Results
A total of 621 patients were included in the study. The stone-free rate was determined as 79.8% (496/621) after fURS. The regression analysis showed that stone area had better predictive power than stone diameter (p=0.025). Lower pole (reference), middle pole [odds ratio (OR)=0.492 p=0.016] and middle ureteral (OR=0.227, p=0.024) localizations, stone density (OR=1.001, p<0.001), and stone volume (OR = 1.008, p <0.001) were determined as independent predictive markers for stone-free status. Based on the effect size of the stone surface area in the nomogram, stone volume was divided into five categories, at 1-point intervals. The AUC values of the T.O.HO., STONE, and modified T.O.HO. score in predicting stone-free status were calculated as 0.758, 0.634, and 0.821, respectively. The modified T.O.HO. created by adding stone volume was statistically significantly superior to the original version (ROC curve comparison, p < 0.001).