Secondary Malignant (Metastases)

Brain metastasis is the most common indication for stereotactic radiosurgery (SRS). Diagnosis-specific graded prognostic assessment has been developed and updated for common malignancies metastasizing to the brain. SRS, delivering treatment in a single fraction, and hypofractionated stereotactic radiotherapy (HSRT), delivering treatment in 3–5 fractions for larger volumes, are safe and effective modalities for patients with good performance status and limited number/volume of brain metastases. In addition, they serve as adjuvant therapy for resected brain lesions with improvement in local control vs. observation and better cognitive preservation vs. whole brain radiation therapy. In recent years, the use of SRS and HSRT in patients with relatively poor performance status has increased, especially for those with limited tumor burden in the brain with controlled systemic disease. The use of SRS and HSRT in patients with numerous brain metastases is also expanding with accumulating evidence for its safety and efficacy.