Affixing The Stereotactic Headring To The Patient - Brainlab RT/RS Hardware User's Manual

Stereotactic Headring
3.1.5

Affixing the Stereotactic Headring to the Patient

Before You Begin
Thoroughly review the patient's records and image data to ensure that no parts of the skull cap
have been removed during previous brain operations.
The posts should be attached to the headring, but to avoid injuring the patient, no fixation pins
should be inserted at this point.
Quality assurance is an important part of every treatment and therefore should be applied prior to
setup of the patient (See page 89).
Notes on Headring Positioning and Fixation
• A sitting position may ease headring fixation. The patient's neck should be in a neutral position
facing forward. Although not recommended, the patient can also be in a supine, non-rotated
position, while the surgeon supporting the patient's head. Under conditions of general
anesthesia, the latter approach is occasionally required.
• The headring is normally at a 0-10° angle to the patient's eyes, with the superior rim positioned
at or slightly inferior to the tip of the nose. The superior rim of the headring should be at least
15 mm below the target area to ensure correct CT scanning access and target localization.
• On the front of the head, pins are generally positioned to either side of the sinuses. During
height adjustment ensure that the pins are fixated well above the eye sockets and below the
hairline (joint of face and cranium). If the pins are positioned too high, they can easily shift due
to the curvature of the skull. Pins should be fixated above the lateral sinus to avoid shifting of
the pins. Moreover, they should be placed medial of the lateral part of the lambdoid suture.
Warnings: Fixation Pins
Do not use pins that are too long. Make sure the selected fixation pins permit the localizer
to fit onto the headring.
The fixation pins must be tightened using a torque wrench adjusted to no more than 30
Ncm, otherwise the pins or posts of the headring may be damaged.
No fixation pins should be inserted into the posts while the headring is being secured, as
the extremely sharp tips of the self-penetrating fixation pins could severely injure the
patient.
54 Hardware User Guide Rev. 4.9 RT / RS Stereotactic Hardware