ESTRO 38 Abstract book

S408 ESTRO 38

E. Jimenez-Jimenez 1 , P. Mateos 2 , N. Aymar 3 , R. Roncero 3 , I. Ortiz 3 , J. Pardo 3 , S. Sabater 1 1 Complejo Hospitalario Universitario de Albacete, Radiation Oncology Department, ALBACETE, Spain ; 2 Clinica IMQ Zorrotzaurre, Medical Physics Department, Bilbao, Spain ; 3 Hospital Universitari Son Espases, Radiation Oncology Department, Palma de Mallorca, Spain Purpose or Objective Our study analyzed the impact of pretreatment PET/CT uptake on pattern of relapse with respect to the volume encompassed by the radiotherapy field among patients Fifty-six patients with stage II-IIIC esophageal cancer who received definitive or neoadjuvant radio/chemotherapy were analyzed. Patients underwent standard follow-up every 4 to 6 months. Loco/regional failures were classified as ‘‘in-field’’, “borderline-field” and “out-field”. The exact site of the disease recurrence was noted and accurately compared with the volume encompassed by the radiotherapy field. Results All patients underwent PET/CT scan before treatment. The median of follow-up was 23 months. The first site of relapse was metastatic recurrence and, secondly, local recurrence of primary tumor. The most frequent were “in- field” local (30.4%) and regional (17.9%) recurrence. We observed a statistically significant relationship between patients classified-N1 by PET/CT and out-field nodal recurrence (p = 0.024). In addition, there was a relationship between patients –N2 by PET/CT and in-field nodal recurrence (p=0.024). However, no relationship was observed between location of involved nodes by PET or SUVmax values of the metastatic lymph nodes and regional recurrences. The total number of relapses and location of relapses within the RT field were also analyzed. However, only the number of PET-positive nodes was an independent significant prognostic predictor for relapse (hazard ratio = 4.87, p< 0.001). Conclusion Our results show that only FDG-PET/CT can provide useful information and it could modify radiation treatment. A larger number of enrolled patients with a longer follow-up is needed. PO-0789 Evaluation of Hepatic Toxicity after Repeated Stereotactic Body RT for Hepatocellular Carcinoma S.M. Yoon 1 , S. Lee 2 , H. Kim 2 , J. Jung 2 , J. Kwak 2 , B. Cho 1 1 Asan Medical Center- University of Ulsan College of Medicine, Radiation Oncology, Seoul, Korea Republic of ; 2 Asan Medical Center, Radiation Oncology, Seoul, Korea Republic of Purpose or Objective This study aimed toevaluate the hepatic toxicity after repeated stereotactic body radiation therapy (SBRT) for recurrent hepatocellular carcinoma (HCC) using deformable image registration (DIR). Material and Methods Between January 2007 and December 2015, 85 patients who received two sessions of SBRT for HCC treatment were retrospectively analyzed. A DIR technique was used to calculate the cumulative dose of the first and second SBRT to the normal liver by matching the two computed tomography simulation images. The Dice similarity coefficient (DSC) index was calculated to evaluate the DIR accuracy. Radiation-induced liver disease (RILD) was defined as the worsening of the Child-Pugh score by ≥2 or elevation of transaminases or alkaline phosphatase of at least 5-fold or that of bilirubin of at least 3-fold compared to either the upper normal limit or the pretreatment with esophageal cancer. Material and Methods

levels without an evidence of disease progression within 3 months of completing each SBRT. Results Median follow-up time was 45 months and median interval time between two SBRT sessions was 15 months (interquartile range [IQR], 7–24). Before the first and second SBRT, 6 (7.1%) and 12 (14.1%) patients were Child- Pugh class B, respectively. Median tumor size was both 1.7 cm before both SBRT treatments. Mean DSC index value was 0.93, being >0.9 in 79 (92.9%) registrations. Median cumulative mean liver dose (MLD) was 9.3 Gy (IQR, 7.6– 11.7). RILD was developed in three patients, and two of them, with Child-Pugh class B, experienced irreversible liver function deterioration following the second SBRT. Grade 3 or higher biliary stricture was not observed during the follow-up period. Conclusion The DIR method provided reliable information regarding cumulative doses to the liver. In patients with Child-Pugh class A liver function, repeated SBRT for small recurrent HCC could be safely performed with acceptable hepatic toxicity. The safety of repeated SBRT at a cumulative MLD around or above 13 Gy in patients with Child-Pugh class B hepatic function needs further evaluation. PO-0790 A nationwide analysis evaluating a role of local treatment including external RT for BCLC C HCCs C.H. Rim 1 , L. Jeongshim 2 1 Korea University Ansan Hospital, Radiation Oncology, Ansan- Danwon-gu, Korea Republic of ; 2 Inha University Hospital, Radiation Oncology, Incheon, Korea Republic of Purpose or Objective Sorafenib was recommended as a standard treatment for hepatocellular carcinoma (HCC) with Barcelona Clinic of Liver Cancer (BCLC) C. However, local treatment including radiation therapy (LRT) is also widely administered in practice. The aim of our study was to define the role of LRT among BCLC C patients using a nationwide cohort. Material and Methods From 2008 to 2014, 3401 patients with HCC BCLC C stage were identified from Korea Liver Cancer Study Group cohort. Among them, patients with information on initial therapy were extracted, and classified with 3 initial treatment groups: LRT, sorafenib, and no treatment. Results 1486 HCC patients with BCLC C were inclusive in this study. Of these, 266 were assigned to LRT (17.9%), 316 to sorafenib (21.3%), and 904 to no treatment group (60.8%). Median survival time of the sorafenib group was shorter than that of the LRT group (3.8 vs. 7.6 months, p < 0.001). In multivariable analysis, sorafenib group showed significantly higher risk related to mortality compared to RT group, not only among all patients (Hazard ratio [HR] 1.50, 95% confidence interval [CI] 1.23-1.84] but also between subgroups cohorts with portal invasions (1.55, 1.23-1.84), with lymph node metastases (2.42, 1.53-3.83), without distant metastases (1.43, 1.10-1.87) and with distant metastases (1.57, 1.13-2.19). Additionally, no treatment group showed the worst survival among three treatment groups not only in all patients, but also in all subgroup’s patients (All Ps < 0.001). Conclusion LRT as an initial treatment showed survival benefit as compared to sorafenib in HCC patients with BCLC C disease. PO-0791 Neoadjuvant treatment potentially improves outcome in resectable pancreatic cancer: meta- analysis E. Versteijne 1 , J.A. Vogel 2 , M.G. Besselink 2 , O.R. Busch 2 , J.W. Wilmink 3 , J.G. Daams 4 , C.H. Van Eijck 5 , B. Groot Koerkamp 5 , C.R. Rasch 1 , G. Van Tienhoven 1 1 Amsterdam UMC, Radiation Oncology, Amsterdam, The Netherlands ; 2 Amsterdam UMC, Surgery, Amsterdam,