[Positron-emission tomography: role of 18F-fluorodeoxyglucose (18FDG) imaging in oncology]

There is a renewed interest in positron emission tomography (PET) using 18F-fluorodeoxyglucose (18FDG) since the development of large field of view cameras and the capability of regional distribution of 18FDG. This method may help solve three types of problems in clinical oncology: tumor diagnosis and extension assessment, prediction of treatment response and follow-up (diagnosis of recurrences and complications). The aim of this paper is to review the literature in this field. This technique is mostly used for brain, lung, rectal and breast tumors as well as for sarcomas. It is possible to diagnose an anaplastic transformation of a low grade glioma since 18FDG uptake correlates with the histological grade. 18FDG plays another important role in the evaluation of the brain tumor response to treatment and of the secondary effects or sequelae of this treatment. This technique is also useful in breast carcinomas: diagnosis in the case of a dense breast, detection of lymph nodes or other metastases which could modify the strategy. One of the most established roles of 18FDG PET is the diagnosis of rectal tumor recurrences. Furthermore, future results will probably confirm its usefulness in lung carcinoma, for the diagnosis and for treatment evaluation. Lastly, it plays an important role in soft tissue sarcomas at all stages of diagnosis and treatment. The results of the literature still have to be completed. However, if the capability of predicting tumor response to treatment is confirmed, this method will play an important role in patient management and will modify treatment strategies.