Elimination of PTV Margins Based on MRI-guided Adaptive Stereotactic Radiotherapy for Non-small Cell Lung Cancer With Brain Metastasis

Inclusion Criteria:

• Aged 18-75 years

• Histologically or cytologically confirmed non-small cell lung cancer

• 1-10 metastases on contrast-enhanced MRI

• Radiotherapy for extracranial lesions is permitted

• Tyrosine kinase inhibitors (TKI) are permitted in patients with progression of

• intracranial metastases during previous TKI therapy

• Patients have measurable or evaluable lesions based on the Response EvaluationCriteria in Solid Tumors (RECIST) criteria

• Eastern Cooperative Oncology Group (ECOG) performance status 0-1

• Normal function of organs and bone marrow within 14 days: Total bilirubin 1.5 timesor less the upper limits of normal (ULN); AST and ALT 1.5 times or less the ULN;absolute neutrophil count≥ 500 cells/mm3; creatinine clearance rate(CCR) ≥45 mL/min;Platelet count≥50,000 cells/mm3; international normalized ratio(INR) ≤1.5#Prothrombin Time (PT)≤ 1.5 × ULN

• Informed-consent

Exclusion Criteria:

• Small cell carcinoma of lung

• Intracranial metastases needed surgical decompression

• Patients with contraindications for MRI

• Previous radiotherapy or excision for intracranial metastases

• Hypertensive crisis, hypertensive encephalopathy, symptomatic heart failure (NewYork class II or above), active cerebrovascular disease or cardiovascular diseaseoccurred within 6 months

• Uncontrolled hypertension (systolic > 150mmHg and/or diastolic > 100mmHg)

• Major surgery within 28 days or minor surgery or needle biopsy within 48 hours

• Urine protein 3-4+, or 24h urine protein quantitative >1g

• Severe uncontrolled disease

• Uncontrollable seizure or psychotic patients without self-control ability

• Women in pregnancy, lactation period

• Other not suitable conditions determined by the investigators