Role of 18F-FDG PET/CT Metabolic Parameters in Treatment Response Evaluation and Prognostic Assessment of Hodgkin Lymphoma: A Retrospective Analysis

Objective: This study aimed to evaluate the predictive value of volumetric metabolic parameters and their longitudinal changes from ¹⁸F-FDG PET/CT for progression-free survival (PFS) and overall survival (OS) in Hodgkin Lymphoma (HL).Materials and Methods: Metabolic tumor volume (MTV), total lesion glycolysis (TLG), and maximum standardized uptake value (SUVmax) were calculated from baseline, interim, and post-treatment PET/CT scans of 63 adult HL patients.Delta (Δ) parameters representing percentage changes were computed.Cox regression and Kaplan-Meier analyses were performed.ROC analysis determined optimal cut-offs for baseline parameters; median dichotomization was used for delta metrics.Results: Pre-treatment MTV1 was significantly higher in patients with progression (650.98±751.34 vs. 354.15±306.72 cm³, p=0.048) and non-survivors (916.91±1040.12vs. 369.44±310.39cm³, p=0.024).Interim and post-treatment parameters showed similar associations (all p≤0.02).Cox regression confirmed MTV1 and TLG1 as significant predictors for both PFS and OS (p≤0.027).Notably, long-interval metabolic changes (ΔMTV₁₋₃, ΔTLG₁₋₃, ΔSUVmax₁₋₃) demonstrated strong prognostic significance (all p≤0.007), with ΔSUVmax₁₋₃ independently predicting PFS (HR 0.30, 95% CI 0.12-0.76;p=0.011).Optimal baseline MTV1 cut-offs were 232 cm³ for PFS and 308 cm³ for OS.Conclusion: Baseline volumetric parameters and long-interval metabolic changes are powerful prognostic markers in Hodgkin Lymphoma.ΔSUVmax₁₋₃ provides additional risk stratification beyond baseline measurements, supporting integration of dynamic PET metrics into clinical practice.