A New Tool to Predict Survival after Radiosurgery Alone for Newly Diagnosed Cerebral Metastases

Many patients with few cerebral metastases receive radiosurgery alone. The goal of this study was to create atool to estimate the survival of such patients. To identify characteristics associated with survival, nine variablesincluding radiosurgery dose, age, gender, Eastern cooperative oncology group performance score (ECOG-PS),primary tumor type, number/size of cerebral metastases, location of cerebral metastases, extra-cerebral metastasesand time between cancer diagnosis and radiosurgery were analyzed in 214 patients. On multivariate analysis, age(p=0.03), ECOG-PS (p=0.02) and extra-cerebral metastases (p<0.01) had significant impacts on survival. Scoringpoints for each patient were obtained from 12-month survival rates (in %) related to the significant variablesdivided by 10. Addition of the scoring points of the three variables resulted in a patient’s total predictive score.Two groups were designed, A (10-14 points) and B (16-17 points). Twelve-month survival rates were 33% and77%, respectively (p<0.001). Median survival times were 8 and 20 months, respectively. Because most patientsof group A died from extra-cerebral disease and/or new cerebral lesions, early systemic treatment and additionalWBI should be considered. As cause of death in group B was mostly new cerebral metastases, additional WBIappears even more important for this group.