Positron emission tomography in diagnosis and therapy monitoring of patients with lymphoma

In contrast to conventional imaging modalities, positron emission tomography using fluorodeoxyglucose detects malignant tumors by their increased glucose metabolism. In patients with Hodgkin's disease or non-Hodgkin's lymphoma, FDG-PET imaging has been shown to sensitively identify enhanced tracer uptake in involved lymph nodes and infiltrated tissue. This brief review will summarize the currently available information on staging of lymphoma patients in comparison with other imaging modalities. In addition, FDG PET imaging has been suggested for differentiation of viable residual or recurrent tumor and scar after tumor therapy. One of the most promising applications of PET in the future will be the metabolic evaluation of early response to tumor therapy. It is hypothesized that changes in tumor metabolism occur before significant decrease of tumor mass. Early assessment of chemotherapy might help to avoid the toxicity of an ineffective therapy. In summary, the results concerning various clinical applications of PET imaging are encouraging for further prospective trials to document the advantage of PET in diagnosis and therapy of lymphoma patients as compared to conventional strategies.