Safety and Effectiveness Outcomes of Lung Stereotactic Body Radiation Therapy (SBRT) in a Very Elderly Population: A Single Institution Experience

While the general use of lung stereotactic body radiation therapy (SBRT) for the management of early stage non-small cell lung cancer (NSCLC) results in excellent control rates with minimal toxicity, data on safety and efficacy in the elderly population are very limited. We herein report the toxicity and oncologic outcomes for a cohort of very elderly patients with early stage primary NSCLC and hypothesize that these patients will have durable local control with an acceptable toxicity profile. We identified 48 consecutive patients ages 70 years and above with medically inoperable primary NSCLC who underwent lung SBRT from 2007-2015. Median age of the cohort was 78.5 years (range: 70-93), with 48% being 80 years or older. Patients had T1 (40%), T2 (46%) or T3 (14%) NSCLC. Underlying COPD was seen in 63.8% of patients, with 73% having biopsy confirmation. Freedom from local recurrence (FFLR), freedom from regional recurrence (FFRR), freedom from distant metastasis (FFDM) rates and overall survival (OS) were calculated using the Kaplan-Meier method. Failure was characterized as local (primary tumor bed or involved-lobe), nodal (regional nodal) or distant (out-of-lobe or extrathoracic). Outcomes are reported as estimates (+/- standard error). Log rank test was utilized to compare outcomes based on age stratification (<80 vs. >80). Most patients were treated to 48Gy in 4 fractions (48%), 50Gy in 5 fractions (31%) or 60Gy in 3 fractions (12.5%). With a median follow-up of 2.1 years, 2-year FFLR, FFRR, FFDM and OS rates were 93.3% (+/- 4.6%), 77.9% (+/- 7.2%), 75% (+/- 9.8%) and 69% (+/- 6.9%), respectively. No statistical difference was observed between patients younger than 80 years and >80 years old with regards to FFLR, FFRR, FFDM or OS. CTCAE v4.0 Grade 2 and 3 pneumonitis rates were 12.5% and 6.3%, respectively. CTCAE v4.0 Grade 1 and 2 Chest Wall Pain was present in 6.25% and 4.2%, respectively. CTCAE v4.0 Grade 1 and 2 Rib Fracture occurred in 2.1%, and 4.2%, respectively. No treatment related deaths were seen. Our series, which represents one of the few dedicated to assessing the use of SBRT in elderly patients, demonstrates safety and oncologic effectiveness of SBRT in patients with a median age of almost 80 years old. Our results are similar to those reported in SBRT series of younger patients, with acceptable rates of grade >3 pneumonitis. This suggests that advanced age should not be a contraindication to delivery of lung SBRT.