Role of PET/CT in diffuse large B-cell lymphoma (Review)

Diffuse large B-cell lymphoma (DLBCL) is the most common subtype of non-Hodgkin lymphoma, and its diagnosis and management are moving steadily toward personalization and precision. As a functional imaging modality, positron emission tomography-computed tomography (PET/CT) plays an irreplaceable role in the management of DLBCL. For diagnosis and staging, PET/CT corrects staging errors made with CT alone and improves the detection of bone marrow involvement; baseline metabolic parameters [metabolic tumor volume (MTV) and total lesion glycolysis] and measures of disease dissemination (Dmax) are independent prognostic factors, and MTV in particular refines the risk stratification provided by the International Prognostic Index. During therapy, an interim ΔSUVmax reduction of ≤66% indicates high-risk patients, while a negative interim Deauville score (1-3) and a negative end-of-treatment PET/CT both predict favorable long-term survival. Before chimeric antigen receptor T-cell therapy and autologous hematopoietic stem cell transplantation, metabolic parameters also carry predictive value for both outcome and toxicity. In addition, radiomics combined with multiparametric data improves prognostic accuracy, and novel tracers and PET/MR offer complementary advantages for distinguishing tumor from inflammation and for assessing extranodal disease. Taken together, PET/CT provides a precise evaluation platform that spans the entire course of diagnosis and treatment. The present study systematically reviews the application of PET/CT to the diagnosis, prognostic prediction, response assessment and special clinical scenarios of DLBCL.