Treatment Outcomes for Elderly Patients over the Age of 70 with Early-Stage Peripheral Non-Small Cell Lung Cancer Who Were Treated with Stereotactic Body Radiation Therapy (SBRT) at a Total Dose of 55 Gy in Four Fractions: A Single-Institution Retrospective Study

Background/Objectives: Due to its rapidly aging population, lung cancer is expected to become the second most common and deadliest cancer in Japan. Although surgery is the primary treatment for early-stage non-small cell lung cancer (NSCLC), advances in radiation therapy technology mean that stereotactic body radiation therapy (SBRT) is also a viable option for elderly patients with various underlying health conditions. Methods: We conducted a retrospective analysis to evaluate the outcomes of SBRT in 50 consecutive elderly patients (37 of whom were aged 80 and older) with early-stage peripheral NSCLC (Tis~T2aN0M0), who were treated with SBRT at our hospital and received a total dose of 55 Gy in four fractions. Results: The three-year overall, disease-free and cause-specific survival rates for all patients were 73.2%, 88.5% and 91.4%, respectively. For patients aged 80 years and older, these rates were 77.5%, 90.6% and 91.4%, respectively. There was no local recurrence. Hematogenous metastases were observed in four patients. However, hilar and subcarinal lymph node metastases developed in only one patient. Grade 2 pneumonitis and chest wall injuries (CWIs) were observed in two and five patients, respectively. Patients with larger tumors had a significantly higher incidence of chest wall injuries. Conclusions: SBRT at a total dose of 55 Gy in four fractions can achieve safe and satisfactory outcomes for early-stage peripheral NSCLC, even in patients aged 80 years and older. While CWIs were limited to Grade 2, attention to the chest wall dose is advisable when treating tumors adjacent to the chest wall.