ESTRO 36 Abstract Book

S361 ESTRO 36 _______________________________________________________________________________________________

alive, 3 died due to the cancer progression of the tumors except ones received the C-ion RT, 5 developed a local recurrence. The 1-year OS of the CRC group and the non- CRC group, the larger tumor group (> 50mm) and the smaller tumor group, the 4-fraction group and the 12- fraction group were 100% and 75% (p value=0.16), 81 % and 100% (p=0.078), 94% and 80% (p=0.030), respectively. The 1-year LCR of those were 70% and 100% (p=0.13), 56% and 100% (p=0.080), 80 % and 75% (p=0.95), respectively. No Grade 3 and worse adverse reactions were observed. No patients experienced radiation-induced liver disease. Conclusion It is suggested the C-ion RT for MLT is an effective and safe treatment even in large MLT. This is the initial result thus it is necessary to analyze more number of patients and for longer observation period. PO-0691 Whole-body total lesion glycolysis is an independent predictor of thoracic esophageal cancer N. Takahashi 1 , R. Umezawa 1 , K. Takanami 2 , Y. Takaya 1 , Y. Ishikawa 1 , M. Kozumi 1 , K. Takeda 1 , N. Kadoya 1 , K. Jingu 1 1 Tohoku University Graduate School of Medicine, Radiation oncology, Sendai, Japan 2 Tohoku University Graduate School of Medicine, Diagnostic Radiology, Sendai, Japan Purpose or Objective The purpose of this study was to determine whether pretreatment whole-body metabolic tumor volume (MTV WB ) and total lesion glycolysis (TLG WB ) are associated with outcomes in patients with thoracic esophageal squamous cell carcinoma treated by definitive chemoradiotherapy (dCRT). Material and Methods We retrospectively reviewed patients with stage II or III thoracic esophageal squamous cell carcinoma who underwent FDG-PET/CT within 60 days before dCRT at our institution between January 2005 and August 2013. Patients who had massive pneumonia caused by perforation of the tumor at FDG-PET/CT were excluded. Ninety patients were enrolled in this study. We calculated all lesion’s SUV max , SUV mean , MTV and TLG by using MIM maestro TM ver. 6.6.1 (MIM Software Inc. USA). TLG was calculated from MTV × SUV mean . TLG WB was sum of TLG of primary lesion (TLG pri ) and lymph-node lesions. MTV WB was sum of MTV of primary lesion (MTV pri ) and lymph-node lesions. Survival estimates were calculated using the Kaplan-Meier method from the first date of dCRT. Predictors were analyzed using Cox’s hazards model. Results The median follow-up period was 64.2 months for survivors. Three-year overall survival (OS), local control (LC) and progression free survival (PFS) were 52.0 %, 42.7 % and 35.2 %, respectively. In univariate analysis, T stage (p = 0.019, hazard ratio [HR]: 1.73), MTV pri ≥ median (p = 0.025, HR: 1.95), TLG pri ≥ median (p = 0.035, HR: 1.88), MTV WB ≥ median (p = 0.004, HR: 2.38) and TLG WB ≥ median (p = 0.007, HR = 2.25) were significant unfavorable predictors of OS. TLG pri ≥ median (p = 0.016, HR: 1.99), MTV WB ≥ median (p = 0.030, HR: 1.86) and TLG WB ≥ median (p = 0.012, HR = 2.05) were significant unfavorable predictors of LC. T stage (p = 0.007, HR: 1.65), 1 cycle of concurrent chemotherapy (p = 0.021, HR: 2.14), SUV max (p = 0.033, HR: 1.76), SUV mean (p = 0.019, HR: 1.85), TLG pri ≥ median (p = 0.009, HR: 1.99), MTV WB ≥ median (p = 0.006, HR: 2.06) and TLG WB ≥ median (p = 0.002, HR = 2.26) were significant unfavorable predictors of PFS. Factors with p < 0.1 in univariate analysis were included in multivariate analysis. In multivariate analysis, MTV WB ≥ median (p = 0.016, HR: 2.34) and TLG WB ≥ median (p = 0.013, HR = 2.34) were significant unfavorable predictors of OS. TLG pri ≥ median (p = 0.023, HR: 2.17), MTV WB ≥ median (p = 0.020, HR: 2.18) and TLG WB ≥ median (p = 0.007, HR = 2.50) were significant unfavorable predictors of LC. MTV pri ≥ median

(p = 0.0495, HR: 1.83), TLG pri

≥ median (p = 0.024, HR:

2.01), MTV WB ≥ median (p = 0.003, HR: 2.44) and TLG WB ≥ median (p = 0.008, HR = 2.79) were significant unfavorable predictors of PFS. SUV max was not selected as a predictor of OS, LC or PFS. Conclusion In multivariate analysis, MTV WB and TLG WB were independent predictors for OS, LC and PFS. In addition, the hazard ratio of TLG WB was highest for OS, LC and PFS in multivariate analysis. TLG WB is one of best predictor in patients with stage II or III thoracic esophageal squamous cell carcinoma treated by dCRT. PO-0692 The role of adjuvant chemoradiotherapy in patients with common bile duct cancer after R1 resection S.W. Kim 1 , S.H. Kang 2 , M. Chun 1 , Y.T. Oh 1 , O.K. Noh 1 , H. Jang 3 , S. Jo 4 1 Ajou University School of Medicine, Radiation Oncology, Suwon City, Korea Republic of 2 Ilsan Paik Hospital- Inje University School of Medicine, Radiation Oncology, Goyang, Korea Republic of 3 Dongguk University School of Medicine Gyeongju Hospital, Radiation Oncology, Gyeongju, Korea Republic of 4 Haeundae Paik Hospital- Inje University School of Medicine, Radiation Oncology, Busan, Korea Republic of Purpose or Objective We investigated the role of adjuvant radiotherapy combined with chemotherapy (CRT) in patients with microscopically positive resection margin after curative resection for extrahepatic cholangiocarcinoma (EHCC). Material and Methods We included 87 patients with EHCC treated with curative surgery at our institution. Of the 35 patients with microscopically positive resection margin, 22 patients received adjuvant chemoradiotherapy (R1 + CRT group) and 13 received adjuvant radiotherapy alone (R1 + XRT group). We compared treatment outcomes between these patients and 52 patients with negative resection margin who did not receive any adjuvant treatments (S group). Results Patients in R1 + CRT and R1 + XRT group were younger than those in S group and pathologically positive lymph node was more common in R1 + CRT group. During the median follow-up period of 26 months, the 2-year disease-free survival rates were 55.8% for S group, 54.5% for R1 + CRT group and 9.6% for R1 + XRT group. There was no significant difference in disease-free survival rate between S group and R1 + CRT group ( p = 0.225). In contrast, R1 + XRT group had significantly inferior 2-year disease-free survival rate compared with S group ( p = 0.013) and R1 + CRT group ( p = 0.008). In multivariate analysis, R1 + XRT group had a trend for increased risk of recurrence (HR, 2.049; 95% CI, 0.930–4.514; p = 0.075). The 2-year overall survival rates were 61.5% for S group, 54.5% for R1 + CRT group and 15.4% for R1 + XRT group. There was significant difference in 2-year overall survival rate between R1 + XRT group versus S group ( p <0.001) and R1 + CRT group ( p = 0.021). Multivariate analysis revealed that R1 + XRT group had an increased risk of mortality (HR, 2.497; 95% CI, 1.242–5.019; p = 0.010). Conclusion Adjuvant CRT after R1 resection showed equivalent survival rates to R0 resection without adjuvant treatments, whereas adjuvant radiotherapy alone after R1 resection had significantly worse survival outcomes compared with other groups. As adjuvant CRT had superior outcomes to adjuvant radiotherapy alone in patients with R1 resection, adjuvant CRT might be a better option for controlling microscopic residual EHCC.