Breast malignant tumors are a serious threat to women's health, and the current treatment for breast malignant tumors is still dominated by surgery, but the problems faced by patients after surgery such as edema and tumor recurrence are still relatively common, and the high recurrence rate and the occurrence of postoperative complications are closely related to the removal of metastatic lymph nodes during surgery. Therefore, accurate assessment of sentinel lymph node (SLN) metastases is essential to determine the extent of axillary lymph node dissection (ALND) and minimize complications. In this study, we developed a new technique that can rapidly distinguish between metastatic lymph nodes and normal sentinel lymph nodes (SLNs) in breast cancer patients. Briefly, fresh tissue is incubated with the probe and imaged immediately after intraoperative sentinel lymph node resection to identify the metastatic status of SLN. The accuracy of fluorescence imaging is confirmed by pathological diagnosis.

Following patient enrollment, surgical interventions were performed in accordance with standardized clinical protocols. During the operative procedure, the excised sentinel lymph nodes (SLNs) underwent specialized incubation processing. The detailed experimental protocol was conducted as follows:

1. Preparation of incubation solution The molecular probe was reconstituted in phosphate-buffered saline (PBS) to create incubation solutions with concentration gradients of 6.25, 12.5, 25, and 50 μg/mL. Solution preparation was performed at ambient temperature under light-protected conditions.
2. Ex vivo SLN tissue incubation Freshly excised SLN specimens were fully immersed in the prepared solutions for designated durations (1, 3, 5, 7, or 10 minutes). Subsequent processing included a 5-minute wash cycle with PBST buffer (0.05% Tween 20 in PBS) followed by blot-drying using absorbent filter paper.
3. NIR-II fluorescence imaging analysis Imaging acquisition was conducted using the Digital Precision Medicine (DPM) NIR-II system. Following initial system parameter calibration and spatial scaling, fluorescence signals were captured and quantitatively analyzed to determine SLN metastatic status through proprietary diagnostic algorithms.
4. Histopathological validation Final diagnostic confirmation was obtained through comprehensive histopathological examination conducted by certified pathologists.

Inclusion Criteria:

• Adult patients between 18-75 years of age
• Patients presenting with a breast nodule or mass presumed to be resectable on pre-operative assessment
• Breast cancer patients who are scheduled to undergo sentinel lymph node biopsy or axillary lymph node dissection;
• Good operative candidate
• Subject capable of giving informed consent and participating in the process of consent

Exclusion Criteria:

• Patients unable to participate in the consent process
• Patients had contraindications to surgery, such as serious cardiopulmonary disease, coagulation dysfunction, etc

The investigators plan to enroll 90 female patients, aged 18 to 75 years, who have been assessed to have resectable breast nodules or masses and are scheduled to undergo surgery. During the surgery, the resected lymph nodes will be incubated with theNIR-II probe(ICG-CK) solution, and NIR-II fluorescence signals from the tissues will be collected.