Effectiveness and Safety of Thulium Fiber Laser in the Conservative Management of Patients with Upper Tract Urothelial Carcinoma.

Background: Few clinical data are available on thulium fiber laser (TFL) and conservative treatment of upper urinary tract urothelial carcinoma (UTUC). Objective: To assess the effectiveness and safety of TFL in the conservative treatment of UTUC in terms of both tumor ablation and complication rates in a short-term follow-up. Design setting and participants: Retrospective data were collected from all patients who underwent endoscopic management of UTUC between January 2021 and April 2022. All patients with nonmetastatic UTUC who were deemed suitable candidates (low- and high-grade disease) for conservative treatment were reviewed. Intervention: All patients underwent ureteroscopy with biopsy and at 2, 6, and 12 mo after the first surgery. UTUC ablation was achieved using TFL. Outcome measurements and statistical analysis: Clinical data were collected in a dedicated database. Intra- and postoperative outcomes were assessed. A descriptive statistical analysis was performed. Results and limitations: In total, 28 patients were evaluated. Thirteen patients (46.4%) were included in the low-risk UTUC treatment group and 15 (53.6%) in the high-risk group. The mean tumor size was 15.3 ± 5.7 mm. Biopsy showed low- and high-grade UTUCs in 19 and eight patients, respectively. Only one biopsy was inconclusive for achieving a diagnosis. At the second procedure biopsy, no tumor was found in 19 cases (70.4%), whereas seven had tumors confirmed (25.9%). To date, 23 and 17 out of 26 patients completed the 6- and 12-mo follow-up, respectively. UTUC recurrence was detected in five of 23 patients (21.7%) and in three of 17 patients (17.7%) at 6 and 12 mo, respectively. A total of 95 procedures were performed. No intraoperative complications were observed. In ten of the 95 procedures (10.5%), Clavien-Dindo grade I-II postoperative complications were experienced. Only one grade IIIB postoperative complication was noted. Conclusions: TFL is a safe and effective technique for conservative treatment of UTUC in a short-term follow-up. Optimal tumor ablation and fine hemostatic control were achieved without major complications. Patient summary: In this study, we looked at the outcomes of upper urinary tract tumors conservatively treated with the new thulium fiber laser (TFL). We conclude that TFL represents a safe and effective technique for the treatment of this kind of tumors in a short-term follow-up.