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Session: Therapy General ePoster Viewing [Return to Session]

An Innovative Modification of a Commercial Mask Used in Gamma Knife Icon Stereotactic Radiosurgery

R He*, W Duggar, E Mundra, S Vijayakumar, C Yang, University of Mississippi Med. Center, Jackson, MS


PO-GePV-T-418 (Sunday, 7/25/2021)   [Eastern Time (GMT-4)]

Purpose: The Leksell Gamma Knife (GK) ICON added an onboard cone-beam computed tomography (CBCT) and an infrared intrafraction motion management (IFMM) system which allow a thermoplastic mask to be used for immobilization of a patient instead of an invasive frame for a single or multiple fraction treatment. During the treatment, the IFMM system pauses the GK treatment when the motion vector reaches to a set tolerance value and it requires a new CBCT scan to realign the system to patient position for an accurate dose delivery when it stays out of the tolerance, which extends the treatment time and patient discomfort. In our clinical practice, we introduced a mouth piece with the commercial mask and we report the results comparing the effect with and without the mouth piece on the number of pausing treatment due to patient movement during the treatment.

Methods: When making a mask, we ask patients to open their mouth when the mask is warm and we press the mask to generate a mouth bite on a wooden piece which provides an additional anchor point. The hypothesis is that this mouth piece helps with reducing patient movement within a mask. 30 patients each with and without a mouth piece of treatment time about 1 hour were randomly selected for this study. The number of CBCT scan required to complete the GK treatment was recorded and used for the analysis. A student T-test was used for the comparison.

Results: The average number of CBCT scan required to complete a treatment including the initial one is 1.7 with and 2.1 without the mouth piece.

Conclusion: The added mouth piece has demonstrated to reduce the number of CBCT scan during a treatment to less treatment interruptions and ultimately reduced treatment time.


Gamma Knife


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