Survival and prognostic factors in patients treated with stereotactic radiotherapy for brain metastases

Background. Stereotactic radiation therapy (SRT) of brain metastases is used with good effect around the world, but no consensus exists regarding which prognostic factors that are related to favourable or unfavourable prognosis after the treatment. A better definition of these factors will ensure a more precise application of the treatment. Material and methods. A consecutive cohort of the 198 patients treated for brain metastases with SRT without concurrent whole-brain radiation therapy at our department from 2001 to 2012 was retrospectively analysed. Results. Median survival was seven months and median time to clinical cerebral progression was eight months. The multivariate analysis revealed age >= 65 years, Performance Status >= 2, extracranial metastases and size of metastasis >20 mm as independent prognostic factors related to shorter survival. No factors were independently related to clinical cerebral progression. Conclusion. We identified four prognostic factors related to survival after SRT for brain metastases. The grouping of patients by these factors is useful to determine the level of treatment. We discourage the delivery of SRT to patients with 3-4 unfavourable prognostic factors because of the very short median survival of two months.