Fractionated Stereotactic Radiotherapy for Limited Small Volume Brain Metastases

Inclusion Criteria: 1. The primary tumor is proved malignant by pathology; 2. Brain metastases are confirmed by enhanced MRI, and the number of lesions is 1-4; 3. The maximum diameter of each lesion is ≤ 2cm; 4. Age ≥ 18 years old; 5. KPS≥ 70; 6. Brain metastases haven't been previously treated locally and patients haven't received prior whole brain radiotherapy (WBRT); 7. expected survival of more than 6 months; 8. The functions of vital organs meet the requirements; 9. The patients voluntarily join the clinical study and sign the informed consent. Exclusion Criteria: 1. Surgical intervention is considered for MDT consultation; 2. Meningeal metastasis; 3. The primary tumor is small cell lung cancer; 4. Follow-up data can't be obtained regularly; 5. patients are combined with other serious diseases, such as serious cardiovascular diseases: myocardial ischemia or myocardial infarction above grade II, poorly controlled arrhythmias (including QTc interval ≥ 450 ms in men and ≥ 470 ms in women); Patients with grade Ⅲ to Ⅳ cardiac insufficiency or left ventricular ejection fraction (LVEF) \< 50% indicated by color doppler examination; 6. neurological lesions such as cerebral hemorrhage and cerebral infarction occurred within 6 months; 7. Other circumstances that, in the investigator's judgment, would render the subject unfit for study enrollment.