Multi-parametric MRI apparent diffusion coefficient and active surveillance in prostate cancer: is it time to re-evaluate the active surveillance inclusion criteria?

To evaluate the potential of mpMRI and ADC values to predict unfavorable disease (UFD) and biochemical recurrence (BCR)/PSA persistence in patients with Grade Group 1 (GG1) or GG2 prostate cancer (PCa) undergoing surgery, with potential implications for active surveillance (AS) risk stratification. We retrospectively selected 689 patients with GG1 or GG2 PCa in the peripheral zone operated between 2012 and 2015. The outcomes of interest were UFD (GG ≥ 3 and/or pT ≥ 3a and/or pN1) and biochemical recurrence (BCR) /PSA persistence. Logistic regression models assessed predictors including age, PSA density, GG at biopsy and percentage of positive cores (Model 1). Additional models incorporated PI-RADS category, extraprostatic extension (EPE) score, and ADC values. 366 patients (53.1%) had UFD and 180 patients (26%) experienced BCR/PSA persistence, respectively. Significantly lower ADC values were observed in UFD vs non-UFD patients (878 vs. 964 µm 2 /s, p < 0.001) and in those with or without BCR/PSA persistence (873 vs. 933 µm 2 /s, respectively; p < 0.001). A nomogram was developed to calculate the individual probability of UFD and BCR based on the final model, incorporating ADC, clinical, biopsy, and mpMRI data. ADC predicted UFD and BCR/PSA persistence in patients with GG1 or GG2 PCa. The integration of ADC values into a nomogram with clinical, biopsy and mpMRI findings improved patient selection for AS.