The Dose Effect of Isocenter Selection during IMRT Dose Verification with the 2D Chamber Array.
- Author:
Chuanbin XIE
;
Xiaohu CONG
;
Shouping XU
;
Xiangkun DAI
;
Yunlai WANG
;
Lu HAN
;
Hanshun GONG
;
Zhongjian JU
;
Ruigang GE
;
Lin MA
- Publication Type:Journal Article
- MeSH:
Gamma Rays;
Humans;
Radiotherapy Dosage;
Radiotherapy, Intensity-Modulated;
instrumentation;
methods
- From:
Chinese Journal of Medical Instrumentation
2015;39(3):222-224
- CountryChina
- Language:Chinese
-
Abstract:
To investigate the dose effect of isocenter difference during IMRT dose verification with the 2D chamber array. The samples collected from 10 patients were respectively designed for IMRT plans, the isocenter of which was independently defined as P(o), P(x) and P(y). P(o) was fixed on the target center and the other points shifted 8cm from the target center in the orientation of x/y. The PTW729 was used for 2D dose verification in the 3 groups which beams of plans were set to 0 degrees. The γ-analysis passing rates for the whole plan and each beam were gotten using the different standards in the 3 groups, The results showed the mean passing rate of γ-analysis was highest in the P(o) group, and the mean passing rate of the whole plan was better than that of each beam. In addition, it became worse with the increase of dose leakage between the leaves in P(y) group. Therefore, the determination of isocenter has a visible effect for IMRT dose verification of the 2D chamber array, The isocenter of the planning design should be close to the geometric center of target.
