[F-18]-Fluorodeoxyglucose PET and PET-CT in diagnostic imaging evaluation of locally recurrent and metastatic bladder...

Little data is available on the utility of positron emission tomography (PET) and positron emission tomography-computed tomography (PET-CT) with [F-18]-fluorodeoxyglucose (FDG) in patients with bladder cancer. We retrospectively assessed the diagnostic utility of dedicated PET and hybrid PET-CT scans with [F-18]-FDG in the imaging evaluation of recurrent and metastatic bladder transitional cell carcinoma.

The study group included 35 patients who were previously treated for the primary disease. We performed PET in 17 patients and 23 PET-CT scans in 18 patients. Diagnostic validation was by biopsy in 1 patient and clinical and radiological follow-up for up to 5 years in the remaining patients.

PET and CT were true negative (TN) in 12 patients and true positive (TP) in 19 patients. In 4 patients in this group, both locally recurrent pelvic mass and distant metastases were demonstrated, while in 3 of these patients, unsuspected skeletal and/or nodal metastases were detected by PET-CT and these patients received additional courses of chemotherapy. PET was discordant with CT in 4 patients. PET was negative in 2 of these patients, while post-chemotherapy CT showed enlarged nodes that were determined to represent successfully treated disease. In another patient, a hypometabolic soft-tissue mass was considered to represent a scar, and a wait-and-watch strategy was pursued. In the remaining patient, PET showed random hypermetabolic osseous lesions that represented early marrow metastatic infiltration. The combined diagnostic information provided by PET-CT affected the clinical management in 17% of patients.

FDG PET and PET-CT scanning may improve the imaging evaluation of patients with recurrent and metastatic bladder cancer.