Suction fixation system for stereotactic radiosurgery of intraocular malignancies.

We designed a suction fixation system for the radiosurgical treatment of intraocular malignancies with the Leksell gamma unit (gamma knife). OUr device consists of a circular suction chamber and an adjustable unit to be fixed to the Leksell stereotactic head frame. All components are made of plastic materials in order to avoid artifacts in CT or MRT imaging. A permanent suction of 600 to 800 millibars is provided by a standard vacuum pump, powered by a portable battery. Suction times up to 40 minutes were well tolerated in all cases. In the gamma knife of the Neurosurgical Department at the University of Vienna, we successfully used this device. Up to January 1994 we have performed 19 radiosurgical treatments in 9 patients with large or extra-large uveal melanomas and in one patient suffering from a choroidal metastasis.