FDG-PET for the early treatment monitoring, for final response and follow-up evaluation in lymphoma

Optimal lymphoma management requires reliable assessment of response, both during and after therapy. Positron emission tomography with computerized tomography (PET/CT) combines functional and anatomical imaging and provides the most sensitive and accurate method for lymphoma imaging. New guidelines for lymphoma imaging and recently revised criteria for lymphoma staging and response assessment recommend PET/CT for both staging, treatment monitoring and response evaluation in all 2-[18F]fluor-2-deoxyglucose (FDG)-avid lymphomas, while CT remains the method of choice for non-FDG-avid histologies. Since interim PET imaging has high prognostic value in lymphoma, a number of trials investigate PET-based, response-adapted lymphoma therapy. PET response is the main determinant of final treatment evaluation according to the new response criteria but PET/CT has little or no role in routine surveillance imaging, which has questionable value in general. This review presents from a clinical point of view the evidence for the use of PET/CT in malignant lymphoma during and after therapy. The reader is given an overview of the current PET-based interventional Hodgkin and non-Hodgkin lymphoma trials and an insight into possible future developments in the field, including new PET tracers.