IVIM-MRI-Derived Robustness Index for Evaluating ADT Response and Hypoxia in Prostate Cancer

Motivation: Our previous study established a Robustness Index (Ri) that optimally combines IVIM-MRI parameters with enhanced stability for treatment response and hypoxia assessment. Goal(s): To investigate the clinical utility of Ri (≈ 2f + Dt) in assessing ADT-induced changes and hypoxic environment in prostate cancer. Approach: We compared Ri in ADT-treated and untreated prostate cancer tissues, evaluating its ability to detect treatment changes and correlate with hypoxia-related gene expression. Results: Ri showed superior discriminative power (p=0.029) compared to conventional parameters (ADC: p=0.065; Dt: p=0.26), and IQR of Ri demonstrated significant correlation with hypoxia hallmark scores, indicating potential for both treatment monitoring and hypoxia assessment. Impact: This optimized IVIM parameter Ri can be used for detection of ADT response and assessment of tumor hypoxic environment in prostate cancer prior to radiation therapy, providing a valuable tool for evaluating treatment effects on the tumor microenvironment.