[1] Kroonwijk M,Pasma KL,Quint S,et al. In vivo dosimetry for prostate cancer patients using an electronic portal imaging device(EPID); demonstration of internal organ motion,Radiother Oncol,1998,49:125-132. [2] Heijmen BJ,Pasma KL,Kroonwijk M,et al. Portal dose measurement in radiotherapy using an electronic portal imaging device(EPID).Phys Med Biol,1995,40:1943-1955. [3] Boellaard R,Essers M,van Herk M,et al. A new method to obtain the midplane dose using portal in vivo dosimetry. Int J Radiat Oncol Biol Phys,1998,41:465-474. [4] Boellaard R,van Herk M,Uiterwaal H,et al. First clinical tests using a liquid-filled electronic portal imaging device and a convolution model for the verification of the midplane dose.Radiother Oncol,1998,47:303-312. [5] McCurdy BM,Luchka K,Pistorius S. Dosimetric investigation and portal dose image prediction using an amorphous silicon electronic portal imaging device. Med Phys,2001,28:911-924. [6] Winkler P,Hefner A,Georg D. Dose-response characteristics of an amorphous silicon EPID. Med Phys,2005,32:3095-3105. [7] McDermott LN,Louwe RJ,Sonke JJ,et al. Dose-response and ghosting effects of an amorphous silicon electronic portal imaging device. Med Phys,2004,31:285-295. [8] McDermott LN,Louwe RJ,Sonke JJ,et al. Comparison of ghosting effects for three commercial a-Si EPIDs. Med Phys,2006,33:2448-2451. [9] 胡逸民,戴建荣,张红志.肿瘤放射物理学.北京:原子能出版社,1999. [10] Chen J,Chuang CF,Morin O,et al. Calibration of an amorphous-silicon fiat panel portal imager for exit-beam dosimetry,Med Phys,2006,33:584-594. [11] Juste B,Miró R,Diez S,et al. Monte Carlo simulation of the iView GT portal imager dosimetry. Appl Radiat Isotopes,2010,68:922-925.