Fluorodeoxyglucose positron emission tomography (18F-FDG PET)-computed tomography (CT) in the initial staging of bladder cancer: a single institution experience.

BACKGROUND: The purpose of this study was to assess the usefulness of fluorodeoxyglucose positron emission tomography (18 F-FDG PET)-computed tomography (CT) scan for staging urinary bladder cancer. The study also sought to determine the effect of 18 F-FDG PET/CT on management decisions and its implications for patient care.

METHODS: A total of 133 patients with bladder cancer who had both conventional imaging and 18 F-FDG PET/CT for initial staging were identified. All 18 F-FDG-PET/CT findings were classified as true positive, true negative, false positive, or false negative based on their potential to impact the intent of treatment. The sensitivity, specificity, positive predictive value, and negative predictive value were calculated using the standard definition. Furthermore, the rate of change in therapy intent was determined for the entire sample and for subgroups with non-muscle-invasive bladder cancer (NMIBC) and muscle-invasive bladder cancer (MIBC) patients.

RESULTS: The overall concordance rate between PET/CT and conventional imaging was around 54%. On conventional images, 18% of patients had localized disease, which was upstaged in 6.8% of cases using 18 F-FDG PET/CT. Pelvic lymph node involvement was detected in 18.8% of cases using conventional imaging, which was downstaged to localized disease in 4.5% of cases using 18 F-FDG PET/CT. While 63.2% of patients had systemic disease on a CT scan, 24.7% of cases were downstaged using PET/CT. Overall, the rate of change in therapy intent was 26.3% for the entire sample, 24.5% for NMIBC subgroup, and 27.3% for MIBC patients.

CONCLUSIONS: The study found that 18 F-FDG PET/CT is an effective and accurate tool for staging bladder cancer in newly diagnosed patients. Approximately one quarter of patients had a change in management intent based on 18 F-FDG PET/CT results. The study suggests that PET/CT should be used as a standard for newly diagnosed patients, but more research is needed to confirm this.