Advanced Diffusion-Weighted Imaging Biomarkers for Non-Invasive Characterization of Rectal Cancer Heterogeneity: Restricted Spectrum Imaging

Motivation: Accurate non-invasive assessment of rectal cancer microenvironment remains challenging. Goal(s): Accurate non-invasive assessment of rectal cancer microenvironment remains challenging. Approach: Prospective study of 63 rectal cancer patients using 3.0T MRI with restricted spectrum imaging (RSI) based diffusion-weighted imaging, correlating imaging findings with histopathology. Results: RSI-derived parameters, particularly RSI3-C1 and RSI3-C2, showed significant associations with tumor stroma, Ki67 status, and differentiation. RSI3-C2 demonstrated highest accuracy for characterizing stroma status (AUC=0.763), while RSI3-C1 was best for Ki67 status (AUC=0.726) and differentiation (AUC=0.731). Impact: RSI-derived parameters offer promising non-invasive biomarkers for characterizing rectal cancer microenvironment heterogeneity. This approach could enhance pre-treatment assessment, facilitate personalized treatment strategies, and improve patient outcomes. Further research may explore RSI's potential in treatment response prediction and monitoring.