ABSTRACT
Lung cancers are the most common tumors with low survival despite significant advances in both diagnostic and therapeutic approaches. F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) is the most accurate method for detecting primary, nodal and metastatic areas for lung cancer staging. Depending on the stage of the disease, treatment options such as surgery, chemotherapy, radiotherapy, targeted therapies, immunotherapy and radiofrequency ablation are available. Post-treatment imaging is important for determining the efficacy of treatment, correct use of treatment options, early recognition of potentially salvageable recurrence and predicting prognosis. Anatomical imaging such as Thorax CT has limited accuracy in distinguishing viable tumor from post-treatment changes (cavitation, inflammation, consolidation, fibrosis). It is known that FDG PET/CT can change patient management by detecting residual/relapsing disease earlier and more accurately. However, the guidelines do not recommend the use of FDG PET/CT in the routine follow-up of lung cancers. It is preferred to perform when CT is non-diagnostic or disease recurrence is suspected. In this article, the role of FDG PET/CT in evaluating treatment response in lung cancers is discussed.