This study included patients with early-stage lung cancer cT1-3N0M0, stage IA-IIB (American Joint Committee on Cancer eighth edition staging, AJCC 8th ) who were inoperable or refused surgery. They were divided into peripheral type and central type according to the tumor location and received radical Stereotactic Body Proton Therapy (SBPT) for Early-Stage Non-Small Cell Lung Cancer. The prescribed dose for patients with peripheral lung cancer is 48-60Gray(Gy) (Relative Biological Effectiveness, RBE)/4-6 fractions, and for patients with central lung cancer, the prescribed dose is 50-70Gy(RBE)/10-15 fractions. After treatment, follow-up visits will be conducted to observe short-term and long-term efficacy, adverse reactions and patient quality of life.

Inclusion Criteria:

1. .Lung cancer confirmed by histology and/or cytology; and in the absence of pathological diagnosis, patients who meet the following conditions can also be included: diagnosed by more than 2 imaging modalities, and the clinical diagnosis of lung cancer is confirmed after multidisciplinary team (MDT) discussion.
2. The clinical staging based on positron emission tomography(PET)-computer tomography(CT) examination is: cT1~3 N0M0, stage IA-IIB (AJCC eighth edition).
3. Age: 18 years and above.
4. Karnofsky(KPS) score ≥60.
5. The doctor assesses that surgical treatment is not suitable or the patient refuses surgery.
6. Relatively good organ function:
7. Normal bone marrow function: white blood cell (WBC)≥3×109/L, Platelet ≥80×109/L, Hemoglobin(HGB)≥90g/L
8. Normal liver and kidney function:
9. Total bilirubin, Aspartate Aminotransferase(AST), and ALT(Alanine Aminotransferase)≤2.0×upper limit of normal values;
10. Creatinine clearance ≥60ml/min or creatinine ≤1.5×upper limit of normal value
11. The patient has signed an informed consent form and is willing and able to comply with planned study visits, treatment plans, laboratory tests, and other study procedures.

Exclusion Criteria:

1. Patients with other malignant tumors.
2. Poorly controlled heart failure, respiratory failure, heart function, and lung function below grade 3 (including grade 3).
3. Those whose laboratory test values do not meet relevant standards before enrollment.
4. Patients who cannot cooperate with regular follow-up due to psychological, social, family and geographical reasons.
5. Women of childbearing age who have a positive pregnancy test and women who are breastfeeding.
6. Patients considered inappropriate for inclusion by other investigators.

Yes. I plan to share relevant non-confidential research progress and academic achievements of this IPD with peer researchers through academic exchanges and academic conferences, while strictly keeping core confidential data undisclosed to comply with clinical research confidentiality rules.