目的:探讨咽喉部鳞癌螺旋断层放射治疗静态和(或)动态铅门模式在危及器官的剂量学差异.方法:选取8例咽喉部鳞癌患者,在放射治疗中分别设计铅门宽度为1.05 cm、2.512 cm和5.05 cm的3组静态铅门计划,即定义为F1.0组、F2.5组和F5.0组,以及宽度为2.512 cm、5.05 cm的2组动态铅门计划,即定义为D2.5组和D5.0组.比较5组计划危及器官剂量分布、剂量体积直方图(DVH)的多个指标情况.结果:在静态和动态两种铅门模式下进行腮腺与口腔的剂量学比较,F1.0组计划优于其他静态铅门计划,动态铅门计划中,D2.5组优于D5.0组.腮腺和口腔的容积剂量参数V5、V10、V20、V30、V40、V50及平均剂量均以F1.0组最低.当铅门宽度相同时,动态铅门计划的各项指标要明显低于静态铅门计划.结论:在咽喉部鳞癌螺旋断层放射治疗中,宽度为2.512 cm的动态铅门与宽度为1.05 cm的静态铅门计划相近,提示实际应用中动态铅门技术比静态铅门技术能更好的降低危及器官剂量.%Objective: To explore the dosimetric difference of fixed state and(or)dynamic state of jaw mode of helical tomotherapy(HT)for organ at risk(OAR)when squamous carcinoma of pars laryngea pharyngis was treated.Methods: Eight patients with squamous carcinoma of pars laryngea pharyngis were enrolled in this study.In the radiotherapy,the three fixed jaw planning which widths included 1.05 cm,2.512 cm and 5.05 cm were designed(F1.0 group,F2.5 group and F5.0 group),besides,two dynamic jaw planning which widths included 2.512 cm and 5.05 cm also were designed(D2.5 group and D5.0 group).And the dose distribution of OAR of 5 groups,dose volume histogram(DVH)and other some indicators were compared.Results: The dosimetric comparison about parotid gland and oral cavity under two kinds of jaw mode which included fixed jaw and dynamic jaw indicated that F1.0 group was better than other group,and D2.5 group was better than D5.0 group in dynamic group.And in the comparisons about V5,V10,V20,V30,V40,V50 and Dmean of parotid gland and oral cavity,F1.0 group was lowest.When the widths of jaw was same,every indicator of dynamic jaw was obviously lower than that of fixed jaw.Conclusion: In the radiotherapy with HT for squamous carcinoma of pars laryngea pharyngis,the effect of dynamic jaw with a width of 2.512 cm is similar to that of fixed jaw with a width of 1.05cm,and this result suggested that the dynamic jaw technique may better reduce the dose of OAR compared with fixed jaw in the practical application.
展开▼
