The auxiliary setup value of fiducial marker tracking with spine during Cyber-knife radiosurgery / 中华放射医学与防护杂志

ABSTRACT

Objective To explore the clinical value of an auxiliary set-up method with fiducial markers and Synchrony tracking implanted in spine during Cyber-knife stereotactic radiotherapy by comparing the rotational setup errors between auxiliary setup with less than and more than three fiducial markers.Methods A total of 145 cases of tumor patients with fiducial tracking and Synchrony tracking were selected for radiotherapy,including 94 cases in the observation group (＜3 fiducial markers) and 51 cases in the control group (≥ 3 fiducial markers).Before treatment,one spinal alignment plan was added to all the cases in the observation group,and the rotation deviation of the selected spinal distance and the assisted spinal alignment correction of the fiducial marker tracking and the fiducial marker respiratory tracking were counted respectively,and the result of the rotation deviation calculated in the observation group and the control group were analyzed.Results Fiducial tracking spine auxiliary setup result:fiducial marks and selected the spine center distance ＜ 20,20-40,40-60,60-80 and ＞ 80 mm rotating statistical average deviation (0.494±0.350) °,(1.291±0.590) °,(1.705±0.739) °,(2.512±0.761) ° and (2.796± 1.081) °,respectively,rotate observation group and control group total deviation (1.742±0.784) °,(1.805±0.562) °,respectively.Synchrony tracking result in the above case rotation statistical average deviation was (1.190± 0.547) °,(1.956± 0.735) °,(2.141 ± 0.670) °,(2.957±0.648) ° and (4.027±0.695) °,respectively,while rotation total deviation in observation group and control group (2.619±0.906) °,(2.233 ±0.763) °,respectively.There was no significant difference in the rotation deviation between the assisted spinal set-fup and the calculation of rotation deviation between the fiducial tracking and the synchrony tracking (P ＞ 0.05).Conclusions In the fiducial tracking treatment,the range of rotation deviation for the spinal auxiliary set-up correction increases with the increase of the distance between the fiducial markers and the selected spinal center.When the distance between the fiducial marker and the selected spinal is less than 60 mm,the rotation deviation calculated by the spinal auxiliary setup has the same tumor rotation correction effect as that calculated by the fiducial markers.When less than 3 fiducial markers are available and the minimum distance between the fiducial marks and the center of the adjacent spine is relatively close (＜ 60 mm),the deviation of the rotation direction of the tumor can be calculated by adding the spinal auxiliary setup plan.