Inclusion Criteria:  Pathological diagnosis is malignant tumor. The location of the target lesion belongs to the ultra-central type of chest. The target lesion had a history of radiotherapy, and the lesion diameter is ≤ 5cm. There is no extensive systemic metastasis or although there is metastasis, the metastasis have been controlled by previous treatment. KPS>70, no serious or uncontrolled underlying diseases, such as severe or uncontrolled hypertension, diabetes, cardiovascular and cerebrovascular diseases and organ dysfunction, and patients are expected to be tolerated by radiotherapy.  Exclusion Criteria:  Poor basic pulmonary function or symptom correlation caused by various reasons, unable to lie flat or cooperate with treatment. The general condition is poor, and the expected survival time is less than 3 months. Psychiatric patients or poor compliance, unable to cooperate to complete treatment. For other reasons, the researcher believes that it is not suitable to participate in this trial.