What PET is changing in follow-up of Hodgkin's disease and non Hodgkin's lymphoma?

Positron emission tomography (PET) with 18-Fluoro-Deoxyglucose is a new imaging tool used to improve the initial extend and the follow-up of Hodgkin's disease and non Hodgkin's lymphoma. This functional imaging, in complement with morphological imaging, helps the clinicians to detect infra radiological disease and to fit therapy. Discordant results with different PET types were described in literature. Now, better results are obtained according to procedure guidelines from clinical indications to staff interpretation. Recently, PET/CT combines morphological and functional imaging to obtain less false negative and false positive findings. PET is useful in aggressive high grade lymphoma and in Hodgkin's disease from the initial staging to the final outcome: (a) PET detects more nodal and extra nodal lesions (b) PET is predictive of early and final response to therapy. PET can track early refractory disease -before grafting or at the end of proceedings- and allows to influence on patient management and improve survival of patients. TEP must be used and evaluated in larger multi-centre prospective studies with economics evaluation. (author)