Monitoring of Breast Cancers Treated by Neoadjuvant Radiotherapy Via Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is the method of choice in breast cancer to perform the loco-regional staging and direct the treatment. European Guidelines (EUSOMA) currently recommend MRI for initial evaluation and assessement of the neoadjuvant chemotherapy (NAC) response, for breast cancer. The standard of care consists of realizing a MRI before the start of the NAC and another one after it's ended, six months later. There is currently no consensus on the realization of an interval MRI for early assessment of the chemosensitivity of the tumor. It would allow though alterations in the therapeutic regimen in the event of a non response. Similarly, there is no consensus on when this interval MRI should be performed. Some recent studies suggest that Diffusion-weighted Magnetic Resonance Imaging is interesting for the evaluation of the early response. However, these are preliminary studies with quantitative measures realized by the region of interest (ROI) method. A response to neoadjuvant chemotherapy results in elevated values of apparent diffusion coefficients (ADC). There is'nt any published data on the potential interest of breast MRI after a radiotherapy treatment and before the surgical treatment. Therefore, the expected benefits of this study are: to monitor the early modifications of the perfusion and diffusion parameters at the level of the tumor after radiotherapy, and correlate them to the histology of the surgical monster. to assess if MRI is able to objectivate the early signs of response after a radiotherapy neo-adjuvant treatment of breast cancer. This record is linked to the NCT02858934 record and will share the same cohort of patients

The histological type of the tumor will be determined by the Anatomo-Pathology Department of the CHU Brugmann hospital, according to standard of care. The determination will be performed on the initial biopsy samples used for diagnosis and/or on the surgical specimen

Apparent diffusion coefficient (ADC) expressed in mm2/sec. Magnetic resonance images realised with the Ingenia 3 Tesla Engine (Philips) and the Area 1,5 Tesla Engine (Siemens).Post-processing realized with the Syngo Onco Care application of Siemens.

Apparent diffusion coefficient (ADC) expressed in mm2/sec. Magnetic resonance images realised with the Ingenia 3 Tesla Engine (Philips) and the Area 1,5 Tesla Engine (Siemens).Post-processing realized with the Syngo Onco Care application of Siemens.

Inclusion Criteria: Age ≥ 18 years Histological diagnosis of unifocal invasive breast carcinoma, no special type (ductal carcinoma) Tumor Staging: cT1-2N0M0 Luminal A or B Candidate for breast conserving surgery N0-status confirmed by lymph node cytology Exclusion Criteria: Multifocal/multicentric disease Prior thoracic radiotherapy Pregnancy SBR3 grading Triple negative status which benefit neoadjuvant chemotherapy