6Lib, Zhu X R,Zhang L,et al. Comparison of 2D radiographic im- ages and 3D conebeam computed tomography for positioning head and neck radiotherapy pations [J]. int J Radiat Oncol Biol Phys, 2008,71 (9):16-25.
7Linthout N,Verellen D,Tournel K,et ol. Six dimensional analysis with daily stereoscopic X-ray imaging of intrafraction patient motion in head and neck treatment using five points fixation masks[J]. Med Phys,2006,33(2) :504-13.
8Stroom J C, Heijmen B J. Geometrical uncertainties,radiotherapy planning margins,and the ICRU-62 report[J]. Radiother Oncol, 2002,64(1 ) :75-83.
9Stroom J C ,Suzanne van Beek,Simon van Kranen,et d. First clini- cal experience with a multiple region of interest registration and cor- rection method in radiotherapy of head and neck cancer patients[J] Radiother Oucol, 2010,94 (2) : 213-217.
10Buelent Polat,Juergen Wilbert,Kurt Baier,et al. Nonrigid patient setup errors in the haed and neck region[J]. Strahlenther Onkol, 2007,183 (9) : 506-511.