Comparison of 68Ga-PSMA-11 PET-CT with mpMRI for preoperative lymph node staging in patients with intermediate to high-risk prostate cancer

To evaluate the diagnostic value of 68 Ga-PSMA-11 PET-CT with multiparametric magnetic resonance imaging (mpMRI) for lymph node (LN) staging in patients with intermediate- to high-risk prostate cancer (PCa) undergoing radical prostatectomy (RP) with pelvic lymph node dissection (PLND). We retrospectively identified 42 consecutive patients with intermediate- to high-risk PCa according to D′Amico and without concomitant cancer. Preoperative 68 Ga-PSMA-11 PET-CT, pelvic mpMRI and subsequent robot assisted laparoscopic RP with PLND were performed in all patients. Among 42 patients assessed, the preoperative PSA value, Gleason score, pT stage and intraprostatic PCa volume of patients with LN metastases were all significantly higher than those without metastases ( P = 0.029, 0.028, 0.004, respectively). The average maximum standardized uptake value (SUV) of 68 Ga-PSMA-11 PET-CT positive PCa of patients with or without LN metastases were 13.10 (range 6.12–51.75) and 7.22 (range 5.4–11.2), respectively (P < 0.001). 68 Ga-PSMA-11 PET-CT and pelvic mpMRI had the ability of succeed on preoperative definite accurate diagnosis and accurate localization of primary PCa in all 42 patients. Fifteen patients (35.71%) had a pN1 stage. 51 positive LN were found. Both 68 Ga-PSMA-11 PET-CT and pelvic mpMRI displayed brillient patient-based and region-based sensitivity, specificity, negative predictive value and positive predictive value. There was no statistical difference for the detection of LNMs according to the diameter of the LNMs between 68 Ga-PSMA-11 PET-CT and mpMRI in this study. Both 68 Ga-PSMA-11 PET-CT and mpMRI performed great value for LN staging in patients with intermediate- to high-risk PCa undergoing RP with PLND. However, despite excellent performance of 68 Ga-PSMA-11 PET-CT, it cannot replace mpMRI that remains excellent for lymph node staging.