ESTRO 2021 Abstract Book

S308

ESTRO 2021

Materials and Methods Patients in the CRITICS trial were asked to complete HRQOL questionnaires (EORTC QLQ-C30) at baseline, after preoperative chemotherapy, after surgery, after postoperative CT or CRT and at 12 months follow-up. The 30-item EORTC QLQ-C30 questionnaire consists of five multi-item function scales (physical, role, cognitive, emotional, and social functioning), three multi-item symptom scales (fatigue, nausea and vomiting, and pain), six single-item symptom scales (dyspnea, insomnia, appetite loss, constipation, diarrhea, financial impact), and a two-item global quality of life scale. Thresholds for clinical importance by Giesinger et al. were used to identify specific domains of the QLQ-C30 questionnaire with problems or symptoms of clinical importance. To determine baseline characteristics associated with EFS and OS, a multivariate Cox proportional hazards analyses was constructed using a backward selection procedure, including baseline characteristics (age, sex, WHO performance score, Lauren classification) and the different QLQ-C30 domains. Results Baseline characteristics of patients who completed the baseline questionnaire (301 (77%) patients in the CT group and 298 (75%) patients in the CRT group) were well balanced between treatment arms. At baseline, the HRQOL questionnaire scores did not significantly differ between treatment arms, therefore further analyses were performed for the entire study population. At baseline, worse social functioning (HR 2.20, 95% CI 1.36- 3.55, p = 0.001), nausea (HR 1.89, 95% CI 1.39-2.56, p < 0.001), worse WHO performance status (HR 1.55, 95% CI 1.13-2.13, p = 0.007) and Lauren classification (diffuse compared to intestinal HR 1.94, 95% CI 1.42-2.67, p <0.001; mixed compared to intestinal HR 2.35, 95% CI 1.35-4.12, p = 0.003) were significantly associated with worse EFS and OS. Conclusion In the CRITICS trial, HRQOL scales at baseline were significantly associated with worse (event-free and overall) survival in gastric cancer patients. Pretreatment HRQOL can therefore play an important role in clinical decision-making and in shaping the patient’s expectations of treatment efficacy. In addition, it can be of importance in individual risk stratification and tailored supportive care. OC-0413 Definition Of LOcal REcurrence Site in resected pancreatic cancer: a multicentric study (DOLORES-1) A. Arcelli 1,2 , F. Bertini 1,2 , S. Strolin 3 , G. Macchia 4 , F. Deodato 4,5 , S. Cilla 6 , S. Parisi 7 , A. Sainato 8 , M. Fiore 9 , P. Gabriele 10 , D. Genovesi 11 , F. Cellini 5,12 , A. Guido 1 , S. Cammelli 1,2 , M. Buwenge 1,2 , E. Loi 3 , M. Renzulli 13 , R. Golfieri 2,13 , A.G. Morganti 1,2 , L. Strigari 3 1 Radiation Oncology, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 2 Department of Experimental, Diagnostic and Specialty Medicine (DIMES), Alma Mater Studiorum, Bologna University, Bologna, Italy; 3 Medical Physics, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy; 4 Radiation Oncology Unit, Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Campobasso, Italy; 5 Istituto di Radiologia, Università Cattolica del Sacro Cuore, Roma, Italy; 6 Medical Physics Unit, Gemelli Molise Hospital – Università Cattolica del Sacro Cuore, Campobasso, Italy; 7 Unit of Radiation Therapy, IRCCS “Casa Sollievo della Sofferenza”, San Giovanni Rotondo, Italy; 8 Radiation Oncology, Pisa University Hospital, Pisa, Italy; 9 Radiation Oncology, Campus Bio-Medico University, Rome, Italy; 10 Radiation Therapy, Candiolo Cancer Institute - FPO, IRCCS Candiolo, Candiolo, Italy; 11 Department of Radiation Oncology, SS. Annunziata Hospital, G. D'Annunzio University of Chieti, Chieti, Italy; 12 UOC di Radioterapia, Dipartimento di Scienze Radiologiche, Radioterapiche ed Ematologiche, Fondazione Policlinico Universitario A. Gemelli, IRCCS, Roma, Italy; 13 Radiology Unit, IRCCS Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy Purpose or Objective To generate a local failures (LF) risk map in resected pancreatic cancer (PC) patients, and validate the results of the previous studies on this topic. We also aimed to propose new guidelines for postoperative target delineation in PC patients. Materials and Methods A retrospective, multicentric, observational study, on behalf of AIRO (Italian Association of Radiation and Clinical Oncology) was conducted collecting data and imaging (contrast enhanced Computed Tomography, (CT)) of resected PC patients with LF from six Italian centers. A radiologist specialized in gastrointestinal tumors delineated the LF on the follow-up contrast enhanced CT and reported the recurrence areas on the CT images of a representative patient ( Figure 1A-B ). The 70% of LF points were randomly extracted from the clinical target volume (CTV) based on RTOG guidelines and combined to the 30% of points randomly obtained from the LF database. Based on a Kernel density estimation the 3D distribution map of LF points was generated and compared with the results of two previously published studies using the Dice index. Results Sixty-four patients were included in this analysis. Most patients (59.4%) underwent adjuvant treatment after surgery. Twenty-one (32.8%) patients experienced LF closer to the root of the celiac axis (CA) and forty-three patients (67.2%) experienced LF closer to the root of the superior mesenteric artery (SMA). The mean (± standard deviation) distance of LF points to CA and SMA was 21.5 ±17.9 mm and 21.6 ±12.1 mm, respectively. The Dice values comparing the isolevel of risk map corresponding to the 80% and 90% probabilistic density and the CTV80s and CTV90s proposed in the previous publications were 0.45-0.53 and 0.58-0.60, respectively. Figure 1A-1B: Local recurrence sites (blue symbols) plotted with respect to the Celiac Axis (yellow) and the Superior Mesenteric Artery (cyan). CTV90 (light blue) and CTV80 (green line) proposed in previuos pubblications