Off-axis dose distribution for rectangle proton beam  

作　　者：勾成俊 罗正明 黄初叶 冯晓宁 吴章文 

机构地区：[1]Key Laboratory of Radiation Physics and Technology (Sichuan University), Ministry of Education and Institute of Nuclear Science and Technology, Sichuan University

出　　处：《Chinese Physics B》2008年第12期4673-4676,共4页中国物理B（英文版）

基　　金：Project supported by the State Key Program of National Natural Science of China (Grant No 10335050)

摘　　要：This papcr modifies an analytical algorithm originally developed for electron dose calculations to evaluate the off-axis dose distribution of rectangle proton bcam. This spatial distribution could be described by Fermi-Eyges theory since a proton undergoes small-angle scattering when it passes through medium. Predictions of the algorithm for relative off-axis dose distribution by a 6 cm ＊ 6 cm initial monoenergetic proton beam are compared with the results from the published Monte Carlo simulations. The excellent level of agreement between the results of these two methods of dose calculation （〈 2%） demonstrates that the off-axis dose distribution from rectangle proton beam may be computed with high accuracy using this algorithm. The results also prompts the necessity to consider the off-axis distribution when the proton is applied to clinical radiotherapy since the penumbra is significant at the distal of its range （about 0.6 cm at the Bragg-peak depth）.This papcr modifies an analytical algorithm originally developed for electron dose calculations to evaluate the off-axis dose distribution of rectangle proton bcam. This spatial distribution could be described by Fermi-Eyges theory since a proton undergoes small-angle scattering when it passes through medium. Predictions of the algorithm for relative off-axis dose distribution by a 6 cm ＊ 6 cm initial monoenergetic proton beam are compared with the results from the published Monte Carlo simulations. The excellent level of agreement between the results of these two methods of dose calculation （〈 2%） demonstrates that the off-axis dose distribution from rectangle proton beam may be computed with high accuracy using this algorithm. The results also prompts the necessity to consider the off-axis distribution when the proton is applied to clinical radiotherapy since the penumbra is significant at the distal of its range （about 0.6 cm at the Bragg-peak depth）.

关 键 词：PROTON RADIOTHERAPY Fermi-Eyges 

分 类 号：TL84[核科学技术—核技术及应用]