Publications

Abstract

OBJECTIVES: First, to review the literature to determine the sensitivity and specificity of (68) Ga-PSMA PET for detecting pelvic lymph node metastases in patients with primary prostate cancer, and the positive predictive value in patients with biochemical recurrence after initial curative treatment. Second, to determine the detection rate and management impact of (68) Ga-PSMA PET in patients with biochemical recurrence after radical prostatectomy. MATERIALS AND METHODS: We performed a comprehensive literature search. Search terms used through Medline, Embase and Science Direct were '(PSMA, (68) Ga-PSMA, (68) Gallium-PSMA, Ga-68-PSMA or prostate-specific membrane antigen)' and '(histology, lymph node, staging, sensitivity, specificity, positive predictive value, recurrence, recurrent or detection)'. Relevant abstracts were reviewed and full-text articles obtained where possible. References to and from obtained articles were searched to identify further relevant articles. RESULTS: Nine retrospective and two prospective studies describe the sensitivity and specificity of (68) Ga-PSMA PET for detecting pelvic lymph node metastases before initial treatment which ranged from 33.3 to 100% and 80 to 100%, respectively. In eight retrospective studies, the positive predictive value of (68) Ga-PSMA PET in patients with biochemical recurrence before salvage lymph node dissection ranged from 70 to 100%. The detection rate of (68) Ga-PSMA PET in patients with biochemical recurrence after radical prostatectomy in the PSA subgroups <0.2 ng/ml, 0.2-0.49 ng/ml and 0.5-<1.0 ng/ml ranged from 11.3 to 50.0%, 20.0 to 72.7% and 25.0 to 87.5% respectively. CONCLUSION: (68) Ga-PSMA PET demonstrates a high specificity for the detection of pelvic lymph node metastases in primary prostate cancer. Furthermore, (68) Ga-PSMA PET has a very high positive predictive value in detecting lymph node metastases in patients with biochemical recurrence. By contrast, sensitivity is only moderate. Therefore, based on the currently available literature, (68) Ga-PSMA PET cannot yet replace pelvic lymph node dissection to exclude lymph node metastases. In the salvage phase, (68) Ga-PSMA PET has both a high detection rate and impact on radiotherapy planning in early biochemical recurrence after radical prostatectomy.