The value of the magnetic resonance apparent diffusion coefficient in predicting Gleason grouping upgrading after radical prostatectomy

Background: This study aims to evaluate the predictive value of apparent diffusion coefficient (ADC) measurements in identifying cases where Gleason grade grouping is upgraded following radical prostatectomy (RP). Accurate preoperative assessment of prostate cancer (PCa) aggressiveness remains a critical challenge, particularly in anticipating discrepancies between biopsy-based and post-surgical Gleason grading. Methods: A retrospective analysis was conducted on clinical and MRI data from 135 patients with PCa who underwent both biopsy and RP. Patients were categorized into two groups based on whether their Gleason grade group was upgraded postoperatively. Variables showing significant differences between the Gleason grade upgrade (GGU) and non-Gleason group upgrade (non-GGU) groups were included in a multivariable logistic regression analysis to identify independent predictors of GGU following laparoscopic radical prostatectomy. Receiver operating characteristic (ROC) curves were generated for each independent predictor to evaluate their diagnostic performance in detecting GGU. Clinical decision curve analysis was performed to assess the clinical net benefit of ADC value, body mass index (BMI) and percentage of positive needles. Results: The univariate analysis indicated statistically significant differences among groups in terms of BMI, ADC, prostate imaging and data reporting system (PI-RADS) v2.1 and so on (p < 0.05). Multivariable logistic regression analysis showed BMI, percentage of positive needles, and ADC as independent risk factors for GGU in PCa (p < 0.05). ROC curve analysis showed that the best threshold for predicting GGU in PCa was ADC ≥0.75 × 10−3 mm2/s. The clinical decision curve analysis demonstrated that the ADC value, BMI, and the percentage of positive biopsy cores provided greater net clinical benefits in predicting GGU. Conclusions: Based on the 2014 International Society of Urological Pathology (ISUP) grading criteria, this study found that ADC value, BMI and percentage of positive biopsy cores demonstrated the strongest diagnostic performance in predicting GGU in PCa.