Effect of helical tomotherapy megavoltage CT under different acquisition pitch and registration conditions on the accuracy of radiotherapy for nasopharyngeal carcinoma
10.3760/cma.j.issn.1004-4221.2018.10.012
- VernacularTitle:HT系统MVCT图像不同采集间距及配准条件对鼻咽癌放疗精度影响
- Author:
Huilang HE
1
;
Xuanguang CHEN
;
Hui LIU
;
Senkui XU
;
Chengguang LIN
Author Information
1. 华南国家肿瘤实验室中山大学肿瘤防治中心放疗科
- Keywords:
Nasopharyngeal neoplasms/helical tomotherapy;
Acquisition pitch;
Registration condition;
Accuracy
- From:
Chinese Journal of Radiation Oncology
2018;27(10):930-932
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the effect of helical tomotherapy (HT) megavoltage CT (MVCT) under different acquisition pitch and registration conditions upon the accuracy of radiotherapy for used nasopharyngeal carcinoma,aiming to provide reference for image-guided radiotherapy (IGRT) for nasopharyngeal carcinoma.Methods MVCT scans were performed on an anthropomorphic head& neck phantom which was simulated the positioning errors in the x,y and z direction.The obtained images were registered with the planning CT images.Acquisition pitch was set as the coarse,normal and fine modes.Registration conditions were set as bone registration,bone and soft tissue registration and full-image registration.Registration accuracy was determined by comparing the measured value with the preset value.The accuracy of radiotherapy under different acquisition pitch and registration conditions was statistically compared.Results The 3D errors of bone,bone and soft tissue and full-image registration under different acquisition pitch (coarse,normal and fine) were (1.51±0.47,1.54±0.35,1.81±0.53) mm and (1.41± 0.37,1.53±0.36,1.56±0.39) mm and (1.51±0.27,1.57±0.32,1.73±0.33) mm,respectively.The bone registration yielded the highest accuracy (P＜0.05).When the registration condition was set as bone registration,the accuracy of three acquisition pitch did not significantly differ (all P＞0.05).The fine mode of acquisition pitch possessed the highest stability,whereas required the longest time.Conclusion The acquisition pitch and registration conditions should be selected during HT MVCT based on the clinical requirement of each patient with nasopharyngeal carcinoma.
