The feasibility of the use of magnetic clips for tumour localisation before preoperative chemotherapy in combination with superparamagnetic iron oxide nanoparticles (SPIO) as tracer for sentinel lymph node (SLN) detection and in combination with a magnetic clip in the index lymph node metastasis is studied.

The overall aim is to demonstrate that the use of magnetic clips for tumour localisation before preoperative chemotherapy is feasible at breast cancer surgery and histopathological evaluation in combination with superparamagnetic iron oxide nanoparticles (SPIO) as tracer for sentinel lymph node (SLN) detection, and in combination with a magnetic clip in the index lymph node metastasis if targeted axillary surgery is planned.

Inclusion Criteria:

1. Age above 18 years
2. Planned for preoperative chemotherapy before breast cancer surgery
3. Planned breast conserving surgery with targeted axillary dissection or sentinel lymph node biopsy using magnetic technique
4. SLN-biopsy with magnetic tracer or targeted axillary dissection using magnetic tracer and Magseed
5. Signed and dated written informed consent before the start of specific protocol procedures

Exclusion Criteria:

1. Pregnant or breast-feeding
2. Iron overload disease
3. Known hypersensitivity to iron or dextran compounds
4. Inability to understand given information and give informed consent or undergo study procedures
5. Planned MRI control for tumour response during chemotherapy

Breast conserving surgery