Accurate evaluation of tumor boundaries in breast-conserving surgery is critical to reducing the second operation of patients. Near-infrared (NIR) fluorescence imaging using molecular agents has shown promise for in situ imaging during resection. However, very effective probes can be applied to clinical trials up to now, which limits the clinical application of fluorescence imaging. Here we developed a new technology that can quickly identify the tumor area of the resected breast tissue during the operation and distinguish the tumor boundary. In brief, the breast tissues were incubated with the probe immediately after intraoperative resection and imaged to identify the tumor area and distinguish the tumor boundary. The accuracy of fluorescence imaging was confirmed by pathological diagnosis.

After enrollment, the patients received surgical treatment according to clinical diagnosis and treatment. During the operation, the excised breast tissue was incubated, and the specific procedure was as follows.

1. Preparation of the incubation solution: The probe was dissolved in phosphate buffer saline(PBS) buffer as the incubation solution at room temperature in the dark.
2. In vitro incubation of fresh breast cancer tissues: The fresh excision breast cancer tissues were completely soaked in the incubation solution for about 10 minutes, followed by 5 minutes rinse with PBS buffer and drying with the use of absorbent paper.
3. Analysis of the images in the "Digital Precision Medicine(DPM)" NIR-II system. The DPM parameter was set up before scaling. Then fluorescence imaging was performed with the DPM NIR-II system. And the result was analyzed to identify the tumor area and distinguish the tumor boundary.
4. Confirmed the diagnosis by pathological examination.

Inclusion Criteria:

• Adult patients over 18 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.