[Application of narrow-band imaging flexible ureteroscopy in the diagnosis, treatment and follow-up of upper tract urothelial carcinomas].

Objective: To investigate application value of narrow-band imaging (NBI) flexible ureteroscopy in the diagnosis, treatment and follow-up of upper urinary tract transitional carcinomas (UTUC). Methods: From June 2015 to June 2017, 16 patients of UTUC were treated by flexible ureteroscopy with white light (WLI) and NBI at Department of Urology, Peking University Third Hospital , including 10 females and 6 males. The age of patients ranged from 43 to 84 years (average 68.9 years). There were 54 cases, including 16 cases with first-suspicion of cancer, and 38 cases with known of UTUC as follow-up. Full renal collecting system examination was performed first under WLI and then under NBI by a single urologist, using the URF-V digital flexible ureteroscope. Then number of tumors visualized by WLI and NBI flexible ureteroscopy were imaged, recorded, and then biopsied or subsequently treated by holmium laser resection with pathological examination. The diagnosis results of NBI flexible ureteroscopy were compared with WLI flexible ureteroscopy results. All the patients underwent 2(nd)-look ureteroscopy after 4 to 6 weeks since the first ureteroscopy, and after that follow-up flexible ureteroscopy was every 6 months. Results: All the operations of 54 cases were successful. One case was treated with flexible ureteroscopy and percutaneous nephroscopy to treat the renal pelvis tumors, duo to the multiple and much larger tumors. Subjectively, NBI significantly provided a much clearer view of the tumors, especially their limits and vascular architecture. Objectively, 4 additional tumors (11.5%), as well the extended limits of 3 tumors (8.5%) were detected by NBI when findings by WLI were considered normal. The rate of diagnosis of tumors raised 20.0%. Conclusions: Compared with WLI, NBI flexible ureteroscopy provided even more image of UTUC especially their border between tumor tissue and normal tissue. NBI improved the detection of UTUC over standard WLI with higher rate of diagnosis or lower rate of missed diagnosis.