Indications for 131I-MIBG therapy: 1. pheochromocytoma/paraganglioma that cannot be removed surgically; 2. residual tumor lesions after surgery and postoperative prophylaxis; 3. metastatic pheochromocytoma/paraganglioma; 4. 131I-MIBG positive systemic imaging; 5. other neuroendocrine tumors that can uptake 131I-MIBG, such as medullary thyroid carcinoma and carcinoid tumor; 6. good general condition, able to take care of themselves, and able to accept radiation protection instruction.