4.3.3 Relative Contraindication
（1）Active connective tissue diseases，especially in patients with scleroderma and systemic lupus or collagen vascular disease，have poor tolerance to radiotherapy.
（2）Those who have received breast or chest wall radiotherapy in the past should be informed of the dose of radiotherapy and the range of radiotherapy fields.
（3）The tumor diameter of 5cm.(https://www.daowen.com)
（4）Those who violate the nipple（e.g.nipple Paget i disease）.
（5）Imaging examination suggests that the multi-center lesions（multi-center lesions refer to the existence of 2 quadrants of the disease，or the pathological type and molecular fractional type is completely different from the 2 breast cancer lesions）.
（6）Patients with known genetic susceptibility to breast cancer（e.g.BRCA1/2 gene mutation）with increased risk of recurrence of the same side breast after breast preservation.