P3.13-022 3D CNNs for Recognition of Epidermal Growth Factor Receptor Mutation Status in Patients with Lung Adenocarcinoma

S2324 Background: Non-small cell lung cancer (NSCLC) is the common type of histology among all cases of lung cancer. Studies have shown that PET/CT is more accurate than CT for the detection of nodal status due to the increased FDG uptake in very small nodes. In fact, tumor-nodemetastasis staging of the mediastinum is currently one the most common indications of PET/CT in lung cancer. The aim of this pilot retrospective review was to assess the role PET/CT as a non-invasive procedure for the visualized lymph nodes in lung cancer. Method: Twenty-nine patients [NSCLC (86%), NET (10%), SCL (4%)] underwent PET/CT imaging and were followed for a period of at least 3 years. There were 15 females (51.72%) and 14 males (48.28%) aged between 38-78 years (mean ± SD¼ 61.24±9.86) and were referred for staging (86%), restaging (10%) and response to therapy (4%). All patients underwent 18F-FDG PET/CT with a mean time of 71.2 minutes after tracer injection. Tumor and lymph node uptake were evaluated with both visual and quantitative assessment. Result: Seven patients (24%) died at 12 months despite treatment induction and by the end of two years follow-up, just a little more than half (51.72%) of the patients died. The majority of those who died were males (r¼-0.38; p¼0.041). Active lymph nodes were seen in one nodal station in 19 patients. They were also seen in two nodal stations in 12 patients and in three nodal stations in 5 patients. The common stations were as follows: Hilar (33.3%), right lower Para tracheal (22.2%) and subcarinal (19.4%). While no significant association was seen between the primary location of tumor and the occurrence of lymph nodes, patients with positive nodes on PET/CT staging tend to have a reduced survival than those without visualized lymph nodes [odd ratio¼ 2.33, 95% CI 1.60-9.02; p¼0.08]. However, when the analysis was only done for the NSCLC group, a significant reduction of survival was noted in patients who had positive lymph nodes (p<0.01). Conclusion: This small cohort confirmed the predominance of NSCLC as described in the literature. While this histological predominance could result from a referral bias, it clearly showed that the male gender was associated with a reduced survival. However, a larger cohort must be studied in a prospective analysis to confirm the significantly reduced survival among NSCLC patients with positive lymph nodes during staging, for PET/CT imaging to become a robust predictor of survival. Keywords: Lung Cancer, 18FFDG PET/CT, Lymph nodes

P3.13-022 3D CNNs for Recognition of Epidermal Growth Factor Receptor Mutation Status in Patients with Lung Adenocarcinoma J. Xiong,1 T. Jia,2 X. Li,2 L. Fu,1 Z. Xu,2 X. Cai,2 J. Zhang,2 X. Fu,2 J. Zhao1 1School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai/CN, 2Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai/CN Background: In this study, we built three 3-dimensional convolutional neural networks (CNN) for recognition of epidermal growth factor receptor (EGFR) mutation status in Chinese patients with lung adenocarcinomas based on non-enhanced computed tomography (CT) images. Method: From October 2008 to December 2015, 405 patients with lung adenocarcinomas were included in this retrospective study. Their pathological phenotypes and EGFR mutation status were gained from surgical resections. Their CT images used in this study were taken before any invasive operation. Tumors with a diameter smaller than 8 mm or have ground glass component were excluded. Region of interest that includes tumors were segmented manually by clinicians and preprocessed to have uniform size and grey-level range before applied to CNNs. The three CNNs have 4 convolutional and 1 full connection layers between input and output layers. The inputs size of three CNNs are 212121, 313131, and 414141, respectively. The outputs of the CNN are the probabilities of mutant and wild status. The CNN classifier’s performance was then validated using an independent set

Journal of Thoracic Oncology

Vol. 12 No. 11S2

and evaluated using area under curve (AUC) values of the receiver operating characteristic. Result: 405 patients diagnosed with lung adenocarcinoma staging I to IV were included in this study (195 male, 210 female; 61 smokers, 344 non-smokers). The patients received surgery based treatment and their tumor stage was based on pathological reports. EGFR mutations (mainly 19del and 21L858R) were found in 198/320(61.9%) and 56/85(65.9%) patients in training and validation sets, respectively. The CNN showed an AUC of 0.767 (95% confidence interval: 0.668-0.866, p<0.001) in the validation set. The sensitivity and specificity are 62.5% and 89.7% at best diagnostic decision point. These results were highest among published results of only using images to recognize EGFR. Conclusion: The CNN showed potential ability to recognize EGFR mutation status in patients with lung adenocarcinomas and could be improved in the future works to help make clinical decisions. Keywords: EGFR, CT, CNN

P3.13-023 Clinicopathological Impacts of the Small Ground-Glass Opacity Surrounding the Solid Type Lung Adenocarcinoma K. Hamanaka Thoracic Surgery, Shinshu University, Matsumoto/JP Background: There were many reports and evidences for part-solid nodules with ground-glass opacity (GGO) in small-sized lung adenocarcinoma, and the component of GGO has been known to be a factor of malignant potency of the tumor, although the relation between radiological appearance of >2cm or >3cm lung adenocarcinoma and clinicopathological features were less noted. Method: A total of 136 patients with >2cm lung adenocarcinoma with >0.75 of consolidation to tumor ratio (C/T ratio) who underwent lung resection at Shinshu University Hospital from February 2003 through December 2010 were assessed. Among these patients, 83 with pure solid appearance in preoperative thin section computed tomography (C/T ratio ¼ 1.0) were placed into Solid group, and 53 with small GGO surrounding the solid type tumor (0.75 < C/T ratio < 1.0) were placed into Subsolid group in this study. We retrospectively analyzed the clinicopathological features and prognosis after surgery in each groups. Result: The maximum standardized uptake value (SUVmax) of the tumor in preoperative radiological assessment using [18F] fluoro-2-deoxyglucose positron emission tomography (FDG-PET) were significantly higher (p¼0.0048) in Solid group (7.65±4.36) than Subsolid group (4.82±3.32). The presence rate of vascular invasion (Ly or V) was 54.2% in solid group and 39.6% in Subsolid group. The numbers of node positive patients were 19 with N1, 27 with N2 in solid group, and 8 with N1, 7 with N2 in Subsolid group respectively, and the rate was significantly higher in Solid group (p¼0.0019). The prognostic analysis of pathological stage 1 patients (29 patients in Solid group and 37 in Subsolid group) revealed that the overall survival and recurrence-free survival was significantly poorer (p¼0.044 and p¼0.019 respectively) in Solid group than in Subsolid group. Conclusion: The small GGO surrounding the solid type adenocarcinoma as C/T ratio >0.75 indicated lower malignant potency and better prognosis than pure solid tumor without GGO component. Even small GGO component was a clinical factor of favorable oncologic outcomes, it may contribute to regarding the decision making for surgical strategy in preoperative assessment. Keywords: ground-glass opacity, lung adenocarcinoma, solid type

P3.13-024 Is Alveolar Spread May Be Predictive with PET CT Scanning? F. Biricik,1 N. Mandel,1 S. Tanju,1 O. Falay,2 P. Bulutay,1 H. Zeren,2 S. Erus,1 S¸. Dilege1 1Medical Oncology, Koc University Medicine Faculty, Istanbul/TR, 2Koc University Medicine Faculty, Istanbul/TR