = （52.2, 49.6）＇ and x^-C =（94. 8,95. 0）＇ （F=55. 003, P〈0.01,P〈0. 01） also. lowest NTCP of carotid sheath by using plan A, while the irradiation technique of pre-auricular portal plus whole neck and NTCP of carotid sheath because of their overlapping incre
出处
《福建医科大学学报》
2006年第2期132-135,共4页
Journal of Fujian Medical University
基金
福建省科技厅科研基金资助项目(2000Z040)
关键词
鼻咽肿瘤
颅神经
临床方案
放射治疗剂量
nasopharyngeal neoplasms
cranial nerves
clinical protocols
radiotherapy dosag
