ESTRO 38 Abstract book

S771 ESTRO 38

T. Kiritoshi 1 , H. Yamashita 1 , W. Takahashi 1 , M. Ogita 1 , K. Nakagawa 1 , O. Abe 1 1 The University of Tokyo Hospital, Radiology, Bunkyo-ku, Japan Purpose or Objective The aim of this study was to evaluate clinical results of salvage CRT for locoregional recurrence after esophagectomy for squamous cell carcinoma of esophagus. Material and Methods We performed a retrospective review of 73 consecutive patients who received salvage chemoradiotherapy between 2001 and 2017 for locoregional recurrence of esophageal carcinoma after curative surgery. The intended radiotherapy regimen was 50-60 Gy in 25-30 fractions combined with concurrent platinum-based chemotherapy. The endpoints of this study were overall survival, progression free survival and prognostic factors. Survival rates were estimated using the Kaplan-Meier method, and statistical analysis was performed using the log-rank test. Univariate and multivariate analysis were performed using the log-rank test and the Cox proportional hazards model respectively. Results The median follow-up period for survivors was 42.7 months. The 1-, 2-, 3-year overall survival were 82.4%, 46.2% and 33.8% respectively with a median survival time of 21.6 months. Out of all 73 patients, 29 patients were alive beyond 2 years from salvage therapy. The median PFS time was 9.7 months. Ten patients survived for more than 5 years from the start of salvage chemoradiotherapy. Overall survival was significantly longer in the nedaplatin plus S-1 group (median 29.1 months, 95% CI 15.2-66.4) than other chemotherapy group (median 16.7 months, 14.0-24.6; hazard ratio 2.34; p=0.012). Re-recurrence within irradiated field was seen in 26 patients and was significantly correlated with shorter overall survival (hazard ratio 3.12; p<0.01). Conclusion Salvage chemoradiotherapy using nedaplatin plus S-1 could be a new treatment option for locoregional recurrence after esophagectomy for esophageal squamous cell carcinoma. EP-1420 Utility of FIB-4 index for hepatocellular carcinoma patients treated with proton beam therapy Y. Sekino 1 , T. Okumura 1 , N. Fukumitsu 2 , T. Iizumi 1 , D. Miyauchi 1 , N. Mizoguchi 1 , K. Murofushi 1 , K. Ohnishi 1 , M. Mizumoto 1 , T. Nonaka 1 , K. Nakai 1 , H. Ishikawa 1 , K. Tsuboi 1 , H. Sakurai 1 1 Faculty of Medicine- University of Tsukuba, Radiation Oncology & Proton Medical Research Center, Tsukuba, Japan ; 2 Kobe Proton Center, Radiation Oncology, Kobe, Japan Purpose or Objective The FIB-4 index is a simple noninvasive index for evaluating hepatic fibrosis which is consists of age, aspartate aminotransferase (AST), alanine aminotransferase (ALT) and platelet count (PLT). This index is reported to be a significantly useful noninvasive surrogate marker for prognosis of hepatocellular carcinoma (HCC) patients received hepatectomy. However, the FIB-4 index has not been validated specifically in HCC patients receiving proton beam therapy (PBT). The purpose of this study is to evaluate the prognostic performance of the FIB-4 index for HCC patients treated with PBT. Material and Methods A total of 55 consecutive HCC patients treated with PBT at the University of Tsukuba between 2001 and 2013 were analyzed. Eligibility criteria included patients with a single lesion, tumor size of ≤5 cm and Child-Pugh (CP) A5. Patients with vascular invasion were excluded. The cutoff

EP-1418 Initial results of carbon ion radiotherapy combined with S-1 for locally advanced pancreatic cancer Y. Mori 1 , M. Okamoto 1 , H. Kiyohara 2 , H. Katoh 3 , K. Shibuya 1 , T. Kaminuma 1 , S. Shiba 1 , N. Okano 1 , T. Ohno 1 , T. Nakano 1 1 Gunma Heavy ion Medical center, Radiation oncology, Maebashi-city, Japan ; 2 Maebashi red cross hospital, Radiation oncology, Maebashi-city, Japan ; 3 Kanagawa cancer center, Radiation oncology, Yokohama city, Japan Purpose or Objective Generally, patient with locally advanced pancreatic cancer (LAPC) is treated with chemotherapy alone or X- ray radiotherapy (RT) concurrent with gemcitabine (GEM). Median survival time (MST) of standard treatment is about 14 months. Recently, there was a report of carbon ion radiotherapy （ C-ion RT ） with concurrent usage of GEM for LAPC which showed 2-year overall survival (OS) rate and MST 48% and 22.5 months, that is better outcome compared with other treatment for LAPC. However, there is no report for C-ion RT combined with other chemotherapy. On the other hand, postoperative adjuvant chemotherapy with S-1 significantly extended both overall and relapse-free survival of Japanese patients with resected pancreatic cancer compared with GEM. [OM1] [Office2] Thus, we hypothesize that C-ion RT concurrent S-1 (tegafur/gimeracil/oteracil potassium) is more effective for LAPC and started prospective phase II Eligibility criteria: (1) Pathologic confirmation of pancreatic invasive ductal carcinomas or clinical diagnosis by imaging. (2) Absence of distant metastasis (patients with para-aortic lymph node metastasis were eligible) (3) Unresectable primary tumors due to T4 disease based on the 7th edition of TNM classification, involving either the celiac axis or the superior mesenteric artery. (4) Without gastrointestinal ulcer (stomach, duodenum) (excluding repaird ulcer) (5) Age at registration is from 20 to 80 years old (6) ECOG performance status (PS) of 0 to 2. (7) Without the surgical resection history to a pancreatic cancer. Without the radiotherapy to a pancreatic cancer.Treatment: Prescribed doses were 55.2 Gy [relative biological effectiveness (RBE)] in 12 fractions. Concurrent S-1 was administered orally during 28 days, the dose levels were 80 mg/-1.00 m 2 , 100 mg/1.00-1.50 m 2 ,120 mg/1.50- m 2 per day.Clinical outcome measures: The primary endpoint was overall survival (OS). The secondary endpoints were local control (LC) rate, progression free survival (PFS) rate and adverse effects. Toxicity was graded using Common Terminology Criteria for Adverse Events, version 4.0 (CTCAE 4.0). Results There were 13 patients enrolled this study from January 2016 to December 2017 in our institute.MST was 23.4 months. 1 and 2-year OS was 100% and 38%.1 and 2-year LC are 80% and 28%. 1 and 2-year PFS rate are 60% and 49%.There were occurrences of acute toxicity, leukopenia grade2 in 2 patients and grade 3 in 1 patient, anemia grade2 in 2 patients and grade 3 in 1 patient, thrombocytopenia Grade 2 in 1 patient. There is no patient with Grade 4 or higher.There were no occurrences of late toxicity of grade 3 or higher. Conclusion Initial results show that C-ion RT combined with S-1 appears to be tolerated and not inferior compared with GEM for LAPC. Although there are still few cases, C-ion RT combined with S-1 is also considered to be one of the options of treatment for LAPC. EP-1419 Salvage concurrent chemoradiotherapy for postoperative locoregional recurrence of esophageal cancer study in our institute. Material and Methods