Analysis of positioning deviation of different body position fixing methods for hepatic carcinoma patients with radiotherapy by MVCT
- VernacularTitle:利用MVCT图像引导技术分析肝脏恶性肿瘤放疗不同体位固定方式的摆位误差
- Author:
Wei-Jie DING
1
;
Zhao-Chong ZENG
;
Jing SUN
;
Yi-Xing CHEN
Author Information
1. 复旦大学附属中山医院放疗科
- Keywords:
hepatic carcinoma;
MVCT;
positioning deviation;
extended boundary
- From:
Chinese Journal of Clinical Medicine
2016;23(3):341-343
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To analyze the positioning deviation of two different body position fixing methods for hepatic carcinoma patients by meta-voltage computed tomography (MVCT) .Methods:The positioning data of 40 hepatic carcinoma patients treated by helical tomotherapy during March to October ,2015 in our Department of Radiotherapy were collected and divided into two groups :users of carbon fiber fixator with vacuum pad (Group C) and users of the vacuum bag (Group V) . MVCT scan was performed before each treatment ,and the amount of both linear and rotary positioning deviation was obtained . The two sets of data were compared through mean functional t-test .Finally ,PTV extended boundary was calculated according to the extension formula M=2 .5Σ+0 .7δ.Results:From deviation direction of linear positioning ,the differences of X-axis and Z-axis on two sets of data had statistical significance (t=22 .02 ,2 .56;P=0 .04 ,0 .01 ;P<0 .05) .From deviation direction of rotary positioning ,the differences of Pitch and Yaw on two sets of data also had statistical significance (t=22 .16 ,2 .26 ;P=0 .03 ,0 .02 ;P<0 .05) .PTV extended boundary of Group V were 8 .29 mm ,9 .87 mm and 7 .72 mm .PTV extended boundary of Group C were 4 .81 mm ,5 .27 mm and 4 .57 mm .Conclusions:In helical tomotherapy ,MVCT image guidance technology could enhance the accuracy of radiotherapy for hepatic carcinoma patients .Compared with vacuum bag ,carbon fiber fixator could fix the patients better ,which could reduce positioning deviation and PTV boundary .
