18F-PSMA PET/CT and mpMRI: A combined approach for enhanced risk stratification in prostate cancer—a diagnostic accuracy study

AbstractPrecise diagnosis and grading of prostate cancer (PCa) are essential for determining treatment strategies and predicting patient outcomes. This study is the first to integrate 18F-labeled prostate-specific membrane antigen positron emission tomography/computed tomography (18F-PSMA PET/CT) and multiparametric magnetic resonance imaging (mpMRI) for dual-parameter risk stratification in PCa, evaluating the noninvasive predictive value of 18F-PSMA PET/CT and mpMRI in assessing PCa risk and Ki-67 expression, and providing a novel noninvasive diagnostic approach. We analyzed 84 PCa patients who underwent 18F-PSMA PET/CT and mpMRI before or after biopsy, assessing the maximum standardized uptake value (SUVmax) from PET/CT and minimum apparent diffusion coefficient (ADCmin) from mpMRI. PCa risk was categorized using National Comprehensive Cancer Network (NCCN) guidelines based on clinical T-staging, Gleason score, and prostate-specific antigen, while Ki-67 expression was determined immunohistochemically. High-risk patients exhibited higher SUVmax, SUVmax/ADCmin ratio, prostate-specific antigen, and Ki-67 positivity. The SUVmax/ADCmin ratio demonstrated the strongest predictive value (area under the curve = 0.832), while ADCmin best predicted Ki-67 positivity (area under the curve = 0.719). Logistic regression confirmed that SUVmax, ADCmin, and SUVmax/ADCmin were significantly associated with PCa risk. The combined approach of 18F-PSMA PET/CT and mpMRI enhances PCa risk assessment and predicts Ki-67 expression, indicating potential for disease progression and metastasis. SUVmax/ADCmin is a key imaging parameter for evaluating tumor biology and may guide treatment strategies.