SBRT (stereotactic radiotherapy) can provide a higher dose to the target area without increasing the risk of surrounding normal tissue / organ injury in selective cases. At present, SBRT has been widely used in radiotherapy of lung cancer and it can also play a better local control for lung metastasis.

However, there are parallel organs and series organs in the chest, and different organs have different tolerance to radiotherapy, so the toxicities of SBRT in different sites are different, and the prescription dose is also different.

This study intends to make a detailed division of the chest region and explore the safety and efficacy of SBRT in different areas. It is divided into four types: chest wall type: the lesion is directly adjacent or overlapped with the chest wall; peripheral type: the lesion is more than 1cm away from the chest wall and more than 2cm away from the bronchial tree; central type: the lesion is less than 2cm away from the bronchial tree; ultral-central type: the lesion is directly adjacent or overlapped with the mediastinal structure.

48-60Gy / 4-10f (EQD2 = 62.5Gy ~ 99.7Gy) was given according to the location of the tumor. Main outcome measures are local progression free survival and radiation toxicities; secondary outcome measure is overall survival.

Inclusion Criteria:

• Pathological diagnosis was malignant tumor.
• The location of the target lesion belongs to one of five types 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.

Patients with chest malignant tumors who received SBRT treatment in our department from 2022 to 2025 are expected to be enrolled.

De-identified individual participant data for all primary and secondary outcome measures will be made available.

Data will be available within 6 months of the study completion.

Data access requests will be reviewed by an external Independent Review Panel. Requestors will be required to sign a Data Access Agreement.