A dosimetric study of neck skin dose for early-stage nasopharyngeal carcinoma treated by Tomotherapy
10.3760/cma.j.issn.0254-5098.2017.12.005
- VernacularTitle:早期鼻咽癌螺旋断层放疗颈部皮肤受量的剂量学研究
- Author:
Yulei ZHANG
1
,
2
;
四川省肿瘤医院放疗中心
;
Xiongfei LIAO
;
Jie LI
;
Lixin BAI
;
Peng XU
;
Churong LI
;
Yazheng CHEN
;
Pei WANG
Author Information
1. 610065 成都,四川大学物理科学与技术学院
2. 四川省肿瘤医院放疗中心
- Keywords:
Nasopharyngeal carcinoma;
Helical tomotherapy;
Skin dose
- From:
Chinese Journal of Radiological Medicine and Protection
2017;37(12):906-910
- CountryChina
- Language:Chinese
-
Abstract:
Objective The purpose of this study is to investigate the method to reduce the radiation dose to the neck skin in the Tomotherapy treatment plans for early-stage nasopharyngeal carcinoma.Methods The 17 patients with early-stage nasopharyngeal carcinoma that have been treated by the Tomotherapy were selected randomly for this skin sparing study.The neck skin sparing region was generated as an internal margin of 3 mm from the out body contour,excluding the intercrossed area with the targets.Candidate patients were planned using TP and NP method respectively:the TP group was planned with the traditional method.The new neck skin region was considered as an organ at risk (OAR) for planning dose constrain in NP group.The dosimetric metrics of targets and OARs,monitor units (MU) and delivery time were compared as the end points of these two groups.Results The two treatment plan groups satisfied the clinical requirement.There were no significant differences for D98,D95 and D2 of the targets (P ＞ 0.05).The Dmax of brainstem,D1cc of spinal cord,D of right parotid were higher in NP group than in theTPgroup (t =2.47,2.34,2.77,P＜0.05).The Dmax of left mandible joint was lower than TP group(t =2.30,P ＜ 0.05).The V30,V40,V50 and V60 of the skin were considerably lower than TP group (t =8.37,6.02,5.82,4.89,P ＜ 0.05).The mean MU and mean delivery time per fraction of NP group were 6.3％ and 8.1％ less than that of TP group respectively.Conclusions The neck skin region should be delineated as an OAR to be spared in the Tomotherapy treatment planning for early-stage nasopharyngeal carcinoma.This method can reduce the skin radiation dose effectively,alleviate the skin reaction,and improve the life quality of patients in radiotherapy.
