Salvage guideline for local-regional failure after stereotactic ablative radiotherapy for early-stage non-small cell lung cancer.

8501Background: Up to 1 in 7 patients receiving stereotactic ablative radiotherapy (SABR) for early-stage non-small cell lung cancer (NSCLC) will develop local-regional recurrence. While SABR is the pillar of treatment for medically inoperable patients, little is known about outcomes and management for this potentially curable, local-regionally recurrent patient group. Methods: We present the first long-term results for the largest group of salvaged patients with local-regional recurrence after SABR. 772 patients with clinically early-stage I-II NSCLC were treated with SABR (50 Gy in 4 or 70 Gy in 10 fractions) between 2004-2014 at our center. Patients with isolated local recurrence (LR, n = 34) or regional recurrence (RR, n = 41) were analyzed and compared to patients with no recurrence (NR, n = 569). Results: Median time to LR or RR after SABR was 14 months. Salvage was performed in 79.4% of LR and 92.7% of RR patients. Salvage consisted of surgery (20% LR, 2% RR), re-irradiation (24% LR, 17% RR), radio...