Abstract book - ESTRO meets Asia

S19 ESTRO meets Asia 2018

5 Institut de Cancérologie de l'Ouest, Radiotherapy, Nantes, France 6 Centre Guillaume Le Conquérant, Radiotherapy, Le Havre, France 7 Centre Paul Strauss, Radiotherapy, Strasbourg, France 8 Centre Antoine Lacassagne, Radiotherapy, Nice, France 9 Institut de Cancérologie de Lorraine, Radiotherapy, Vandoeuvre-Les-Nancy, France Purpose or Objective In esophageal cancer (EC), 30 to 45% of patients suffer from local persistent or recurrent disease after exclusive chemoradiotherapy. Improvements in target definitions with planning CT and 18 F-FDG PET/CT together with better adjustment in radiation dose delivery that better protect healthy tissues led us to test dose escalation in the modern era of new technologies. Material and Methods Patients with biopsy-proven locally advanced EC or who were unfit for surgery were randomly assigned to 40Gy elective nodal irradiation with either a 10Gy boost (Arm A) or 26Gy boost (Arm B) combined with concomitant chemotherapy (FOLFOX-4). The primary endpoint was acute toxicity according to the NCIC-CTCAE (version 4.0). Quality of life according to the EORTC QLQ-C30 and OG25 was a secondary endpoint. All analyses were performed in intent-to-treat. 160 patients were randomized: 81 patients in arm A and 79 patients in arm B. Sixty-eight (84.0%) and 67 (84.8%) patients were men in arms A and B, respectively. The mean age at diagnosis was 61.9 (7.9) years and 62.1 (7.8) years, respectively. Seventy patients in each arm had squamous cell carcinoma (86.4% in arm A and 88.6% in arm B) and 59 patients (72.8%) and 58 patients (73.4%) had stage III disease in arms A and B, respectively. Intensity- Modulated Radiation Therapy (IMRT)/Volumetric Modulated Arc Therapy (VMAT) was performed in 57 (70.4%) and 55 (69.6%) patients in arms A and B, respectively while 3D conformal RT was chosen in 21 (25.9%) and 21 (26.6%) patients (data missing for 6 patients). Results The rates of G3+ non-hematological toxicity were not significantly different between arms A and B (76.5% vs 86.0%, p= 0.12). The rates of G3+ hematological toxicity were not significantly different between arms A and B (82.7% vs 88.6%, p= 0.29). The rates of G3+ non- hematological toxicity were not significantly different between patients treated with 3DRT (83.3%) and IMRT (81.3%) (p=0.77). The mean global health scores at baseline and 3 months were 63.9 (sd=21.4) vs 69.6 (sd=23.1) in arm A (p=0.10) and 65.27 (sd=19.54) vs 58.8 (sd=19.9) in arm B (p=0.16). Looking at QLQ-OG25, the presence of dysphagia was neither significantly different between arm A (89.23%) and arm B (86.21%) (p=0.61) at baseline nor at 3 months (77.78% vs 86.84%, p=0.29). Odynophagia was present at baseline in 78.46% in arm A and 75.86% in arm B (p=0.73) while the rates observed at 3 months were 68.18% and 73.68%, respectively (p=0.59). At baseline, pain and discomfort were observed in 36.92% of patients in arm A and 27.59% in arm B (p=0.27). Rates at 3 months were respectively 33.33% and 50.0% in arms A and B (p=0.12). Conclusion Modern dose escalation with elective nodal irradiation is feasible with no increased acute toxicity and no differences in the main QLQ-C30 and QLQ-OG25 scores. A phase III trial comparing arms A and B is on-going to conclusively address the issue of locoregional relapse-free survival with exclusive chemoradiation. OC-049 Retrospective study of adjuvant chemoradiotherapy for R0 resected patients with pN3 gastric cancer M.L. Zhou 1 , Y.Q. Wang 1 , W. Yang 1 , M. Mo 2 , R. Hu 1 ,

Y. Wang 1 , G.C. Li 1 , Z.W. Long 3 , X.W. Liu 3 , Y.N. Wang 3 , Z. Zhang 1 1 Fudan University Shanghai Cancer Center, Department of Radiation Oncology, Shanghai, China 2 Fudan University Shanghai Cancer Center, Department of Cancer Prevention, Shanghai, China 3 Fudan University Shanghai Cancer Center, Department of Gastric Surgery, Shanghai, China Purpose or Objective Stage pN3 gastric cancer (GC) is characterized by heavy load of lymph node metastasis and high postoperative recurrence rate. At present, there is a lack of randomized controlled clinical trials regarding the question if the addition of radiotherapy to postoperative chemotherapy (ChT) can further benefit stage pN3 GC. And the findings of several retrospective studies are inconsistent. The purpose of this study was to compare the effectiveness of postoperative CRT and postoperative ChT for stage pN3 GC after R0 resection, aiming to provide more evidence for the strategy of treatment for stage pN3 GC. Material and Methods From January 2004 to December 2015, cases of stage pN3 GC in the database of our center were retrospectively reviewed. The patients were enrolled into the postoperative CRT group and the postoperative ChT group if they met the inclusion criteria. The patients who received mono-drug ChT are excluded. The four different methods based on propensity score model (adjustment, inverse probability of treatment weighting, stratification and matching) were used for the balance of baseline characteristics and survival analysis between the two groups. Subgroup analyses of various clinicopathological factors were performed. Results There were 193 and 389 patients who met the inclusion criteria were enrolled into the CRT group and ChT group. The baseline characteristics of the unmatched data were unbalanced. After matching, balance of baseline features was achieved. Without adjustment, there was no significant difference of disease-free survival (DFS) and overall survival (OS) between the two groups. After the application of the four methods, the DFS of the CRT group was significantly better than that of the ChT group (p=0.017; HR=0.73; 95% CI: 0.56-0.94), but there was no significant difference of OS (p=0.331; HR=0.88; 95% CI: 0.67-1.14). Subgroup analyses showed that patients who are younger than 60 years or females, or that with well differentiated tumor, stage T3, N3a or IIIB GC or the administration of triple drugs could benefit from postoperative CRT. Conclusion Compared with postoperative ChT, postoperative CRT can further improve the DFS of patients with stage pN3 GC after R0 resection. OC-050 Quality of life for gemcitabine+nab-paclitaxel+SBRT vs. gemcitabine+S-1+SBRT in pancreatic cancer X. Zhu 1 , Y. Cao 1 , Y. Shen 1 , S. Qing 1 , F. Cao 1 , L. Gu 1 , F. Fang 1 , Z. Jia 1 , X. Ju 1 , H. Zhang 1 1 Changhai Hospital, Radiation Oncology, Shanghai, China Purpose or Objective Nearly 50% of patients had metastatic pancreatic cancer at initial diagnose. Therefore, priority may be given to quality of life, which required improvement of survival without simultaneously compromise of health-related quality of life (HRQOL) during treatment. Moreover, radiotherapy could be an option for amelioration of local symptoms in addition to potential abscopal effects, contributing to improvement of HRQOL. Hence, we sought to evaluate the HRQOL after SBRT and different chemotherapy regimens in the management of metastatic pancreatic cancer.