Utility of Routine Preoperative 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography (18F-FDG PET/CT) in Identifying Pathologic Lymph Node Metastases at Radical Cystectomy
Menée à partir de données portant sur 185 patients atteints d'un cancer urothélial de la vessie avec envahissement musculaire, cette étude évalue l'intérêt, du point de vue de la sensibilité, de la spécificité, de la valeur prédictive positive et de la valeur prédictive négative, d'utiliser en routine une tomographie numérique par émission de positrons à base de fluorodésoxyglucose (18F) pour détecter des métastases ganglionnaires avant une cystectomie radicale
Purpose: To determine the diagnostic performance of 18F-FDG PET/CT for detecting nodal metastases in patients with muscle-invasive urothelial bladder cancer prior to radical cystectomy.
Materials and Methods: Preoperative 18F-FDG PET/CT scans (n = 208) were retrospectively reviewed. Scans were routinely performed in 185 patients with muscle-invasive urothelial bladder cancer between August 2012 and February 2017, all of whom underwent radical cystectomy and pelvic lymph node dissection. Analyses were stratified by clinical node involvement and chemotherapy status. The diagnostic performance of 18F-FDG PET/CT was assessed according to sensitivity, specificity, positive predictive value, and negative predictive value.
Results: Lymph node metastases at time of PLND were present in 21.8% of those without suspicious nodes on computed tomography (clinically node negative) and 52.6% of those with suspicious nodes on CT (clinically node positive). Median metastatic focus size was 5 mm. In clinically node negative patients, 18F-FDG PET/CT rarely detected nodal metastases (sensitivity 7–23%). In clinically node positive patients, a negative 18F-FDG PET/CT was useful in ruling out lymph node metastases (sensitivity 92–100%). This study was limited by its mixed population and focus on pelvic nodal metastases only.
Conclusions: 18F-FDG PET/CT appears to be most useful for better characterization of enlarged nodes identified by CT. Routine preoperative 18F-FDG PET/CT has limited utility in clinically node-negative patients.
Journal of Urology , résumé, 2019