Leksell Frame Fixation Using Zygomatic Bone for Stereotactic Radiosurgery

The present report describes a unique frame fixation technique for γ-knife radiosurgery that was used on a patient with an arteriovenous malformation (AVM) located in the occipital pole. Because the patient had a relatively long head and the nidus was located near the occipital pole, the nidus was out of the coordinate frame indicator when applied in the routine frontal pin position. Therefore, the anterior pins were placed on the zygomatic bone for frame fixation. Using this frame fixation technique, the target point could be moved anteriorly by 2.0 cm, or slightly more, within the coordinate frame, as compared with the ordinary frontal pin position. Therefore, appropriate γ-knife treatment could be carried out and treatment was successful; the AVM was confirmed to be completely obliterated on 2-year postradiosurgical angiography. This technique is applicable to all stereotactic procedures using a Leksell frame in patients with conditions such as that of the present case.