Delayed Sentinel Lymph Node Biopsy in Ductal Cancer in Situ

The trial aims to investigate the use of superparamagnetic iron oxide (SPIO) nanoparticles as a tracer for delayed sentinel lymph node dissection (d-SLND) in patients where upfront axillary surgery (SLND) is oncologically deemed unnecessary and should be avoided. This includes but is not limited to patients with a preoperative diagnosis of ductal cancer in situ of the breast (DCIS), an unclear BIRADS 4-5 planned for diagnostic excision or women planned for risk reducing mastectomy. SPIO is injected in the primary operation, and should final specimen pathology demonstrate invasive breast cancer, only then is an operation in the axilla (d-SLND) performed.