Clinical Research Directory

Inclusion Criteria: * 1.Age 18 to 75 years at the time of written informed consent. * 2\. Histologically confirmed unilateral invasive breast cancer with documented estrogen receptor, progesterone receptor, HER2, and Ki-67 status. * 3\. No prior systemic therapy, radiotherapy, or definitive surgery for the current breast cancer. * 4\. Nonmetastatic disease on a curative-intent pathway; clinical stage cT1c to cT4c and cN0 to cN3, excluding cT4d inflammatory breast cancer. * 5\. At least one measurable breast primary tumor with a longest diameter of 15 mm or greater on baseline contrast-enhanced MRI; paired baseline BSGI and required lesion marking completed. Multifocal or multicentric disease must meet protocol imaging requirements. * 6\. Suspicious or confirmed involved regional lymph nodes have undergone protocol-required pathological confirmation and marking when applicable. * 7\. ECOG performance status 0 or 1 and organ function adequate for planned systemic therapy, radiotherapy, and surgery. * 8\. Able and willing to comply with MRI, BSGI, treatment, follow-up, and contraception requirements. Participants of childbearing potential must have a negative pregnancy test before examinations involving a radiopharmaceutical. * 9\. A guideline-recommended, curative-intent neoadjuvant systemic therapy plan has been documented before entry. HER2-positive disease includes anti-HER2 therapy, and at least six cycles or the regimen-defined complete course is planned. Exclusion Criteria: * 1\. Distant metastatic disease, inflammatory breast cancer, or bilateral breast cancer requiring simultaneous definitive treatment. * 2\. Prior radiotherapy to the ipsilateral breast, chest wall, or regional lymph nodes when cumulative dose constraints cannot be met. * 3\. Active infection, interstitial lung disease, or another condition making planned standard therapy, research radiotherapy, or surgery unacceptably risky. Active autoimmune disease or organ transplantation is exclusionary only when contraindicated by the planned systemic-therapy component or considered an unacceptable risk by the multidisciplinary team. * 4\. Pregnancy or breastfeeding, or inability to implement required contraception. * 5\. Inability, in the investigator's judgment, to complete definitive surgery or key follow-up procedures.