Extracapsular extension of transitional zone prostate cancer miss-detected by multiparametric magnetic resonance imaging

Objectives To demonstrate the importance of extracapsular extension (ECE) of transitional zone (TZ) prostate cancer (PCa), examine the causes of its missed detection by Mp-MRI, and develop a new predictive model by integrating multi-level clinical variables. Materials and methods This retrospective study included 304 patients who underwent laparoscopic radical prostatectomy after 12 + X needle transperineal transrectal ultrasound (TRUS)-MRI-guided targeted prostate biopsy from 2018 to 2021 in our center was performed. Results In this study, the incidence rates of ECE were similar in patients with MRI lesions in the peripheral zone (PZ) and TZ ( P = 0.66). However, the missed detection rate was higher in patients with TZ lesions than in those with PZ lesions ( P < 0.05). These missed detections result in a higher positive surgical margin rate ( P < 0.05). In patients with TZ lesions, detected MP-MRI ECE may have grey areas: the longest diameters of the MRI lesions were 16.5–23.5 mm; MRI lesion volumes were 0.63–2.51 ml; MRI lesion volume ratios were 2.75–8.86%; PSA were 13.85–23.05 ng/ml. LASSO regression was used to construct a clinical prediction model for predicting the risk of ECE in TZ lesions from the perspective of MRI and clinical features, including four variables: the longest diameter of MRI lesions, TZ pseudocapsule invasion, ISUP grading of biopsy pathology, and number of positive biopsy needles. Conclusions Patients with MRI lesions in the TZ have the same incidence of ECE as those with lesions in the PZ, but a higher missed detection rate.