2Ghee M C, Chu P, Leszczynski T, et al. The Siemens virtual wedge[J]. Phys Med Biol, 2003,48(12) : 1785-1794.
3van Santvoort J. Dosimetric evaluation of the Siemens Virtual Wedge[J]. Phys Med Biol,1998,43(9) :2651-2663.
4Popescu A,Lai K,Singer K,et al. Wedge factor dependence with depth,field size, and nominal distance-A general computational rule[J]. Med Phys,1999,26(4):541-549.
5Zhu X R, Gillin M T, Jursinic P A, et al. Comparison of dosimetric characteristics of Siemens virtual and physical wedges[J]. Med Phys,2001,28(2) :174-177.
6Zhu X R, Gillin M T, Ehlers K, et al. Dependence of virtual wedge factor on dose calibration and monitor units[J]. Med Phys, 2001,28(2):174-177.
7Letourneau D, Gulam M, Yan D, et al. Evaluation of a 2D diode array for IMRT quality assurance[J]. Radiother Oncol, 2004, 70(2), 199-206.
8Jursinic P A, Nelms B E. A 2-D diode array and analysis software for verification of intensity modulated radiation therapy delivery[J]. Med Phys,2003,30(5) :870-879.
9Rathee S, Kwok C B, MacGillivray C. Commissioning clinical implementation and quality assurance of Siemen's Virtual Wedge [J]. Phys Med Biol,1998,43(9);2651-2663.
4ZHU X R,Gillin M T,Jursinic P A,et al. Comparison of dosimetric characteristics of Siemens VW and physical wedges[J]. Medical Phy- sics,2007,27(10) :2 267-2 277.
5IAEA 398 2000 Absorbed dose determination in eeternal beam ra- diotherapy:an international code of practice for dosimetry based on standards of absorbed dose to water[S].
6IEC 977 1989 Medical electrical equipment-medical electron ac- celerators in the range 1 MeV to 50 1VIeV : guidelines for performance characteristics[S].
7Varatharaj C, Ravikumar M,Sathiyan S,et ol. Variation Of beam cha- racteristics between three different wedges from adual-energy accel- erator[J]. Journal of Medical Physics, 2011,36(3 ) : 133-137.
8LI Z ,Klein E E. Surface and peripheral doses of dynamic and physi- cal wedges[J]. International Journal Radiation Oncology,Biology, Physic, 1997,37 (4) : 921-925.
