Diagnostic Value of 18F-fluorodeoxyglucose Positron Emission Tomography with Computed Tomography for Lymph Node Staging in Patients with Upper Tract Urothelial Carcinoma

Abstract

BackgroundPresence of lymph node metastases (LNM) is an important prognostic factor for cancer-specific survival (CSS) in patients with upper tract urothelial carcinoma (UTUC). In various neoplasms, 18F-fluorodeoxyglucose positron emission tomography with computed tomography (FDG-PET/CT) is an established modality for preoperative lymph node (LN) staging. In UTUC, the diagnostic value of FDG-PET/CT for LN staging is unknown. ObjectiveTo determine the diagnostic value of FDG-PET/CT for LN staging in patients with UTUC. Design, setting, and participantsData of 152 patients with UTUC who underwent FDG-PET/CT followed by surgical treatment in eight centers between 2007 and 2017 were retrospectively collected. Patients receiving neoadjuvant chemotherapy were excluded. Outcome measurements and statistical analysisFDG-PET/CT results were compared with histopathology after lymph node dissection (LND). Recurrence-free survival (RFS), CSS, and overall survival (OS) were analyzed using Kaplan-Meier estimates, and compared for patients with and without suspicious LNs on FDG-PET/CT. Results and limitationsWe included 117 patients, of whom 62 underwent LND. Seventeen patients had LNM at histopathological evaluation. Sensitivity and specificity of FDG-PET/CT for diagnosis of LNM were 82% (95% confidence interval [CI]: 57–96) and 84% (95% CI: 71–94), respectively. RFS was significantly worse in patients with LN-positive FDG-PET/CT than in those with LN-negative FDG-PET/CT (p=0.03). CSS (p=0.11) and OS (p=0.5) were similar between groups. This study is limited by its retrospective design and by its sample size. Our results warrant further validation. ConclusionsFDG-PET/CT has 82% sensitivity and 84% specificity for the detection of LNM in patients with UTUC. Presence of suspicious LNs on FDG-PET/CT is associated with worse RFS. Patient summaryIn patients with upper tract urothelial cancer, positron emission tomography with computed tomography (PET/CT) scans can detect lymph node metastases with noteworthy accuracy. Presence of suspicious lymph nodes on 18F-fluorodeoxyglucose PET/CT is associated with worse recurrence-free survival.