Technetium Tc 99m Sulfur Colloid Injection for Tracing Sentinel Nodes in Breast Cancer

All enrolled subjects with breast cancer will receive Technetium Tc 99m Sulfur Colloid Injection and Mitoxantrone Hydrochloride Injection for Tracing sequentially, to evaluate the efficacy of the two methods for sentinel lymph node (SLN) mapping in breast cancer patients. Due to the characteristics of the investigational product and sentinel lymph node biopsy (SLNB) procedure, blinding is not feasible for this trial; therefore, an open-label design is adopted.

At least 8 subjects will be enrolled in the initial exploratory phase to investigate the lymph node uptake of 99mTc-SC, and to determine the optimal administration time, dosage, and preoperative SPECT/CT imaging schedule. These 8 subjects will not be included in the final efficacy and safety analysis set, and an additional 8 subjects will be enrolled subsequently.

• At least 4 subjects will receive no more than 0.5 mCi of Technetium Tc 99m Sulfur Colloid Injection at 6 h ± 36 min before surgery. Dynamic scintigraphy (5 min per frame, with supplementary lateral imaging of the ipsilateral side) will be performed for 60 minutes as soon as possible (2-3 min) after injection. Planar static imaging (anterior and ipsilateral lateral views) of the ipsilateral breast and axillary regions will be conducted at 2 h ± 12 min and 3 h ± 18 min, and SPECT/CT imaging (anterior view, ipsilateral lateral view, and tomographic scan) will be performed at 5 h ± 30 min, for a total of 4 scans.
• At least 4 subjects will receive no more than 1 mCi of Technetium Tc 99m Sulfur Colloid Injection at 18 h ± 120 min before surgery. Dynamic scintigraphy within 60 minutes (5 min per frame, with supplementary lateral imaging of the ipsilateral side) will be acquired as soon as possible (2-3 min) after injection. Planar static imaging (anterior and ipsilateral lateral views) of the ipsilateral breast and axillary regions will be performed at 2 h ± 12 min, 3 h ± 18 min and 6 h ± 36 min, and SPECT/CT imaging (anterior view, ipsilateral lateral view, and tomographic scan) will be conducted at 18 h ± 120 min, for a total of 5 scans.

For the remaining subjects, procedures will be implemented based on the exploratory results from the aforementioned 8 subjects:

• For subjects undergoing same-day SLNB: 0.5 mCi of 99mTc-SC will be administered; SPECT/CT imaging will be performed at 2 h ± 12 min to 5 h ± 30 min after dosing, and SLNB will be conducted at 3-6 h ± 36 min after dosing.
• For subjects undergoing next-day SLNB: 1 mCi of 99mTc-SC will be administered; SPECT/CT imaging will be performed at 3 h ± 30 min to 18 h ± 120 min after dosing, and SLNB will be completed within 18 h ± 120 min after dosing.

Technetium Tc 99m Sulfur Colloid Injection will be injected subcutaneously over the tumor surface. For subjects with an excisional biopsy cavity, or with tumors located in the upper outer quadrant close to the axilla which may interfere with imaging, subareolar injection is recommended (surgeons are advised to perform preoperative skin marking based on clinical conditions and confirm the appropriate injection site through consultation with the nuclear medicine department).

Approximately 15 minutes before surgery, all subjects will receive 0.5-2 mL (5.0 mg/mL) of Mitoxantrone Hydrochloride Injection for Tracing. For subjects undergoing total mastectomy, the injection will be administered subcutaneously around the tumor or posterior to the areola; for subjects undergoing breast-conserving surgery, the injection will be administered via two deep peritumoral subcutaneous injection points or a single point with multi-directional injection (intradermal injection and injection into the areolar area are strictly prohibited). After injection, the injection site will be massaged for 5-8 minutes, followed by sentinel lymph node biopsy.

A hand-held gamma probe will then be used to locate "hot spot" lymph nodes and mark their surface positions. An incision will be made along the skin crease over the "hot spot" lymph node, or via the total mastectomy surgical incision, to perform SLNB. Guided by the hand-held gamma probe within the incision, "hot spot" lymph nodes will be resected until no further "hot spots" are detected (radioactive count no higher than 1/10 of the maximum ex vivo SLN count). Meanwhile, blue-stained lymph nodes will be identified and removed. Subsequently, total mastectomy or breast-conserving surgery will be performed, and all blue-stained tissues will be resected as thoroughly as possible intraoperatively.

Resected lymph nodes with radioactive uptake and/or blue staining are defined as SLNs. Clinically suspicious lymph nodes that are neither "hot spots" nor blue-stained will also be resected and labeled separately.

The in vivo radioactive counts of "hot spots" and ex vivo radioactive counts of SLNs will be recorded. The following quantities will all be documented: the number of SLNs positive for both radioactive "hot spot" and blue staining, the number of SLNs positive only for radioactive "hot spot", the number positive only for blue staining, and the number of suspicious SLNs negative for both radioactive "hot spot" and blue staining.

Both intraoperative pathological diagnosis and postoperative pathological diagnosis of breast cancer SLNs are acceptable in this study. Pathological examination will be performed in accordance with the standard procedures of each investigational center, and the pathological diagnosis of each sentinel lymph node will be recorded.

• Intraoperative pathological examination: Intraoperative SLN specimens will be sectioned into 2 mm-thick frozen sections. A portion of the tissue will be used for intraoperative histopathological examination with hematoxylin and eosin (HE) staining; the remaining tissue sections will be processed for routine paraffin pathological examination after surgery, with HE staining and immunohistochemistry (IHC, if indicated). In case of discrepancy between intraoperative and postoperative pathology for an individual subject, the positive pathological result shall prevail.
• Postoperative pathological examination: All resected SLN tissues will be sampled and prepared into paraffin-embedded sections, sectioned at 2 mm thickness, and subjected to HE staining and immunohistochemistry (if indicated).

SLN metastasis will be classified according to the AJCC Cancer Staging Manual, 8th Edition. In this study, a positive SLN is defined as metastatic foci with a maximum diameter > 0.2 mm detected by histological examination or immunohistochemistry. A positive subject refers to a patient in whom at least one positive SLN is identified.

Inclusion criteria

• Able to understand and voluntarily sign a written informed consent.
• Female subjects aged 18-70 years ( including 18 and 70 years ).
• Histologically confirmed diagnosis of invasive breast cancer or primary invasive breast cancer or ductal carcinoma in situ (DCIS) ；
• Clinical stage 1 or 2；
• For subjects undergoing surgical treatment, axillary sentinel lymph node biopsy is part of the surgical plan；
• The axillary lymph nodes were negative by imaging examination or confirmed by fine needle aspiration.
• Conventional preoperative examination showed no clear surgical contraindications Exclusion criteria

1)Participants are allergic to the test drug or its excipients or have a history of severe drug allergy ; 2)Participants with prior surgery for breast cancer or neoadjuvant chemotherapy ; 3)inflammatory breast cancer ; 4)Ipsilateral axillary clinical examination or imaging examination positive or puncture lymph node pathology positive, no breast cancer histopathological diagnosis or no puncture pathological examination ; 5)Have received any form of breast augmentation surgery ; 6)Participants with liver or kidney dysfunction, ALT, AST>2.5 times ULN, Bilirubin >1.5 times ULN, Serum creatinine >1.5 times, or Investigators believe that liver and / or kidney damage to the extent that patients should not participate in this study;； 7)With serious or uncontrollable diseases : such as severe cardiovascular and cerebrovascular diseases ( blood disease, chronic congestive heart failure NYHA classification ≥ III level, etc. ), severe pulmonary insufficiency ( one second rate FEV1 / FVC < 50 % or FEV1 < 50 % predicted value or maximum ventilation volume per minute MVV < 50L / min ), psychiatric patients ; 8)Participants with active infection of infectious diseases screening ( hepatitis B surface antigen, hepatitis C antibody, syphilis antibody, HIV antibody ) ; 9)participated in clinical trials of other drugs within 3 months before screening; 10)) Patients with positive pregnancy test or pregnancy plan during lactation or screening period to 3 months after administration and unwilling to take effective contraceptive measures or egg donation plan; 11)Investigators considered that it was not suitable for the patients to participate in this trial