Document Type : Original Paper
Authors
1
Assistant Professor, Medical Physics Dept., Golestan University of Medical Sciences, Golestan, Iran
2
Professor, Medical Physics Research Center, Bu-Ali Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
3
Assistant Professor, Medical Physics Research Center, Bu-Ali Research Institute, Mashhad University of Medical Sciences, Mashhad, Iran.
4
Assistant Professor, Radiation Oncology Dept., Imam Reza Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
Abstract
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.
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