[Clinical usefulness of FDG-PET in oncology]

The clinical diagnosis of tumors is mainly performed using conventional radiography, CT, MRI, and ultrasonography, which provide anatomic and morphologic information. On the other hand, nuclear medicine imaging, which exploits the biochemical aspects of tissue, is considered to be useful for the characterization of tumors but is still clinically underutilized. Positron emission tomography (PET) with 2-deoxy-2-[18F] fluoro-D-glucose(FDG), an in-vivo imaging method that measures glucose metabolism, has been used to detect tumors with increased glucose metabolism. Over the past 20 years, numerous reports have demonstrated the usefulness of FDG-PET in diagnosing tumors, although FDG-PET has only been performed at a small number of institutions. Since FDG-PET has been shown to be superior to other morphologic imaging modalities in diagnosing tumors, FDG-PET has now become widespread at many institutions and has also been incorporated into the clinical pathways for disease management. FDG-PET is a safe and cost-effective method with several advantages over morphologic imaging and is already covered by many insurance companies in a variety of countries. This article discusses the current application of FDG-PET in oncology, especially regarding lung cancer, malignant lymphoma, and thyroid cancer. In addition, practical approaches for the clinical use of FDG-PET are discussed.