BACKGROUND: Hemorrhagic cystitis (HC) is a serious complication following hematopoietic stem cell transplantation (HSCT) associated with significant morbidity and mortality. Early identification of at-risk patients and prompt diagnosis are crucial for effective management. This prospective cohort study evaluated the potential of uroflowmetry as a predictive tool for detecting HC in pediatric HSCT patients. METHODS: Thirty-one children who underwent allogeneic HSCT were enrolled. Uroflowmetry was performed on admission (Day 0), post-HSCT Day 1 and Day 15, and at HC onset. Uroflowmetric parameters, including maximum flow rate (Qmax), average flow rate (Qavg), voided volume (VV), and flow curve shape, were compared between HC and non-HC patients. RESULTS: The incidence of HC within 100 days post-HSCT was 58 %, with a mean onset time of 35 days. At baseline (Day 0), HC patients had significantly lower Qmax (12.5 vs. 17.8 mL/s), Qavg (6.8 vs. 9.5 mL/s), and VV (185 vs. 245 mL) compared to non-HC patients (all p <
0.05). Age-stratified analysis revealed the observation of these differences across all age groups. At HC onset, compared to Day 0, patients experienced a significant decrease in Qmax (8.7 vs. 12.5 mL/s) and Qavg (4.2 vs. 6.8 mL/s) (both p <
0.05). Flow curve analysis demonstrated a shift from bell-shaped to interrupted curves in HC patients over time. CONCLUSIONS: Uroflowmetry can potentially predict and detect HC in pediatric HSCT patients. Lower baseline uroflowmetric parameters may identify patients at higher risk for HC, while a significant decrease in these parameters from baseline may indicate HC onset. Uroflowmetry is a simple, non-invasive tool that can be performed at home and monitored remotely, facilitating early detection and intervention for HC in this population.