ESTRO 38 Abstract book

S761 ESTRO 38

medically unfit for surgery for esophageal squamous cell carcinoma (clinical stage I to III) were randomly assigned to receive four cycles (two concomitant and two postradiotherapy) of S-1 or S-1 plus cisplatin along with radiotherapy 60–66Gy/30 to 33 fractions. The primary outcome was the complete response rate of the primary tumor as measured by endoscopy and computer screening at three months after treatment completion. The secondary outcomes included survival and toxicity. Results In August 2018, 88 patients were enrolled, 43 of which were evaluated by gastroscopy (45 cases have not yet been followed up by gastroscopy), including 25 cases in the experimental group receiving S-1 concurrent intensity- modulated radiotherapy treatment and 18 cases in the control group receiving concurrent S-1 plus cisplatin intensity-modulated radiation therapy. In the experimental group,13 patients (52%)achieved complete remission, six(24%)achieved partial remission, four (16%)had stable disease, and two (8%)had progressed. In the control group, eight patients (44.4%)achieved complete remission, seven (38.9%)achieved partial remission, two(11.1%)had stable disease, and one (5.6%)had progressed. There was no significant difference in the rates of complete remission between the two groups (P > 0.05). The radiotherapy completion rates were 95.6% and 88.9% in the experimental and control groups, respectively. The radiotherapy interruption rates in the two groups were 52% and 55.5%, respectively. The chemotherapy completion rates were 100% and 88.9% in the experimental and control groups, respectively. The chemotherapy interruption rate was 4% in the experimental group and 11.1% in the control group.The incidence of grade 2, 3, and 4 hematological toxicity was 56%, 4%, and 0%, respectively, in the experimental group and 66.6%, 16.6%, and 5.5%, respectively, in the control group. Conclusion Conclusions: The mid-term data of this trial indicate that S-1 synchronous intensity-modulated radiation therapy is no significant differences in complete response rate to S- 1 combined with cisplatin synchronous intensity- modulated radiation therapy, with fewer side effects. Therefore, patients are more likely to complete treatment with S-1 synchronous intensity-modulated radiation therapy alone. EP-1398 Lymphopenia and accidental splenic doses for locally advanced gastric cancer F. Sert 1 , D. Yalman 1 , S. Ozkok 1 1 Ege University Medical School&Hospital, Radiation Oncology, Izmir, Turkey Purpose or Objective Considering the high recurrence and mortality rates, additional predictive and/or prognostic factors have to be identified for the patients with locally advanced gastric cancer (LAGC).There is limited data evaluating the certain reason of lymphopenia and the relation between splenic doses and immunological response including NLR(neutrophil-tolymphocyte ratio) and white blood cell counts over oncological outcomes for the patients with LAGC.The purposes of the present study are to determine the effect of CRT(chemoradiotherapy)-induced lymphopenia, and irradiated splenic volume and splenic doses on oncological outcomes in patients with LAGC. Material and Methods A consecutive cohort of 52 patients with LAGC (pT3-4 and/or pN0-3b) treated with adjuvant CRT at our department between 2005 and December 2016 was identified for this trial. The absolute neutrophil, lymphocyte and platelet counts were recorded prior to any treatment (baseline), just after the completion of CRT, and 2-6 weeks after the completion of CRT (control evaluation).

Conclusion MDT was associated more chemotherapy receipt in patients underwent radiotherapy for esophageal cancer, which may improve OS. EP-1397 S-1 versus S-1 plus cisplatin concurrent radiationtherapy for esophageal cancer: a mid-term report Y. Wen 1 , Z. Zhao 1 , Y. Chen 2 , Y. Gui 3 , X. He 4 , Q. Yang 5 , M. Sun 6 , J. Miao 7 , Q. Jia 8 , H. Tian 9 , X. Du 1 1 Mianyang Central Hospital, Oncology Department, Mianyang, China ; 2 Jianyang People's Hospital, Oncology Department, Jianyang, China ; 3 Affiliated Hospital of North Sichuan Medical College, Oncology Department, Nanchong, China ; 4 Langzhong people's Hospital, Oncology Department, Langzhong, China ; 5 Ziyang People's Hospital, Oncology Department, Ziyang, China ; 6 The first people's Hospital of Guangyuan, Oncology Department, Guangyuan, China ; 7 Zigong Fourth People's Hospital, Oncology Department, Zigong, China ; 8 The second people's Hospital of Jiangyou, Oncology Department, Jiangyou, China ; 9 The first people's Hospital of Jiangyou, Oncology Department, Jiangyou, China concurrent chemotherapy and radiotherapy for esophageal cancer (EC) often comprise two drugs. However, retrospective studies have reported severe toxicity for patients with EC receiving radiotherapy combined with two-drug chemotherapy. While the incidence of side effects of single-drug chemotherapy is relatively low. Therefore, we designed a prospective, randomized, multicenter phase II trial to compare the efficacy and toxicity of combining S- 1 or S-1 plus cisplatin with intensity-modulated radiation therapy for esophageal squamous cell carcinoma. Material and Methods This randomized, controlled, multicenter trial compared S-1 versus S-1 plus cisplatin concurrent radiotherapy in patients with esophageal squamous cell carcinoma. Eighty-eight patients with unresectable or who were Purpose or Objective The chemotherapy regimens for