Study of the ICG Distribution in Breast Tumours or in Axillary Lymph Nodes of Patients After Neoadjuvant Therapy

In the operating room:

ICG 0.25 mg/kg will be given as an iv injection at least 20 minutes before the beginning of the operation.

Optionally, dynamic NIR imaging centered on the tumor bearing breast will be acquired during the 15 minutes after injection (in comparison with standards of known fluorescence intensity).

Optionally and in case of tumorectomy, peroperative "in vivo" imaging of the surgical dissection will be acquired. The tumour and/or the mammary piece (and the axillary piece) of dissection will be directly imaged "ex vivo" using the PDE camera (in comparison with standards of known fluorescence intensity).

In the Laboratory of Pathology:

The fresh mammary piece will be processed as usual, but the "gross-thick" sections will be imaged using the PDE and the fluorescent areas will be defined (and later analyzed in comparison with standards of known fluorescence intensity).

After fixation, the tumoral tissues as well as - if identified - non tumoral fluorescent foci will be thereafter processed "as usual".

All the slides obtained will be analyzed using the NIR fluorescent microscope for the presence or not of detectable ICG and the ICG-positive tissues or compartments (vascular spaces, interstitial spaces, normal and/or tumoral cells, macrophages…) will be determined.

If fluorescent foci are identified at the level of the axillary piece, they will be isolated and analyzed like the other lymph nodes. Using the NIR fluorescent microscope, these isolated macroscopically fluorescent structures will be analyzed (lymph node? Other?).

Additionally, metastatic lymph nodes will also be controlled for their microscopic fluorescence or not.