Introduction

Recently, ultrafast dynamic contrast-enhanced (ultrafast DCE) MRI has been developed because of its very high temporal resolution^1-4. According to recent several studies, its diagnostic performance for breast cancer is equal to superior compared to conventional breast MRI^1-4. However no study has established the relationship between ultrafast DCE findings and prognostic factor of breast cancer. The purpose of our study is to determine the correlation between the parameters obtained from ultrafast DCE and prognostic factors of breast cancer.

Materials and Methods

This retrospective study was approved by institutional review board. From May 2016 to April 2017, 87 patients with 95 surgically proved breast lesions were performed breast MRI including ultrafast DCE sequence. Of these, benign cases, cases performed neoadjuvant chemotherapy before surgery, cases without complete pathological data and cases with technical error were excluded. Thus, 52 patients (median age; 59) with 55 breast cancers (median size; 19mm) were included in this study. All examinations were performed using a 3T MR system (Magnetom Prisma, Siemens Healthcare, Erlamgen, Germany) with a dedicated 18 channel breast coil. Ultrafast DCE sequence was performed using higher than usual parallel imaging (GRAPPA) factor and its spatial resolution was 0.9x0.9x2.5mm. Its sequence was just started with contrast enhancement material injection and obtained 12 phases with 8.3 second temporal resolution. Enhancement ratio at each time point, area under the curve (AUC) of the kinetic curve at each time point and maximum slope based on the steepest part of the kinetic curve were obtained from dedicated workstation (PM view, JMAC systems) and compared with prognostic factors, including invasive component status (ductal carcinoma in situ [DCIS] or invasive cancer), hormone receptor (estrogen receptor [ER] and progesterone receptor [PgR]) status, human epidermal growth factor receptor 2 (HER2) status, proliferative marker (ki 67) status, nuclear grade, intrinsic subtype, and lymph node status. T-test, one way ANOVA test and Pearson’s correlation test were used for statistical analysis. P-value < 0.05 was considered significant.

Results

Mean maximum slope of invasive cancer (10.2) was significantly higher than that of DCIS (8.2) (Figure1-3). Mean enhancement ratio at first phase of HER2 negative cancer (81.1%) tended to be higher than that of HER2 positive cancer (54.2%) but there was not significant correlation (P=0.07). Other prognostic factors were not significant correlated with kinetic parameters of ultrafast DCE MRI.

Conclusion

Ultrafast DCE MRI is useful for not only differentiating benign and malignant breast lesion but also differentiating DCIS and invasive breast cancer.

Acknowledgements

No acknowledgement found.