Increased FDG metabolism is a way of describing it in PET-CT, which could potentially indicate a malignant tumor, i.e., cancer, but is not completely definitive. Other hypermetabolic conditions, such as inflammatory infections, inflammatory pseudotumors, and tuberculosis, may also cause increased metabolism. The diagnosis of cancer must rely on pathological examination, although the imaging examination may find occupying lesions, but can not completely determine the nature of the PET-CT belongs to the functional metabolic imaging and CT imaging combined into a new test, for the diagnosis of malignant tumors with unknown primary foci of value is relatively high, and in some cases, can also be made to make a clinical diagnosis of cancer. However, elevated metabolism alone does not determine cancer, but should be combined with imaging, and it is best to do pathologic examination. If the diagnosis of cancer is confirmed, early detection and treatment are needed, with comprehensive treatment such as surgery, radiotherapy and chemotherapy.