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

Study Type – Diagnostic (case series) Level of Evidence 4 OBJECTIVE To investigate the role of 18F‐fluorodeoxyglusose positron‐emission tomography (FDG‐PET), combined with computed tomography (CT) and forced diuresis, in the staging and follow‐up of urothelial carcinoma (UC). PATIENTS AND 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.