Correlation between apparent diffusion coefficient on diffusion-weighted imaging, prostate-specific antigen levels with Gleason histological grading in prostate cancer

Abstract

Objective: To investigate the correlation between the apparent diffusion coefficient (ADC), prostate-specific antigen (PSA) and Gleason Score (GS); as well as the performance of these metrics in differentiating between clinically insignificant and significant prostate cancer (Pca).
Methods: A retrospective cross-sectional study was carried out at the Ho Chi Minh City Medical University Center, involving 162 patients diagnosed with histologically confirmed prostate carcinoma. Region-ofinterest- based measurements were employed to evaluate the mean ADC of defined lesions and of contralateral normal tissue, then calculated intrapatient normalized ADC (nADC: ADC of lesions divided by ADC of contralateral normal tissue).
Result: ADC and nADC exhibited strong negative correlations with GS (r=-0.66 and r=-0.77, p<0.05; respectively), while PSA and PSA density (PSAd) showed moderate positive correlations (r=0.35 and r=0.33, p<0.05; respectively). AUC values for distinguishing GS6 from GS>6 were 0.837 (ADC), 0.929 (nADC), 0.701 (PSA), and 0.703 (PSAd). When distinguishing GS≤7(3+4) and GS≥7(4+3), AUC values changed to 0.847 (ADC), 0.914 (nADC), 0.723 (PSA), and 0.731 (PSAd). An
nADC threshold of 0.47 achieved accurate differentiation between GS6 and GS>6 with 80.9% accuracy, 96.8% sensitivity, and 76.7% specificity. Similarly, distinguishing GS≤7(3+4) from GS≥7(4+3) with the same nADC threshold resulted in 87.0% accuracy, 87.3% sensitivity, and 86.9% specificity.
Conclusion: ADC showed stronger correlation with GS and proved to be a more effective predictor of prostate cancer malignancy compared
to PSA.