FDG-PET/CT is a diagnostic procedure that, since 2010, has been utilized for all malignant tumors, including gynecological cancers, for staging and diagnosing metastasis and recurrence. However, its application is inconsistent across healthcare institutions due to differing perceptions of its usefulness, limited availability, high expenses, and its perceived role as supplementary to morphological imaging techniques like CT and MRI. Notably, an FDG-PET/CT primarily generates images reflecting glucose metabolism, with a strong accumulation not always indicating malignancy. While the standardized uptake value (SUV), a measure of FDG accumulation, is often employed, it is not a definitive tool to determine the severity of the disease. This chapter delves further into the significance and application of FDG-PET/CT.