P1.03-082 18F-FDG PET/CT Value Staging NSCLC Extension to the Lymph Nodes, Single Center Experience

Abstract

Non small-cell lung carcinoma (NSCLC) is the most common type of lung cancer. Correct clinical and pathological lymph node (N) staging is critical for choosing the best treatment. Positron emission tomography/computed tomography (PET/CT), being non-invasive pre-operative diagnostic method is becoming increasingly popular. Therefore, we aimed to evaluate the accuracy same as false-negative and false-positive results of PET/CT when compared to histopathological diagnoses at Vilnius university hospital Santariskiu klinikos (VUL SK). A retrospective analysis included 15 NSCLC patients who underwent preoperative PET/CT scan and postoperative histopathological analysis for the N staging at VUL SK. PET/CT N stage was compared with gold standard histopathological N stage to assess the sensitivity, specificity, positive and negative predictive values for N staging of NSCLC. There were 15 patients (11 men (73,3%), 4 women (26,7%)) with average age of 66,1±10,2 years included into the study. Ten patients (66,7%) were staged N>0 by PET/CT, histopathological analysis confirmed 4 diagnoses (40%), other 6 diagnoses (60%) were considered false positive. Five patients (33,3%) were staged N0 by PET/CT, histopathological analysis confirmed 3 diagnoses (60%), other 2 diagnoses (40%) were false negative. Estimated specificity of PET/CT for N staging of NSCLC was 25%; sensitivity – 57,14%, positive predictive value – 40%, negative predictive value – 60%. Despite many advantages, PET/CT still has limited value staging NSCLC. Significant number of inaccuracies in N staging may occur evaluating inflammatory lymph nodes. The necessity of histologic confirmation of N stage in stage I-IIIa NSCLC is crucial as these patients may have surgical treatment combination and better outcomes.