Early parenchymal changes on MRI and fluoroestradiol db-PET during neoadjuvant endocrine therapy in patients with ER +/HER2- breast cancer

The aim of our study was to assess early parenchymal changes during neoadjuvant endocrine therapy (NET) using both DCE-MRI and dedicated breast PET with [18F]-fluoroestradiol (FES-dbPET). We investigated background parenchymal enhancement (BPE) on MRI and background parenchymal uptake on FES-dbPET for seventeen patients with ER+/HER2- breast cancers. Statistically significant decrease in BPE was shown after 3 weeks of NET. Estimated SUVs (mean, max and peak) were lower after 3 weeks of NET, although the difference did not reach statistical significance. Our results illustrate the potential of DCE-MRI and FES-dbPET to detect early change in breast parenchyma during NET.