Beam dosimetric comparison between Zap-X and G4 CyberKnife
10.3760/cma.j.cn113030-20221124-00396
- VernacularTitle:Zap-X系统与CyberKnife G4系统射束剂量学比较
- Author:
Jinyuan WANG
1
;
Zhongjian JU
;
Chengcheng WANG
;
Baolin QU
;
Longsheng PAN
;
Xiangkun DAI
Author Information
1. 中国人民解放军总医院第一医学中心放射治疗科，北京 100853
- Keywords:
Zap-X;
CyberKnife;
Off-axis ratio;
Penumbra;
Flatness
- From:
Chinese Journal of Radiation Oncology
2023;32(11):990-996
- CountryChina
- Language:Chinese
-
Abstract:
Objective:To compare the dosimetric characteristics of beams between Zap-X and G4 CyberKnife and provide reference for clinical application of Zap-X.Methods:PTW three-dimensional water tank and dosimetry diode ionization chamber were used to measure the two orthogonal off-axis ratio and field size at isocenter of 7 different collimators (5 mm, 7.5 mm, 10 mm, 12.5 mm, 15 mm, 20 mm and 25 mm) of Zap-X and CyberKnife at the water depth of maximum dose, 50 mm, 100 mm, and 200 mm. The penumbra, flatness, symmetry and field size under each parameter condition were analyzed by using PTW supporting software PTW MEPHYSTO (version 5.1). Data analysis and graph were performed using Origin 2021 software.Results:With the same collimator, the dose plateau area of Zap-X was wider than that of G4 CyberKnife, and the dose fall-off at the field edge of Zap-X system was faster. With the increase of the collimator, the penumbra of Zap-X and CyberKnife tended to become larger, and the flatness tended to become smaller, the penumbra and flatness of Zap-X were significantly smaller than those of CyberKnife. Both of them had excellent symmetry (<1%), and the symmetry results of CyberKnife (<0.39%) were better than that of Zap-X (0.99%). The accuracy of Zap-X collimator size at isocenter was better than that of CyberKnife.Conclusion:Compared with G4 CyberKnife, Zap-X system has smaller penumbra, better flatness and higher accuracy of collimator size, which is suitable for stereotactic radiosurgery.
