The Background Parenchymal Enhancement in Preoperative Breast MRI: The Effect on Tumor Extent Evaluation

Abstract

Objective: To evaluate whether the level of background parenchymal enhancement (BPE) on MRI has an effect on the accurate assessment of tumor extent of breast cancer.
Methods: This retrospective study included the preoperative MR images from 62 patients, who had been diagnosed with breast cancer and imaged between 2005 and 2014. The BPE was classified into minimal-mild and moderatemarked groups by visual evaluation. The tumor extent was classified into three types (unifocal, multifocal and multicentric). The concordance and discordance of the tumor extent at low and high BPE were evaluated, and
compared with the pathological results.
Results: Minimal-mild BPE was more common in post-menopausal or older women, while pre-menopausal or younger women had more moderate-marked BPE with statistical significance (p = 0.01). 84% of tumors with minimal-mild level of BPE and 73% of tumors with moderate-marked level of BPE, were accurately evaluated for the tumor extension. There was no significant difference in accuracy of tumor extent between minimal-mild and moderate-marked groups (p = 0.35).
Conclusion: The preoperative MRI can evaluate the tumor extent of breast cancer with high accuracy and moderatemarked background enhancement does not affect to the tumor extent assessment.