*3.1. Surgery*

BMs from DTC tend to be highly destructive, resulting in pathological fractures and spinal cord compression from lesions in the spine. These SREs, including intractable pain and neurological symptoms, severely compromise the PS and QOL of patients. Local tumor control without SREs is important for patients with DTC-BMs because the prognosis of these patients is more favorable compared with that of patients with BMs from other cancers. Therefore, surgery for BMs is indicated more often than that for other organ metastases. For BMs, there are palliative and excisional surgery (metastasectomy) categories. Palliative surgery is performed to prevent symptomatic SREs, including pathological fractures and spinal cord compression, or to alleviate symptoms due to SREs. Metastasectomy is the complete excision of the tumor, aimed at achieving long-term local tumor control.
