Staging 18F-fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Changes Treatment Recommendation in Invasive Bladder Cancer

Given the high risk of systemic relapse following initial therapy for muscle-invasive bladder cancer (MIBC), improved pretreatment staging is needed. We evaluated the incremental value of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) after standard conventional staging, in the largest cohort of MIBC patients to date. This is a retrospective analysis of 711 consecutive patients with invasive urothelial bladder cancer who underwent staging contrast-enhanced CT (chest and abdomen) and FDG-PET/CT in a tertiary referral center between 2011 and 2020. We recorded the clinical stage before and after FDG-PET/CT and treatment recommendation based on the stage before and after FDG-PET/CT. Clinical stage changed after FDG-PET/CT in 184/711 (26%) patients. Consequently, the recommended treatment strategy based on imaging changed in 127/711 (18%) patients. In 65/711 (9.1%) patients, potential curative treatment changed to palliative treatment because of the detection of distant metastases by FDG-PET/CT. Fifty (7.0%) patients were selected for neoadjuvant/induction chemotherapy based on FDG-PET/CT. Moreover, FDG-PET/CT detected lesions suspicious for second primary tumors in 15%; a second primary malignancy was confirmed in 28/711 (3.9%), leading to treatment change in ten (1.4%) patients. Contrarily 57/711 (8.1%) had false positive secondary findings. In conclusion, FDG-PET/CT provides important incremental staging information, which potentially influences clinical management in 18% of MIBC patients, but leads to false positive results as well. Patient summary In this report, we investigated the impact of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) scanning on treatment of bladder cancer patients. We found that FDG-PET/CT potentially influences the treatment of almost one-fifth of patients. We therefore suggest performing FDG-PET/CT as part of bladder cancer staging.