What is the rate of dementia following whole brain radiotherapy in patients with brain metastases who survive for over a year?

To answer this question we need to have a common understanding of "dementia." I think that those of us who follow patients long-term after WBRT all agree that there are cognitive changes that develop. From the placebo arm of RTOG 0614 we know that at 6 months 65% of patients experienced cognitive dy...