PT - JOURNAL ARTICLE AU - Geraldine J. Liao AU - Amy S. Clark AU - Erin K. Schubert AU - David A. Mankoff TI - <sup>18</sup>F-Fluoroestradiol PET: Current Status and Potential Future Clinical Applications AID - 10.2967/jnumed.116.175596 DP - 2016 Aug 01 TA - Journal of Nuclear Medicine PG - 1269--1275 VI - 57 IP - 8 4099 - http://jnm.snmjournals.org/content/57/8/1269.short 4100 - http://jnm.snmjournals.org/content/57/8/1269.full SO - J Nucl Med2016 Aug 01; 57 AB - Estrogen receptor (ER) expression in breast cancer is associated with a more favorable prognosis and is necessary for a response to endocrine therapies. Traditionally, ER expression is assessed by in vitro assays on biopsied tumor tissue. However, recent advances have allowed in vivo evaluation of ER expression with 18F-fluoroestradiol (18F-FES) PET. Clinical studies have demonstrated the use of 18F-FES PET as a method for quantifying in vivo ER expression and have explored its potential as a predictive assay and method of assessing in vivo pharmacodynamic response to endocrine therapy. This review outlines the biology and pharmacokinetics of 18F-FES, highlights the current experience with 18F-FES in patient studies on breast cancer and other diseases, and discusses potential clinical applications and the possible future clinical use of 18F-FES PET.