ESTRO 37 Abstract book

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ESTRO 37

EP-1412 The pattern of postoperative recurrence in patients of stage pN0 ESCC after two-field esophagectomy Y.X. Wang 1 , S.L. Dong 1 , M. He 2 , J. Li 1 , J. Yang 1 , Z. Qi 2 , X.Y. Qiao 1 1 The Fourth Hospital of Hebei Medical University, Department of Radiation Oncology, Shijiazhuang, China 2 The Fourth Hospital of Hebei Medical University, Department of thoracic surgery, Shijiazhuang, China Purpose or Objective The recurrence rates was high in esophageal squamous cell carcinoma (ESCC) patients after surgery. This study was arm to retrospectively analysized of factors on postoperative recurrence in patients of stage pT1-3N0M0 thoracic ESCC after radical resection. Material and Methods From Jan 2008 to Dec 2012, there were 488 thoracic ESCC patients which had treated with two-field R0 resection, stage pT1-3N0M0, without neoadjuvant or adjuvant radiotherapy and/or chemotherapy, survival time 3 months or more were erolled in this study. Factors on postoperative recurrence for those patients was anlysized with SPSS22.0 software. o-fareast-font- family: 宋体 ;esophageal squamous cell carcinoma (ESCC) patients after surgery. This study was arm to retrospectively analysized of factors on postoperative recurrence in patients of stage pT1-3N0M0 thoracic ESCC after radical resection. Results The end date of follow-up was Dec 2016. The total recurrence rate for all patients was 36.9% (180/488); the rates of locoregional recurrence (LR), distant metastasis (DM) and LR add DM were 21.5%(105/488), 6.8% (33/488) and 8.6% (42/488), respectively. Logistic unvariate and multivariate analysis showed that, tumor site and stage pT were independent factors for total recurrence, LR and DM in pT1-3N0M0 ESCC patients after R0 resection. The rates of total recurrence, LR and DM were 54.1%, 44.3%, 24.6% in upper-thoracic –segment, 37.2%, 30.5%, 14.8% in middle-thoracic-segment, 22.9%, 18.1%, 10.8% in low- thoracic-segment ESCC. The rates of total recurrence, LR and DM were 15.7%, 11.8%, 4.9% for pT1, 41.3% , 34.9%, 9.4% for pT2, and 43.1%, 35.0%, 14.4% for pT3 patients, respectively. Conclusion umor site and stage pT were most important factors for postoperative recurrence in pT1-3N0M0 ESCC patients; and its results probably be use to direct target of postoperative adjuvant radiotherapy in those patients. EP-1413 clinical efficacy between single and dual- agent chemoradiotherapy in esophageal carcinoma J. Li 1 , D. Xiaobo 2 1 Mian Yang Central Hospital, Department of Oncology, Mian Yang city- Fucheng Distri, China 2 Mian Yang Central Hospital, Department of Oncology, No. 12- lane- alarm street- Fucheng District- Sichuan- Mianyang, China Purpose or Objective In China, single-agent concurrent chemoradiotherapy is commonly used to treat patients with unresectable esophageal squamous cell carcinoma, those who are older, or those who have reduced food intake. However, it remains unknown whether single-agent and dual-agent concurrent chemoradiotherapy are equally clinically effective. The main purpose of this retrospective study was to compare the clinical efficacies of single-agent and dual-agent concurrent chemoradiotherapy in patients with unresectable esophageal squamous cell carcinoma. Material and Methods This study enrolled 133 patients who received definitive concurrent chemoradiotherapy for locally advanced unresectable esophageal squamous carcinoma at 10

hospitals between 2010 and 2015. Patients who were treated with definitive concurrent chemoradiotherapy with or without adjuvant chemotherapy were included in the study. Patients were categorized into different treatment arms based on treatment with single-agent or double-agent chemoradiation. Results In this study, 81 (60.9%) and 52 patients (39.1%) received single-agent and dual-agent combination chemoradio- therapy, respectively. The 5-year progression-free survival (PFS) rate and overall survival (OS) rate of dual- agent therapy was higher than that of single-agent therapy (59.6% and 43%, 76.4% and 61.2%, respectively), but there were no significant differences (P = 0.260 and 0.387, respectively). Furthermore, patients treated with adjuvant chemotherapy after concurrent chemoradio- therapy exhibited significant improvements in both OS and PFS (P = 0.04 and 0.042, respectively). Multivariate analysis showed that sex, age, radiotherapy dose, and adjuvant chemotherapy had no significant effects on OS or PFS. Only disease stage was associated with OS and PFS in the multivariable analysis (P = 0.007 and 0.006, respectively). Conclusion We conclude that the 5-year PFS and OS rates of dual- agent therapy were higher than those of single-agent concurrent chemoradiotherapy for patients with unresectable esophageal squamous cell carcinoma; however, there were no significant differences in univariate analysis and multivariable analysis. The better PFS and OS might be attributable to the younger age of patients in the double-agent group. Therefore, we hypothesize that double-agent therapy is not better than single-agent therapy. In the future, we aim to confirm our hypothesis through a prospective randomized study. EP-1414 Stereotactic body radiotherapy with image- guided delivery for liver metastasis F. Ricchetti 1 , S. Fersino 1 , R. Mazzola 1 , A. Fiorentino 1 , N. Giaj Levra 1 , D. Aiello 1 , F. Gregucci 1 , U. Tebano 1 , G. Sicignano 1 , S. Naccarato 1 , R. Ruggieri 1 , F. Alongi 1 1 Ospedale Sacro Cuore-Don Calabria, Radiation Oncology, Negrar, Italy Purpose or Objective Stereotactic body radiation therapy (SBRT) is an emerging treatment option for liver metastasis (LM) unsuitable for ablation or surgery. An accurate treatment planning with risk-adapted dose prescription and the identification of specific constraints for organs at risk (OARs), daily Cone Beam CT (CBCT) as image-guidance, could allow an effective and safe treatment delivery. The diagnostic accuracy of 18 F-FDG PET-CT as imaging pre-SBRT and post-SBRT is a very useful tool to evaluate the response to treatment. Here, feasibility and efficacy of SBRT in LM treated in our Cancer Care Center are reported. Material and Methods Between October 2014 and February 2017, 41 LM on 22 patients underwent SBRT. The clinical target volume (CTV) was identified on planning contrast-enhanced CT scan and PET-CT. An additional margin of 3-5 mm was added for the planning target volume (PTV). The dose- volume constraints for duodenum and stomach were D 1cc <36Gy and D 3cc <36Gy, respectively. Volume of healthy liver receiving 15 Gy was kept lower than 700cm 3 , and in order to reduce interfraction liver deformation a thermoplastic mask with abdominal compression was used. In order to achieve OARs dose-constraints a risk- adapted dose prescription strategy was adopted, choosing between schedules with biologically effective dose (BED) <70Gy or >70Gy, according to ICRU83. SBRT was delivered with volumetric modulated arc technique (VMAT) using RapidArc and flattening filter-free (FFF) mode. Daily CBCT was performed. The patients were evaluated at the