A method for determination of parameters of the initial electron beam hitting the target in linac

10th International Seminar on Medical Physics; 1st AMDI International Oncology Symposium

物理学;医药卫生

Tai, D.T.^1,3 ; Son, N.D.^2 ; Loan, T.T.H.^3 ; Tuan, H.D.^3

Department of Radiation Oncology, Dong Nai General Hospital, Bien Hoa City, Dong Nai Province, Viet Nam^1

Chi Anh Med. Tech. Co. Ltd., Ho Chi Minh City, Viet Nam^2

Faculty of Physics and Engineering Physics, VNUHCM-University of Science, Ho Chi Minh City, Viet Nam^3

关键词: Acceptance criteria;    Average difference;    Determination of parameters;    Dose distributions;    General hospitals;    Monte Carlo model;    Monte Carlo techniques;    Simulations and measurements;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/851/1/012032/pdf
DOI  :  10.1088/1742-6596/851/1/012032

学科分类：卫生学

来源: IOP

【 摘 要 】

Detailed characteristics of the electron beam incident on the target of the Linac are almost impossible to be measured. With Monte Carlo technique it is possible to simulate the transport of radiation through the accelerator head and find out the initial beam parameters. These parameters, such as energy spectrum and spatial distribution can be ascertained by matching the simulated dose distributions with the measured dose distributions using trial and error. In this work, a Monte Carlo modeling of the HPD Siemens Primus linear accelerator in 6 MV photon beams at Dong Nai general hospital was performed. The simulated Percent depth doses (PDD) and beam profiles (OCR) were then compared with the measured ones. Excellent agreements were obtained between simulations and measurements with an average difference of 0.7% for PDD less than 2% for OCR. The percentage gamma passing rate is 100% with 1% dose difference and 1 mm distance to agreement as acceptance criteria. The best suited energy and radius of the electron beam incident on the target were found at 6.04 MeV and at FWHM = 1.2 mm respectively.