Dynamic Brain [F18]-Fluoroestradiol (FES) PET Protocol Optimization for Improved Detection of Breast Cancer Brain Metastases

Time window-3 at 60-75 minutes post-injection provided optimal LMR for brain [¹⁸F]FES PET in ER⁺ BC and suspected BM. Imaging beyond this interval may not further improve diagnostic yield and may reduce visibility. Limitations of this study include small cohort size, population heterogeneity with regard to prior treatment, and lack of pathologic confirmation. Our findings suggest that 60-75 minutes post-injection may represent the optimal acquisition time window and highlight the importance of timing standardization for neuro-oncologic applications of brain [¹⁸F]FES PET.