Can the Hounsfield unit predict the success of medical expulsive therapy using silodosin in 4- to 10-mm distal ureteral stones?

Abstract

We aimed to investigate the predictive ability of the Hounsfield unit (HU) on non-contrast computed tomography (NCCT) for the success of medical expulsive therapy (MET) using silodosin in distal ureteric stones of 4-10mm. The data of patients who underwent MET were retrospectively screened. The patients were divided into two groups as Groups 1 and 2 depending on the presence or absence of stone expulsion, respectively. In addition to HU calculated using the NCCT images, state of the collecting systems, daily fluid intake, number of emergency department visits, and number of pain attacks were compared. A total of 88 patients were included in the study. Sixty-four patients (72.7%) expelled the stone after MET while the treatment was not successful in 24 patients (27.3%). The stone area was significantly larger in Group 2 (28.4±15.7mm2 vs 46.8±16.1mm2 ; P<.001). NCCT-HU was calculated as 542.5±256.8 for Group 1 and 873.1±335.2 for Group 2, indicating a significant difference (P<.001). The mean number of pain attacks was 1.5±1.2 in Group 1 and 2.2±1.4 in Group 2 (P=.048). The number of visits to the emergency department significantly differed between Groups 1 and 2 (1.1±1.0 and 1.8±1.3, respectively; P=.010). In this study, HU and stone area values calculated on NCCT were found to be effective factors in predicting the treatment success for MET. Therefore, we consider that it would be useful to consider these parameters in the selection of an appropriate treatment for distal ureteric stones.