Development of A Head Docking Device for Linac-based Stereotactic Radiosurgery System to be Installed on Neptun 10 PC Linac

Introduction:  Stereotactic  radiosurgery  is  a  technique  for  the  treatment  of  intracranial  lesions  with  highly  collimated  x-ray  beam.  Linac-based  radiosurgery  is  currently  performed  by  two  techniques:  couch or pedestal mounted. In the first technique, a device is required to affix patient s head to a couch  and  moreover  to  translate  it  accurately.  Structure  of  such  a  device  constructed  by  the  authors  in  addition to the acceptance test which was performed to evaluate the device has been described in this  article.  Materials and Methods:  A head docking device has been designed and constructed according to the  geometry of linac s couch and desired functions. The device is completely made from aluminum and  consists  of  four  major  components:  attachment  bar,  lower  structure  with  four  movements,  upper  structure with two movements equipped with a lock, two handles and a mounting ring for stereotactic  frame. Translating accuracy, mechanical stability and isocentric accuracy were assessed in the frame of  acceptance test.  Results:  Translating  accuracy,  mechanical  stability  and  isocentric  accuracy  within  95%  confidence  intervals were found to be 1, 1.64 and 3.2 mm, respectively.  Discussion and Conclusion: According to AAPM report no.54 recommendation head docking device  should translate head with accuracy of 1 mm, the property which was met by the constructed device.  Moreover  considering  the  measured  isocentric  accuracy,  encompassing  mechanical  stability,  constructed device can confidently be used in stereotactic treatment.  

کلیدواژه ها:

Stereotactic radiosurgery ، head docking device ، translating accuracy ، mechanical stability