402 FDG PET-CT vs CT scan in the staging of urothelial neoplasms

Abstract

INTRODUCTION AND OBJECTIVES: Thoracic and abdominal CT scan remains the gold standard for staging of urothelial carcinoma. No prospective trials have adequately assessed the role of FDG PET-CT. METHODS: From May 2011 to April 2015, we prospectively collected data of 47 patients referred to the hospital for treatment of either bladder or upper urinary tract tumors and staged by CT as surgical candidates with localized or locally advanced disease. PET-CT was performed either before neoajuvant or adjuvant chemotherapy for final clinical staging. RESULTS: Median age was 68 years (47-87), 87% (41) were men. 41 patients (87%) had bladder cancer, 5 an upper urinary tract tumor (10%) and 1 patient had a cancer of the urethra (2%). Histology was urothelial in 45 cases (96%) and squamous in 2 (4%).Median time fromCT to PET-CTwas1.7months (0.33-5.87). PET-CTwasdonebefore taking final therapeutic decision in 27 cases (57.4%), and after surgery in 20 (42.6%). Overall, discrepancies between CT and PET were seen in 26/47 cases (55%), implicating a change in the recommended treatment of 19 patients (40%). PET-CT identified unknown visceral metastases in 16 patients (34%); of them 5 patients had thoracic metastases (31%), 6 extrathoracic (38%), and 5 had both (31%). For patients referred for neoadjuvant chemotherapy, 11/27 patients (40%) were restaged as M1 by PET-CT. For patients referred for adjuvant chemotherapy, 8/20 (40%) patients had metastatic disease detected by PET-CT (3 nodal, 5 visceral). Final Staging by CT vs PET was as follows: II on 36% vs 28%, III on 15% vs 10%, IV on 49% vs 62%. From the 32 patients (66%) who had finally surgery, pathological stage was II on 7 (23%), III on 8 (26%) and IV on 16 (52%). CONCLUSIONS: In our experience, FDG PET-CT in urothelial cancer not only provided additional prognostic information compared to CT, but also changed management of patients.