Performance of [68Ga] Ga-PSMA 11 PET for detecting prostate cancer in the lymph nodes before salvage lymph node dissection: a systematic review and meta-analysis

Background Salvage lymph node dissection (sLND) for nodal recurrence in prostate cancer (PCa) patients with biochemical recurrence (BCR) is still not recommended in current guidelines, because of the diagnostic inaccuracy of current conventional imaging. To assess the performance of [Ga-68] Ga-prostate-specific membrane antigen conjugate 11 positron emission tomography (PSMA-PET) in detecting PCa lymph node metastasis using pathologic confirmation through sLND. Methods Literature search was conducted using the MEDLINE, SCOPUS, Web of Science, and Cochrane Library on November 11th, 2018 to identify the eligible studies. Studies were eligible if they investigated the diagnostic performance of PSMA-PET before sLND in PCa patients with BCR and reported the number of true positive, false positive, false negative, and true negative on a lesion-based and/or field-based analyses to compare with histopathologic findings in sLND specimens. Results Fourteen studies published between 2015 and 2018 comprising 462 patients were selected in this systematic review and meta-analysis. The positive predictive value of PSMA-PET before sLND on a patient-based analysis ranged between 0.70 and 0.93. The pooled sensitivity using lesion-based and field-based analyses were 0.84 (95%CI: 0.61-0.95) and 0.82 (95%CI: 0.72-0.89), respectively. The pooled specificity using lesion-based and field-based analyses were 0.97 (95%CI: 0.95-0.99) and 0.95 (95%CI: 0.70-0.99), respectively. The diagnostic odds ratio using lesion-based and field-based analyses were 189 (95%CI: 39-920) and 82 (95%CI: 8-832), respectively. Conclusions PSMA-PET before sLND provided highly accurate performance with clinically relevant high positive and negative predictive values for detecting lymph node disease in patients with BCR after local treatment with curative intent for PCa. PSMA-PET can identify the patients who are likely to benefit from sLND and possibly direct to lesion or region-based dissection.