Background: The purpose of this study was to assess the ability of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) to detect upper urinary tract urothelial carcinomas (UTUC) compared with pathological examination of tissues obtained by ureteroscopic biopsy and split cytologic analysis of urine obtained after retrograde pyelography.
Methods: Clinicopathological records of patients at our institution were retrospectively reviewed. Fifty patients with clinically suspected UTUC, who were histologically diagnosed by nephroureterectomy, partial ureterectomy, or endoscopic biopsy, were included. The patient cohort included 42 men and 8 women, with a median age of 73 (range 54-92) years.
Results: Only 27 % of 49 patients with UTUC had positive voided urine cytology, and 33 % of 40 patients had positive split urine cytology. In addition, 40 % of 10 patients had a positive endoscopic biopsy. However, 83 % of 48 patients with UTUC had positive results from FDG-PET/CT examination. The positive predictive value of FDG-PET/CT was 95 %. There were no correlations between sensitivity and tumor stage or tumor grade. Sensitivity of FDG-PET/CT for patients with and without diabetes mellitus was 60 and 89 %, respectively.
Conclusions: These preliminary results from a small number of patients revealed that FDG-PET/CT enabled effective detection of UTUC.
Keywords: FDG-PET/CT; Upper urinary tract urothelial carcinoma; Ureteroscopy; Urine cytology.