PET-guided early identification of CAR-T candidates in diffuse large b-cell lymphoma: a multidisciplinary expert consensus

Purpose This expert consensus aims to define how 2-deoxy-2-[18 F]-fluoro-D-glucose ([¹⁸F]FDG) positron emission tomography/computed tomography (PET/CT) can be systematically integrated into clinical pathways for early identification of diffuse large B-cell lymphoma (DLBCL) patients who may benefit from chimeric antigen receptor T-cell (CAR-T) therapy. The main research question is how PET-derived parameters and timing can optimize risk stratification and guide timely referral for advanced therapies. Methods A multidisciplinary panel of nuclear medicine physicians and hematologists conducted a structured consensus process based on current literature, international guidelines, and expert discussion. Key clinical scenarios and statements were evaluated across multiple meetings to assess the role of PET/CT at baseline, interim, and end-of-treatment stages. Results PET/CT provides critical prognostic information throughout the disease course. Baseline quantitative metrics (e.g., metabolic tumor volume) improve risk stratification beyond conventional indices. Interim PET, particularly using Deauville score and the change in the maximum standardized uptake value, enables early identification of high-risk or refractory patients. End-of-treatment PET remains essential for response assessment and therapeutic decision-making. Standardization of acquisition, reporting, and interpretation is necessary to enhance reproducibility and clinical integration. Conclusion PET/CT should be considered a central biomarker in DLBCL management, enabling earlier identification of high-risk patients and facilitating timely CAR-T referral. Harmonized, multidisciplinary implementation is essential to optimize outcomes and improve access to potentially curative therapies.