RaSOLVE: 125I Radioactive Seed Marking Effects on Pathological Complete Response Rate and Prognosis Post-Neoadjuvant Therapy in Early/Advanced Breast Cancer

This study is an open-label, controlled, multicenter phase III clinical trial designed to evaluate whether the use of iodine-125 radioactive seed markers can improve treatment response for patients with early or locally advanced breast cancer undergoing neoadjuvant therapy. Neoadjuvant therapy is widely used for breast cancer to shrink tumors, increase the chances of breast-conserving surgery, and help determine the most effective postoperative treatments. Achieving a pathological complete response (pCR) after neoadjuvant therapy is strongly associated with better long-term outcomes. In this study, qualified participants will be randomly assigned in a 1:1 ratio to either the experimental group or the control group. Experimental group: Patients will receive placement of iodine-125 seed markers in the primary breast tumor and biopsy-proven positive axillary lymph nodes before starting neoadjuvant therapy. Control group: Patients will undergo standard neoadjuvant therapy without seed placement. All participants will then complete neoadjuvant therapy followed by surgery. Pathological evaluation will determine whether the cancer has completely disappeared. Long-term outcomes, including invasive disease-free survival, will be followed for at least five years. The goal of this study is to determine whether radioactive seed marking can increase the rate of pathological complete response and improve prognosis in patients receiving neoadjuvant therapy for breast cancer. The study will also explore whether iodine-125 seeds may activate immune responses that contribute to treatment effectiveness.