ESTRO 36 Abstract Book

S223 ESTRO 36 2017 _______________________________________________________________________________________________

Italy 5 University of Bologna, Department of Medical and Surgical Sciences - DIMEC, Bologna, Italy 6 University of Bologna- S. Orsola-Malpighi Hospital, Department of Oncology, Bologna, Italy 7 Università Cattolica S. Cuore, Department of Surgery, Rome, Italy 8 Hospital General Universitario Gregorio Marañón- Complutense University, Department of Oncology, Madrid, Spain 9 University of Virginia- Charlottesville, Department of Radiation Oncology, VA, USA 10 Mayo Clinic, Department of Radiation Oncology, Rochester, USA 11 S. Raffaele Scientific Institute, Department of Oncology, Milano, Italy 12 Fondazione Giovanni Paolo II, Unit of Radiotherapy- Unit of General Oncology, Campobasso, Italy 13 Fondazione Giovanni Paolo II, Unit of Medical Physics, Campobasso, Italy THIS ABSTRACT FORMS PART OF THE MEDIA PROGRAMME AND WILL BE AVAILABLE ON THE DAY OF ITS PRESENTATION TO THE CONFERENCE. OC-0427 Prediction models in rectal cancer: an update of a pooled analysis of 3770 randomized patients V. Valentini 1 , C. Masciocchi 1 , J. Van Soest 2 , G. Chiloiro 1 , E. Meldolesi 1 , M. Gambacorta 1 , J. Gerard 3 , S. Ngan 4 , J. Bosset 5 , A. Sainato 6 , A. Damiani 1 , N. Dinapoli 1 , P. Lambin 2 , A. Dekker 2 , C. Roedel 7 1 Università Cattolica del Sacro Cuore -Policlinico A. Gemelli, Radiation Oncology Department, Rome, Italy 2 Maastricht University Medical Center, Radiation Oncology MAASTRO-GROW School for Oncology and Development Biology, Maastricht, The Netherlands 3 Unicancer- Centre Antoine Lacassagne, Radiotherapy, Nice, France 4 Peter MacCallum Cancer Centre, Division of Radiation Oncology, Melbourne, Australia 5 Besançon University Hospital J Minjoz, Radiation and Oncology, Besançon, France 6 Azienda ospedaliera Universitaria Pisana, Radiotherapy, Pisa, Italy 7 Goethe University Frankfurt, Radiotherapy and Oncology, Frankfurt am Main, Germany Purpose or Objective In the last years, several prognostic and predictive models (PMs) for locally advanced rectal cancer (LARC) patients (pts) have been developed. Aim of this study was to update the previous PMs [1] developed for local recurrence (LR), distant metastases (DM) and overall survival (OS) at 2, 3, 5 and 10 years based on a more copious pooled set of LARC pts. Material and Methods The PMs were developed using the data of the following LARC trials: Accord 12/0405, EORTC 22921, FFCD 9203, CAO/ARO/AIO-94, CAO-ARO-AIO-04, INTERACT, I-CNR-RT and TROG 01.04. Pts were selected applying the following exclusion criteria: neoadjuvant and adjuvant oxaliplatin based chemotherapy, no surgery procedure, short-course radiotherapy and no neoadjuvant radiotherapy. As the current pooled dataset contains different trials, we used 20% of the data (stratified per trial) as a validation dataset. Due to variable influence over time, a logistic regression model was used. Follow-up times (2, 3, 5 and 10 years) for the survival outcomes (LR, DM and OS) were used as the model outcome. Variable selection was performed using a stepwise Akaike's information criterion (AIC) feature selection to determine the optimal subset of covariates and nomograms developed as a visual representation. The nomogram shows only significative covariates (p<=0.01). According to the TRIPOD [2], all Pms

Results SMART was delivered in 45 fractions in nine pts (4F, 5M; ages 55-87 yrs) with LAPC. Two pts had biliary stents. All pts were able to complete the BH delivery. Median duration of the SMART delivery was 54 min (range 42-73). With the video-feedback method, median gated treatment efficiency (ratio between actual beam-on time and delivery time) was 0.66 for all fractions, ranging from 0.40-0.92 (Fig 2). Pt follow-up is still limited, but early results show no grade ≥3 acute toxicity. Prospectively- scored patient reported outcomes revealed maximum Grade 2 fatigue and nausea in, respectively, 6 pts and 1 pt.

Conclusion SMART is novel treatment approach for LAPC that requires no placement of fiducials, and is well tolerated, even by elderly pts and those with stents. Initial experience revealed that delivery within a one hour time-frame per fraction is feasible. Updated clinical follow-up data will be presented. OC-0426 Adjuvant chemoradiation in pancreatic cancer: impact of radiotherapy dose on survival A.G. Morganti 1 , M. Falconi 2 , G.C. Mattiucci 3 , A. Arcelli 1,4 , F. Bertini 1 , A. Farioli 5 , A. Guido 1 , M.C. Di Marco 6 , L. Fuccio 5 , S. Alfieri 7 , F.A. Calvo 8 , B.W. Maidment 3rd 9 , R.C. Miller 10 , M. Reni 11 , G. Macchia 12 , F. Deodato 12 , S. Cilla 13 , G. Di Gioia 12 , F. Cellini 3 , V. Valentini 3 1 University of Bologna- S. Orsola-Malpighi Hospital, Radiation Oncology Center- Department of Experimental- Diagnostic and Speciality Medicine- DIMES, Bologna, Italy 2 San Raffaele Hospital, Department of Surgery- Pancreatic Surgery Unit, Milano, Italy 3 Università Cattolica S. Cuore, Department of Radiotherapy, Rome, Italy 4 Ospedale Bellaria, Radiotherapy Department, Bologna,