[Diagnosis of early cancer with positron emission tomography]

PET using 18F-fluorodeoxyglucose(FDG) or 11C-L-methionine(Met) enables cancer diagnosis based on higher metabolic demand of malignant tumor. PET using FDG or Met is useful for differential diagnosis or staging of early cancer in lung mediastinum, brain, head and neck, breast, adrenal, pancreas, and others. Whole-body FDG-PET is especially useful for the detection of unexpected distant metastasis. PET can provide useful information to improve patient management in oncology.