[18F]FDG PET/CT in the Preoperative Diagnostic and Staging of Lung Cancer-A Pictorial Evaluation.

Background/Objectives: Lung cancer is one of the most prevalent malignant diseases in humans. Numerous studies have demonstrated the significance of [18F]fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) in the staging of this condition. Methods: The pictorial evaluation is based on a recent study comparing preoperative imaging with postoperative histopathological findings following thoracic surgery. It confirmed the value of PET/CT in assessing primary tumor extent and metastatic lymph node involvement; but also revealed discrepancies in primary tumor (T) and lymph nodes (N) classification in 25% and 14% of patients, respectively. Results: The aim of this pictorial review is to highlight and further analyze the causes of inaccurate staging, identify potential diagnostic pitfalls, and provide practical recommendations to help avoid misinterpretation of PET/CT findings. Additionally, the impact of the newly introduced ninth edition of the International Association for the Study of Lung Cancer (IASLC) primary tumor, lymph nodes, and metastasis (TNM) staging system for lung cancer is discussed. Conclusions: In this pictorial review, we presented various sources of error in preoperative staging observed at our institution. Awareness of these potential pitfalls may aid in improving staging accuracy and distinguishing physiological or reactive (benign) processes from pathological findings.