Real-World Results of Stereotactic Body Radiotherapy for 399 Medically Operable Patients with Stage I Histology-Proven Non-Small Cell Lung Cancer

SIMPLE SUMMARY: According to current guidelines, surgery is the standard treatment for stage I non-small cell lung cancer (NSCLC), despite no clear randomized trial demonstrating that surgery is superior to stereotactic body radiotherapy (SBRT). Therefore, this study aimed to provide real-world evidence of the usefulness of SBRT for medically operable patients with pathologically proven stage I NSCLC using a large Japanese multi-institutional database. A total of 399 patients from 20 institutions were included in the database. In the results, local progression-free survival was 84.2%, and the 3-year overall survival was 77.0%. The local progression-free survival rate was better in cases with tumors ≤ 20 mm in diameter and in the adenocarcinoma subgroups. Low performance status, male sex, and pulmonary interstitial changes were poor prognostic factors for overall survival. This real-world evidence will be useful in shared decision-making for optimal treatment, including SBRT for operable stage I NSCLC, particularly in older patients. ABSTRACT: Surgery is the standard treatment for stage I non-small cell lung cancer (NSCLC); however, no clear randomized trial demonstrates its superiority to stereotactic body radiotherapy (SBRT) regarding survival. We aimed to retrospectively evaluate the treatment outcomes of SBRT in operable patients with stage I NSCLC using a large Japanese multi-institutional database to show real-world outcome. Exactly 399 patients (median age 75 years; 262 males and 137 females) with stage I (IA 292, IB 107) histologically proven NSCLC (adenocarcinoma 267, squamous cell carcinoma 96, others 36) treated at 20 institutions were reviewed. SBRT was prescribed at a total dose of 48–70 Gy in 4–10 fractions. The median follow-up period was 38 months. Local progression-free survival rates were 84.2% in all patients and 86.1% in the T1, 78.6% in T2, 89.2% in adenocarcinoma, and 70.5% in squamous cell subgroups. Overall 3-year survival rates were 77.0% in all patients: 90.7% in females, 69.6% in males, and 41.2% in patients with pulmonary interstitial changes. Fatal radiation pneumonitis was observed in two patients, all of whom had pulmonary interstitial changes. This real-world evidence will be useful in shared decision-making for optimal treatment, including SBRT for operable stage I NSCLC, particularly in older patients.