P0084 Post-operative hypofractionated radiotherapy in non-small-cell lung cancer

Background We aimed to evaluate the effect of hypofractionated post-operative radiotherapy on overall survival, disease-free survival (DFS), and local control rate in completely resected stage IA–IIIB non-small-cell lung cancer (NSCLC); to estimate radiation-induced toxicity. Methods We retrospectively investigated 306 (266 male, 40 female) patients with stage IA–IIIB NSCLC who underwent complete resection of the lung tumour followed by post-operative radiotherapy in our institution from 1995 through 2012. Patients underwent pneumonectomy (34%), lobectomy (5%), bilobectomy (55%), or segmentectomy (6%). The post-operative pathological stages were I (41%), II (32%), and III (27%). Histology concluded adenocarcinoma (26%), squamous cell carcinoma (59%) or other (15%) pathologies. Following surgery, 149 patients received post-operative radiotherapy of 36 Gy in 12 daily fractions of 3 Gy (group 1), and 157 patients received post-operative radiotherapy of 44 Gy in 22 daily fractions of 2 Gy (group 2). Median follow-up was 25 months. Radiotherapy toxicity was scored in accordance to RTOG scale. Findings In group 1 and group 2, respectively, 5-year overall survival was 49.5 ± 5.2% and 45.6 ± 4.3%, 5-year DFS was 54.1 ± 5.1% and 52.1 ± 4.1%, and 5-year local control rate was 88.0 ± 4.5% and 87.0 ± 4.5%. Grade 1 oesophagitis was observed in 82.8% patients (group 1 79.8%; group 2 86.0%), grade 2 in 15% patients (group 1 17.8%; group 2 12.1%), and grade 3 in 2.2% patients (group 1 2.4%; group 2 1.9%). No late oesophageal toxicity was observed in either group. Grade 1 subclinical radiotherapy-induced pneumonitis was detected in about 67% of patients. Symptomatic radiation pneumonitis (grade ⩾ 2) was not detected in either group. Interpretation Hypofractionated post-operative radiotherapy achieved local disease control in 88% of patients with NSCLC without increasing treatment-related toxicity compared with a conventional irradiation regimen. Decreasing the number of fractions and length of the treatment allows radiation apparatuses to be occupied 30% less, and in turn allows more patients to be treated.