Clinical outcomes of carbon-ion radiotherapy for locally advanced non-small-cell lung cancer

The efficacy and safety of carbon-ion radiotherapy (CIRT) for locally advanced non-small-cell lung cancer (LA-NSCLC) remain unclear. We reported the clinical outcomes of CIRT for LA-NSCLC. Data for 141 eligible patients who received CIRT between 1995 and 2015 were retrospectively analyzed. Local control (LC), locoregional control (LRC), progression-free survival (PFS) and overall survival (OS) were calculated using the Kaplan-Meier method. The median age was 75.0 years. Overall, 21 (14.9%), 57 (40.4%), 43 (30.5%) and 20 (14.2%) patients had T1, T2, T3 and T4 disease, respectively. Moreover, 51 (36.2%), 45 (31.9%), 40 (28.4%) and 5 (3.5%) patients had N0, N1, N2 and N3 disease, respectively. Furthermore, 34 (24.1%), 42 (29.8%), 45 (31.9%) and 20 (14.2%) patients had stages IIA, IIB, IIIA and ΙΙΙB disease, respectively. Overall, 62 (44.0%), 60 (42.6%), 8 (5.7%) and 11 (7.8%) patients had adenocarcinoma, squamous cell carcinoma, large cell carcinoma, and others, respectively. The median dose was 72.0 Gy (relative biological effectiveness). No patient received concurrent chemotherapy. Median follow-up periods were 29.3 (1.6-207.7) and 40.0 (10.7-207.7) months for all patients and survivors, respectively. Two-year LC, PFS and OS rates were 80.3%, 40.2% and 58.7%, respectively. Overall, 1 (0.7%), 5 (3.5%) and 1 (0.7%) patient developed Grades 4 (mediastinal hemorrhage), 3 (radiation pneumonitis) and 3 (bronchial fistula) toxicities, respectively. Multivariate analysis showed adenocarcinoma and N2/3 classification as significant poor prognosticators of PFS. CIRT is an effective treatment with acceptable toxicity for LA-NSCLC, especially for elderly patients or patients with severe comorbidities who cannot be treated with surgery or chemoradiotherapy.