How do you decide between whole brain radiotherapy vs partial brain irradiation vs SRS for treatment of CNS metastases?

Many factors are at play in choosing WBRT vs. SRS: number, size, and location of the brain metastases – goals of care/patient wishes/comorbidities — pace of the disease, histology, concurrent therapy — to name only the main factors... In the end, it often is usually a subjective recommendation for a patient with more than 4 metastases and we encourage randomization on the intergroup trial CE.7 comparing HA-WBRT+memantine vs. SRS (open to NRG, Alliance, and CCTG sites). This is the only way that we will properly document how much progress we have made in cognitive preservation as compared to SRS.