——参考文献——

［1］Meeks S L，Harmon J F，Langen K M，et al.Performance characterization of megavoltage computed tomotherapy imaging on a helical tomotherapy unit［J］.Med Phys，2005，32：2673-2681.(https://www.daowen.com)

［2］J.Boda-Heggemann，P.Mennemeyer，H.Wertz，N.Riesnehacker，B.kuper，F.Lohr and F.Wenz.Accuracy of ultrasound-based image guidance for daily positioning of the upper abdomen：an online comparison with cone-beam CT，Ⅰnt［J］.J.Radiation Oncology Biol.Phys.2009 74（3）892-897.