Object: The purpose of this retrospective study was to compare the effectiveness of gamma knife radiosurgery (GKS) for multiple cerebral metastases with that of whole-brain radiation therapy (WBRT).
Methods: Ninety-six consecutive patients with cerebral metastases from nonsmall cell lung cancer were treated between 1990 and 1999. The entry criteria were the presence of between one and 10 multiple brain lesions at initial diagnosis, no surgically inaccessible tumors with more than a 30-mm diameter, no carcinomatous meningitis, and more than 2 months of life expectancy. The patients were divided into two groups: the GKS group (62 patients) and the WBRT group (34 patients). In the GKS group, large lesions (> 30 mm) were removed surgically and all other small lesions (< or = 30 mm) were treated by GKS. New distant lesions were treated by repeated GKS without prophylactic WBRT. In the WBRT group, the patients were treated by the traditional combined therapy of WBRT and surgery. In both groups, chemotherapy was administered according to the primary physician's protocol. The two groups did not differ in terms of age, sex, initial Karnofsky Performance Scale (KPS) score, type, lesion number, and size of lesion, systemic control, and chemotherapy. Neurological survival and qualitative survival of the GKS group were longer than those of the WBRT group. In multivariate analysis, significant poor prognostic factors were systemically uncontrolled patients, WBRT group, and poor initial KPS score.
Conclusions: Gamma knife radiosurgery without prophylactic WBRT could be a primary choice of treatment for patients with as many as 10 cerebral metastases from nonsmall cell cancer.