Added Clinical Value of 18 F-FDG-PET/CT to Stage Patients With High-Risk Non-Muscle Invasive Bladder Cancer Before Radical Cystectomy

• Published in: Clinical genitourinary cancer 2023-06, Vol.21 (3), p.342
• Main Authors: van Ginkel, Noor, van Gennep, Erik J, Oosterbaan, Liselot, Greidanus, Joyce, Boellaard, Thierry N, Wondergem, Maurits, Vis, André N, de Reijke, Theo M, van Rhijn, Bas W G, Mertens, Laura S
• Format: Article
• Language: English
• Subjects: Aged; Cystectomy; Fluorodeoxyglucose F18; Humans; Lymphatic Metastasis; Neoplasm Staging; Non-Muscle Invasive Bladder Neoplasms; Positron Emission Tomography Computed Tomography - methods; Positron-Emission Tomography; Radiopharmaceuticals - therapeutic use; Retrospective Studies; Urinary Bladder Neoplasms - diagnostic imaging; Urinary Bladder Neoplasms - drug therapy; Urinary Bladder Neoplasms - surgery
• ISSN: 1938-0682

18F-fluorodeoxyglucose positron-emission tomography-computed tomography (FDG-PET/CT) is increasingly used in the preoperative staging of patients with muscle-invasive bladder cancer. The clinical added value of FDG-PET/CT in high-risk non-muscle invasive bladder cancer (NMIBC) is unknown. In this study, the value of FDG-PET/CT in addition to contrast enhanced (CE)-CT was evaluated in high-risk NMIBC before radical cystectomy (RC). This is a retrospective analysis of consecutive patients with high risk and very-high risk urothelial NMIBC scheduled for RC in a tertiary referral center between 2011 and 2020. Patients underwent staging with CE-CT (chest and abdomen/pelvis) and FDG-PET/CT. We assessed the clinical disease stage before and after FDG-PET/CT and the treatment recommendation based on the stage before and after FDG-PET/CT. The accuracy of CT and FDG-PET/CT for identifying metastatic disease was defined by the receiver-operating curve using a reference-standard including histopathology/cytology (if available), imaging and follow-up. A total of 92 patients were identified (median age: 71 years). In 14/92 (15%) patients, FDG-PET/CT detected metastasis (12 suspicious lymph nodes and 4 distant metastases). The disease stage changed in 11/92 (12%) patients based on additional FDG-PET/CT findings. FDG-PET/CT led to a different treatment in 9/92 (10%) patients. According to the reference standard, 25/92 (27%) patients had metastases. The sensitivity, specificity and accuracy of FDG-PET/CT was 36%, 93% and 77% respectively, versus 12%, 97% and 74% of CE-CT only. The area under the ROC curve was 0.643 for FDG-PET/CT and 0.545 for CT, P = .036. The addition of FDG-PET/CT to CE-CT imaging changed the treatment in 10% of patients and proved to be a valuable diagnostic tool in a selected subgroup of NMIBC patients scheduled for RC.