8501 Background: 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), radiofrequency ablation (15% LR), chemotherapy (15% LR, 26% RR), and chemoradiation (6% LR, 44% RR) based on a standard multi-disciplinary decision approach (Figure 1). 5-year OS was 37.1% for LR and 39.1% for RR patients. Of LR and RR patients, those receiving salvage had significantly better 5-year OS compared to those not receiving salvage (45.2% LR, 42.9% RR, 0% no salvage; p = 0.009). 5-year OS for salvaged patients was not statistically different from patients with NR (53.5% NR, p = 0.466). 5-year lung-cancer specific survival was 51% for LR and 55.1% for RR patients. Subsequent DM occurred in 20.5% of LR and 29.3% of RR patients at a median of 8.4-10.3 months. No salvaged patient experienced grade 5 toxicity. Conclusions: Patients with local or regional recurrence after SABR have excellent outcomes with salvage therapy, with no statistical difference in 5- year OS between LR and RR patients salvaged after SABR, and patients with no recurrence. Because a standard multidisciplinary approach was applied to any LR or RR patient after SABR, a novel treatment algorithm is generated. We offer a much needed management guide for thoracic oncologists treating patients who local-regionally recur after SABR.
A retrospective study of clinicopathologic and molecular features of inoperable early-stage non-small cell lung cancer treated with stereotactic ablative radiotherapy
