Prognostic Utility of Metabolic Parameters and Tumour Markers in Treatment-Naïve Gallbladder Cancer: A Radiometabolic Analysis.

Objectives: Gallbladder cancer (GBC) is an aggressive malignancy often detected at an advanced stage, resulting in poor prognosis and limited treatment options. This study evaluates the prognostic and diagnostic significance of metabolic parameters, namely Metabolic Tumour Volume (MTV) and Total Lesion Glycolysis (TLG), in combination with serum tumour markers CA 19-9 and CEA in treatment-naïve GBC patients. Material and Methods: A cohort of 50 patients with newly diagnosed, treatment-naïve GBC underwent baseline FDG PET/CT imaging. Parameters, including MTV, TLG, and maximum standardised uptake value (SUVmax), were recorded. Additional evaluations included nodal involvement and the pattern of liver infiltration (direct vs. metastatic). Serum levels of CA 19-9 (Carbohydrate Antigen) and CEA (Carcinoembryonic Antigen) were measured. Statistical analysis utilised Spearman correlation, Mann-Whitney U test, ROC curve analysis, and logistic regression to identify predictors of tumour resectability, survival markers, and hepatic infiltration patterns. Results: High values of MTV and TLG were significantly associated with non-resectable tumours, direct liver invasion, and elevated CA 19-9 and CEA levels ( p < 0.05). Tumour markers CA 19-9 and CEA showed a strong ability to differentiate types of liver involvement, achieving area under the curve (AUC) values exceeding 0.80 in ROC analysis. On multivariate analysis, MTV, CA 19-9 , and nodal status were identified as independent predictors of non-respectability. Conclusion: The integration of radiometabolic measures with serum tumour markers provides significant prognostic and diagnostic utility in treatment-naïve gallbladder cancer. This integrated model facilitates early risk classification, improving decision-making for surgical eligibility and treatment planning.