If tumor is a sharp sword to attack the human body, tumor metastasis is the most fatal blow. Even with the rapid development of science and technology and the great progress in the research of tumor occurrence, treatment and diagnosis, tumor metastasis is still the biggest stumbling block that prevents significant improvement of cancer cure rate. Brain metastasis, depending on radiotherapy Lung cancer is the most common intracranial metastatic tumor. When patients experience symptoms such as headache, vomiting, weakness of limbs, mental abnormality, vision change and mobility impairment, they must be highly alert and undergo brain CT and MRI to determine whether brain metastasis has occurred to buy time for treatment. Once brain metastasis is confirmed, immediate treatment is necessary. Dehydration therapy is the most common symptomatic treatment, while if radical treatment is desired, only radiotherapy can be relied upon. To relieve symptoms of certain multiple and single lesions, gamma knife can be used, but it is not effective in suppressing metastases that cannot be detected by CT or brain MRI, and it is more difficult to treat newly occurring lesions. Liver metastasis, surgical relief The liver is also a common site of metastasis for lung cancer, and about 30% of lung cancer patients will develop liver metastasis. The most common symptom of liver metastasis is persistent pain in the liver area, along with loss of appetite and indigestion. For isolated metastatic lesions in the liver, surgery can be used to relieve the symptoms, but it still depends on the patient’s specific situation. Bone metastasis, pain relief first About 50% of lung cancer patients will eventually develop bone metastasis in multiple locations, with ipsilateral rib and spine being the most common. Bone metastases have no symptoms in the early stage, but in the late stage, they manifest as localized intractable pain with fixed pressure points. The most terrible thing after bone metastasis occurs is that once the tumor metastasizes to the cervical, thoracic, lumbar spine and other weight-bearing bone parts of the body, it may cause serious consequences of paralysis. In addition, bone metastasis will also lead to osteolysis, hypercalcemia and pathological fracture, which will seriously reduce the quality of life of patients. Therefore, patients with lung cancer should routinely undergo whole-body bone scan after diagnosis to exclude possible bone metastases. After the diagnosis of bone metastasis, while actively treating the lung tumor, the advantages and disadvantages should be weighed and the treatment of bone metastasis should also be carried out in a timely manner under the premise that local control is beneficial. For isolated bone metastases, Zheng Mingming, director of radiotherapy department of Beijing Military General Hospital, emphasizes that after the lung lesions are controlled and stabilized by chemotherapy, high-dose and short-course radiation therapy can be given to relieve pain and kill cancer cells to control the development of lesions. For those patients with multiple bone metastases throughout the body, experts suggest that radionuclide therapy can be used instead of radiation therapy, but extra attention is needed because radionuclide therapy can cause bone marrow suppression reaction, so in principle, it cannot be used simultaneously with chemotherapy.