Early 18F-labeled fluoro-2-deoxy-D-glucose positron emission tomography scanning in the lymphomas: Changing the paradigms of treatments?
Lymphoma, Large B-Cell, Diffuse
The identification of refractory or nonresponding tumors at an early period during therapy may lead to abbreviation of the current therapy regimen or timely institution of an alternative therapy protocol. Nevertheless, evaluation of treatment response is consequential clinically if the tumor potentially is curable and if effective treatment alternatives exist, so that change in treatment ultimately may increase the probability of response and survival. Hodgkin disease (HD) and diffuse large cell lymphoma (LCL) fit in this model well. However, a subset of patients is either refractory to first-line treatment or develops recurrent disease after an initial remission. Improvements in the treatment of these diseases rely not only on new therapy modalities and accurate assessment of disease extent but also on the assessment of disease extent and on timely and accurate therapy response to enable a more effective management plan. Although the International Prognostic Score for HD and International Prognostic Index for LCL have proved valuable for the stratification of patients in clinical trials, there is variability in outcome within the individual risk groups. Recently, positron emission tomography using (18)F-labeled fluoro-2-deoxy-D-glucose (FDG-PET) imaging has been suggested as a sensitive and relatively more specific means to reflect tumor biologic changes after therapy. With increasingly compelling evidence, early FDG-PET provides a reliable means to assess tumor response accurately that may lead to better management with an effective therapeutic approach.