Salvage Concurrent Chemo-radiation Therapy for Loco-regional Recurrence Following Curative Surgery of Non-small Cell Lung Cancer

PURPOSE: This study is to report clinical outcomes of salvage concurrent chemo-radiation therapy (CCRT) in treating patients with loco-regional recurrence (LRR) following initial complete resection of non-small cell lung cancer. MATERIALS AND METHODS: Between February 2004 and December 2016, 127 patients underwent salvage CCRT for LRR. The median radiation therapy (RT) dose was 66 Gy and clinical target volume was to cover recurrent lesion with margin without elective inclusion of regional lymphatics. Majority of patients (94.5%) received weekly platinum-based doublet chemotherapy during RT course. RESULTS: The median follow-up time from the start of CCRT was 25 months. The median survival duration was 49 months, and overall survival (OS) rates at 2 and 5 years were 72.9% and 43.9%. The 2- and 5-year rates of in-field failure-free survival, distant metastasis free survival, and progression free survival were 82.4% and 73.8%, 50.4% and 39.9%, and 34.6% and 22.3%, respectively. Grade ≥ 3 radiation-related esophagitis and pneumonitis occurred in 14 (11.0%) and six patients (4.7%), respectively. On both univariate and multivariate analysis, higher biologically equivalent dose (BED(10)) (≥ 79.2 Gy(10) vs. < 79.2 Gy(10); hazard ratio [HR], 0.431), smaller CTV (≤ 80 cm(3) vs. > 80 cm(3); HR, 0.403), and longer disease-free interval (> 1 year vs. ≤ 1 year; HR, 0.489) were significantly favorable factors for OS. CONCLUSION: The current study has demonstrated that high dose salvage CCRT focused to the involved lesion only was highly effective and safe. In particular, higher BED(10), smaller CTV, and longer disease-free interval were favorable factors for improved survival.