Positive surgical margins are closely associated with local recurrence in breast-conserving surgery (BCS). Meanwhile, accurately assessing sentinel lymph node (SLN) metastasis is crucial for determining the extent of axillary lymph node dissection (ALND) and minimizing complications. Indocyanine green (ICG)-based the second near-infrared (NIR-II) fluorescence imaging offers real-time visualization during surgery, potentially reducing positive margin rates and improving SLN detection, while the specificity remains a challenge. Herein, the investigators will introduce a novel NIR-II probe, TTP-ICG, based on a Trop2-targeting peptide and an approach which enables rapid differentiation between cancer and para-cancer tissue as well as metastatic and normal lymph nodes. In brief, fresh tissues will be soaked in TTP-ICG immediately after resection, and their histological characterization will be determined under NIR-II fluorescence imaging. Pathological confirmation will further validate our approach.

After patient enrollment, surgical treatment will be administered based on clinical diagnosis and treatment. During the surgery, excised breast masses or lymph nodes will undergo incubation with TTP-ICG following this specific procedure:

1. Preparation of the incubation solution: TTP-ICG will be dissolved in phosphate-buffered saline (PBS) at room temperature in the dark, with varying concentrations (5, 10, 20 μg/mL).
2. Incubation of fresh breast masses or lymph nodes: The freshly excised breast masses or lymph nodes will be immersed and gently agitated in the incubation solution for 3, 5, or 10 minutes. Subsequently, they will be rinsed with PBST buffer (PBS with Tween 20) for 5 minutes and dried using absorbent paper.
3. Acquisition of NIR-II images: NIR-II images and fluorescent intensities will be captured using the "Digital Precision Medicine (DPM)" NIR-II system, optimized with appropriate parameters.
4. Pathological diagnosis and data analysis: Hematoxylin and eosin staining, along with immuno-histochemistry, will be performed. The subsequent correlation between pathological characterization and fluorescent information will be further analyzed.

Inclusion Criteria:

• Adult patients between 18-75 years of age
• Female
• Patients presenting with a breast nodule or mass presumed to be resectable on pre-operative assessment
• 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
• Other conditions that the researcher considers inappropriate to participate in the study

The investigation involved 48 breast cancer patients and 11 fibroadenoma 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 tumors and lymph nodes were incubated with the TTP-ICG solution, and NIR-II fluorescence images from the tissues were collected.