Abstract
PURPOSE: To investigate and compare the prognostic value of tumor volumetric characteristics during induction chemotherapy (IC) for advanced nasopharyngeal carcinoma (NPC). MATERIALS AND METHODS: A retrospective cohort of 250 patients with NPC treated with IC followed by radiotherapy or chemoradiotherapy was analyzed. Tumor volumes were measured using MRI at two time points of before-treatment and after-IC. Cohorts with high and low tumor heterogeneity were identified by analyzing the gross tumor volume (GTV) through the gray-level co-occurrence matrix (GLCM). Incorporating the clinical factors, volumetric characteristics (V(pre−IC), V(post−IC), ΔV(abs), and ΔV(rel)) were evaluated to identify the prognostic value using univariable and multivariable analyses in various cohorts, respectively. Kaplan-Meier survival analyses with median and optimal cutoff values were conducted. Multivariable analysis was repeated on 1 × 10(5) resampled cohorts with the Bootstrap method to identify the feature importance. Subgroup analyses were performed based on T-category, IC regimens, post-IC treatment protocols, and tumor changes. RESULTS: There is virtually no correlation between V(post−IC) and ΔV(rel) with ρ = -0.08. Various analyses all suggest V(post−IC) emerged as the most robust biomarker across all endpoints (P < 0.001 ∼ 0.002), followed by ΔV(rel) and T-category, which were more important than the other features. The predictive value of V(post−IC) surpasses that of ΔV(rel) especially in the high heterogeneity cohort. Specifically, a V(post−IC) value of 20.6 cm³ could be regarded as a threshold provided optimal risk stratification for progression-free survival (PFS) and overall survival (OS). CONCLUSION: V(post−IC) is a critical biomarker for determining clinical outcomes in advanced NPC. Patients with V(post−IC) measurements above 20.6 cm³ are classified as high-risk, indicating a requirement for escalating radiotherapy and/or chemotherapy. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13014-025-02677-w.