摘要
Abstract
Objective To compare the dose distribution, radiation in organs at risk and treatment time of five-fields static intensity-modulated radiotherapy (IMRT) with different segment quantities in the target area of the middle and late stage cervical cancers, and to provide references for clinical treatment. Methods Altogether 25 patients withⅡb-Ⅲb stage cervical cancers were enrolled in this study. The target area and organs at risk were contoured on the contrast-enhanced CT images. The radiotherapy plan was designed by Eclipse 10.0 Treatment Planning System (TPS), and the number of segments were set up as 50 (G1 Group), 35 (G2 Group) and 25 (G3 Group) respectively. Through analysis of DVH (Dose-volume Histogram), the homogeneity index (HI), conformity index (CI) in the target area, radiation in organs at risk and treatment time of three different methods were compared. Results G1 Group had the lower maximum dose (Dmax) average dose (Dmean), and its homogeneity and conformity were the best, better than the other two methods signiifcantly (P<0.05). For bladder, intestine and rectum, V20 differed little among three methods. As for V30, V40, V50 and Dmax, G1 was lower than the other two methods and G2 was lower than G3, among which statistical signiifcance existed between Dmax and V50 for rectum (P<0.05). G1 had the fewest machine units (MUs) than G2 and G3 (P>0.05), and the treatment time of G1, G2 and G3 was about 8.5, 7.2 and 6.5 minutes respectively. Conclusion Static intensity-modulated radiotherapy with more segments had better homogeneity and conformity, and could protect the organs at risk effectively, but had a prolonged treatment time. The quantity of segments should be selected according to practical demand reasonably.关键词
宫颈癌/调强放射治疗/静态调强/子野数量/剂量学Key words
cervical neoplasm/intensity-modulated radiotherapy/static intensity-modulated radiotherapy/segment quantities/dosimetry分类
机械制造
