Image not available

Sfoungaristos S et al, 2014: Do we really need a KUB to predict stone radiopacity prior treatment with shockwave lithotripsy? Development and internal validation of a novel predictive model based on computed tomography parameters.

Sfoungaristos S, Hidas G, Gofrit ON, Yutkin V, Latke A, Landau EH, Pode D, Duvdevani M

Hadassah Hebrew University Hospital, Urology , Jerusalem, Israel , Jerusalem, Israel , 26500.

Abstract

Objective: To produce and validate a predictive model based on computer tomography (CT) parameters for calculating the probability of a stone to be visible in fluoroscopy of shockwave lithotripsy (SWL) and to compare its accuracy to that of kidney-ureter-bladder (KUB) film. Materials and methods: We retrospectively analyzed 306 patients (sample group) who underwent an SWL between March 2011 and August 2012. A multivariate analysis of several parameters extracted from preoperative CT scan was conducted in order to identify independent predictors for radiopacity in SWL fluoroscopy. The results were used for the creation of a predictive model. Internal validation was made on a group of 75 patients (validation group) treated from September 2012 until December 2012. Predictive accuracy of the
model was evaluated by receiver operating characteristic (ROC) curve and calibration plot. ROC curve was also used for comparing the predictive accuracy of the model to that of KUB. Results: From 306 evaluated stones, 238 (77.8%) were visible in fluoroscopy. Results of the multivariate analysis revealed that stone size (p<0.001), stone attenuation (p<0.001), location in the mid ureter (p<0.001), the distance between the stone and the anterior abdominal wall (p<0.001) and fat thickness of the anterior abdominal wall (p=0.001) were all independent predictors for stone radiopacity in fluoroscopy. A predictive model was produced based on the above parameters. The model
demonstrated high calibration and areas under the curve of 0.923 and 0.965 in the sample and validation group, respectively while its predictive performance was significantly higher (p<0.001) of that of KUB (area under the curve=0.727). Conclusions: This novel model can estimate with high accuracy stone radiopacity in SWL fluoroscopy utilizing parameters of CT scan and thus, it can be used as an alternative to KUB for treatment planning. 

J Endourol. 2014 Aug 8. [Epub ahead of print]

Rate this blog entry:
0
 

Comments 1

Peter Alken on Thursday, 13 November 2014 10:53

This is a nice idea. The authors even created a web-based calculator, to estimate the probability of a stone to be visible in fluoroscopy: https://www.dropbox.com/s/puhmmb8bgt6zsow/Fluoro.html. Does not matter that it did not work when I tried it. Enthusiastic as the authors are they will improve it.
A limitation given by the authors is: “All procedures were performed with a single lithotripter system which is not available in all institutes, meaning that fluoroscopy images may vary depending on the system setup and settings, and thus the present results may not be extended to other systems”. All treatments were done in a supine position. In some situations different positions for a successful ESWL are necessary. Also overlying bony structures like ribs and vertebral bones may interfere with the universal application of the calculator.
See also Tran TY, McGillen K, Cone EB, Pareek G. Triple D Score Is a Reportable Predictor of Shockwave Lithotripsy Stone-Free Rates. J Endourol. 2014 Sep 19.

This is a nice idea. The authors even created a web-based calculator, to estimate the probability of a stone to be visible in fluoroscopy: https://www.dropbox.com/s/puhmmb8bgt6zsow/Fluoro.html. Does not matter that it did not work when I tried it. Enthusiastic as the authors are they will improve it. A limitation given by the authors is: “All procedures were performed with a single lithotripter system which is not available in all institutes, meaning that fluoroscopy images may vary depending on the system setup and settings, and thus the present results may not be extended to other systems”. All treatments were done in a supine position. In some situations different positions for a successful ESWL are necessary. Also overlying bony structures like ribs and vertebral bones may interfere with the universal application of the calculator. See also Tran TY, McGillen K, Cone EB, Pareek G. Triple D Score Is a Reportable Predictor of Shockwave Lithotripsy Stone-Free Rates. J Endourol. 2014 Sep 19.
Guest
Tuesday, 22 August 2017
STORZ MEDICAL AG
Lohstampfestrasse 8
8274 Tägerwilen
Switzerland
Tel.: +41 (0)71 677 45 45
Fax: +41 (0)71 677 45 05

www.storzmedical.com
Personal data
Address
Contact data
Message