The goal of this clinical trial is to learn how to successfully introduce a new method for finding the sentinel lymph node during breast cancer surgery into routine hospital care. The method uses a dye called indocyanine green (ICG) and a special camera to see the lymph node. The sentinel lymph node is the first lymph node that cancer is likely to spread to. In the Netherlands, about 1 in 7 women develops breast cancer. Finding out whether cancer has spread to the lymph nodes is important for planning treatment and predicting outcomes. The current standard method for sentinel lymph node biopsy (SLNB) uses a radioactive tracer called radioisotope technetium-labeled (99mTc)-nanocolloid. While accurate, this method has several drawbacks: it exposes patients to radioactivity, requires an extra hospital visit or travel to another hospital due to limited nuclear medicine facilities, and is not sustainable. Surgeries using 99mTc can only take place on certain days due to logistical issues, and the signal from 99mTc can be disturbed by the tumor marker placed in the breast. ICG works as well as 99mTc for SLNB and offers several advantages: it is given during surgery (no extra visit needed), produces no radiation, and reduces costs. However, it is still not widely used in the Netherlands because hospitals may not be familiar with it or unsure how to make the switch. This study will introduce ICG step-by-step in several Dutch hospitals and evaluate how to make the change as smooth and effective as possible. It will take place in three stages: I) SLNB with 99mTc only (current practice); II) SLNB with both 99mTc and ICG (transition phase); III) SLNB with ICG only (full implementation). All study procedures take place during planned surgery, with no extra hospital visits. After surgery, participants will receive a short questionnaire (10-15 minutes) to share their experiences with the procedure. Their feedback, combined with input from healthcare providers, will help researchers develop a uniform medical protocol, an implementation guide, and educational materials for surgeons and surgical trainees. The aim is to make ICG widely available across the Netherlands, ensuring that care is less burdensome, more sustainable, and more cost-effective, while keeping treatment accessible in local hospitals.