ESTRO 36 Abstract Book

S660 ESTRO 36 _______________________________________________________________________________________________

EP-1223 Comparing concurrent versus sequential chemoradiotherapy in locally advanced NSCLC G. Wei 1 , G. Xiaobin 1 , G. Xian-Shu 1 , M. Mingwei 1 , C. Ming 1 , P. Chuan 1 1 Peking University First Hospital, Department of Radiation Oncology, Beijing, China Purpose or Objective The aim of this study was to compare concurrent （ concurrent arm ） versus sequential chemotherapy （ sequential arm ） with hypofractionated radiotherapy in the treatment of inoperable locally advanced non-small cell lung cancer （ NSCLC ）（ stage Ⅲ A or Ⅲ B ） by using meta-analysis. The primary objective of this study was to compare the outcomes including tumor response and overall survival (OS) between sequential arm and concurrent arm. The secondary objective was to compare the progression-free survival (PFS) and late adverse event Relevant studies were identified through searching PubMed, Embase and Web of Science databases till July, 2016. Odds ratio (OR) with 95% confidence interval (CI) was used as pooled statistics for all analyses. between the two arms. Material and Methods

Conclusion Our meta-analysis demonstrated that concurrent arm was not significantly better than sequential arm in clinical outcomes. EP-1224 Therapeutic effects of accelerated hyperfractionation and conventional fractionation CRT on NSCLC T. Mitsuyoshi 1 , Y. Matsuo 1 , T. Shintani 1 , Y. Iizuka 1 , W.A. Mampuya 1 , H. Nagai 2 , H. Ozasa 2 , Y.H. Kim 2 , T.F. Chen- Yoshikawa 3 , M. Sonobe 3 , N. Nakajima 4 , A. Yoshizawa 4 , T. Mizowaki 1 , H. Date 3 , M. Hiraoka 1 1 Kyoto University Hospital, Department of Radiation Oncology and Image-Applied Therapy, Kyoto, Japan 2 Kyoto University Hospital, Department of Respiratory Medicine, Kyoto, Japan 3 Kyoto University Hospital, Department of Thoracic Surgery, Kyoto, Japan 4 Kyoto University Hospital, Department of Diagnostic Pathology, Kyoto, Japan Purpose or Objective Definitive concurrent chemoradiotherapy (CRT) is a standard treatment for locally advanced non-small-cell lung cancer (NSCLC); however, no consensus exists regarding the most therapeutically effective radiotherapy schedule. In this study, we directly assessed the local and regional pathological effectiveness of CRT using either accelerated hyperfractionation (AHF) or conventional fractionation (CF) by retrospective histopathologic examination of resection specimens after CRT. Material and Methods Data were analyzed from NSCLC patients treated with induction-concurrent CRT followed by thoracotomy between October 2006 and June 2015 in our hospital. All patients received three cycles of induction platinum- based doublet chemotherapy and concurrent radiotherapy using either AHF (42 Gy/1.5 Gy bid) or CF (50 Gy/2 Gy qd). The pathological responses of primary tumor and metastatic lymph nodes after induction CRT were assessed using resection specimens. The differences in pathological responses between the AHF and CF groups were analyzed using Fisher's exact test. Results A total of 51 patients were treated with induction CRT followed by thoracotomy. There were 39 male (76%) and 12 female (24%), with a median age of 62 (range, 43–78) years. All patients had a performance status (PS) score [Eastern Cooperative Oncology Group (ECOG)] of 0. Of the 51 patients, 7 were diagnosed with clinical stage IIB disease, 34 with clinical stage IIIA disease and 7 with clinical stage IIIB disease. The histologic subtypes were adenocarcinoma in 29 patients (59%) and squamous cell carcinoma (SqCC) in 22 patients (41%). No significant

Results The analysis was conducted based on the data from 3 studies with 370 patients. The pooled data showed that 3 years OS was not improved in concurrent arm compared to sequential arm [OR=0.72, 95% CI: 0.42-1.24, P=0.235] . Whereas the combined results for 1-year OS was OR=1.64, 95% CI ： 1.03-2.61 ， P=0.037. There was no significant difference of 1- year PFS [OR=1.16, 95% CI ： 0.72-1.84 ， P=0.542] between these arms. Moreover, no significant difference was found regarding tumor response [OR=1.02, 95% CI ： 0.48-2.19 ， P=0.950] and Grade≥3 late adverse events [OR=1.42, 95% CI ： 0.77-2.60 ， P=0.261].