Dual phase 18F-fluorodeoxyglucose positron emission tomography/computed tomography with forced diuresis in diagnostic imaging evaluation of bladder cancer.

INTRODUCTION (18)F-FDG PET has been regarded as a limited value in urooncology due to urinary excretion of the tracer. The purpose of this retrospective study was to investigate the clinical value of dual-phase FDG PET/CT with forced diuresis protocol (iv furosemide-voiding and oral hydration) in invasive or high grade bladder cancer. METHODS Fifty-one patients were included in this study. All patients underwent standard staging procedures and dual-phase FDG PET/CT before planned therapy. PET/CT findings before and after furosemide were compared with each other for pelvic region. Dual phase PET/CT findings were also compared with the results of prior imaging studies and all findings were correlated with final diagnosis (histopathology or clinical follow-up for at least 12 months). RESULTS Intravesical FDG activity significantly decreased in 90% of the patients with forced diuresis protocol. Eighty eight percent of the bladder findings and 20% of the local lymph node metastases, and other pelvic findings (local invasion and second primary malignancy of prostate) were detected only by the additional pelvic PET/CT images. As a result, dual phase PET/CT changed the staging and/or the therapy strategy in 16 patients (31%). CONCLUSION Dual phase FDG PET/CT contributes staging and decision of therapy strategy by detecting local disease and pelvic metastases with high accuracy when combined with forced diuresis protocol. Thus, we recommend dual phase imaging method with forced diuresis protocol in FDG PET/CT for bladder cancer and all other urogenital system malignities.