Prospective Study on Exemption of Tumor Bed Boost Radiotherapy for pCR Patients After Breast Conserving Surgery With Neoadjuvant Therapy

New neoadjuvant chemotherapy (NAC) is mainly used for patients with locally advanced or those who wish to preserve their breast. It not only helps to downstage the tumor but also increases the success rate and possibility of breast-conserving treatment for patients. Moreover, NAC provides doctors with the opportunity to assess the chemotherapy response, which can be used to predict the survival of patients. Studies have shown that patients who achieve pathological complete response (PCR) after NAC and surgery have a lower local-regional recurrence rate, higher disease-free survival rate and overall survival rate. Currently, there are no treatment guidelines for this group of patients. Avoiding unnecessary tumor bed dose escalation can reduce radiotherapy toxicity and help promote the effective utilization of medical resources. This study is the first prospective single-arm study to explore the prognostic significance of NAC and breast-conserving surgery without tumor bed dose escalation for patients with pCR breast cancer. The aim is to identify the appropriate population for exemption from tumor bed dose escalation and to develop more precise adjuvant radiotherapy plans.