Sentinel Node Biopsy Vs Observation After Axillary PET

Inclusion Criteria: stage 1: 1. female 2. ≥18 years old 3. invasive ductal carcinoma or DCIS proved by core needle biopsy 4. tumor size ≤ 5cm 5. negative preoperative axillary assessment(including body examination, ultrasound and MR examination) 6. patients is accessible for the following axillary surgery and pathological test(including sentinel lymph node biopsy and axillary lymph node dissection) stage 2: 1. female 2. ≥18 years old 3. invasive carcinoma proved by core needle biopsy 4. has plan for breast conserving surgery and adjuvant radiation after surgery 5. negative preoperative axillary assessment(including body examination, ultrasound and axillary PET mSUV\<0.27) 6. patients is accessible for the follow up Exclusion Criteria: stage 1: 1. distant metastases 2. in the procedure of neoadjuvant therapy 3. positive preoperative axillary assessment (including body examination, ultrasound and MR examination) 4. pregnancy or breastfeeding 5. axillary biopsy or axillary surgery before LymphPET 6. suffer from diabetes mellitus and without well control of bloodglucose 7. previous malignancy 8. allergic to tracer of LymphPET stage 2: 1. distant metastases 2. in the procedure of neoadjuvant therapy 3. positive preoperative axillary assessment (including body examination, ultrasound and PET mSUV≥0.27) 4. pregnancy or breastfeeding 5. axillary biopsy or axillary surgery before LymphPET 6. suffer from diabetes mellitus and without well control of bloodglucose 7. previous malignancy 8. allergic to tracer of LymphPET