Locally advanced breast cancer: contrast-enhanced subtraction MR imaging of response to preoperative chemotherapy.

Purpose: To determine the value of contrast material-enhanced subtraction magnetic resonance (MR) imaging in assessment of response to chemotherapy in locally advanced breast cancer.
Materials and Methods: Eighteen women treated with chemotherapy because of locally advanced breast cancer underwent preoperative MR examination including both routine and dynamic MR sequences after injection of gadolinium tetraazacyclododecanetetraacetic acid. Any early contrast enhancement, concomitant with early vascular enhancement during the dynamic MR study, was considered pathologic.
Results: Dynamic MR studies showed early contrast enhancement in all women with residual tumor except one with nodular residual tumor. Histopathologic analysis and dynamic MR images of contrast-enhanced lesions correlated well, but in one patient, intraductal extension was not seen on MR images, and in another, additional isolated tumor cells were seen in the histologic specimen. Subtraction images always facilitated visualization of vascular and pathologic contrast enhancement.
Conclusion: Dynamic MR contrast-enhanced subtraction studies are useful in assessment of residual tumor after chemotherapy.