Abstract:Objective To carry out the constancy test of Siemens large-aperture CT simulator newly introduced by our department
to ensure that its performance parameters meet the requirements of radiotherapy simulation localization. Methods According
to national standards and the international regulations, the constancy test of Siemens large-aperture CT simulator was carried
out by adopting the phantom provided by the manufacturer. The performance parameters included the position of the internal
positioned laser light, the position of the external positioned laser light, the position of the sagittal and coronal positioned laser
light, the position of the topogram, the thickness of the Tomographic slice, the CT value and uniformity, the pixel noise, the
spatial resolution calculated by the modulation transfer function, and the position of the patient table. Results The performance
parameters of this Siemens large-aperture CT simulator met the clinical requirements and national standards. Conclusion CT
simulator is closely related to the radiation therapy process, so the quality assurance of the CT simulator should be done carefully, so
as to be better applicated to the radiotherapy localization.