Sentinel lymph node biopsy is a local anesthetic procedure without drainage tubes, and the stitches are removed 7 days after the procedure. The common precautions are the same as for other procedures, except for those after local anesthesia, avoiding pulling and contaminating the wound, avoiding strenuous activities, bumping the surgical area, and dressings that are strictly prohibited from water. The special precautions for this surgery are mainly the principles of treatment after the injection of isotope tracer, drinking more water can promote the discharge of isotope tracer, and the excrement should be discharged in the designated bathroom. On the day of surgery, try to stay away from people who are vulnerable to radiation, such as pregnant women and children, to avoid harming their bodies. Since the dose of isotope injected in the preoperative tracer is very small, no additional protective measures are theoretically required.