Purpose: To investigate factors influencing the evaluation of backgroundparenchymal enhancement (BPE) at follow-up breast magnetic resonance imaging(MRI) after adjuvant endocrine therapy.
Materials and Methods: One hundred twelve women with breast cancer and MRIof the contralateral unaffected breast before and after endocrine therapy wereidentified. Two readers in consensus performed blinded side-by-side comparison ofBPE (minimal, mild, moderate, and marked) before and after therapy with categoricalscales. Age, body mass index, menopausal status, treatment regimen (selectiveestrogen receptor modulator or aromatase inhibitor), chemotherapy, follow-upduration, BPE at baseline MRI, MRI field strength before and after therapy, andrecurrence were analyzed for their influences on decreased BPE.
Results: Younger age, premenopausal status, treatment with selective estrogenreceptor modulator, MRI field strength, and moderate or marked baseline BPE weresignificantly associated with decreased BPE. In multivariate analysis, MRI fieldstrength and baseline BPE showed a significant association.
Conclusion: MRI field strength and baseline BPE before and after therapy .wereassociated with decreased BPE at post-therapy, follow-up MRI.