Salvage radiation therapy for postoperative locoregionally recurrent non-small cell lung cancer: a single-center experience

PURPOSE: To determine the effectiveness of salvage radiation therapy (RT) in patients with locoregional recurrence (LRR) following initial curative resection of non-small cell lung cancer (NSCLC) and identify the prognostic factors affecting survival. MATERIALS AND METHODS: Between January 2009 and January 2019, 54 patients with LRR after NSCLC surgery were treated with salvage RT (83.3%) or concurrent chemoradiation therapy (16.7%). Twenty-three (42.6%), 21 (38.9%), and 10 (18.5%) patients had local, regional, and both recurrences, respectively. The median RT dose was 66 Gy (range, 37.5 to 70 Gy). The radiation target volume included recurrent lesions with or without regional lymphatics depending on the location and recurrence type. RESULTS: The median follow-up time from the start of RT was 28.3 months (range, 2.4 to 112.4 months) and disease-free interval (DFI) from surgery to recurrence was 21.0 months (range, 0.5 to 92.3 months). Tumor response after RT was complete response, partial response, stable disease, and progressive disease in 17, 29, 5, and 3 patients, respectively. The rates of freedom from local progression at 1 and 2 years were 77.2% and 66.0%, respectively. The median survival duration after RT was 24.8 months, and the 2-year overall survival (OS) rate was 51.1%. On univariate analysis, initial stage, recurrence site, DFI, and tumor response after RT were significant prognostic factors for OS. DFI ≥12 months and tumor response after RT were statistically significant factors on multivariate Cox analysis for OS. CONCLUSION: Our results demonstrated the effectiveness of salvage RT for LRR of NSCLC following curative surgery.