Lung cancer is one of the most common and deadliest forms of cancer worldwide. Over the past two decades, significant changes have occurred in the classification of lung cancer, involving multidisciplinary input and emphasizing the growing contribution of immunohistochemistry and molecular techniques to morphology in the classification scheme. This comprehensive review will cover the background and epidemiology of lung cancer as well as advancements in its staging and management, including discussions of new surgical techniques, targeted therapies, and immunotherapy. The review will detail the role of 18F-FDG-PET-CT in lung cancer, highlighting its importance in staging, treatment response assessment, and recurrence detection. While immunotherapy has transformed lung cancer management and improved patient outcomes, it presents major challenges and opportunities for optimal assessment of treatment response in lung cancer patients using 18F-FDG-PET-CT. This review will also explore future directions, including a discussion of promising new targeted diagnostic radiopharmaceuticals for PET/CT imaging. Additionally, there will be a brief discussion of evolving and exciting treatment options for lung cancer using targeted therapeutic radiopharmaceuticals. Several case-based illustrations are included to exemplify the role of 18F-FDG-PET-CT in various clinical scenarios.