18F-fluorodeoxyglucose positron emission tomography combined with computed tomography for bladder cancer staging: Diagnostic accuracy and prognostic implications.

Abstract

Background: Muscle-invasive bladder cancer has a poor prognosis. Accurate lymph node (LN) staging is crucial, yet conventional imaging demonstrates limited sensitivity for detecting metastasis, necessitating improved pre-operative assessment.

Objectives: To evaluate the diagnostic accuracy of ¹⁸F-fluorodeoxyglucose positron emission tomography combined with computed tomography (FDG-PET/CT) compared to computed tomography (CT) for LN staging in patients with bladder cancer(BC) undergoing radical cystectomy (RC), and to assess the impact of imaging-determined nodal status on survival outcomes.

Methods: This retrospective study analyzed 138 patients who underwent RC and pelvic LN dissection (PLND) at a multisite tertiary institution from 2008 to 2021. All patients received either pre-operative CT or FDG-PET/CT within 8 weeks before RC and PLND. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value for detecting LN metastasis (LNM) were calculated using pathological analysis as the reference standard. Kaplan-Meier survival analysis and Cox regression were employed to assess overall survival (OS).

Results: FDG-PET/CT exhibited higher sensitivity (70% vs. 23.3%) and PPV (70% vs. 38.46%) compared to CT, but lower specificity (78.57% vs. 85.7%). Survival outcomes showed statistically significant differences in OS between node-positive and node-negative groups in the FDG-PET/CT cohort, but not in the CT cohort.

Conclusion: FDG-PET/CT provides superior sensitivity and PPV compared to CT for LN staging in BC, facilitating more accurate pre-operative evaluation. The improved prognostic stratification associated with FDG-PET/CT may guide individualized treatment strategies.