The treatment of dedifferentiated chondrosarcoma is primarily surgical and requires extensive or radical surgery. The effect of chemotherapy is not certain. So if surgery can reach the surgical border of extensive or radical, the local recurrence rate will be reduced, but you still need long-term and close review, mainly including local plain films (every 3 months), lung CT (every 3 months), whole body bone scan (every 4-6 months), and local CT if necessary. there is no good preventive means.