Penumbra measuremnts of BeamModulatorTM multileaf collimator

VernacularTitle:BeamModulator新型多叶准直器半影的测量
Author: Xiaoguang LU ; Yunlai WANG ; Xiaoqing HUO ; Xiangyan SHA ; Xiongfei LIAO
Publication Type:Journal Article
Keywords: Radiotheray; Multileaf collimator; Penumbra; Dosimetry
From: Chinese Journal of Radiological Medicine and Protection 2010;30(4):452-455
CountryChina
Language:Chinese
Abstract: Objective To evaluate the penumbra of a new multileaf collimator equipped with Elekta Synergy accelerator. Methods The penumbra were derived from beam profiles measured in air and water using PinPoint ion chamber with PTW MP3 water phantom. Variations of penumbra with X-ray beam energy, depth in water, and leaf position were investigated. Results The penumbra in air for 6 MV X-ray was 2 mm less than that at depth of maximal dose in water. The penumbra of leaf side was 1 mm less than that of the leaf end. The penumbra had close relationship with beam energy, depth in water and leaf position. Penumbra was increased with beam quality and water depth. The leaf position had great influence on the penumbra. Conclusions The penumbra of the multileaf collimator is related to its original design and radiation delivery technique. Special considerations should be taken into during treatment planning.Regular measurement should be performed to guarantee the delivery quality.