[¹⁸F]FDG PET/CT for outcome prediction in diffuse large B-cell lymphoma treated with polatuzumab vedotin-containing...

To investigate the prognostic values of 2-deoxy-2-[¹⁸F]fluoro-D-glucose positron emission tomography/computed tomography ([¹⁸F]FDG PET/CT) in patients with diffuse large B-cell lymphoma (DLBCL) treated with Polatuzumab vedotin (Pola)-containing regimens.

Thirty-nine patients who received Pola-containing regimens and underwent pre-treatment [¹⁸F]FDG PET/CT were retrospectively enrolled and followed up. Qualitative response was assessed using Lugano criteria on follow up PET. Quantitative [¹⁸F]FDG PET parameters including maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV), and total lesion glycolysis (TLG) were evaluated using two segmentation methods (SUV 4.0 and 41% SUVmax), and changes in these indices (Δvalues) between pre-Pola and first follow-up PET scans were calculated. The prognostic values of PET metabolic parameters, clinical characteristics, and laboratory indicators were evaluated using time-dependent receiver operating characteristic (ROC) curve, and Cox regression analysis. Survival functions were estimated by Kaplan-Meier analysis.

The median follow-up duration was 17.2 months (range 3.28 months - 26.2 months). During this period, 16 patients (41.0%) experienced progression. Patients with complete metabolic responses (CMR) exhibited superior outcomes than patients with partial metabolic responses (PMR). ROC and Cox analysis demonstrated that MTV and TLG based on SUV 4.0 segmentation showed superior predictive performance than those based on the 41% SUVmax method. Multivariate Cox regression analysis identified SUVmean (P = 0.016, HR = 1.27) and MTV (P = 0.002, HR = 1.01) on first follow-up PET as independent predictors of progression-free survival (PFS).

CMR patients exhibited superior outcomes than PMR patients, and SUVmean and MTV on the first follow-up PET were independent predictors of PFS, suggesting that [¹⁸F]FDG PET/CT may play an important role in predicting outcomes of DLBCL patients treated with Pola-containing regimens.