Abstract Book

S779

ESTRO 37

Medicine - University of Freiburg, Department of Radiology, Freiburg, Germany 5 Medical Center University of Freiburg- Faculty of Medicine - University of Freiburg, Department of General and Visceral Surgery, Freiburg, Germany 6 Medical Center University of Freiburg- Faculty of Medicine - University of Freiburg, Department of Radiation Oncology, Freiburg, Germany 7 Kliniken Maria Hilf- Moenchengladbach- Germany, Department of Radiation Oncology, Moenchengladbach, Germany Purpose or Objective To evaluate the feasibility and toxicity profile of reirradiation of recurrent primary or secondary liver tumors after stereotactic body radiotherapy (SBRT). Material and Methods Patients with hepatocellular carcinoma (HCC, n=8) cholangiocarcinoma (CCC, n=2) and liver metastases (LM, n=9) with a total of 23 lesions, with intrahepatic recurrence or progression after SBRT, underwent re-SBRT in 3 to 12 fractions with a median time of 7.4 (range: 2- 67) months between treatments. Results The median follow-up after re-irradiation for patients alive was 14 months with a median overall survival of 10 months. The median prescribed dose for the first SBRT was 45 (range: 33-66 Gy, EQD2 10 =56) Gy and 48 (range: 27-66 Gy, EQD2 10 =71) Gy for the re-SBRT. The median mean liver dose (D mean,liver ) was 7 (1-25) Gy with a corresponding EQD2 3 of 7 (0.2-25) Gy for the initial treatment and 10(1-63)Gy and 9 (1-67) Gy for the re- treatment. Of the 23 lesions 6 were re-irradiated in-field resulting in a median EQD2 3, maxium of 269 (range: 120-406) Gy for both treatments, with an α/β=3 to account for liver parenchyma, and a median EQD2 3, mean of 213 (range: 105-352) Gy. Treatment was well tolerated. Two patients with stent placement before SBRT developed a cholangitis 4 and 14 months after re-SBRT. One patient developed a CTC grade 3 gastrointestinal bleed. There was no radiation induced liver disease observed. Conclusion Repeated liver SBRT is feasible, without excessive liver toxicity, when there is no considerable overlapping with pre-irradiated portions of the stomach or bowel. EP-1433 Induction chemotherapy of albumin-bound paclitaxel in carcinoma of esophagus unsuitable for surgery A.K. Gandhi 1 , M. Rastogi 1 , S.S. Nanda 1 , S. Rath 1 , R. Khurana 1 , R. Hadi 1 , K. Sahni 1 , A. Srivastava 1 , S. Farzana 1 , S. Mishra 1 1 Dr Ram Manohar Lohia institute of Medical Sciences, Radiation Oncology, Lucknow, India Purpose or Objective Weekly chemotherapy (WK-PC) with concurrent radiation (CCRT) using solvent based paclitaxel (SB-Pac) and carboplatin as neo-adjuvant treatment prior to surgery is the standard of care for resectable carcinoma of oesophagus. WK-PC as induction regimen (NACT) followed by definitive radiotherapy (RT) or CTRT with WK-PC is a novel approach in patients unsuitable for surgery or cisplatin based CTRT; however the tolerance of this regimen could be an issue. With a hypothesis that this regimen could be better tolerated if nano-particle albumin bound paclitaxel (NB-Pac) is used instead of SB- Pac, we aimed to evaluate the role of this regimen using NB-Pac. Material and Methods Details of 52 patients (Jan 2013-Dec 2016) of histopathologically proven carcinoma of oesophagus deemed unsuitable for surgery or cisplatin based CTRT treated with induction WK-PC (NB-Pac 80 mg/m 2 + carboplatin AUC 2 intravenous Day1) followed by

definitive RT alone or CTRT (same as induction regimen) were retrieved from departmental archives. Toxicities were evaluated using acute morbidity scoring criteria of RTOG. Responses were evaluated as per WHO criteria. Recurrence free survival (RFS) and overall survival (OS) were estimated from the date of diagnosis using Kaplan Meier method. Results Patient characteristics are summarized in table 1. Median number of NACT and concurrent chemotherapy cycles was 4 (2-6) and 4 (3-6) respectively. 45 patients (86.5%) received RT after NACT. Of these 45, 30 patients (66.6%) received CTRT. Median RT dose for RT alone group was 60 Gray and for CTRT patients was 50 Gray (both at 2 Gray per fraction delivered 5 days a week with 3-dimensional conformal plans). Patients <70 years vs. ≥ 70 years (68% vs. 41%; p=0.094) and male vs. female (70% vs. 33%; p=0.033) had more chances to receive CTRT. Grade 1, 2 and 3 leucopenia was noted in 5.7%, 28.8% and 5.7% patients respectively. Grade 1, 2, 3 dysphagia was noted in 4.4%, 51.1% and 15.5% patients respectively. Median follow up was 13.34 months (5.2-51.5 months). Overall complete response, partial response, progressive disease and death at the time of last follow up were 35%, 29%, 25% and 11% respectively. 1-year and estimated 2 year RFS were 92.1% and 70% respectively. Estimated 2 year OS was 89.6%. Patients receiving CTRT had better outcome as compared to those with RT alone (one year RFS: 80.2% vs. 41.3%; two year RFS: 47.1% vs. 13.8%; p=0.005). Conclusion Weekly NACT with NB-Pac and carboplatin followed by definitive CTRT with same regimen is well tolerated, feasible and associated with decent survival outcomes in patients of carcinoma esopahgus deemed unsuitable for surgery or cisplatin based CTRT. In this subset of patients, age <70 years and male sex have higher chances of receiving CTRT after NACT and delivery of CTRT (as compared to RT alone) is associated with significant increase in survival. This novel approach needs further evaluation in prospective phase II/III trials. EP-1434 Patient reported outcomes after palliative radiotherapy for metastatic pancreatic cancer X. Zhu 1 , S. Dongchen 1 , L. Fuqi 1 , J. Xiaoping 1 , C. Yangsen 1 , Q. Shuiwang 1 , C. Fei 1 , S. Yuxin 1 , F. Fang 1 , J. Zhen 1 , Z. Huojun 1 1 Changhai Hospital, Radiation Oncology, Shanghai, China Purpose or Objective Patients with metastatic pancreatic cancer may experience distressing symptoms, which require palliative treatment and supportive care promptly because any benefits associated with a short overall survival may be counterbalanced by negative impacts on quality of life (QoL) attributable to cancer-related local symptoms and complications. Therefore, local treatment modality, such as stereotactic body radiation therapy (SBRT), may be an option to ameliorate these symptoms. Hence, the aim of this study was to evaluate patient reported outcomes after palliative SBRT for metastatic pancreatic cancer. Material and Methods Patients with biopsy-proven and radiologically metastatic pancreatic cancer were included from 2012 to 2016. Data were collected prospectively from 2013 to 2016 and retrospectively collected before 2013. Brief Pain Inventory (BPI), a five-level EuroQol five-dimensional questionnaire (EQ-5D-5L) and Edmonton Symptom Assessment System (ESAS) 3 months after treatment were employed for pain measures, evaluation of QoL and symptoms. Patient-reported global changes were defines as better, the same and worse, used as the reference standard for responsiveness. Cox proportional hazards regression was used to identify factors predictive of survival. Propensity score matching (PSM) analysis was