Photodynamic diagnostic ureteroscopy using the VISERA ELITE video system for diagnosis of upper-urinary tract urothelial carcinoma: a prospective cohort pilot study

Background The advantages of photodynamic diagnostic technology using 5-aminolevulinic acid (ALA-PDD) have been established. The aim of this prospective cohort study was to evaluate the usefulness of ALA-PDD to diagnose upper tract urothelial carcinoma (UT-UC) using the Olympus VISERA ELITE video system. Methods We carried out a prospective, interventional, non-randomized, non-contrast and open label cohort pilot study that involved patients who underwent ureterorenoscopy (URS) to detect UT-UC. 5-aminolevulinic acid hydrochloride was orally administered before URS. The observational results and pathological diagnosis with ALA-PDD and traditional white light methods were compared, and the proportion of positive subjects and specimens were calculated. Results A total of 20 patients were enrolled and one patient who had multiple bladder tumors did not undergo URS. Fifteen of 19 patients were pathologically diagnosed with UT-UC and of these 11 (73.3%) were ALA-PDD positive. Fourteen of 19 patients were ALA-PDD positive and of these 11 were pathologically diagnosed with UC. For the 92 biopsy specimens that were malignant or benign, the sensitivity for both traditional white light observation and ALA-PDD was the same at 62.5%, whereas the specificities were 73.1% and 67.3%, respectively. Of the 38 specimens that were randomly biopsied without any abnormality under examination by both white light and ALA-PDD, 11 specimens (28.9%) from 5 patients were diagnosed with high grade UC. In contrast, four specimens from 4 patients, which were negative in traditional white light observation but positive in ALA-PDD, were diagnosed with carcinoma in situ (CIS). Conclusions Our results suggest that ALA-PDD using VISERA ELITE is not sufficiently applicable for UT-UC. Nevertheless, it might be better particularly for CIS than white light and superior results would be obtained using VISERA ELITE II video system. Trial registration: The present clinical study was approved by the Okayama University Institutional Review Board prior to study initiation (Application no.: RIN 1803-002) and was registered with the UMIN Clinical Trials Registry (UMIN-CTR), Japan (Accession no.: UMIN000031205).