P2.02-058 Moderately Hypofractionated Radiotherapy in Locally Advanced Non-Small Cell Lung Cancer: A Single Institution Retrospective Analysis

Abstract

Radiation dose escalation using hypofractionation might improve clinical outcomes. Aim of the study was to evaluate outcomes, safety and feasibility of a moderately hypofractionated Radiotherapy (Hypo-RT) regimen for pts with LA-NSCLC. Between 2008 and 2015 44 consecutive pts with LA-NSCLC were treated using a HYPO-RT regimen. Thirty-two pts were male, 12 female. Mean age was 66.2 years. Primary tumor was adenocarcinoma in 16 pts, SCC in 27, Giant Cell neurendocrine Carcinoma in 1 pt. Three pts had clinical stage IIA-IIB, 19 pts IIIA and 22 IIIB. Chemotherapy was administered before Hypo-RT in 37 pts, 7 pts underwent exclusive RT. Mean total RT dose delivered to site of persistent disease was 61 Gy (range 45-66Gy) and mean total treatment time was 40 days in 5,7 weeks(range 3-8). Daily fraction ranged between 2.2 and 3 Gy. RT was temporarily interrupted in 3 pts due to acute toxicity. After a median follow up of 17.3 months, 19 pts were alive, whereas 25 pts had died (18 pts due to disease progression and 7 from other causes). Complete response was achieved in 6 pts, partial response in 16 and stable disease in 10 with an overall response rate (ORR) equal to 72,7%. Twenty-one pts showed locoregional relapse; 17 pts distant metastasis and 6 pts both of them. Median overall survival (OS) was 41.7 months while 1,3- and 5-year OS were 68.9% (±7,2%SE), 44.9% (±8.3%SE) and 25.1 (±9.0SE), respectively. At univariate analysis local failure, stage and response to CHT-RT treatment showed a statistically significant impact on OS with better prognosis for pts in stage IIIA, achieving a complete response and not experiencing locoregional relapse (p< 0.04, <0.05, <0.02 respectively). At the same interval progression free survival was 52.3% (ES±7.8), 17.8% (ES±6.6) and 11.9 (ES±6.5) while 3- and 5-years locoregional control was 24.6% (ES±5,5) and 11.7% (ES±4,7%).Acute toxicities were reported in 27 pts: 4 pts had G1-G2 skin dermatitis, 16 pts G1-G2 esophagitis and 4 pts G1-G2 pneumonitis. About late toxicities 7 pts experienced G1-G2 pneumonitis while 3 pts had G1-G2 esophagitis. No deaths related to the treatment were recorded. Hypo-RT proved to be a feasible and well tolerated treatment for pts with LA-NSCLC showing very promising results in terms of overall response rate and clinical outcomes. Further studies are needed to confirm these results and introduce HYPO-RT in the clinical routine.