Imaging predictors of response and outcomes after CAR T-cell therapy in lymphoma: from clinical trials to real-world practice.

Chimeric antigen receptor (CAR) T-cell therapy has transformed the treatment of relapsed or refractory large B-cell lymphoma, with overall response rates in real-world practice broadly comparable to those in pivotal clinical trials. However, progression-free survival is consistently shorter in real-world cohorts, suggesting that baseline disease characteristics may influence long-term outcomes more than initial treatment sensitivity. This review examines the role of baseline Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) features as predictors of response and survival after CAR T-cell therapy in lymphoma. We synthesize the evidence on established imaging predictors, including total metabolic tumor volume, extranodal disease distribution and site-specific organ involvement, and bulky disease, and discuss emerging biomarkers such as body composition metrics. Despite a growing body of evidence linking these imaging features to outcomes, clinical adoption has been limited by heterogeneous measurement methodologies, inconsistent definitions, and a lack of prospective validation. We propose practical considerations for structured baseline imaging assessment, including a reporting checklist designed to ensure systematic documentation of the imaging features with demonstrated or emerging prognostic relevance. By moving beyond descriptive staging toward structured, predictive baseline imaging evaluation, radiologists and lymphoma clinicians may improve pretreatment risk stratification and facilitate more informed therapeutic decision-making in the expanding landscape of CAR T-cell therapy.