The patient, female, 59 years old, hospitalization number: 60752, was admitted to the hospital with a “progressively enlarged left breast mass for 10 years with 2 months of rupture”. PET-CT showed a large metabolic hyperplasia in the left breast area, consistent with malignant lesion, with bilateral axillary, bilateral hilar and mediastinal lymph node metastases, bilateral lung metastases, multiple bone metastases, and chest wall invasion. Pathological biopsy showed “invasive ductal carcinoma of the left breast”. Five weeks after particle implantation (chemotherapy was also administered 2 weeks after surgery), the left anterior chest mass was significantly collapsed and reduced in size to about 16*11*3 cm. At 3 months after surgery, the tumor wound was nearly healed. 5 weeks after surgery, the left anterior chest mass was obviously collapsed and shrunken, about 16*11*3cm in size.