18F-FDG PET/CT in Childhood Cancers: Practical Clinical Applications, Pitfalls, and Case-Based Imaging Scenarios.

18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) is an important but unevenly useful tool in pediatric oncology. Its clearest role is in lymphoma, especially Hodgkin lymphoma, where metabolic imaging informs staging and response-adapted therapy. In sarcoma, neuroblastoma, CNS tumors, Langerhans cell histiocytosis, germ cell tumors, and Wilms tumor, FDG PET is best used selectively as an adjunct to anatomic imaging, disease-specific tracers, and pathology. This review summarizes practical indications, limitations, pediatric protocol issues, and case-image scenarios in which FDG PET adds clinically meaningful information.