Comparison of holmium:YAG laser and thulium fiber laser in stone dusting at their respective optimal settings

Laser lithotripsy with Holmium:YAG (Ho:YAG) laser has been the primary modality for urinary stone treatment for over two decades. Although thulium fiber laser (TFL) has recently emerged as a potential alternative, its relative dusting efficiency compared with the Ho:YAG laser remains debated. Most prior studies compared the two lasers under identical settings, which may not reflect their optimal performance. In this study, we treated BegoStone phantoms and human calcium oxalate monohydrate stones at optimized settings of the two lasers and across varying standoff distances (SDs). Results showed the TFL was more efficient at smaller SD (0.2 mm) due to predominant photothermal ablation, while the Ho:YAG laser surpassed TFL at larger SDs (0.5–1.0 mm) as a result of greater cavitation-induced damage. These findings highlight SD-dependent dusting performance of each laser and provide mechanistic insights into improving treatment efficiency.