Is scoring system of computed tomography based metric parameters can accurately predicts shock wave lithotripsy stone-free rates and aid in the development of treatment strategies?

Abstract

Objective:The objective was to determine the predicting success of shock wave lithotripsy (SWL) using a combination of computed tomography based metric parameters to improve the treatment plan.Patients and Methods:Consecutive 180 patients with symptomatic upper urinary tract calculi 20 mm or less were enrolled in our study underwent extracorporeal SWL were divided into two main groups, according to the stone size, Group A (92 patients with stone ≤10 mm) and Group B (88 patients with stone >10 mm). Both groups were evaluated, according to the skin to stone distance (SSD) and Hounsfield units (≤500, 500–1000 and >1000 HU).Results:Both groups were comparable in baseline data and stone characteristics. About 92.3% of Group A rendered stone-free, whereas 77.2% were stone-free in Group B (P = 0.001). Furthermore, in both group SWL success rates was a significantly higher for stones with lower attenuation <830 HU than with stones >830 HU (P < 0.034). SSD were statistically differences in SWL outcome (P < 0.02). Simultaneous consideration of three parameters stone size, stone attenuation value, and SSD; we found that stone-free rate (SFR) was 100% for stone attenuation value <830 HU for stone <10 mm or >10 mm but total number SWL sessions and shock waves required for the larger stone group were higher than in the smaller group (P < 0.01). Furthermore, SFR was 83.3% and 37.5% for stone <10 mm, mean HU >830, SSD 90 mm and SSD >120 mm, respectively. On the other hand, SFR was 52.6% and 28.57% for stone >10 mm, mean HU >830, SSD <90 mm and SSD >120 mm, respectively.Conclusion:Stone size, stone density (HU), and SSD is simple to calculate and can be reported by radiologists to applying combined score help to augment predictive power of SWL, reduce cost, and improving of treatment strategies.

Feasibility of single‐session endoscopic combined intrarenal surgery for ipsilateral large renal stones and retrograde intrarenal surgery for contralateral renal stones: Initial experience

“…Accumulation of surgical experience was a significant predictor for stone‐free status; the number of stones showed a statistically significant difference between the successful and the remnant stone groups. According to the study of Badran et al ., the SFR was significantly higher in patients with HU <830 . Ganpule et al .…”

Role of Hounsfield Unit in Predicting Outcomes of Shock Wave Lithotripsy for Renal Calculi: Outcomes of a Systematic Review

“…The stone sizes included was heterogenous, with minimum sizes used in 23 studies, documented as 4 mm, 5 mm, 6 mm, and 10 mm in 2, 19, 1, and 1 study, respectively [9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26]. Maximum stone sizes were used in all 28 studies listed as 10 mm, 15 mm, 20 mm, 25 mm, and 30 mm, assessed in 1, 3, 21, 2, and 1 studies, respectively .…”

“…Seven studies measured the stones on a single axial plane that displayed the stone at its maximal diameter [ 13 , 18 , 19 , 27 , 30 , 34 •, 35 ]. Whilst others took the average HU from ROIs in three separate axial planes: the upper pole, the stone at its maximal diameter, and the lower pole [ 11 , 12 ]. A single study defined MSD as the average of the minimum and maximum HU readings [ 13 ].…”

Can we successfully predict the outcome for extracorporeal shock wave lithotripsy (ESWL) for medium size renal stones? A single-center experience

“…They described SSD as the only significant factor for prediction of ESWL success and they attributed that to loss of shock waves energy during penetration through excess body fat with increased SSD. 9 Also, Badran et al 17 suggested that shock waves lose their energy by 10% to 20% for every 6-cm penetration and Perks et al 18 defined 90 mm as the threshold value for SSD beyond which the success rate decreases. While, Waqas et al 1 reported that SSD of 100 mm as a cut off value with success rate of 71% in patients having SSD less than 100 mm.…”