Planning target volume margin based on the image-guided radiotherapy in nasopharyngeal carcinoma
10.3760/cma.j.issn.1006-9801.2018.03.009
- VernacularTitle:影像引导放射治疗技术基础上的鼻咽癌计划靶区外放研究
- Author:
Yibiao CHEN
1
;
Hanxiong ZHANG
;
Zhendong JIANG
;
Haidong YU
;
Tianbin MA
;
Aihui CHEN
;
Youhai XIE
;
Jian ZHANG
;
Ting LIU
;
Wenbiao ZHU
Author Information
1. 514031,广东省梅州市人民医院放疗科
- Keywords:
Nasopharyngeal neoplasms;
Radiotherapy;
computer-assisted;
Cone-beam computed tomography;
Set-up errors
- From:
Cancer Research and Clinic
2018;30(3):180-183,189
- CountryChina
- Language:Chinese
-
Abstract:
Objective To analyze set-up errors for irradiation of nasopharyngeal carcinoma by using kilo-voltage cone beam computed tomography (kV-KBCT) scanning, and to calculate the external margin from planning target volume (PTV) of nasopharyngeal carcinoma. Methods A total of 150 nasopharyngeal carcinoma patients in Meizhou People's Hospital from December 2014 to November 2016 were treated by image-guided radiation therapy (IGRT), kV-KBCT, CT image scanning matcthed by bone and grey alignment. PTV of nasopharyngeal carcinoma was also calculated. Results According to PTV formula, the external distance before radiotherapy guided by grey alignment was 0.5 mm in X-axis, 0.4 mm in Y-axis, 0.8 mm in Z-axis. While the distance was 0.1 mm in X-axis, 0.5 mm in Y-axis, 1.7 mm in Z-axis guided by bone alignment. After radiotherapy, the external distance guided by grey alignment was 0.4 mm in X-axis, 0.5 mm in Y-axis, 0.9 mm in Z-axis. While the distance was 0.1 mm in X-axis, 0.9 mm in Y-axis, 2.0 mm in Z-axis guided by bone alignment. There was no significant difference in set-up errors of 3 directions and 2 aligned ways before and after treatment.Conclusions The PTV within 3 mm is safe when IGRT is used for directing radiotherapy of nasopharyngeal carcinoma,and kV-KBCT is an effective image equipment.
