Evaluation of induction chemotherapy response using multiphasic dual-energy CT in nasopharyngeal carcinoma

To develop a nomogram that assists in selecting nasopharyngeal carcinoma (NPC) patients suitable for induction chemotherapy.

This retrospective study included NPC patients who underwent multiphasic contrast‑enhanced DECT (comprising non-contrast, arterial, and venous phase scanning) between May 2019 and December 2023. The relationships between quantitative DECT-derived parameters and treatment response to induction chemotherapy were analyzed using logistic regression analysis. The predictive performance of a nomogram integrating key predictors was assessed using the area under the receiver operating characteristic curve (AUC).

A total of 294 patients (median age, 53 years; interquartile range, 46-59 years; 224 men) were included. Among these, 215 were responders and 79 were non-responders. The normalized iodine concentration in the arterial phase (nIC_arterial) (odds ratio (OR), 0.71; 95% confidence interval (CI), 0.52-0.98; p = 0.036), arterial enhancement fraction (AEF) (OR, 1.45; 95% CI, 1.04-2.00; p = 0.026), and extracellular volume fraction (ECVf) (OR, 0.65; 95% CI, 0.15-0.87; p = 0.019) of tumors were identified as independent predictors of chemotherapy response. This nomogram demonstrated excellent performance (AUC = 0.803 [95% CI, 0.740-0.864]) across all participants, as well as in subgroup analyses of Epstein-Barr virus DNA (high and low) (AUC: 0.761, 0.799) and across five subgroups with different chemotherapy regimens (AUC, 0.773-0.833).

We developed a comprehensive nomogram to predict treatment response to induction chemotherapy by integrating nIC_arterial, AEF, and ECVf. This nomogram demonstrated superior predictive performance compared to the individual parameters when assessed separately.

Question To date, no reliable method has been established to predict the efficacy of induction chemotherapy for nasopharyngeal carcinoma prior to treatment. Findings nIC_arterial, AEF, and ECVf were the independent predictors of induction chemotherapy response, and the combined nomogram demonstrated strong performance to predict response. Clinical relevance The multiphasic contrast‑enhanced parameters derived from dual-energy CT offer a noninvasive approach to predict treatment response to induction chemotherapy and identify nasopharyngeal carcinoma patients who may benefit from induction chemotherapy.