Reirradiation of recurrent brain metastases: where do we stand?

Brain metastases occur in a large portion of patients with cancer. While advances in radiation therapy help improve survival, they also raise questions of what is the best modality for retreatment in the context of recurrent disease. The spectrum of treatment options for recurrent intracranial metastatic disease after prior radiotherapy includes salvage SRS, WBRT, and brachytherapy. In this study, we comprehensively review the existing data on the efficacy and toxicity of the various reirradiation treatment modalities. Importantly, we examine key clinical considerations that guide patient selection such as dose, tumor size, interval to retreatment, local control, and survival rates.