Evaluation of fluorodeoxyglucose positron-emission tomography with computed tomography for staging of urothelial carcinoma.

Objective: To investigate the role of (18) F-fluorodeoxyglusose positron-emission tomography (FDG-PET), combined with computed tomography (CT) and forced diuresis, in the staging and follow-up of urothelial carcinoma (UC).

Methods: We recruited 44 patients with muscle-invasive urothelial bladder cancer (UBC) before radical cystectomy (RC), 19 under follow-up after RC and seven after systemic chemotherapy. For those who had RC, histopathology was used as the reference standard to compare the sensitivity and specificity of FDG-PET/CT and standard CT in detecting UBC and pelvic lymph node metastasis. Furthermore, 36 patients with ≥ 6 months of follow-up imaging were considered to describe the progression of UC and extrapelvic positive FDG-PET/CT images.

Results: For the detection of primary UBC, FDG-PET/CT was slightly more sensitive than CT (85% vs 77%) but less specific (25% vs 50%). For the detection of pelvic node metastasis FDG-PET/CT was more sensitive than CT (57% vs 33%) with a specificity of 100% for both imaging techniques. In 20 patients, extrapelvic FDG-PET/CT images showed suspected disease at the first evaluation. UC progressed in nine of the 10 patients who had synchronous multiple PET-positive retroperitoneal or mediastinal lymph nodes, and in only two of the nine with unique hyperactive lesions in the lung. FDG-PET/CT also detected a pT1G3 UC of the renal pelvis and all bone metastases detected by bone scintigraphy.

Conclusions: FDG-PET/CT could replace standard CT and bone scintigraphy in the presurgical staging and monitoring of patients with UC after surgery or chemotherapy.