Disadvantages of ct simulation localizer are

CT simulation positioning machine does not have the light field, can not simulate the projected shape of a certain angle irradiation field.CT simulation positioning machine is more inclined to localization, that is, through the scanning to obtain the CT image, so as to determine the location of the tumor tissue, the size and shape of the information, etc., based on the CT image for the target area outlining (endangered organs outlining) and plan design.CT simulation positioning machine appearance is more similar to the imaging department of the CT, using a slip ring frame, because of the design of the frame. It adopts a slip ring frame. Because of the frame design, the CT simulator does not have a light field and cannot simulate the projected shape of the irradiation field at a certain angle. This is also the reason why two-dimensional radiotherapy and electron beam radiotherapy are used to use conventional analog positioning machine (personal understanding, mainly because it is more convenient and easy). Because the current radiotherapy technology to three-dimensional conformal radiotherapy and intensity-modulated radiotherapy is mainly, so the CT analog positioning machine used more, and some also support 4DCT scanning function.