A single institutional outcome analysis of Gamma Knife radiosurgery for single or multiple brain metastases

Although Gamma Knife stercotactic radiosurgery (SRS) is widely used for met astatic brain tumors, optimal patient selection and treatment strategy cont inue to be investigated. The aim of this study was to provide treatment res ults with Gamma Knife SRS and to establish prognostic factors. Of the 54 pa tients treated from 1990 to 1997, 51 patients were evaluable. There were 28 males and 23 females, with a median age of 60 years. Median Karnofsky Inde x was 80. There were 19 non-small cell lung cancers, eight colon cancers, s ix renal cell cancers, five ovarian cancers, four gastric cancers, three br east cancers, and six others. Primary tumors were controlled in 33 patients , and extracranial tumors were absent in 25 patients. Sixty-eight metastati c brain tumors in 37 patients underwent SRS as an initial treatment for the brain metastasis. Brain metastasis was solitary in 32 patients. Convention al radiation was combined with SRS in 29 patients. 24 of whom received whol e brain radiotherapy. Eight patients had some form of surgical resection. M edian survival time was 7.4 months. Five-year actuarial survival and local control rates were 16 and 52%, respectively. Median duration time of keepin g pretreatment quality of life was 6.9 months. On a multivariate analysis, uncontrolled primary turner, combined conventional radiotherapy, and perfor mance status were statistically significant prognostic factors. Four patien ts who underwent whole brain radiation developed low grade dementia. (C) 20 00 Published by Elsevier Science B.V.