The verification analysis of beam-matched plans between Clinac iX and Trilogy linacs(PDF)
《中国医学物理学杂志》[ISSN:1005-202X/CN:44-1351/R]
- Issue:
- 2021年第1期
- Page:
- 15-20
- Research Field:
- 医学放射物理
- Publishing date:
Info
- Title:
- The verification analysis of beam-matched plans between Clinac iX and Trilogy linacs
- Author(s):
- WANG Guangshan; LIU Guimei; LI Xiaobo; LI Xiangyong; ZHANG Xu
- Department of Radiation Oncology, Beijing Chest Hospital Affiliated to Capital Medical University, Beijing101149, China
- Keywords:
- Keywords: linacs beam matching swapping plan verification analysis of γ
- PACS:
- R811.1；R730.55
- DOI:
- DOI:10.3969/j.issn.1005-202X.2021.01.004
- Abstract:
- Abstract: A beam-matched plan was designed firstly for the two linacs. Then the parameters of the plan were compared, the differences and γ pass rate of the swapping treatment was identified, with an aim to verify the possibility and reliability of beam matching. 15 cases including g head & neck, thorax and pelvis were selected to design two 3D-CRT plans with Clinac IX and Trilogy respectively. Another 15 cases containing head & neck, thorax and pelvis were selected to design two IMRT plans with Clinac iX and Trilogy respectively. The same type of plan was compared in different machines. Evaluation parameters include PTV D98%, D2%, Dmax and OAR (Organ At Risk) (lens Dmax, brain stem Dmax, left or right lung V5 Gy, two lungs V20 Gy, spinal cord Dmax, bladder D50%, small intestine D2 cc, femoral head V40 Gy, et al ) and MU. Absolute and relative dosimetry were derived when plan were delivered on accelerators. The maximum average number and standard deviation of PTV D98%, D2%, Dmax and OAR (bladder D50%) were-0.52%±0.30%, 0.53%±0.45%, -0.55%±0.17%, 0.94%±0.84% respectively. The maximum absolute dosimetric deviations of Clinac iX and Trilogy executing plans were 2.36% and -2.80%. The average γ pass rate of planar verification of MatriXX and PV were greater than 97.00% and 96.00% respectively. The minimum for iX and TR were 95.40% and 95.90% respectively. Because various parameters were accurately delivered, the dosimetric deviation of swapping plans between beam-matched machines was clinically acceptable. If necessary, it was feasible to shift patients to other plans without any modification and re-planning between two beam-matched linacs to ensure integrality of patients treatment course.
Last Update: 2021-01-29