Metabolic tumour volume as an independent predictor of chemoradiotherapy response in oesophageal cancer

Abstract Purpose To assess whether traditional quantitative [ 18 F]-FDG PET/CT parameters, Maximum Standardized Uptake Value (SUVmax), Metabolic Tumour Volume (MTV), and Total Lesion Glycolysis (TLG), can predict patients´ response to chemoradiotherapy (CRT) in oesophageal cancer (OC) and to evaluate their potential for clinical stratification and prognostic insight. Methods This retrospective study included 89 OC patients who underwent both baseline and post-treatment [ 18 F]-FDG PET/CT scans. Patients were divided into complete, partial, or non-response groups. PET parameters were compared using one-way ANOVA or the Kruskal–Wallis test, applying either Tukey or Dwass-Steel-Critchlow-Fligner post-hoc analysis when appropriate. Receiver operating characteristic (ROC) curve analysis identified optimal cut-off values based on the Youden index. Logistic regression models, both univariate and adjusted for age, gender, and histological type, were evaluated using AIC, BIC, Nagelkerke’s R², and AUC. Results Initial MTV and TLG values were significantly lower in patients with complete response compared to others. ROC analysis revealed that MTV < 32.74 was associated with a 3.7-fold higher likelihood of complete response ( p = 0.010), which increased to nearly 4-fold after adjustment for confounding variables ( p = 0.008). Among the three PET parameters MTV showed the strongest predictive performance. No significant association was found between CRT response and demographic or histological variables. Conclusion Pre-treatment MTV derived from [ 18 F]-FDG PET/CT serves as an independent predictor of CRT response in OC. These findings demonstrate the potential of MTV for patient stratification and support the integration of metabolic imaging markers into personalized treatment planning while highlighting the need for multicentric validation studies.