Pre-infusion 18 F-FDG PET/CT for Prognostic and Toxicity Prediction in B-cell Non-Hodgkin Lymphoma Patients Undergoing Chimeric Antigen Receptor T-cell Therapy.

Objective: The aim of this study was to evaluate the value of 18 F-FDG PET/CT in predicting outcomes and toxicity for patients with B-cell non-Hodgkin lymphoma (B-NHL) who underwent chimeric antigen receptor T (CAR-T) cell therapy.

Methods: This retrospective study included B-NHL patients who underwent CAR-T therapy and had pre-infusion 18 F-FDG PET/CT images. We recorded SUVmax, metabolic tumor volume (MTV), total lesion glycolysis (TLG), and various clinical and laboratory indexes. The primary endpoints were progression-free survival (PFS) and overall survival (OS). PFS and OS were estimated using the Kaplan-Meier method. In addition, we reported the correlation between PET/CT parameters and the objective response (OR), as well as cytokine release syndrome (CRS).

Results: A total of 133 patients were enrolled in this study. The median follow-up duration was 20.8 months. SUVmax (with a cutoff value of 15.65) emerged as an independent metabolic parameter associated with PFS, OS, and OR. Patients with SUVmax ≥15.65 had a median PFS of 9.13 months (95% CI: 0.11-18.16), while the PFS for those with SUVmax<15.65 was not reached ( P =0.006). Furthermore, patients with SUVmax ≥15.65 exhibited significantly shorter average OS compared with those with SUVmax<15.65 (26.89 mo vs. 45.14 mo, P =0.010). In addition, the odds ratio for achieving an OR in patients with SUVmax ≥15.65 was found to be lower at 0.173 (95% CI: 0.056-0.539). Other factors associated with PFS included ECOG-PS, B symptoms, bulky mass, and extranodal sites, whereas IPI and LDH were associated with OS. Furthermore, SUVmax and Deauville scores showed a weak positive correlation with the occurrence of CRS.

Conclusions: The pretreatment PET/CT parameter SUVmax appears to be a promising predictive factor for efficacy and prognosis, as well as being associated with the occurrence of CRS. Consequently, we can conclude that this metabolic parameter from pretreatment PET/CT scans may serve as a valuable tool in guiding patient selection for CAR-T therapy and predicting potential side effects.