GAMMA-KNIFE(R) RADIOSURGERY - ITS USE AND INDICATIONS IN NEUROOPHTHALMOLOGY

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.