[Clinical application of FDG-PET for cancer diagnosis]

Positron emission tomography using 18F-FDG is accepted in clinical medicine as an imaging tool for the diagnosis and assessment of a large variety of cancers. Medicare reimbursement for these studies has been accepted in Japan since 2002. The number of requests for FDG-PET examinations has been increasing in institutions where a PET device is installed. PET is considered to be especially effective in re-staging and detecting recurrence of disease. In order to evaluate PET images properly, it is important to be familiar with the various physiological uptake patterns of FDG, and also to be alert to the possibility of false-positive and false-negative findings. Quantitative values obtained in PET images are widely used for the differentiation of benign and malignant tumors and for monitoring treatment; however, it should be kept in mind that these values may be influenced by many factors. To complement the poorer spatial resolution of PET, a combined PET/CT scanner has been created and its clinical application has begun. It is expected that this imaging tool will be useful and have a great effect on patient management.