Role of Novel PET-CT Metabolic Measures Total Lesion Glycolysis (TLG) and Total Metabolic Tumor Volume (TMTV) in Prediction of Treatment Response in Hodgkin and Non-Hodgkin Lymphoma Patients

Background Advances in imaging have significantly enhanced the management of lymphoma, particularly through ¹⁸ F-FDG PET/CT use, which combines metabolic and anatomical assessment. However, conventional dependence on SUVmax alone provides a limited view of total disease burden. Recently, metabolic volumetric metrics such as total metabolic tumor volume (TMTV) and total lesion glycolysis (TLG) have emerged as promising tools, offering more robust prognostic information. This study aims to evaluate TMTV and TLG predictive role in assessing early treatment response in patients with Hodgkin (HL) and non-Hodgkin lymphoma (NHL), and to correlate these measures with established prognostic indices. Results A total of 91 patients (HL: 38; NHL: 53) were analyzed. Following three chemotherapy cycles, median TMTV and TLG showed substantial reductions in both HL and NHL groups. ΔTLG demonstrated a diagnostic accuracy of 95.7% (sensitivity 95.8%, specificity 95.2%) and ΔTMTV 92.4% (sensitivity 94.4%, specificity 85.7%) for predicting metabolic response. In HL, TLG >200 and MTV >20 were associated with progressive disease, while in NHL, thresholds of TLG >150 and MTV >15 yielded AUCs of 0.768 and 0.761 , respectively. Significant correlations were observed between interim TMTV, TLG, and IPS in HL (r = 0.545 and 0.549; p < 0.05), but not with IPI in NHL. Conclusions TMTV and TLG are reliable PET/CT-derived biomarkers for early response prediction in lymphoma. Their dynamic changes outperformed conventional SUVmax and correlated significantly with prognostic scores in HL. Incorporating these metabolic volumetric metrics may enhance individualized treatment strategies. Clinical trial number: not applicable.