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.
