68Ga-PSMA Positron Emission Tomography/Computed Tomography Provides Accurate Staging of Lymph Node Regions Prior to Lymph Node Dissection in Patients with Prostate Cancer

Annika Herlemann, Vera Wenter, Alexander Kretschmer, Kolja M. Thierfelder, Peter Bartenstein, Claudius Faber, Franz-Josef Gildehaus, Christian G. Stief, Christian Gratzke, Wolfgang P. Fendler

We evaluated the accuracy of (68)Ga-prostate-specific membrane antigen-HBED-CC ((68)Ga-PSMA) positron emission tomography/computed tomography (PET/CT) for nodal staging prior to lymph node dissection (LND) in patients with prostate cancer (PCa). Thirty-four patients with histologically proven PCa underwent (68)Ga-PSMA-HBED-CC PET/CT prior to radical prostatectomy with primary LND (pLND; n=20) and PET/CT prior to secondary LND (sLND; n=14). Accuracy of PET and CT were analysed separately for staging of the following 71 lymph node (LN) regions: pelvic left (n=30), pelvic right (n=31), presacral (n=3), and para-aortic (n=7). Postoperative histopathology was taken as a reference standard. Thirty-seven of 71 (52%) regions showed LN metastases on histopathology. Sensitivity, specificity, positive predictive value, and negative predictive value for detection of LN metastases were 84%, 82%, 84%, and 82% for PET criteria and 65%, 76%, 75%, and 67% for CT criteria. PET was more accurate for nodal staging compared with CT both at pLND (88% vs 75%) and sLND (77% vs 65%). Overall, (68)Ga-PSMA PET/CT provides accurate nodal staging prior to pLND and sLND for PCa. PATIENT SUMMARY: (68)Ga-PSMA positron emission tomography/computed tomography is accurate in detecting tumour spread to lymph nodes before patients undergo surgery for prostate cancer.