Frame-Based Stereotactic Surgery

With frame-based stereotactic surgery, a lightweight
frame is attached to the skull at four points.
Local anesthesia is used to numb the places where
the pins contact the skull. Once the frame is
attached a CT, MRI or dye scan (angiography) is
done. Since the scan images both the tumor and
the frame, it is able to show the exact location of
the tumor in three dimensions in relation to the
head frame. The neurosurgeon takes these
coordinates and precisely inserts a probe through
a small incision in the skull to perform the biopsy
or other procedure.
It also has some limitations. The frame can
sometimes obstruct the neurosurgeon’s view of
the site; it can be time-consuming to manually
set the frame and read the scans; there is a
limited space to work within the radius of the
arc; and the scans and surgery usually need to
be performed the same day.