Introduction: Gamma Knife(R) radiosurgery combines the technologies of
converging gamma ray radiation with modern imaging techniques to crea
te sharply localized, controllable tissue destruction within the crani
um without craniotomy. This technique allows for treatment of small in
tracranial lesions that may be inaccessable to conventional neurosurge
ry, either because of patient health or because of lesion proximity to
sensitive structures. Materials and methods: All patients had ophthal
mological examination by neurosurgery, extensive neuroimaging, and car
eful dosimetry planning prior to treatment. Delivery of the radiosurge
ry with the Gamma Knife(R) then involves positioning the patient in a
special dome-shaped structure, which allows the precise delivery of Co
balt-60 generated gamma rays in a focused beam to the lesion. Results:
We illustrate how seven patients with vision-threatening lesions were
successfully treated with the Gamma Knife(R) with preservation of vis
ual function. Conclusions: Gamma Knife(R) can be successfully used to
treat vision-threatening lesions that are not accessible to convention
al surgery or where conventional surgery carries a large risk of damag
e to the visual apparatus.