[Evaluation of therapies in oncology by positron emission tomography: towards therapeutical personalization]

Recently introduced into clinical practice, positron emission tomography (PET) with 18F-fluorodeoxyglucose (FDG) has proven its utility for diagnosis and staging of malignant diseases on account of its ability for tissue identification. Its utilization is now moving toward the evaluation of anti-tumoral effects of anticancer therapy, because of the correlation between the uptake of a metabolic tracer and malignant cells viability. Metabolic effects of chemotherapy are first observed in cells and this is the explanation for the precocity of scintigraphic visualisation of therapeutic activity. However, monitoring response with FDG-PET requires rigorous method and needs to take into account the limitations of SUV. Moreover, in order to go beyond the limitations of FDG, new tracers are developed and their main indication could be precisely the monitoring of therapy response. The properties of positron emitters allow us to foresee the labelling of the therapeutic molecules themselves in order to try them in vivo before their utilization for a given patient. These prospects are the ground for real treatment personalization in oncology. They open up a wide field of clinical research but the means for image acquisition and radioactive tracers production will be mandatory for anyone who wants to contribute to this work. Due to the current performances of the imaging systems, the critical point will be availability of equipment allowing the designing and synthesis of the radiopharmaceuticals of the future.