李洪明 1于浪 1孙显松 1王欣海 1胡克 1张福泉 1邱杰1
作者信息
- 1. 中国医学科学院北京协和医院放疗科 北京 100730
- 折叠
摘要
Abstract
Objective: To analyze the position error of patient received intensity modulated helical tomotherapy under guidance of megavoltage computed tomography (MVCT) and discuss the whole position level of department. Besides, to provide references for safe margin of target region. Methods: 192 patients were treated by using intensity modulated helical tomotherapy. They were scanned by MVCT before every therapy was implemented and their scanned results were compared with planning CT. The errors of 4 directions including LNG, LAT, VRT and ROLL were recorded, and these data were divided into three groups (head and neck group, chest and abdomen group and pelvic group) as the different body parts. The error distribution law of whole treatment for every patient, the system error (Σ) and random error (σ) for all of patients were calculated. And then the Margin value of different direction of various body parts was obtained by using Margin formula (M=2.5Σ +0.7(σ)). Results: 4416 images were obtained from 192 patients, and the position error of different body parts on 4 directions (LNG, LAT, VRT and ROLL) were: head and neck(1.94±1.78 mm, 0.94±0.81mm, 1.07±0.98mm and 0.75±0.89mm), chest and abdomen (3.72±2.92mm, 2.12±1.96mm, 2.04±1.65 mm and 0.47±0.71mm ), and pelvis (3.68±2.52mm, 1.36±1.20mm, 1.83±1.41mm and 0.47±0.51mm), respectively. The whole position errors were 3.172.96mm, 1.401.42mm, 1.581.40mm and 0.580.74mm. The Margin values of different body parts on LNG, LAT and VRT were: head and neck (5mm, 2mm and 2mm), chest and abdomen (8mm, 7 mm and 5mm) and pelvis (6mm, 4mm and 3mm), respectively. Conclusion: Through the data analysis about position errors of patients treated by using intensity modulated helical tomotherapy under the guidance of MVCT, the whole position situation of department is grasped and these relative data provide reliable reference for Margin of different body parts. And its clinical effects and adverse reaction need more research in next stage.关键词
摆位误差/边界外放/螺旋断层放射治疗/影像引导放射治疗/医院直线加速器Key words
Position errors/Margin/Tomotherapy/IGRT/Medical linear accelerator分类
医药卫生
