Abstract book - ESTRO meets Asia

S89 ESTRO meets Asia 2018

The gastric fundus was retrospectively contoured on the pre-treatment planning CT. Dosimetric data was collected from ARIA charts, dose parameters were calculated. Surgical data was collected from patients' files at Surgery department. We collected data regarding mean and minimal dose to fundus, V25, V30, and V35. Statistical analyses were conducted using t-test and ANOVA. Results A total of 14 pts (20%) where diagnosed with an anastomotic leak. Dose to fundus was affected by location of the primary lesion and was higher in lower 3 rd -GEJ lesions, but no significant difference in pts with or without leak was found. Mean dose to fundus was 31Gy in pts without versus 35 Gy with leak, p=0.4. Mean minimal dose to fundus was 11 Gy versus 13Gy, p=0.5. We did not find a significant difference between mean V25, V30, and V35 dose in 2 pts groups. Difference in treatment planning (3D, IMRT, VMAT) was not predictive for leakage. Radiation dosimetry did not affect leak risk in any of the parameters tested. Conclusion Neoadjuvant radiation dose to the gastric fundus doesn’t have a significant influence on the risk of postoperative anastomotic leak in pts with esophageal cancer treated with nCRT. We were not able to replicate existing literature regarding the effect of doses to fundus on anastomotic leak. We feel this issue needs further review. PO-217 Prognostic factors for patients with locally advanced esophageal cancer after subtotal esophagectomy Y.C. Hu 1 From January 2000 to December 2013, 112 patients with ESCC after subtotal esophagectomy and a pathologic diagnosis of T3/T4 or lymph node metastases were enrolled. Of these patients, 60 underwent postoperative radiotherapy (PORT). The radiation dose to the esophageal tumor bed and regional lymphatics was 45–54 Gy/25–30 fractions. Moreover, 30 patients received concurrent chemotherapy with a regimen of cisplatin and 5- fluorouracil. Factors including age of 60 years or more, sex, tumor differentiation, tumor length > 5 cm, pathologic T status, pathologic nodal status, and adjuvant treatment of PORT with or without concurrent chemotherapy were analyzed to determine prognostic factors for overall survival (OS) and disease-free survival (DFS). Results The median follow-up duration was 26.5 months. In total, 62 (55.4%) cases of death, and 66 (58.9%) cases of locoregional recurrence or metastasis were observed. The 3-year OS and 3-year DFS rates were 50.0% and 38.6%, respectively. Positive lymph nodes were associated with a low 3-year OS rate (40.0% vs. 69.1%, P < 0.05) and a low 3-year DFS rate (27.0% vs. 62.4%, P < 0.05). Multivariate analyses revealed that positive lymph nodes was the only negative prognostic factor for OS and DFS (all P < 0.05). Adjuvant treatment of PORT with or without concurrent chemotherapy had no statistical significance in terms of improving OS or DFS. Conclusion Positive lymph nodes was the most critical prognostic factor in the pathologic diagnosis of T3/T4 or lymph node 1 Kaohsiung Veterans General Hospital, Radiation Oncology, Kaohsiung, Taiwan Purpose or Objective This study identified prognostic factors for survival of patients with locally advanced esophageal squamous cell carcinoma (ESCC) after subtotal esophagectomy. Material and Methods

metastases in patients with ESCC after subtotal esophagectomy. More than half of these patients experience treatment failure with recurrence or metastasis. PO-218 Prediction of overall survival after re-irradiation with SBRT for pancreatic cancer with a new model X. Zhu 1 , Y. Cao 1 , S. Qing 1 , F. Cao 1 , Y. Shen 1 , L. Gu 1 , F. Fang 1 , Z. Jia 1 , X. Ju 1 , H. Zhang 1 1 Changhai Hospital, Radiation Oncology, Shanghai, China Purpose or Objective Despite advances of management of pancreatic cancer, disease recurrence is still the predominant cause of death. A significant number of patients may develop local recurrence within the primary regions. However, these patients may not be candidates for surgery or chemotherapy due to its poor response rates and toxicities. Furthermore, conventional radiotherapy may not be appropriate in the setting of re-irradiation of pancreatic cancer owing to its inclination to exceed dose constraints of organs at risk resulting in severe adverse effects, while stereotactic body radiation therapy (SBRT) has been taken as the option for re-irradiation of pancreatic cancer. Therefore, the aim of the study was to develop a clinical point score to guide the decision for re- irradiation with SBRT in patients with pancreatic cancer. Material and Methods Despite advances of management of pancreatic cancer, disease recurrence is still the predominant cause of death. A significant number of patients may develop local recurrence within the primary regions. However, these patients may not be candidates for surgery or chemotherapy due to its poor response rates and toxicities. Furthermore, conventional radiotherapy may not be appropriate in the setting of re-irradiation of pancreatic cancer owing to its inclination to exceed dose constraints of organs at risk resulting in severe adverse effects, while stereotactic body radiation therapy (SBRT) has been taken as the option for re-irradiation of pancreatic cancer. Therefore, the aim of the study was to develop a clinical point score to guide the decision for re- irradiation with SBRT in patients with pancreatic cancer. Results In the training cohort, the median BED 10 of the first and second SBRT was 59.5Gy (48-85.5Gy) and 50.2Gy (43.7- 66.9Gy) in 5-8 fractions, while in the validation cohort, the median BED 10 of the first and second SBRT was 59.5Gy (52.5-66.9Gy) and 47.7Gy (40.6-54.8Gy) in 5-8 fractions. The interval between the first and second SBRT of the training cohort and validation cohort was 10.5 months (6.1-24.3 months) and 12.8 months (6.5-29.1 months), respectively. Multivariable analysis showed that tumor stage (P=0.005), BED 10 (P=0.006) and CA19-9 response (P=0.04) were significantly predictive of overall survival, which formed SCAD score (named after the initials of factors). Patients with the score <4 points had a superior OS compared with those with the score ≥4 points in the validation cohort (median OS has not been reached vs. 15.9 months, P=0.032). Conclusion The SCAD score may have the potential to identify individuals benefiting from re-SBRT and be a step towards more personalized medicine. PO-219 Clinical outcome and failure patterns after D2 resection and adjuvant chemoradiation in ca stomach R. Khurana 1 , S. Mitra 2 , A. Dewan 2 , I. Kaur 2 , S. Dutta 2 , V. Muthagi 2 , H. Khurana 3 1 Rajiv gandhi cancer institute and research centre, Radiation Oncology, Delhi, India