Activity of extracranial metastases as a prognostic factor influencing survival after radiosurgery of brain metastases

Information about prognostic factors influencing survival have been only occasionally reported in studies on the use of radiosurgery in the treatment of patients with brain metastasis. To answer the question of whether activity of extracranial metastases is an independent prognostic factor influencing survival in radiosurgery of brain metastases, a review of the literature was performed. Fourteen studies were identified in the English language literature that dealt with this topic. Only three studies showed borderline insignificance of the influence of activity of extracranial metastases when analysed by univariate methods. When multivariate analysis was used to test for the independent influence of this factor on survival, of nine studies that used that statistical approach eight showed that it is an independent prognosticator influencing survival, most often being the strongest one. This review of literature supports the view that the “activity of extracranial metastases” is an independent prognostic factor influencing survival of these patients as documented in published reports. However, prospective randomised trials are necessary to definitely establish the independent influence of this prognostic factor.