Abstract Book

S52

ESTRO 37

6 UMC Utrecht, Department of Surgery, Utrecht, The Netherlands 7 The University of Texas MD Anderson Cancer Center, Department of Thoracic and Cardiovascular Surgery, Houston, USA 8 The University of Texas MD Anderson Cancer Center, Department of Radiation Oncology, Houston, USA Purpose or Objective Patients with esophageal cancer who suffer from early disease progression after completing trimodality therapy (TMT; chemoradiation plus surgery) may be better served by alternative treatment strategies. The aim of this study was to develop a preoperative risk prediction model for 1-year progression free survival (PFS) after TMT for esophageal cancer, and assess the survival benefit of subsequent surgery in low-risk and high-risk patients, respectively Material and Methods In total 568 consecutive patients with potentially resectable esophageal adenocarcinoma who underwent TMT (n= 373) or bimodality therapy (BMT; definitive chemoradiotherapy; n=195) between 2006 and 2015 were included. A nomogram for 1-year PFS after TMT was created using Cox’s regression model and performance was assessed by discrimination and calibration after internal validation. Patients were stratified into risk groups based on predicted 1-year PFS. Overall 5-year survival was compared between TMT and BMT in low-risk and high-risk patients after propensity score matching, respectively. Results Of 373 patients who underwent TMT, 102 (28%) had disease progression within the first year following esophagectomy. The final prognostic model for 1-year PFS included male gender, poor histologic grade, signet ring cell adenocarcinoma, cN1, cN2-3, and baseline SUV max , with accurate calibration and reasonable discrimination (optimism-adjusted C-statistic: 0.66). TMT was associated with a significantly higher overall survival compared to BMT in the low-risk group ( p =0.003), whereas it showed no significant survival benefit in the high-risk group ( p =0.302).

Rescheduled QA and service reduced the fraction of treatment course time violations according to guidelines to less than 20 % for accelerated treatments and to less than 40 % for the non-accelerated treatments after 2011 (fig. 2). The introduction of the systematic review of treatment schedule reduced the fractions of treatment course time violations to 4 % for accelerated treatments, and to 13 % for the non-accelerated treatments (fig. 2). The surveillance alternates between two radiation therapists and takes approximately 5-15 minutes per week.

Conclusion Awareness and continual review of treatment schedules of head and neck cancer patients reduced the treatment course duration.

Poster Viewing : Poster viewing 2: Upper GI

PV-0098 Preoperative Nomogram for Early recurrence after Trimodality Therapy in Esophageal Adenocarcinoma. L. Goense 1 , P.S.N. Van Rossum 1 , M. Xi 2 , D.P. Maru 3 , B.W. Carter 4 , G.J. Meijer 1 , L. Ho 5 , R. Van Hillegersberg 6 , W.L. Hofstetter 7 , S.H. Lin 8 1 UMC Utrecht, Department of Radiation Oncology, Utrecht, The Netherlands 2 Collaborative Innovation Centre for Cancer Medicine, Department of Radiation Oncology, Guangzhou, China 3 The University of Texas MD Anderson Cancer Center, Department of Pathology, Houston, USA 4 The University of Texas MD Anderson Cancer Center, Department of Diagnostic Radiology, Houston, USA 5 The University of Texas MD Anderson Cancer Center, Department of Gastrointestinal Medical Oncology, Houston, USA