Photodynamic Diagnosis-guided Dual Laser Ablation for Upper Urinary Tract Carcinoma: Preoperative Preparation, Surgical Technique, and Clinical Outcomes

Background: Although ureteroscopic surgery (URS) is beneficial for low-risk upper urinary tract carcinoma (UTUC), there is no standardized URS technique or navigation system for challenging cases.

Objective: To present a URS technique for UTUC using thulium (Tm):YAG and holmium (Ho):YAG lasers under photodynamic diagnosis (PDD) guidance, named PDD-guided dual laser ablation (PDD-DLA) and compare its efficacy with that of conventional Ho:YAG laser ablation (HLA; historical control).

Design Setting And Participants: The study included ten consecutive UTUC patients who underwent PDD-DLA between 2017 and 2019. The control group comprised 16 consecutive patients who underwent HLA between 2006 and 2016.

Surgical Procedure: After oral administration of 5-aminolevulinic acid (20 mg/kg), UTUC tumors were endoscopically resected via PDD-DLA.

Measurements: Clinical data were prospectively collected for our institutional UTUC data set. Disease progression, UTUC recurrence, and clinical outcomes were assessed.

Results And Limitations: PDD-DLA was successfully performed in all patients. The median tumor size was 23.5 mm (interquartile range [IQR] 12.8-30.0) and there were four cases (40.0%) of high-grade tumor. The median operative time was 120 min (IQR 98.5-142.5). No Clavien-Dindo grade ≥3 complications were observed. There were no differences in most clinical characteristics between the PDD-DLA and HLA groups. The 2-yr progression-free survival rate was 100% in the PDD-DLA group and 58.7% in the HLA group ( = 0.0197), and the 2-yr recurrence-free survival rate was 57.1% and 41.3%, respectively ( = 0.072). The PDD-DLA group had a lower incidence rate of salvage RNU compared with the HLA group (0.0% vs 50%;  = 0.009). The small sample size might affect the reproducibility of these results.

Conclusions: PDD-DLA seems to be an effective and feasible endoscopic technique for UTUC treatment with favorable oncological outcomes.

Patient Summary: We investigated a new laser technique for treating cancer of the upper urinary tract called photodynamic diagnosis-guided dual laser ablation. Our strategy was effective in removing tumors and stopping bleeding. Further studies in larger groups of patients are needed to confirm whether this technique improves cancer outcomes.