Metabolic Tumor Area: A Clinically Practical Prognostic Marker for Improved Risk Stratification in IPI Non-High-Risk DLBCL.

Metabolic tumor volume (TMTV) is a core 18F-FDG PET/CT prognostic marker for diffuse large B-cell lymphoma (DLBCL), but its complex measurement and limited standardization restrict clinical utility. Metabolic tumor area (MTA) features simple operation and good reproducibility, holding potential as a practical alternative to TMTV. This retrospective study aimed to validate MTA's substitutability and explore its prognostic value in DLBCL risk stratification. A total of 295 newly diagnosed DLBCL patients were enrolled. TMTV and MTA were measured via semi-automatic segmentation (41% SUVmax threshold). Survival analysis, Cox regression, 5-fold cross-validation, and time-dependent ROC curves were used to evaluate prognostic performance. Multivariate analysis revealed MTA, rather than TMTV, independently predicted progression-free survival (PFS) and overall survival (OS) (all p < 0.05), with stability confirmed by cross-validation. The combined MTA and Dmax model provided IPI-independent prognostic value, and exhibited improved predictive capacity compared with conventional IPI and TMTV and Dmax model in non-high-risk IPI patients (all p < 0.05). It successfully identified occult high-risk subgroups that were undetectable by standard IPI grading. MTA possesses favorable prognostic performance and may serve as a practical alternative to TMTV for DLBCL assessment. The MTA and Dmax model complements the traditional IPI system, facilitating refined risk stratification and individualized clinical management. Further validation in multi-center prospective cohorts is warranted. TRIAL REGISTRATION: Ethics Committee of Jiangsu Cancer Hospital (Approval KY-2025-095, 16 July 2025).