Stereotactic irradiation using the Leksell gamma knife and its importance for solitary brain metastases treatment

Between November 1992 and February 1995, 64 patients with 98 intracerebral metastases were treated at the Stereotactic and Radiation Neorosurgery Department of Hospital Na Homolce. In 21 patients mainly with larger volumes of the pathological lesion or its location near the critical structure, for reasons of radioprotection fractionated irradiation was used in 2-5 daily fractions while maintaining a sufficiently effective dose to the treatment target. The properties of the optimum group of solitary metastases indicated for Leksell Gamma Knife treatment are characterized: volume up to 20 cm3, location in the brain hemispheres, the proper histological type (breast carcinoma, Grawitz tumor and malignant melanoma), Karnofsky rate of 70% and more, age under 60 years, and without proven further organ generalization (apart from the central nervous system). Three clinical cases are presented with stereotactically irradiated solitary metastases. A detailed evaluation of local control, the quality of survival and late postirradiation complications of the authors' group of patients will require a longer time interval (min. 18 months following the treatment). The main advantages of the described method, however, are already apparent: zero operation mortality, minimal morbidity, a short hospital stay and almost no claims to change of patient's way of life. (author) 6 figs., 13 refs