[Locally advanced breast tumors. Role of magnetic resonance in the assessment of response to preoperative therapy and of neoplastic residue before the operation].

Introduction And Purpose: Induction chemotherapy is the preoperative treatment for locally advanced breast carcinoma. The patients affected with this kind of tumor were previously considered inoperable. The sequential use of different cytotoxic drugs reduces the tumor mass effectively, thus allowing resection and improving patients prognosis. Tumor debulking is at times so significant that conservative treatment can even be considered. A reliable assessment of the response to drug therapy by conventional diagnostic procedures is usually hindered by chemotherapy-induced fibrosis. Magnetic resonance imaging (MRI) is a better tool for distinguishing fibrosis from still vascularized pathologic tissue and thus permits more accurate evaluation of tumor response to chemotherapy, namely tumor debulking and residual viability.

Material And Methods: We selected 27 patients with breast cancer and submitted them to MRI both before and after chemotherapy. All examinations were performed with a high field system using 3D Flash sequences with optimized spatial and temporal resolution.

Results And Discussion: The morphologic and dynamic parameters of MRI were in agreement with pathologic findings. In case of persistent disease after chemotherapy, MRI demonstrated increased contrast agent uptake at restaging, with dynamic curves indicating early and intense uptake. In case of marked post-chemotherapy changes, the dynamic curves had a shorter and less steep trend. Finally, when no or very little (few microns) tumor tissue was left, MRI showed no uptake.

Conclusions: Our initial experience indicates MRI as a valid too for monitoring chemotherapy response in breast cancer patients.