The Role of 68Ga-PSMA Positron Emission Tomography/Computerized Tomography for Preoperative Lymph Node Staging in Intermediate/High Risk Patients With Prostate Cancer: A Diagnostic Meta-Analysis

Abstract

Purpose: To evaluate the accuracy of 68 Ga-PSMA positron emission tomography/computerized tomography (PET/CT) for preoperative lymph node staging using histopathological results of pelvic lymph node dissection (PLND) as reference standard in patients with intermediate/high risk of prostate cancer. Material and Methods: A systematic search of PubMed, Embase, and the Cochrane Library was completed up to May 2020. We included studies investigating accuracy of 68 Ga-PSMA PET/CT in primary lymph node staging before radical prostatectomy and PLND. The pooled sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), diagnostic odds ratio (DOR), and the summary receiver operating characteristic (SROC) curve with an area under the curve (AUC) were synthesized. Results: Eleven studies comprising 904 patients were identified. Based on per-patient analysis, the pooled sensitivity and specificity reached 0.63 (95% CI: 0.46–0.78) and 0.93 (95% CI: 0.88–0.96), respectively, with the DOR of 22 (95% CI: 10–47). An overall accuracy was revealed by the SROC curve with AUC of 0.91 (95% CI: 0.88–0.93). Using the lymph node as unit, the pooled sensitivity and specificity were 0.70 (95% CI: 0.49–0.85) and 0.99 (95% CI: 0.96–1.00), respectively. And the DOR reached 167 (95% CI: 40–695) with an AUC of 0.96 (95% CI: 0.94–0.98). The pooled PPV and NPV all reached above 0.8 on basis of per-patient or per-node analysis. Conclusions: 68 Ga-PSMA PET/CT represented as a promising test for preoperative lymph node staging and patients without lymph node metastatic status can rarely be misdiagnosed. However, its sensitivity ought to be improved before forgoing PLND.

Current and Emerging Clinical Applications of PSMA PET Diagnostic Imaging for Prostate Cancer

“…In this setting, PSMA PET for lymph node and bone spread detection has shown high specificity and positive predictive values but a suboptimal sensitivity, which remains, however, significantly higher than that of conventional imaging (7). In the most recently published metaanalysis, the results of 11 studies, including 904 intermediate-or high-risk patients, were grouped: pooled sensitivity and specificity on a patient basis were 63% (95% CI, 0.46-0.78) and 93% (95% CI, 0.88-0.96), respectively (24). On a lymph-node basis, they were 70% (95% CI, 0.49-0.85) and 99% (95% CI, 0.96-1.00), respectively.…”

Significance of pelvic lymph node dissection during radical prostatectomy in high-risk prostate cancer patients receiving neoadjuvant chemohormonal therapy

“…Additionally, nomogram cannot be applied in the neoadjuvant setting. Meanwhile, novel imaging modalities such as whole-body magnetic resonance imaging 32 , 33 and prostate-specific membrane antigen–targeted positron emission tomography (PSMA-PET) 34 , 35 can differentiate patients with cN1 from those diagnosed with cN0 by conventional imaging. Ongoing trials (NCT04832958 and NCT04457245) for image-guided treatment protocols for localized PC using PSMA-PET will provide us with a novel treatment strategy for PLND during RP.…”

Prognostic Impact of Pelvic Lymph Node Dissection During Radical Prostatectomy on Patients With High-risk Prostate Cancer Treated With Neoadjuvant Chemohormonal Therapy

“…Additionally, nomogram cannot be applied in the neoadjuvant setting. Meanwhile, novel imaging modalities such as whole-body magnetic resonance imaging 32,33 and prostate-speci c membrane antigen-targeted positron emission tomography (PSMA-PET) 34,35 can differentiate patients with cN1 from those diagnosed with cN0 by conventional imaging. Ongoing trials (NCT04832958 and NCT04457245) for image-guided treatment protocols for localized PC using PSMA-PET will provide us with a novel treatment strategy for PLND during RP.…”