ESTRO 38 Abstract book

S407 ESTRO 38

The median overall survival (OS) was 52 days (Figure 2). The median OS values of the non re-irradiation (one-time) and re-irradiation groups were 54 days and 36 days, respectively, which was not a statistically significant difference. There were no grade three or higher adverse events.

Poster: Clinical track: Upper GI (oesophagus, stomach, pancreas, liver)

PO-0786 Hemostasis radiotherapy for inoperable gastric cancer: A prospective study O. Tanaka 1 , A. Sugiyama 2 , T. Omatsu 3 , T. Taniguchi 1 , K. Ono 1 , Y. Kunishima 4 , M. Matsuo 5 1 Asahi University Hospital, Department of Radiation Oncology, Gifu, Japan ; 2 Gifu Municipal Hospital, Department of Radiation Oncology, Gifu city, Japan ; 3 Asahi University Hospital, Department of Gastroenterology, Gifu, Japan ; 4 Asahi University Hospital, Division Of Nursing, Gifu, Japan ; 5 Gifu University Hospital, Department of Radiology, Gifu city, Japan Purpose or Objective Standard treatment for progressive gastric cancer with bleeding includes hemostasis radiotherapy (RT). However, no prospective study of the ideal dosage has been conducted. We thus clarified the utility of RT for gastric cancer at a fixed dose and field. Material and Methods A total of 28 patients with gastric cancer with bleeding were enrolled in this study. The flow of treatment was shown in Figure 1. The initial RT plan was whole stomach irradiation. Although the examination indicated tumor spread, it was difficult to determine the border between normal tissue and malignancy tissue. We contoured the outer wall of the stomach with an injection of butylscopolamine on an empty stomach. The initial dose was 20 Gy / 5 fractions for full stomach. Hemostasis was achieved when hemoglobin levels in the blood tests stabilized within two weeks of irradiation. If re-bleeding occurred, patients decided whether or not to undergo re- irradiation. The salvage re-irradiation dose was 15 Gy / 5 fractions. Before RT, three or four clips were placed near the gastric tumor by endoscopy. The radiation oncologist contoured the tumor, CTV and PTV under guidance with clips. CTV was not for the whole stomach and only the partial stomach was irradiated. We scored the adverse events (AEs) each day during RT and one week after treatment.

Conclusion Re-irradiation followed by initial RT was effective for reducing adverse events and did not cause adverse events. OS did not differ between the one-time irradiation and re- irradiation groups. No predictive factors were identified. It may be necessary to determinate the ideal dose and fraction number of initial irradiation, which is preferably lower than 20 Gy. PO-0787 Adjuvant chemoradiation in resected gallbladder cancer: A prognostic model for overall survival C. Solé 1 , L. Vargas 2 , V. Solé 2 , F. Larsen 2 , S. Solé 2 1 Instituto de Radiaciones Médicas, Radiotherapy, Santiago, Chile ; 2 Clinica IRAM, Santiago, Chile Purpose or Objective Patients with gallbladder cancer (GBC) have a dismal prognosis. We investigated outcomes and risk factors for overall survival (OS) in patients treated with radical surgery and adjuvant chemoradiotherapy (CRT). Material and Methods A total of 212 patients with LAGC [ ⩾ pT3 59% and/or pN+ 52%) were studied. The primary endpoint of the analysis was OS. We constructed a risk scoring system in which points were assigned to each risk factor by dividing each ß coefficient in the final model by the lowest ß coefficient and rounding to the nearest integer. A risk score was assigned to each subject by adding up the points for each risk factor present. Subjects were then divided into three risk groups based on their risk scores (0 points=low risk, 1- 2 points= intermediate risk, 3-6 points= high risk). Results Median follow-up was 46.2 months (2-235). Five-year OS for the entire cohort was 53%. In multivariate analysis higher pT stage [HR: 2.43 (1.29-3.68), p = 0.01], R1 resection [HR 5.06 (3.12-8.19), p < 0.001], and number of surgical procedures [HR 1.41 (1.01-2.16), p = 0.05] were associated with an increased risk of death. Five-year OS for patients with low (n=63), intermediate (n=94) and high (n=55) risk was 79.1%, 51.2% and 9.5%, respectively. Conclusion Overall results after multimodality treatment of GBC are promising. A risk model was generated to determine a prognostic index for individual patients with GBC. Classification of risk factors for death has contributed to propose a prognostic index that could allow us to guide risk-adapted tailored treatment. PO-0788 Preliminary analysis of PET/CT imaging on radiation field and relapse rates in esophageal cancer

Results Two patients were excluded because they did not complete RT due to stroke and pneumonia. The response ratio of initial RT was 85% (22/26 patients). Six patients underwent re-irradiation, all of which responded (100%).