Purpose

To investigate the correlation of pharmacokinetic parameters with prognostic factors of breast cancers in T1-weighted dynamic contrast-enhanced MR imaging (DCE-MRI) based on CAIPIRINHA-Dixon-TWIST-VIBE (CDT-VIBE) technique.

Method

A total of 96 patients with known invasive ductal carcinoma (DCIS) were enrolled in this study with their informed consent. Patients underwent dynamic breast imaging at 3T MRI (MAGNETOM Skyra, Siemens Healthcare, Erlangen, Germany) using a prototype CDT-VIBE sequence, and their histopathologic results were subsequently confirmed. The imaging protocol included 1 min 05 s for T1 mapping (FA = 2 and 14 degrees) and 6 min 58 s for CDT-VIBE imaging (11 s X 35 phases ). The detailed imaging parameters of CDT-VIBE included TR = 5.4ms, TE = 2.46/3.69ms, FA = 9 degree, FOV = 320 mm, matrix = 320 X 320，slice thickness = 1.5mm. In addition, a contrast medium (Omniscan, GE Healthcare) was administrated at the beginning of the fourth phase of the DCE sequence, via a power injector (0.1 mmol/kg body-weight). Ktrans (volume transfer constant between plasma and EES), kep (constant flux rate between EES and plasma) and ve (EES volume per unit volume of tissue) were then calculated using the functional Tissue4D software (Siemens Healthcare, Erlangen, Germany). The prognostic factors including estrogen receptor (ER), progesterone receptor (PR), Ki-67, human epidermal growth factor receptor 2 (HER2) were obtained from histopathological reports. Single-sample K-S test andpaired t-test with Bonferroni correction were used for statistical analysis.

Results

Mean Ktrans and kep were higher in PR-negative tumors than in PR-positive tumors (P < 0.005 and P < 0.001 for Ktrans and kep, respectively) (Fig.1). However, mean ve did not show significant difference between PR negative and PR positive tumors. Mean Ktrans and kep were lower, and mean ve was higher, in Ki-67 negative tumors compared to Ki-67 positive tumors (P < 0.005, P < 0.001, P < 0.005). The other prognostic factors ER and HER2 showed no significant difference in quantitative parameters (Ktrans, kep, ve) (Table 1).

Discussions & Conclusions

Significant correlations were found between quantitative parameters (Ktrans, kep) of high spatial and temporal resolution DCE-MRI and prognostic factors (PR, Ki-67) in DCIS breast cancers. These imaging tools may provide a non-invasive method for evaluating the therapeutic effect of neoadjuvant therapy.

Acknowledgements

No acknowledgement found.

References

No reference found.