The role of multiparametric magnetic resonance imaging in the diagnosis of local recurrence after radical prostatectomy and before salvage radiotherapy

Purpose: Assess multiparametric-MRI (mp-MRI) diagnostic accuracy in the detection of local recurrence of prostate cancer (PCa) after radical prostatectomy (PR) and before radiation therapy (RT). Materials and methods: A total of 188 patients underwent 1.5-T mp-MRI after RP before RT. Patients were divided into 2 groups: with biochemical recurrence (group A) and without but with high risk of local recurrence (group B). Continuous variables were compared between 2 groups using Student-t test; categoric variables were analyzed using Pearson chi-square. ROC analysis was performed considering PSA before RT, ISUP, pT and pN as grouping variables. Results: PCa recurrence (reduction of PSA levels after RT) was 89.8% in group A and 80.3% in group B. Comparing patients with and without PCa recurrence, there was a significant dif-ference in PSA values before RT for group A and for PSA values before RT and after RT for group B. In group A, there was a significant correlation between PSA before RT and diameter of recurrence and between PSA before RT and time spent before recurrence. The mp-MRI diagnos-tic accuracy in detecting PCa local recurrence after RP is of 62.2% in group A and 38% in group B. Diffusion weighted imaging is the most specific MRI-sequence and dynamic contrast enhan-ced the most sensitive. For PSA = 0.5 ng/ml, the AUC decreases while sensitivity and accuracy increase for each MRI-sequence. For PSA = 0.9 ng/ml, dynamic contrast enhanced-AUC increases significantly.Conclusion: mp-MRI should always be performed before RT when a recurrence is suspected. New scenarios can be opened considering the role of diffusion weighted imaging for PSA < 0.5 ng/ml.(c) 2022 AEU. Published by Elsevier Espana, S.L.U. All rights reserved.