Not all malignant tumors are not recommended for ablation therapy. 1. Ablation therapy can be chosen when the tumor is small, the number does not exceed 3 or no metastasis occurs; however, when the tumor is large and there are more than 3 multiple tumors or there is tumor metastasis, ablation therapy cannot be done. 2. For example, liver cancer patients can choose local ablation therapy when the diameter of a single tumor does not exceed 5 cm or the number of tumors does not exceed 3. Also liver cancer patients without invasion of blood vessels, bile ducts and neighboring organs or distant metastasis can choose ablation surgery for treatment. However, when liver cancer patients have a single tumor with diameter larger than 5 cm, 2-3 tumors with diameter larger than 3 cm, or vascular invasion or extra-hepatic metastasis, they cannot undergo ablation surgery. 3. For lung cancer patients, ablation can be done when the diameter of single lesion is not more than 5 cm or the number of lesions is not more than 3, and there is no metastasis from other parts of the body. However, when there is brain metastasis of lung cancer and some intracranial hypertension, serious consciousness disorder, or some serious cardiopulmonary insufficiency caused by lung cancer, ablation therapy is not allowed. If patients with malignant tumors want to undergo ablation therapy, they should consult with professional doctors first and tell their conditions truthfully to avoid adverse consequences.