Non-invasive prediction of KRAS mutation in rectal cancer using hybrid intravoxel incoherent motion and diffusion kurtosis model

Purpose: This study seeks to evaluate the efficacy of the hybrid intravoxel incoherent motion and diffusion kurtosis imaging (IVIM-DKI) model in predicting Sarcoma Viral Oncogene Homologue (KRAS) mutation status in rectal cancer patients. Materials and Methods: Rectal cancer patients received hybrid IVIM-DKI MRI, surgery, and KRAS mutation status was assessed. The parameters derived from the hybrid IVIM-DKI model, including the apparent diffusion coefficient (ADC), true diffusion coefficient (D), diffusion kurtosis (K), perfusion fraction (f), and pseudo-diffusion coefficient (D*), were compared between the KRAS mutation group and wild-type group. The diagnostic performance was evaluated using the receiver operating characteristic (ROC) curve. The hybrid IVIM-DKI parameters and their association with clinicopathological features were also explored. Results: In this prospective study, 73 patients (mean age, 66 ± 11 years) of 50 men and 23 women were included. Significant differences were observed between the KRAS mutation and wild-type groups for ADC, D, and K values ( p < 0.05). The K value derived from the IVIM-DKI model demonstrated the highest area under the ROC curve (AUC = 0.779) in characterizing KRAS mutation status, with a sensitivity of 88.1% and specificity of 70.3%. The ADC value also showed satisfactory diagnostic performance (AUC = 0.702). Specific IVIM-DKI parameters, such as f and K, were associated with various clinicopathological features, suggesting their potential as imaging biomarkers. Conclusion: The hybrid IVIM-DKI model, especially the K value, shows promise as a non-invasive tool for predicting KRAS mutation status in rectal cancer patients, potentially improving personalized treatment strategies.