Clinical Research Directory

Inclusion Criteria: 1. Age \>=18 years; 2. Female; 3. Pathologically confirmed invasive breast cancer; 4. Unilateral breast cancer; 5. Clinical stage T1-4 and N1-3 (post-neoadjuvant therapy staging for patients receiving neoadjuvant treatment); 6. No clinical or radiographic evidence of distant metastasis; 7. Scheduled to undergo axillary lymph node dissection with planned adjuvant radiotherapy; 8. Willing and able to provide written informed consent. Exclusion Criteria: 1. Currently participating in other clinical trials that, in the investigator's judgment, may affect upper limb lymphatic drainage. 2. No definitive indication for axillary lymph node dissection or adjuvant radiotherapy after neoadjuvant therapy. 3. Pregnant or lactating women. 4. Patients undergoing concurrent autologous tissue flap breast reconstruction or chest wall repair. 5. Upper limb deformities, prior upper limb trauma, or surgical history that, in the investigator's assessment, may compromise lymphatic drainage. 6. Pre-existing upper limb lymphedema at baseline.