GAMMA-KNIFE RADIOSURGERY FOR BRAIN METASTASES OF RENAL-CELL CARCINOMA- RESULTS IN 23 PATIENTS

From Jan. 1993 to Sept. 1995 23 patients suffering from brain metastas es from renal cell carcinoma were treated with the Leksell Gamma Knife at the University of Vienna. At the time of diagnosis 13 patients had single and 10 patients presented with multiple metastatic lesions wit h a total of 44 metastases in MRI scans. Median tumour volume was 5500 cmm (range 100-24000 cmm). Predominant neurological symptoms and sign s were different forms of hemiparesis, focal and generalized seizures, cognitive deficit, headache, dizziness, ataxia and CN XII paresis. Fo urteen patients received Gamma Knife Radiosurgery (GKRS) with a median dose of 22 Gy (range 8-30 Gy) at the tumour margin. Nine patients und erwent a combined treatment of a radiosurgical boost with a median dos e of Is Gy (range 10-22 Gy) at the tumour margin followed by Whole Bra in Radiotherapy (total dose 30 Gy/2 weeks). In 20 patients tumour volu me reduction up to 30% of the primary tumour volume was found after 4 weeks, evaluated on CT or MRI. A total remission was seen in 4 cases 3 months after GKRS. We achieved a local tumour control of 96%. Rapid n eurological improvement after GKRS was seen in 17 patients. The median survival time was 11 months; the one-year actual survival in this uns elected group was 48%. Five long term survivors were still alive, 18 p atients had subsequently died, 15 of them of general tumour progressio n. GKRS induces a significant tumour remission accompanied by rapid ne urological improvement and therefore provides the opportunity for exte nded high quality survival. Neither local tumour control was improved nor CNS relapse free survival was prolonged significantly by additiona l WBRT.