Résumé
Total metabolic tumor volume (TMTV) at baseline becomes a key biomarker in several lymphoma subtypes. Variability in segmentation methods such as 41%SUVmax and SUVmax > 4 has limited its clinical application. Additionally, immune-checkpoint-inhibitors introduced challenges in response assessment due to pseudoprogression, complicating the use of traditional metrics. This study investigates the prognostic impact of baseline- and residual-TMTV and introduces a novel personalized-liver-based-threshold (pTMTV
) to enhance precision in patient stratification.
We analyzed 91 patients with relapsed/refractory diffuse-large-B-cell lymphoma and follicular lymphoma from the GATA trial, comparing patient's outcome according to three segmentation methods: TMTV
, TMTV
, and pTMTV
. pTMTV
used a threshold of 200%SUVmean
aligning with 125%SUVmax
to enhance standardization and reduce variability.
Baseline-TMTV significantly influenced prognosis with higher TMTV correlating with shorter PFS and OS (p < 0.0001 for all methods). Residual-TMTV, particularly with pTMTV
and TMTV
, stratified no-CMR patients with the lowest predictive errors and better predictive accuracy compared to TMTV
Multivariate analyses confirmed residual-pTMTV
as superior for prognostic performance for PFS (HR:5.10; C-index:0.724) and OS (HR:4.00; C-index:0.853) compared to TMTV
and Deauville Score (DS). The DS alone did not fully capture the heterogeneity of outcomes of DS4-5 patients.
Baseline- and residual-TMTV strongly influence prognosis and response in lymphoma patients. The novel personalized pTMTV
method offers improved accuracy of patient stratification, particularly for those with DS4-5, providing more reliable risk assessment. Larger cohorts are needed to validate these findings and optimize residual-TMTV-based clinical applications.