Patients (groups A-C) undergo bioavailable estradiol measurements, PET scans, and MRI scans at baseline and 1 and 18 months after treatment. Patients also undergo cognitive, neuropsychological, sociodemographic, and quality of life assessments using a battery of study tests and questionnaires at baseline and at 1, 9, and 18 months after treatment. Group D participants (controls) undergo the same testing at equivalent intervals.