Abstract Book

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non-squamous histology, the median PFS was 11.6 months in patients with EGFR/ALK mutations compared with 12.5 months in patients without mutation (p=0.78). The median OS was 30.7 months in patients with EGFR/ALK mutations vs 28.6 months in patients without mutations (p=0.45). Conclusion Although EGFR and ALK mutation were known to be associated with favourable outcome in metastatic non- small cell lung cancer, they were not shown to be significant prognostic factors in patients with stage III non-small cell lung cancer who received concurrent chemoradiotherapy. The risk of distant metastasis in patients with EGFR/ALK mutation was very high and the 5-year overall survival of them was poor. EP-1392 Trimodality treatment of Stage III non-small cell lung cancer in Western Australia J. Croker 1 , M. Ariyapperuma 2 , S. Sharma 3 , S. Mukhedkar 4 , W.S. Lam 2 , T. Lim 1 1 Fiona Stanley Hospital, Department of Radiation Oncology, MURDOCH, Australia 2 Fiona Stanley Hospital, Department of Medical Oncology, MURDOCH, Australia 3 Fiona Stanley Hospital, Department of Cardiothoracic Surgery, MURDOCH, Australia 4 St John of God Medical Centre, Department of Medical Oncology, MURDOCH, Australia Purpose or Objective To assess the outcomes of patients with Stage III Non- Small Cell Lung Cancer (NSCLC) undergoing trimodality therapy (neoadjuvant chemoradiotherapy followed by definitive surgery) in tertiary Western Australian cancer centres Material and Methods Patients with biopsy proven Stage III NSCLC were assessed in a lung cancer multidisciplinary clinic. Patients of good performance (ECOG 0-1) deemed fit for radical treatment but whose tumours were borderline resectable were offered treatment with neoadjuvant chemoradiation (CRT), followed by assessment of response to treatment prior to curative intent surgery. Neoadjuvant CRT consisted of cisplatin and etoposide in combination 3D conformal or intensity modulated radiotherapy, delivered to a total dose of 45-50 Gy in 25 fractions. Restaging PET and CT scans were performed 3- 4 weeks post-neoadjuvant CRT. Patients with good tumour response were offered lobectomy and mediastinal lymph node dissection, while those with progressive local disease (PD) or deemed unresectable were offered consolidative radiotherapy dose of 20-24 Gy in 10-12 fractions. Pathology specimens were examined for response to neoadjuvant treatment. Patients were followed 3 monthly or until death with examination and imaging at clinician discretion. Data was retrospectively collected for all patients treated from February 2010 to October 2017. Analysis was made of response to neoadjuvant treatment, survival, disease recurrence and pattern of recurrence. Results Thirty-one patients were planned to undergo trimodality treatment. Eighty four percent of patients were male and 14% female. The median age was 65 years (range 48-75 years). Two patients (6%) had Stage IIIB disease and the remaining 29 (94%) patients had Stage IIIA disease. All except one patient had node positive disease. Median tumour size was 40mm (range 15-84mm). Twelve (39%) of patients had squamous cell carcinoma, 17 had adenocarcinoma (55%) and 2 had mixed adenosquamous (6%) histopathology. All patients completed their CRT. Twenty-two patients (71%) underwent surgical resection. Of the nine patients who did not have surgery, four underwent consolidation

radiotherapy. Five patients had PD outside the radiation field and did not have further radiotherapy to the primary site. Of those that underwent surgery, six patients had a complete pathological response at primary site and 17 patients (77%) had a pathological complete survival was 18.1 months. For those who underwent surgery, median survival was 23 months (range 3-98 months) compared with 17 months for those who did not have surgery. Fifty percent of patients were alive at most recent follow-up. Of those, 45% in the surgical group were disease free, compared to 11% in the non-surgical group. Conclusion Trimodality therapy for highly selected patients with borderline resectable Stage IIIA NSCLC is feasible, well tolerated, and is associated with encouraging survival outcomes. EP-1393 Risk adapted schemes for lung SBRT in central or close to chest-wall tumours A. Fernández Forné 1 , A. Román Jorbacho 1 , A. Otero Romero 1 , A. Pérez Rozo 1 , I. Navarro Domenech 1 , I. García Rios 1 , R. Correa Generoso 1 , M.J. García Anaya 1 , S. Segado Guillot 1 , J. Gómez Millán 1 , J.A. Medina Carmona 1 1 HOSPITAL VIRGEN DE LA VICTORIA, RADIATION ONCOLOGY, Malaga, Spain Purpose or Objective To evaluate efficacy and toxicity of two Stereotactic Body Radiation Therapy (SBRT) schemes of a cohort of patients treated in a single institution. Material and Methods Analysis of 100 patients, stage I non-mall-cell lung cancer or lung metastasis considered medically inoperable or patients who declined surgery were treated from August 2011 to October 2015. Patients were positioned supine with both arms elevated above the head. Breathing mobility was reduced by abdominal pressure. Determination of respiratory motion was based on an additional 4-dimensional CT scans. The 4D-IGRT protocol (Symmetry) was characterized using a kilovoltage CB-CT scanner installed on an Elekta Synergy linear accelerator and on-line correction of target position errors before every fraction. The prescription dose was 18Gy×3 fractions for peripherally located lesions and the risk adapted scheme of 10 Gy×5 fractions for central lesions. Kaplan-Meier and Chi-square tests were performed for statistical analysis. Results In our institution, 106 lesions from 100 patients were treated, 41 central(C), 59 peripheral (P). Median follow- up 26 months. Median age 72 year (80 men,20 women). Tumor size ranged from 0.50 to 6 cm. Acute toxicity was absent in 73% of the patients. Most frequent acute toxicity was grade 1 asthenia (10%C,8%P) and grade 2 asthenia (5%C,2%P) , grade 1 skin toxicity (2%C, 5%P) and grade 2 skin toxicity (0%C, 2%P) There were no grade 4 or 5 acute toxicities and only one patient (central) developed grade 3 lung toxicity (pneumonitis). Grade 2 late pulmonary toxicity was observed in 2 patients (both peripheral) and grade 3 in other 2 patients (1C, 1P, all diagnosed of EPOC). 3 Asymptomatic radiation-induced rib fractures were identified in two patients (3%) with peripheral tumors (17 and 26 months) and one (2%) with central tumor (40 months). Of all patients treated, 87% achieved local control (85%C, 88%P). 2-year progression free survival and 2-year overall survival was 52 % and 70% respectively. In tumors with a SUV >10, local control was significantly lower (75% vs 92%; p: 0.03). response at the nodal sites of disease. For all patients combined, median overall