Aside from the number and volume of brain metastases, what factors do you consider when choosing between repeat WBRT or SRS in a patient who has received prior WBRT?

Given the toxcity of repeat whole brain, I typically reserve it for patients with recurrent disease in the brain who are on their way to hospice. Otherwise, I will treat with SRS. Having said that, I think factors (in addition to number and volume of brain mets) that are important to consider includ...