Predicting epidermal growth factor receptor mutations in non-small cell lung cancer through dual-layer spectral CT: a prospective study

Abstract Objective To determine whether quantitative parameters of detector-derived dual-layer spectral computed tomography (DLCT) can reliably identify epidermal growth factor receptor (EGFR) mutation status in patients with non-small cell lung cancer (NSCLC). Methods Patients with NSCLC who underwent arterial phase (AP) and venous phase (VP) DLCT between December 2021 and November 2022 were subdivided into the mutated and wild-type EGFR groups following EGFR mutation testing. Their baseline clinical data, conventional CT images, and spectral images were obtained. Iodine concentration (IC), iodine no water (INW), effective atomic number (Zeff), virtual monoenergetic images, the slope of the spectral attenuation curve (λ HU), enhancement degree (ED), arterial enhancement fraction (AEF), and normalized AEF (NAEF) were measured for each lesion. Results Ninety-two patients (median age, 61 years, interquartile range 51, 67; 33 men) were evaluated. The univariate analysis indicated that IC, normalized IC (NIC), INW and ED for the AP and VP, as well as Zeff and λ HU for the VP were significantly associated with EGFR mutation status (all p < 0. 05). INW (VP) showed the best diagnostic performance (AUC, 0. 892 95% confidence interval CI: 0. 823, 0. 960). However, neither AEF (p = 0. 156) nor NAEF (p = 0. 567) showed significant differences between the two groups. The multivariate analysis showed that INW (AP) and NIC (VP) were significant predictors of EGFR mutation status, with the latter showing better performance (p = 0. 029; AUC, 0. 897 95% CI: 0. 816, 0. 951 vs. 0. 774 95% CI: 0. 675, 0. 855). Conclusion Quantitative parameters of DLCT can help predict EGFR mutation status in patients with NSCLC. Critical relevance statement Quantitative parameters of DLCT, especially NIC (VP), can help predict EGFR mutation status in patients with NSCLC, facilitating appropriate and individualized treatment for them. Key Points Determining EGFR mutation status in patients with NSCLC before starting therapy is essential. Quantitative parameters of DLCT can predict EGFR mutation status in NSCLC patients. NIC in venous phase is an important parameter to guide individualized treatment selection for NSCLC patients. Graphical Abstract